Kadasne's textbook of anatomy : clinically oriented [1ed.] 9788184484557, 8184484550, 9788184484564, 8184484569, 9788184484571, 8184484577

Table of contents :
Prelims
Chapter-01_Osteology of the Superior Limb
Chapter-02_Superior Limb in General
Chapter-03_Regional Anatomy of the Superior Limb
Chapter-04_Mammary Gland
Chapter-05_Axilla
Chapter-06_Study of the Back
Chapter-07_Shoulder Joint
Chapter-08_The Arm
Chapter-09_Elbow Joint
Chapter-10_Forearm
Chapter-11_Nerves and Vessels of the Forearm
Chapter-12_Cubital Fossa
Chapter-13_Superior Radioulnar Joint
Chapter-14_Wrist and the Hand
Chapter-15_Wrist Joint
Chapter-16_Osteology of the Inferior Limb
Chapter-17_Femur
Chapter-18_Patella
Chapter-19_Tibia
Chapter-20_Fibula
Chapter-21_Talus
Chapter-22_Calcaneus
Chapter-23_Navicular Bone
Chapter-24_Front of Thigh
Chapter-25_Hip Joint
Chapter-26_Back of Thigh
Chapter-27_Knee Joint
Chapter-28_Leg
Chapter-29_Muscles of the Flexor Compartment
Chapter-30_Foot
Chapter-31_Sole of Foot
Chapter-32_Ankle Joint
Chapter-33_Arches of Foot
Chapter-34_Clinical Pictures
Index

Citation preview

Kadasne’s Textbook of

ANATOMY (Clinically Oriented)

Kadasne’s Textbook of

ANATOMY (Clinically Oriented) Volume 1: Upper and Lower Extremities DK Kadasne MS FRCS FICS

Emeritus Professor Department of Anatomy Pandit Jawaharlal Nehru Medical College DMIMS (a Deemed University) Sawangi, Wardha Maharashtra, India

®

JAYPEE BROTHERS MEDICAL PUBLISHERS (P) LTD New Delhi • Ahmedabad • Bengaluru • Chennai • Hyderabad • Kochi • Kolkata • Lucknow • Mumbai • Nagpur

Published by Jitendar P Vij Jaypee Brothers Medical Publishers (P) Ltd Corporate Office 4838/24 Ansari Road, Daryaganj, New Delhi - 110002, India, +91-11-43574357 (30 lines) Registered Office B-3 EMCA House, 23/23B Ansari Road, Daryaganj, New Delhi 110 002, India Phones: +91-11-23272143, +91-11-23272703, +91-11-23282021, +91-11-23245672, Rel: +91-11-32558559 Fax: +91-11-23276490, +91-11-23245683 e-mail: [email protected], Website: www.jaypeebrothers.com Branches  2/B, Akruti Society, Jodhpur Gam Road Satellite Ahmedabad 380 015 Phones: +91-79-26926233, Rel: +91-79-32988717 Fax: +91-79-26927094, e-mail: [email protected]  202 Batavia Chambers, 8 Kumara Krupa Road, Kumara Park East Bengaluru 560 001 Phones: +91-80-22285971, +91-80-22382956, +91-80-22372664 Rel: +91-80-32714073, Fax: +91-80-22281761, e-mail: [email protected]  282 IIIrd Floor, Khaleel Shirazi Estate, Fountain Plaza, Pantheon Road Chennai 600 008 Phones: +91-44-28193265, +91-44-28194897, Rel: +91-44-32972089 Fax: +91-44-28193231, e-mail: [email protected]  4-2-1067/1-3, 1st Floor, Balaji Building, Ramkote Cross Road Hyderabad 500 095 Phones: +91-40-66610020, +91-40-24758498, Rel:+91-40-32940929 Fax:+91-40-24758499, e-mail: [email protected]  No. 41/3098, B & B1, Kuruvi Building, St. Vincent Road Kochi 682 018, Kerala Phones: +91-484-4036109, +91-484-2395739, +91-484-2395740 e-mail: [email protected]  1-A Indian Mirror Street, Wellington Square Kolkata 700 013 Phones: +91-33-22651926, +91-33-22276404, +91-33-22276415 Rel: +91-33-32901926, Fax: +91-33-22656075, e-mail: [email protected]  Lekhraj Market III, B-2, Sector-4, Faizabad Road, Indira Nagar Lucknow 226 016 Phones: +91-522-3040553, +91-522-3040554 e-mail: [email protected]  106 Amit Industrial Estate, 61 Dr SS Rao Road, Near MGM Hospital, Parel Mumbai 400012 Phones: +91-22-24124863, +91-22-24104532, Rel: +91-22-32926896 Fax: +91-22-24160828, e-mail: [email protected]  “KAMALPUSHPA” 38, Reshimbag, Opp. Mohota Science College, Umred Road Nagpur 440 009 (MS) Phone: Rel: +91-712-3245220, Fax: +91-712-2704275, e-mail: [email protected] USA Office 1745, Pheasant Run Drive, Maryland Heights (Missouri), MO 63043, USA, Ph: 001-636-6279734 e-mail: [email protected], [email protected] Kadasne’s Textbook of Anatomy (Clinically Oriented) (Volume 1) © 2009, Jaypee Brothers Medical Publishers All rights reserved. No part of this publication should be reproduced, stored in a retrieval system, or transmitted in any form or by any means: electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the author and the publisher. This book has been published in good faith that the material provided by author is original. Every effort is made to ensure accuracy of material, but the publisher, printer and author will not be held responsible for any inadvertent error(s). In case of any dispute, all legal matters to be settled under Delhi jurisdiction only. First Edition: 2009 ISBN 978-81-8448-455-7 Typeset at JPBMP typesetting unit Printed at Rajkamal Press

Dedicated to the Sacred Memory of My Late Beloved Parents

FOREWORD Peeping into memory lanes of the yester years, it vividly comes into my focused attention of the Herculean difficulties which I had to face as an ordinary student of first MBBS in the early 70's, while groping into the annals of Anatomy as a subject. It appeared to be "tough, baffling and difficult to grasp", and much more, difficult to 'retain' for the purposes of 'recall'. Frankly speaking, it was genuinely a dreadful proposition till we were told by our seniors to just fall back to the notes titled' Approach to Anatomy' penned by none else than respected Dr DK Kadasane Sir. It realistically had an astonishing effect to the extent that what was 'dreadful; till the previous day became understandingly lovable subsequent thereto. It was some sort of realistic magic which till date does not go out of the memory. I therefore feel greatly privileged to be writing this foreword for the present book, which is a genuine manifestation of unparalleled creativity brought out by respected Dr DK Kadasane Sir in his lucid and free flowing style. The contents, description, syntaxing and diagrammatic depiction, all taken together make it look as if it is "Anatomy made easiest" for one and all. Indeed, it is a great venture which is nothing but a depiction of the commitment that Dr DK Kadasane Sir has harboured deep in his heart and mind for the subject of anatomy all his life and has never fallen short when he started writting the book which would cater to the cause of the learners as well as teachers in a meaningful way. No amount of praise showered on him would be sufficient to commensurate with his single minded devotion to the teaching and learning of the subject of anatomy and facilitating it in a way which would really be memorable on all counts. I have every reason to believe that this book entitled Kadasne's Textbook of Anatomy (Clinically Oriented) would not only be handy, useful, purposive and relevant to the requirements of students and teachers of anatomy but would also be of significant consequence to the teachers of surgery and its allied specialities. The unique feature of applied aspects in this book is due to the fact that Dr Kadasne is a qualified Anatomist as well as Surgeon of cognition and repute. I take the privilege of saluting the 'unending zeal and unfathomable commitment of 'teacher of teachers' respected Dr DK Kadasane Sir, inspite of being aware of the fact that any expression howsoever, genuine and bonafide it be, would not be able to match his creative prowess.

Vedprakash Mishra Chairman Post Graduate Medical Education Committee, Medical Council of India, New Delhi

PREFACE I had the pleasure of teaching Anatomy at the Government Medical College, Nagpur and Surgery at the Indira Gandhi Medical College, Nagpur. I am convinced that surgery brings meaning to anatomy. Surgery is an applied anatomy in the true sense. Anatomy was written and taught by surgeons and physicians in the golden era of rise of medicine. Anatomy was brought to a respectable stage by great surgeons and physicians. It happened in the days when touching of dead and the blood was considered a sin. The call was given to all the anatomists over the world by a famed and the pioneer surgeon as “Anatomist should come out of the dead house and prove their worth in other clinical sciences. In case of the members of clinical sciences prevent them, the loss is theirs—the loss of humanity”. Every structure in the body has the hidden surgical and clinical thrill of practical importance. It is only on the foundation of anatomy the clinical sciences progressed to the stage of organ transplant. Emergence of the non-invasive techniques of investigation have acted as a boon for anatomy in its further research and clinical application. Keeping in view the thoughts expressed, I ventured to write a book to create interest and enthusiasm amongst the students while learning anatomy. No book is complete and no book can be comprehensive. DK Kadasne

ACKNOWLEDGMENTS My acknowledgements are due to my revered teachers, i.e. Dr NS Sahastrabuddhe, Dr Gopal Rao, Dr SL Robert, Dr PC Bansal and Dr PN Dubey for their support and guidance. Mr Datta Meghe, MP and the Chancellor of the DMIMS gave me an opportunity to enter into the academic field of teaching anatomy in addition to my surgical practice. This is the major factor which inspired me to write a book of this type. Mr Sagar Meghe, MLA played a pivotal role in keeping me engaged in the teaching of anatomy. Dr Dilip Gode, presently the Professor of Surgery in Pandit Jawaharlal Nehru Medical College, Sawangi, Wardha has always acted as my well wisher and supporter, whom I can never forget. I am indebted to Dr Joharapurkar, Director, Datta Meghe Institute, Department of Post Graduate Research and Medical Education and the member of the Management Council for encouragement and support. My thanks are due to Dr Patel, the Dean of the Pandit Jawaharlal Nehru Medical College, Sawangi for appreciation. Dr Mrs Fulzele, Professor and Head of the Department of Anatomy of the Pandit Jawaharlal Nehru Medical College, Sawangi deserves my grateful thanks for discussions during the preparation of the book. Dr Mrs Rawalani deserves thanks for showing interest in my undertaking. I could not have presented the book in the present form without the generous donation of the clinical material provide by my friends who are renowned experts in their respective fields. Dr Shirish Dhande, a renowned radiologist of the city made the X-rays and the MRI available. It is my honour that Dr Vedprakash Mishra, Vice-Chancellor of the DMIMS University, Sawangi, Wardha, and the Chairman of Post Graduate Medical Education Committee, Medical Council of India, New Delhi, a doyen in the science of physiology agreed to write a foreword for this book. Dr GM Taori, the Director of CIMS, Bajaj Nagar, Nagpur whole heartedly co-operated with me in obtaining the consent of the management committee of the institution for permission of using the beautiful cerebral angiogram. The skill and the knowledge of Dr Kothekar, who is the master in his own field need not be highlighted any more. Dr Prakash Heda of Nairobi, a student and my friend has supported me constantly whether he lived in India or abroad. I thank him sincerely. My thanks also go to Dr Neeta Kulkarni, Professor and Head of the Department of Anatomy, Dr SMCSI Medical College, Karakonam, Trivendrum who always enquired about the progress of the book. I also thank to Dr Sushma Deshmukh, Dr Ravi Deshmukh, Dr Tule, the pediatric surgeon, and Dr Mukewar, the Director of Gastrointestinal Institute of Central India. Dr SD Suryawanshi Professor and Head of the Department of Medicine, Indira Gandhi Medical College, Nagpur, acted as my constant critic during the preparation of this book. I thank him profusely. I have all the appreciation for the work done by Manoj Dharmadhikari for computerised typing of the manuscript. Mr Avinash Kokate did an excellent work in drawing the diagrams artistically with colour. I cannot forget both of them for their devotion and punctuality. I shall be failing to furnish my duty if I do not express my gratitude to Dr Kishore Taori, the dynamic professor of radiology of the Government Medical College, Nagpur for providing me the necessary material for the production of this book. My better half, Mrs Arati Kadasne, took pains to go through the manuscript and helped me untiringly till the completion of the book. Dr Shivraj Mulik, ophthalmic surgeon provided actual photographs of fundoscopic examination showing retinal vessels. Dr BJ Chikodi, Ex-civil Surgeon and Dr JS Mulik, ophthalmic surgeon encouraged me in the production of this book. I express my gratitude to them.

XII Kadasne’s Textbook of Anatomy (Clinically Oriented) My thanks also go to Dr Dasgupta, Dean, Lata Mangeshkar Medical Hospital, who provided the clinical photographs for publication of my book and Dr Kothe, the plastic surgeon who provided beautiful clinical photographs of cleft lip and palate. My thanks are due to Dr Padole, surgeon and Dr Neral and Dr Jape, radiologists for their encouraging comments and helping hands. Dr Mrs Pushpa Jagtap, Ex-Dean of Indira Gandhi Medical College, Nagpur and her two brilliant sons, namely Dr Prashant, cardiovascular surgeon of Wockhardt Hospital, Nagpur and Dr Jitendra Jagtap, renowned orthopedic surgeon have extended their supports whole heartedly, I cannot forget them. Dr Mangrulkar took pains to provide necessary photographs for their reproduction, I am also grateful to him. Dr KN Ingle, Professor of Pandit Jawaharlal Nehru College, Sawangi, Wardha has always acted as my source of inspiration, so, I cannot forget him. I am under the heavy obligations of Hon’ble Datta Meghe, MP and the Chancellor of Datta Meghe Institute of Medical Sciences for the friendly approach, advice and appreciation, who allowed me to continue my academic association with the subject of anatomy by appointing me as Professor Emeritus of Anatomy in his prestigious institute. It is this institute which encouraged me to continue my academic activity. Although I was engaged in my surgical practice, the credit for production of this book goes to the DMIMS. I cannot forget the friendly and helpful approach of the Professor of surgery, Dr Vinay Shahapurkar, who also made available so many clinical photographs in the publication of this book. I am grateful to Shri Jitendar P Vij, CMD of M/s Jaypee Brothers Medical Publishers Pvt. Ltd. for publishing this book. I acknowledge the contribution of Mr Tarun Duneja, the Director (Publishing) of Jaypee Brothers and his team particularly Mr DC Gupta (Copyeditor), Ms Seema Dogra (Cover Designer) and Mr Sumit Kumar (Graphic Designer) who deserve my sincere thanks. I am extremely grateful to my beloved students who always appreciated and inspired me for teaching the subject. Last but not least, I am extremely grateful to Almighty who has allowed me to achieve my goal.

CONTENTS Osteology of the Superior Limb .................................................................................................. 1 Superior Limb in General .........................................................................................................27 Regional Anatomy of the Superior Limb ................................................................................ 31 Mammary Gland ........................................................................................................................43 Axilla .............................................................................................................................................49 Study of the Back ........................................................................................................................66 Shoulder Joint .............................................................................................................................. 77 The Arm ....................................................................................................................................... 85 Elbow Joint ................................................................................................................................ 101 Forearm ...................................................................................................................................... 107 Nerves and Vessels of the Forearm ...................................................................................... 115 Cubital Fossa ............................................................................................................................. 130 Superior Radioulnar Joint ....................................................................................................... 132 Wrist and the Hand .................................................................................................................. 148 Wrist Joint .................................................................................................................................. 168 Osteology of the Inferior Limb .............................................................................................. 177 Femur ......................................................................................................................................... 182 Patella ........................................................................................................................................ 187 Tibia ........................................................................................................................................... 189 Fibula ......................................................................................................................................... 192 Talus .......................................................................................................................................... 195 Calcaneus .................................................................................................................................. 197 Navicular Bone ......................................................................................................................... 199 Front of Thigh ........................................................................................................................... 204 Hip Joint .................................................................................................................................... 253 Back of Thigh ........................................................................................................................... 261 Knee Joint .................................................................................................................................. 269 Leg .............................................................................................................................................. 282 Muscles of the Flexor Compartment ..................................................................................... 294 Foot ............................................................................................................................................. 310 Sole of Foot ................................................................................................................................ 314 Ankle Joint ................................................................................................................................ 325 Arches of Foot ........................................................................................................................... 336 Clinical Pictures ........................................................................................................................ 343 MCQs of Upper Limb .................................................................................................................. 350 MCQs of Lower Limb .................................................................................................................. 356 Index ............................................................................................................................................. i-iv

Kadasne’s Textbook of Anatomy (Clinically Oriented)

1

OSTEOLOGY OF THE SUPERIOR LIMB General Remarks:

Axial Skeleton: Appendicular Skeleton:

Functions of the Bones:

Classification of Bones:

Functions of Paranasal Air Sinuses (WAR):

Skeleton of the body is divided in two main groups namely: 1. Axial and 2. Appendicular. It consists of skull, thoracic cage, pelvis and vertebral column. It is the term used for bones of the limbs. The bones of the upper limb are as under: 1. Scapula 2. Clavicle 3. Humerus 4. Radius 5. Ulna 6. Eight carpal bones 7. Five metacarpals and 8. The phalanges: Three for each finger except the thumb which has only two. Morphologically the first metacarpal is supposed to be the first phalanx of the thumb. They can be described as SUPPORT, SHIELD, SHAPE and STORE. Support: Support the weight of the body. Shield: Protect the organs. Shape: Give shape to the body. Store: Store house for calcium. In addition to above functions they give attachment to muscles and act as levers, during locomotion. They are classified in seven types as under: 1. Long bones 2. Short bones 3. Flat bones 4. Pneumatic 5. Irregular bones 6. Vermian bones and 7. Sesamoid bones 1. Long bones: The long bones are situated along the long axis of the body having shaft, two ends and the medullary cavity. For example, humerous, femur. 2. Short bones: They are box like bones having compact tissue outside and the cancellous tissue inside. They have six surfaces. For example, carpals and tarsals 3. Flat bones: They have compact plates outside and the cancellous tissue inside like a sandwitch. For example, bones of the vault of the skull. 4. Pneumatic bones: Skull bones having a cavities lined with ciliated epithelium and containing air. For example, maxilla, frontal, ethmoidal and the sphenoidal bones. Cavities of the bones are known as paranasal sinuses. 1. Weight—Reduce weight. 2. Additional area—Additional area for purification, humidification and warming of the air entering the respiratory passage. 3. Resonance—Resonance of the voice.

2 Kadasne’s Textbook of Anatomy (Clinically Oriented)

Terminology Used While Describing a Bone:

Formation of Bone:

Figure A Development of bone

4. Irregular bones: As the name indicates they are irregular having spongy tissue inside and the compact tissue outside. For example, vertebrae and the hip bone. 5. Sesamoid bone: They differ from normal bone in two respects (i) absence of periosteum and (ii) absence of Haversian canals. They develop in the tendons at the sites of friction. For example, pisiform, patella. 6. Vermian bones: They are small bones situated near the ossifying sutures of the skull. 1. Facet - Flattened impression 2. Trochlea - Pulley 3. Condyle - Round elevation 4. Fovea - Depression 5. Process - Projecting structure 6. Spine - Spine like process with a pointed end 7. Epicondyle - The point on the maximum convexity of a condyle 8. Cornu - Horn 9. Hamulus - Hook 10. Crest - Sharp raised line 11. Line - Linear marking 12. Notch - Incomplete foramen 13. Foramen - A hole 14. Canal - A foramen having some length 15. Sulcus - Groove 16. Hiatus - Opening 17. Lamina - A thin sheet Let us consider the process of the bone formation: Bones develop from the mesoderm. The initial mesodermal tissue is premature and is known as mesenchyme. Mesenchyme gets converted into the cartilage and the cartilage into the bone. (Figure A). The bone formed by this process is known as cartilage bone. (For example, Humerus, Femur). When the mesenchyme instead of passing through the stage of the cartilage, directly jumps to form the bone. These bones are known as membrane bones (e.g., clavicle and the bones of the vault of the skull).

Osteology of the Superior Limb Clinical:

Primary Center of Ossification: Secondary Center of Ossification: Ossification:

3

1. Achondroplasia: It is due to the defective ossification of the cartilage bones resulting in short strature and short limbs (Dwarf – short stature person – commonly seen in the circus – buffoon or a joker). 2. Cleidocranial dysostosis: It is due to defective ossification of the membrane bones such as clavicle and the vault of the skull. There is partial or complete absence of clavicle. Due to its absence of clavicle, the shoulder can be brought in front of the chest touching each other. A center of ossification, which appears before birth is known as the primary center of ossification. The center of ossification which appears after birth is known as the secondary center of ossification. In this process, the central calcified cells degenerate and are replaced by osteoblasts from the periosteum. The process of deposition of calcium in an osteoid tissue is known as the center of ossification.

JOINT Definition: Classification:

Fibrous Joints:

Sutural Joints:

Cartilaginous Joints:

Secondary Cartilaginous Joints:

When two or more bones articulate directly or indirectly is known as the joint. They are classified into three, namely 1. The fibrous 2. The cartilaginous and the 3. Synovial. They are of three types, 1. Sutural, 2. Gomphosis and 3. Dyndesmosis. They are situated between the flat bones of the skull. The fibrous tissue in the suture is continuous with pericranium outside and the endocranium inside. The obliteration of the sutures of the skull begin from inside. Sutures obliterate internally at the age of 35 to 40 and externally between the age of 40 to 50 years. Gomphosis: Joint between tooth and the gum. Syndesmosis: Inferior tibiofibular joint. Articular surfaces are an connected by interosseous ligaments. They are divided into two categories: 1. The primary and 2. Te secondary. Primary cartilaginous joint is situated at the junction of the epiphysis and diaphysis. They are temporary as they get ossified. They do not allow movements. They are situated in the midline of the body, are permanent and allow movements. The articulating surfaces of the adjoining bones are connected by means of hyaline cartilage. Symphysis They are the joints between the two vertebral bodies, the joint between the manubrium and the body of the sternum. The joint between the two vertebral bodies is known as intervertebral joint and is effected by the fibrocartilaginous intervertebral disc. The disc has two parts: the peripheral and the central. The peripheral portion is known as annulus

4 Kadasne’s Textbook of Anatomy (Clinically Oriented) fibrosis and the central portion is known as nucleus pulposus. Nucleus pulposus develops from the notocord. It forms the main weight bearing component due to the presence of water. The nucleus pulposus forms the ball bearing of the vertebral column gets desiccated in old age. Synovial Joints:

Movements in joints are free. They present following structural peculiarities (Figure B). 1. Bones are away. 2. Articular surfaces of the bones are covered with the hyaline cartilage. 3. The fibrous capsule is attached to the bones taking part in the formation of joint beyond the articular areas. Thickened bands of the fibrous capsule form ligaments. 4. It has a cavity. 5. The joint has synovial membrane which covers the capsule from inside and other structures except the articular areas. 6. Cavity contains a thin film of fluid known as synovial fluid. 7. Some joints are completely or partially divided into two compartments by an articular disc. Synovial joints are classified on the basis of various criterias: 1. Axis 2. Structural peculiarity 3. Number of bones: Two bones form a simple articulation and more than two the compound. According to the axis the joints are divided into three categories: 1. Polyaxial: Movements take place along more than two axes. (Shoulder joint) 2. Biaxial: Movements take place along two axes (radiocarpal joint) 3. Uniaxial: Movements occur along the long axis of the body is known as pivot (Superior and inferior radio ulnar joints) and when the movements take place across the long axis of the body is known as hinge type of joint (Elbow).

Figure B Showing typical synovial joint

Osteology of the Superior Limb

Clinical:

5

According to structural peculiarities, the joints are classified into two: 1. Saddle joint: It is biaxial. Articular surfaces are concavo-convex. Some degree of rotation is allowed in these joints. (carpometacarpal joint of the thumb). 2. Ellipsoid: It is biaxial. Oval convex articular surface fits into the elliptical concavity (radiocarpal joint and metacarpophalangeal joint). Structural break in the continuity of the bone is known as fracture. Before diagnosing the fracture in long bone please remember that the epiphysis and the diaphysis are separated by the plate of cartilage known as epiphyseal cartilage, before ossification. They look like fracture lines. Similarly the markings produced by blood vessels on the skull bones may be interpreted as fracture lines. Differences between the bone and cartilage are given as under: Type of tissue

Haversian canals

Blood supply Repair Covering Division

Definitions:

Classification of Epiphysis:

Compression: Traction: Atavastic:

Aberrant Blood Supply of Long Bone (Figure B-1):

Bone

Cartilage

It is the hardest connective tissue, vascularized, mineralized, changing and living Presents Haversian canals with concentric laminae, canaliculi, lacunae, osteocyte, Bone has a blood supply Bone has power to regenerate and repair therefore fractures heal. It has periosteum Compact and cancellous

It is a less harder connective tissue. Haversian canals are absent.

Cartilage has no blood supply Cartilage has no power to regenerate It has perichondrium Divided into three 1. Hyaline cartilage 2. Fibro cartilage 3. Yellow elastic cartilage

The bone has shaft (diaphysis) ends epiphyses and the junction of the diaphysis and epiphysis the metaphysis. 1. Diaphysis: Diaphysis is the part of the bone which develops from primary center of ossification. 2. Epiphysis: It is the part of the bone which develops from secondary center of ossification. 3. Metaphysis: It is the junctional zone between diaphysis and epiphysis. It is placed at the junction of diaphyses and epiphysis. It is classified into four. 1. Compression 2. Traction 3. Atavastic 4. Aberrant. Epiphysis is placed at the ends of the long bones which transmit weight. It is produced by traction of a tendon on the bone. It is an old and forgotten, e.g. coracoid process of the scapula was a separate bone in the early stages now it is the part of the scapula. Abnormal, e.g. deviating from normal. Following are the sources of blood supply of the Long bone: 1. Nutrient 2. Epiphyseal 3. Metaphyseal

6 Kadasne’s Textbook of Anatomy (Clinically Oriented) 4. 5. 6. 7.

Periarticular Periosteal Endosteal and Muscular

Figure B-1 Showing blood supply of long bone

Haversian Canals: Volkman’s Canals:

They are the vertical system of canals placed along the long axis of the long bone having concentric laminae, lacunae, canaliculi and osteocyte. They are the horizontal system of canals connecting the Haversian canals with the medullary cavities.

BONES OF UPPER LIMB Scapula (Figure C):

Infraglenoid Tubercle: Supraglenoid Tubercle: Glenoid Cavity:

Coracoid Process:

It is the flat triangular bone placed at the posterio-lateral aspect of the chest wall. It has three borders, three processes, three angles and three fossae. Three borders : Superior, axillary and the vertebral Three angles : Superior, inferior and the lateral Three processes : Spinous, acromion and the coracoid. Three fossae : Subscapular, supraspinatus and the infraspinatus. (The spinus process is placed on the dorsal aspect of scapula as a shelf). It is the rough triangular area situated below glenoid cavity. It is above the glenoid cavity. It is a shallow pear shaped cavity at the lateral angle of the scapula, narrow above and broad below. It is covered with the hyaline cartilage. It takes part in the formation of the shoulder joint with the head of humerus which is larger in size and is grossly disproportionate to the size of the glenoid cavity. This makes the joint, freely mobile. It is a thick stout process above the supraglenoid tubercle like a bent thumb. It can be felt below the lateral one third of the clavicle. Keep your hand on the top of your friend’s shoulder with little finger behind and thumb in front. Tip of thumb is just near the tip of the coracoid process which points anteriorly. Superior border of scapula extends from the superior angle to the base of coracoid process. It presents the suprascapular

Osteology of the Superior Limb

7

notch or foramen. Medial border of scapula extends from the superior angle which lies at the level of second rib to the inferior angle which lies at the level of seventh rib. Figure C Showing anterior view of right scapula

Neck of Scapula: Costal Surface: Dorsal Surface (Figure D):

Part adjoining the glenoid cavity is known as the neck of scapula. It presents fine ridges produced not by the ribs but by the fibrous origin of the muscle subscapularis. (sub-means-below). Shelf like partition is placed horizontally on the dorsum of the scapula known as spine of scapula. It begins at the junction of upper one thirds and the lower two thirds of the medial border of the scapula. The spine is continuous laterally with the acromion process, which makes an angel of 90° with it. Lower border of the spine of scapula continues the lateral border of acromion. This turning point is known as acromial angle. It is the landmark which is seen with eyes and easily felt with fingers. Upper border of the spine continues as the medial border of the acromion. Deltoid originates from lower lip of the spine of scapula and the lateral border of the acromion. Trapezius muscle is inserted into the upper lip of the spine of scapula and the medial border of the acromion. Base of the spine near the medial border presents a small triangular area where the fibres of trapezius glide. To reduce friction, there lies a small bag of synovial membrane containing fluid between the triangular area and the fibres of trapezius (Bursa). Supraspinous fossa is above the spine and infraspinous fossa below. These two fossae communicate with each other through the spino-glenoid notch. Supraspinous fossa gives origin to the supraspinatus muscle and the infraspinous fossa to the infraspinatus muscle.

8 Kadasne’s Textbook of Anatomy (Clinically Oriented) Figure D Showing posterior view of right scapula

Glenoid Cavity:

Medial Border:

Inferior Angle: Lateral Border:

Spinoglenoid notch lies between the lateral border of the spine and the glenoid cavity. It gives passage to the suprascapular nerve and vessels. The subscapular fossa gives origin to the subscapularis muscle. Coracoid process provides insertion to the pectoralis minor muscle and its tip gives origin to the coracobrachialis and the short head of the biceps brachii muscles. The coraco-acromial, coracoclavicular, and the coracohumeral ligaments are attached to the coracoid process. It presents flattened impression around the periphery, which gives attachment to the glenoidal labrum. It is triangular fibrocartilaginous ring. Functions of the glenoidal labrum can be remembered as (DMP). D—deepens the cavity, M—maintains the bony contact, P—protects the edges of the glenoid cavity. Medial border of the scapula on its ventral aspect provides an insertion to the serratus anterior muscle from the superior to the inferior angle. Dorsal aspect of the medial border provides insertions to three muscles namely the levator scapulae, rhomboideus minor and the rhomboid major muscles from above downwards. Medial border of the scapula can be described as “blue” being the conventional colour for the insertions. Dorsal aspect of the inferior angle of the scapula gives origin to the latissimus dorsi muscle. Dorsal aspects of the lateral border provides origin to teres major muscle from the flattened impression, just above the inferior angle of scapula. The rest of the border provides origin to the two heads of the teres minor muscle. Groove for the circumflex scapular artery lies between the two heads of the teres minor muscle. Origin is conventionally shown in red

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colour. Since the lateral border of the scapula gives origin to three muscles namely the teres major, teres minor on the dorsal aspect and the subscapularis muscle on the ventral aspect of the lateral border of the scapula. It can be said that the lateral border of scapula is red. Glenoid Tubercles: Supraglenoid tubercles provides origin to the long head of the biceps brachii muscle while the infraglenoid tubercle provides origin to the long head of triceps muscle. Ossification: Scapula ossifies from eight centers, one primary for the body and seven secondary for the other parts of the bone. Primary center appears in the 8th week of intrauterine life. Other appear at 14th year and unite at 20th year. Center for the coracoid appears in the 1st year of life. All other centers appears at the time of puberty. They unite at the age of twenty. Glenoid cavity ossifies from two centers. Upper one third develops from the subcoracoid center. It units with lower two third in the 14th year in female and 17th year in male. Flat glenoid cavity is converted into a so called fossa by the curved epiphysis at the margin. This makes the margin thick and center thin, giving it an appearance of a fossa. Important features of scapula: 1. Whole of the costal surface and the groove at the lateral border give origin to the subscapularis muscle. Near the neck of the scapula, subscapular bursa is placed between the neck of the scapula and the subscapularis tendon. 2. Area near the inferior angle and the whole of the costal aspect of the medial border give insertion to the serratus anterior muscle. 3. Infraglenoid tubercle gives origin to the long head of triceps. 4. Lateral border on its dorsal surface gives origin to teres minor muscle from its upper two thirds. There is a groove at its lateral border between the two heads of the teres minor muscle for the circumflex scapular artery. 5. An oval impression on the dorsal aspect of the lateral border of scapula above the inferior angle gives origin to the teres major muscle. 6. Dorsal aspect of inferior angle gives origin to latissimus dorsi. 7. Infraspinatus fossa, gives origin to infraspinatus muscle. 8. Supraspinatus fossa, gives origin to supraspinatus muscle. 9. Dorsal aspect of medial border gives insertions to three muscles, (Insertion – is conventionally shown in blue colour.). From superior angle to the root of spine, levator scapulae is inserted. At the root of the spine rhomboideus minor and the rest of the border up to the inferior angle provides insertion for the rhomboideus major. 10. Superior border medial to the suprascapular notch gives origin to the inferior belly of omohyoid muscle. Suprascapular notch is converted into the foramen by the suprascapular ligament. Foramen gives passage to suprascapular nerve, while the suprascapular artery passes above the ligament. 11. Glenoid cavity: Nature protects the nerve more than the artery. It is shallow pear shaped cavity at the lateral angle of scapula. It is covered with articular cartilage which is thick at the periphery and thin in the center. Around the periphery, there is a flattened impression for the glenoidal labrum. It is a fibrocartilaginous ring, which helps to increase

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Kadasne’s Textbook of Anatomy (Clinically Oriented) the depth of glenoid cavity. However, its main function is the protection of edges of the cavity. When arm is by the side of the body, the articular surface of the glenoid cavity looks forwards, upwards and laterally. Long head of biceps brachii arises from the supraglenoid tubercle, hence it is intracapsular. 12. Acromion: It articulates with the lateral end of clavicle to form the acromioclavicular joint. 13. Coracoid process: Tip of coracoid process gives origin to the short head of biceps brachii medially and coracobrachialis laterally. Superior surface gives insertion to the pectoralis minor. In addition to these, coracohumeral and coraco-acromial ligaments are attached to it.

Clinical:

1. Springle shoulder: The phenomena of descent of the scapula with the advancement of the age is known as springle shoulder. There is an arrest of the scapular descent and scapula remains high and small. 2. Omovertebral bar: Scapula is attached to the spines of the vertebral column by a bar of bone. Resection of the part of the bony bar is the treatment.

Clavicle (Figures E and F) It is a long bone placed horizontally in the body. It presents shaft, which is like letter ‘f’ and two ends, acromial or lateral and sternal or medial. It articulates laterally with the acromion to form acromioclavicular joint, and medially with the manubrium sterni to form sternoclavicular joint. Shaft presents two curvatures. Lateral one-thirds is concave anteriorly, while medial two-thirds is convex anteriorly. Naturally meeting point of the two curvatures is a weak spot, which commonly gets fractured. Lateral one third of the shaft is flat presenting superior and inferior surfaces. It has anterior and the posterior borders. Medial two-thirds is quardri-lateral and has superior, inferior, anterior and the posterior surfaces. Superior surface of the entire clavicle is subcutaneous and smooth, while the inferior surface is rough as it presents rough ridges and tubercles for attachment of conoid and trapezoid parts of coracoclavicular ligament at the lateral end. Middle part presents a small shallow groove for the insertion of subclavius muscle and the nutrient foramen. Inferior aspect of the medial end of the clavicle presents an impression for the attachment costoclavicular ligament. Figure E Showing superior surface of right clavicle

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Figure F Showing inferior view of right clavicle

With eyes closed one can differentiate superior surface of the clavicle from the inferior by mere touch of the fingers. Attachments:

Lateral one third of the anterior border of the clavicle gives origin to the deltoid muscle. Lateral one thirds of the posterior border of the clavicle provides insertion to the trapezius muscle.

Sternal end:

If seen from the medial side, it looks quardrilateral. Its superior and posterior borders give attachment to the intra-articular disc of the sternoclavicular joint. Pectoralis major takes origin from the superior and the anterior surfaces of the medial two thirds of the shaft of the clavicle. Sternomastoid muscle takes origin from the medial part of the superior surface.

Ossification:

1. It is the first bone to ossify. 2. It ossifies in membrane. 3. It has two primary centers of ossification. They appear on 35th day and 40th day and fuse together on 45th day 4. Secondary center appears for the sternal end at the 7th year in male and fuses at the 22nd year.

Clinical:

Pseudoarthrosis of the clavicle: Middle third of the clavicle is absent. Ends of the proximal and the distal parts of the clavicle present as rounded eminences which are connected by the fibrocartilaginous mass. It is seen on the right side only and is attributed to higher position of the right subclavian artery. Peculiarities of clavicle: 1. It is a long bone placed horizontally in the body. 2. It is a long bone having no medullary cavity. 3. It is a bone which ossifies first and ossifies in the membrane. 4. It ossifies from two primary centers. 5. It is the only bone in the body which is pierced by cutaneous nerves.

HUMERUS It is the long bone of the arm having the shaft, upper and the lower ends. It takes part in the formation of the shoulder joint at the upper end and the elbow joint at the lower (Figures G, H and H-1)

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

Figure G Humerus anterior view

Figure H Left humerus posterior view

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Figure H-1 Showing anatomical carrying angle and clinical carrying angle

Upper End:

Greater Tubercle:

Surgical Neck:

Capsular Attachment:

Shaft:

Upper end of the humerus presents the hemispherical head, covered with the articular cartilage, greater tubercle and the lesser tubercle. Head of the humerus is directed backwards, upwards and medially. The head articulates with the glenoid cavity of the scapula and forms the shoulder joint. Area beyond the articular surface of the head is known as the anatomical neck. Lesser tubercle is situated in front of the upper end and forms the medial limit of the groove known as the intertubercular groove or the sulcus. Lesser tubercle gives insertion to the subscapularis muscle. It is the lateral prominence at the upper end. It forms the lateral boundary of the intertubercular groove. It presents three impressions starting from the top to the back. They are: 1. for supraspinatus, 2. infraspinatus, and 3. the teres minor. (Attachments of the greater tubercle can be remembered as SIT). S-Supra-spinatus, I-Infra-spinatus, T-Teres minor. These three muscles SIT on the greater tubercle. Note: As the lessor tubercle of the humerus provides insertion for subscapularis muscle an additional S be added to the SIT making it SITS It is at the upper end of the shaft of humerus below the anatomical neck. Axillary nerve and the posterior humeral circumflex artery are intimately related to it. In case of fracture at this site, axillary nerve gets damaged. It leads to loss of abduction of the shoulder beyond 15° and wasting of the deltoid muscle leading to the loss of rounded contour of the shoulder. It is attached at the upper end around and beyond the articular surface of the head (anatomical neck) leaving a gap for the passage of long head of biceps. The capsular attachment descends 1.5 cm below, on the medial side of the neck. It is cylindrical in the upper part and triangular in the lower. It presents three borders namely the anterior, medial and the lateral. Medial border is traced downwards from the lesser tubercle and it ends as the medial supracondylar ridge.

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

Anterior border begins in front of the greater tubercle and descends downwards running in the middle of the front of the shaft. In the upper part it forms lateral border of the intertubercular groove. To its medial side, is the antero-medial surface and to its lateral side the anterolateral surface. Lateral border begins at the back of the greater tubercle and runs downwards to continue as the lateral supracondylar ridge. Lateral border is interrupted in the middle by the spinal groove. Anterolateral surface in the middle, presents a V-shaped impression known as the deltoid tuberosity meant for the insertion of the deltoid. Middle of the antero-medial surface gives insertion to the coracobrachiales muscle. As already stated, the bicipital groove is limited by the lateral and the medial lips. Pectoralis major is inserted into the lateral lip. “The teres major is inserted into the medial lip. Latissimus dorsi finds its insertion into the floor of the groove. Contents of Groove: The bicipital or intertubercular groove contains the long head of biceps alongwith the synovial sheath the ascending branch of the anterior humeral circumflex artery and the insertion of latissimus dorsi in the floor. Supracondylar ridges give attachment to medial and the lateral intermuscular septae. Medial supracondylar ridge provides origin to the pronator teres and the lateral supracondylar ridge gives origin to the brachoradialis and the extensor carpi radialis longus muscles. Origin of branchoradialis is above the origin of extensor carpiradialis longus. Epicondyles give attachment to the collateral ligaments. Well marked groove lies behind the medial epicondyle meant for the ulnar nerve. Note: “Mark the sites of the nerves related to the humerus.” It is a common question. 1. Axillary nerve at the surgical neck. 2. Radial nerve in the radial groove on the back of the shaft of humerus. 3. Ulnar nerve in the groove on the back of medial epicondyle. Posterior Surface It is divided into two by the groove which runs downwards and laterally. of the Humerus: The groove provides passage to the radial nerve and the profunda brachii artery. Upper limit of the groove gives origin to the lateral head of triceps and the rest of the posterior surface provides origin to the medial head of triceps. Lower End of the It presents lateral epicondyle, capitulum, trochlea and the medial Humerus: epicondyle from lateral to medial side. Lateral epicondyle gives origin to the common extensors, while the medial epicondyle gives origin to the common flexor muscles of the forearm. Capitulum is covered with an articular surface and it articulates with the head of radius. Trochlea lies medial to the capitulum. It has two flanges. Its medial flange is seen projecting downwards more, as compared to the lateral. Long axis of the forearm makes an angle with the long axis of the arm when the elbow is extended and the forearm is supinated. It is known as carrying angle which is 160° to 170°. It gets obliterated in pronation when the elbow is extended. This position has best working advantage for the hand. The angle keeps the forearm away from the hip and the thigh.

Osteology of the Superior Limb Angle of Humeral Torsion: Clinical Carrying Angle:

Capsular Attachment: Ossification:

Lower End: Upper End:

Clinical:

Supracondylar Fracture:

15

Axis of the proximal end of the humerus, makes an angle with the axis of the distal end of the humerus. It is known as the angle of humeral torsion (164°). It lies between the long axis of the forearm and the arm, it comes to 10° to 15°. In cubitus valgus carrying angle is more due to supracondylar fracture as a result the ulnar nerve is stretched and gets damaged which leads to the tardy ulnar palsy. In cubitus varus carrying angle is reduced and the ulnar side of the forearm comes in contact with the thigh. When the carrying angle is zero it is known as the cubitus rectus. Capsule at the lower end is attached to the bone beyond the articular area and it includes the fossae. It ossifies from eight centers, one primary and seven secondary centers. Primary center for the shaft appears in the eight week of intrauterine life. There are three secondary centers for the upper end and four centers for the lower. One each, for medial epicondyle, lateral epicondyle, the medial trochlea, and the capitulum with the lateral trochlea. Time of appearance of centers for the head - 1st year For the greater tubercle - 2nd year For the lesser tubercle - 6th year (ONE – TWO – SIX – for upper end) Time of appearance of centers for the lower end. Medial epicondyle - 4th year Medial trochlea - 10th year Capitulum - 1st year Lateral epicondyle - 12th year Upper end unites at the age of 20th year and lower end at 16th year. There is a separated epiphysis for the medial epicondyle which unites with the bone at 20th year. This epiphysis is extracapsular. Upper end is the growing end. 1. It is commonly fractured. 2. Fracture at the surgical neck damages the axillary nerve leading to the loss of abduction of shoulder beyond 15°. The rounded contour of the shoulder becomes square due to wasting of the deltoid muscle. 3. Fracture of the shaft results in injury of the radial nerve, which causes wrist drop. 4. Fracture of the medial epicondyle injures the ulnar nerve and causes claw hand. 5. Supracondylar fracture at the lower end of the humerous is common in children. It is the most important fracture seen in children due to fall on the out stretched hand on the flexed elbow. Distal fragment goes backwards gets angulated and pronated. Injury to the brachial artery is important as it can be trapped by the broken sharp distal end of the proximal fragment. Reduction of the supracondylar fracture should be done without loss of time by an experienced surgeon only. To check the compression of the brachial artery the radial pulse is checked constantly. Fracture should be reduced without loss of time as the swelling at the fracture site distorts the normal anatomy.

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

Supracondylar Process:

It is a hook like process arising from the antero-medial surface of the humerus 5 cm above the medial epicondyle. It is attached to the medial border, proximal to the medial epicondyle by a fibrous band. The fibrous band gives an attachment to the pronator teres muscle. The foramen thus formed gives passage to the brachial artery and the median nerve.

RADIUS (Figures I and J) It is the long bone of the forearm situated on the lateral side. It is connected to the ulna at the upper, middle and lower sites. Head of radius articulates with the ulna and forms the superior radioulnar joint. Head of ulna articulates with the radius at the lower end and forms the inferior radioulnar joint. Middle articulation is formed by the interosseous membrane, connecting interosseous borders of radius and ulna. Figure I Showing front of ulna and radius

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Figure J Showing posterior view of radius and ulna

Figure J-1 Colles’ fracture dinner fork deformity

Upper End:

Shaft:

It has the head having an articular facet on the top which articulates with the capitulum. Head is encircled by the annular ligament, which is attached to the anterior and the posterior borders of the radial notch, on the ulna. Neck lies below the head and the radial tuberosity is placed below the neck. Posterior part of the radial tuberosity receives insertion of the tendon of biceps brachii. A bursa exist between the radial tuberosity and the tendon of biceps brachii. It is concave in front and convex laterally. It has three borders namely anterior, posterior and the interosseous. It is cylindrical above and quadrilateral below. All three borders start from radial tuberosity. Interosseous border comes from lower part of the tuberosity and runs downwards and ends as the posterior limit of the ulnar notch on the radius.

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

Anterior Surface: Lateral Surface:

Posterior Surface: Lower End:

Ossification:

Clinical:

Anterior border begins from the anterior part of the tuberosity, runs obliquely downwards and ends near lower end. Posterior border begins from the posterior aspect of the radial tuberosity and runs obliquely downwards and laterally to end near lower end. It gives origin to flexor pollicis longus in the upper two thirds and provides insertion to the pronator quardratus in the lower one fourth. Due to obliquity of the anterior border, upper part of the lateral surface which provides insertion to the supinator muscle, can be seen from the front. Middle part of the lateral surface provides insertion to the pronator teres. The brachioradialis is inserted in the lower part of the lateral surface above the styloid process. All the muscular attachments on the lateral surface of the radius are insertions which are conventionally shown in blue colour (Lateral surface of the radius is blue so “Say Please Blue”,: Ssupinator, P– Pronator teres, B – Brachioradialis. It gives origin to abductor pollicis longus and extensor pollicis brevis muscles from above downwards. It is broad and quadrilateral. The lower lateral part presents the styloid process. Tip of the radial styloid is lower than the tip of ulnar styloid. This anatomical fact is important clinically as in Colle’s fracture, the styloid processes of the radius and the ulna are at the same level. Distal surface of the lower end of the radius articulates with scaphoid and the lunate. Dorsal aspect of the lower end of radius presents tubercle which is in a line of the web between index and the middle finger. It is known as dorsal tubercle of Lister. Medial side of the lower end presents an ulnar notch for the head of ulna. Triangular articular disc of the wrist joint intervenes between the head of ulna and the triquetral. The disc is attached to the base of styloid process of ulna medially and to the lower border of the ulnar notch on the radius laterally. Anterior border of the radius: It gives origin to the flexor digitor sublimis muscle. It ossifies from three centers. One for the shaft and one for the each end. Center for the shaft appears in the 8th week of intrauterine life. Center for the lower end appears in the 1st year and the center for the upper end appears at 5th year of life. Upper epiphysis joins the shaft at the age of 16th years and lower at the age of 18th years. The lower end is the growing end. 1. Radial club hand: In this condition there is total or partial absence of the radius, and the radial deviation of the hand (Medlung’s deformity). 2. Colles’ fracture: It is common in old women due to osteoporosis. It is the fracture of the lower end of the radius where the fracture line lies 2 cm proximal to the articular surface of the lower end of the radius. The deformity of the wrist appears as Dinner Fork deformity. Distal fragment goes dorsally, proximally, with radial deviation and supination. 3. Smith’s fracture is reverse of the Colles’: The distal fragment is palmar flexed. 4. Barton’s: It is the intra-articular fracture of the distal end of the radius with anterior displacement of the whole carpus. 5. Chauffor’s fracture: It the fracture of the radial styloid due to backkicking of the handle used for starting the car. It is not seen these days as the handle is no more required to start the car in the advanced technical era.

Osteology of the Superior Limb

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6. Children’s Colles’ fracture: It is the fracture of the distal epiphysis of the radius. 7. Galeazzi fracture dislocation: It consists of the fracture of the lower part of the radius and the dislocation of the inferior radioulnar joint. Note: Nutrient artery is directed away from the growing end. “To the elbow I go”.

ULNA (Figures I to J)

Upper End:

Anterior Surface:

Posterior Surface:

It is the long bone of the forearm placed medially. It presents shaft, upper and the lower ends. It articulates with the humerus and the radius above and the lower end of the radius below. Articulations with the radius, it forms superior radioulnar, middle radioulnar, and the inferior radioulnar joints. It is concave anteriorly. It presents two processes. The olecranon and the coronoid processes having concavity presenting anteriorly. Articular surface of the coronoid process is like a seat of the chair while the articular surface of the olecranon is like the back-rest of the chair. Small nonarticular strip lies between the articular areas of the coronoid and the olecranon processes. Top of the olecranon gives insertion to the tendon of the triceps muscle. On the posterior surface of the olecranon there is triangular area which can be felt subcutaneously and, its apex runs downward as the subcutaneous posterior border of the ulna. It gives origin to three muscle, flexor carpi ulnaris, extensor carpi ulnaris and the flexor digitorum profundus. On the lateral aspect of the upper end of the ulna is the notch for the head of radius. Attached to the anterior and the posterior borders of the notch is the annular ligament. There is a depression below the radial notch, the posterior limit of which is formed by the supinator crest. Supinator crest gives origin to the supinator muscle. Supinator crest continues downwards as the interosseus border of the ulna. Anterior border starts from the ulnar tubercle and ends at the styloid process. Anterior surface of the coronoid process is triangular in shape and presents an ill-defined tubercle known as tubercle of ulna. Anterior surface of the coronoid process provides insertion to the brachialis muscle. Medial border of the coronoid process is prominent. Upper collateral ligament is attached to the medial border of the coronoid process. Lower down it provides origin to the pronator teres and the flexor digitorum sublimis muscles. At times the flexor policis longus arises from the medial border of the coronoid process. Trochlear surface is covered with articular area which articulates with trochlea of the humerus. It gives origin to the flexor digitorum profundus in its upper three fourth. Lower rough ridge in the lower one fourth gives origin to the pronator quandratus. It must be noted that origin of flexor digitorum profound extends on the medial side of the coronoid process. It is situated between the posterior and the interosseous borders. It is divided by an oblique line. Anconeus muscle is inserted in the zone above this line. Rest of the posterior surface is divided in two by the vertical ridge. Portion lateral to the ridge gives origin to three muscles namely the abductor pollicis longus, extensor pollicis longus and the extensor indicis.

Lower End of Ulna: Lower end presents the head and the styloid process. Head articulates with the ulnar notch on the radius and the styloid process gives attachment to ulnar collateral ligament of the wrist joint. The articular disc is attached

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Kadasne’s Textbook of Anatomy (Clinically Oriented) to the base of the styloid process medially and lower part of the ulnar notch of the radius laterally. On the back of the lower end of ulna there is a shallow groove meant for the extensor carpi ulnaris tendon. The triangular articular disc prevents the lower end of the ulna from taking part in the formation of the wrist joint.

CAPSULAR ATTACHMENT Upper End: Lower End: Ossification:

General Account of the Carpal Bones (Figures K and L): Figure K Showing skeleton of the left hand (anterior view)

Figure L Showing skeleton of the left hand (posterior view)

Capsule is attached to the upper end of the ulna beyond the articular area and also to the annular ligament. Capsule is attached to the bone beyond the articular area. It ossifies from 3 centers. 1. Center appears in the shaft (Primary Center) at the 8th week of intra uterine life. 2. Center for the lower end appears in the 8th year. 3. Center for upper end appears in the 11th year. Fusion of the upper end with the shaft occurs at the 16th year and that at the lower end occurs at the 18th year of age. Lower end is the growing end.

Osteology of the Superior Limb

Scaphoid (Figure M):

21

They are arranged in two rows namely the proximal and the distal. Bones of the proximal row are arranged from lateral to medial side as under. 1. Scaphoid 2. Lunate 3. Triquetral 4. Pisiform. Please note that the pisiform tops the triquetral. All the four bones are connected by the interosseous ligaments and show convexity on the proximal side i.e. towards the bones of the forearm for the radiocarpal joint. Bones of the distal row are arranged in a row from lateral to medial side as under: 1. Trapezium, 2. Trapezoid. 3. Capitate, 4. Hamate. All eight bones of hand present concavity on the palmar side and convexity on the dorsal. This concavity is converted into the tunnel by the flexor retinaculum and is known as carpal tunnel. It resembles a boat. It is the largest of all the carpals. It is placed distally, laterally and forwards. Its tubercle is on the palmar surface and directed laterally. It provides attachments to two important structures: (i) Flexor retinaculum and (ii) Abductor pollicis brevis.

Figure M Showing dorsal aspect of the left scaphoid

Lunate (Moon) (Figure N):

Figure N Showing the left lunate

Dorsal surface has narrow rough zone for the arteries. Fracture of the bone at this site, results in necrosis of the proximal part of the bone, as the blood supply comes through the distal segment. Radial collateral ligament is attached to the bone. It articulates with the radius. It is like a moon. The palmar surface is larger than dorsal. It articulates with the 1) triquetral 2) capitate 3) radius and the 4) scaphoid. Medial surface of the lunate is quadrilateral in shape and articulates with triquetral.

22 Kadasne’s Textbook of Kadasne’s Textbook of Anatomy (Clinically Oriented) (Clinically Oriented) Triquetral (Figure O):

It is the medial most bone of the proximal row and articulates with lunate laterally. It is pyramidal in shape. On its palmar surface, it is provided with an oval facet for the pisiform. Medial part of it gives attachment to the ulnar collateral ligament.

Figure O Showing palmar surface of left triaquetral

Distally it articulates with the hamate. It does not take part in the formation of radiocarpal joint, due to the triangular articular disc, which intervens between the head of the ulna and the triquetral. Pisiform (Figure P):

It is like a pea, which sits on the palmar surface of the triquetral bone. It has one articular facet meant for triquetral. It is supposed to be a sesamoid bone which develops in the tendon of flexor carpi ulnaris muscle. It has been proved by serial microscopic sections that bone appears before tendon (Kadasne, Jr ASI 68) and is not a true sesamoid.

Figure P Showing left pisiform bone (dorsal surface)

Trapezium (Figure Q):

Figure Q Showing palmar view of the left trapezium please note the groove

Flexor retinaculum, and the flexor carpi ulnaris are attached to the bone. Piso-hamate and piso-metacarpal ligaments are attached, which are considered as extensions of the flexor carpi ulnaris. It is the first bone of the distal row of the carpus. It has the groove limited by crests on its palmar surface. The groove is converted into the osseofibrous tunnel by the flexor retinaculum. Tendon of the flexor carpal radialis passes through the tunnel. Hence, it can be called as Royal tendon

Osteology of the Superior Limb

Trapezoid (Figure R):

23

as it is the sole occupant of the tunnel. It articulates with the trapezoid medially and scaphoid proximally. There is saddle-shaped facet for the base of first metacarpal bone distally. It forms the important joint known as carpometacarpal joint of the thumb. It is like a boot (shoe). Its distal surface articulates with the base of the second metacarpal bone. Its dorsal surface is broader than the palmar surface.

Figure R Showing the trapezoid of left side please note the dorsal surface

Capitate (Figure S):

It has head hence the named as capitate (caput means head). It is situated in the intermediate position in line with the third metacarpal bone.

Figure S Showing the left capitate

Hamate (Figure T):

It has a hook on the palmar surface. It gives attachment to the flexor retinaculum and is related to or even grooved by the deep branch of the ulnar nerve. Distally it articulates with bases of the fourth and the fifth metacarpal bones.

Figure T Showing left hamate (A) medial view (B) lateral view

Metacarpals:

They are miniature long bones and are five in numbers. They are numbered form lateral to medial side. Each metacarpal has rounded head, shaft and an expanded base. Head presents convex articular surface for the proximal phalanx to form the metacarpophalangeal joint. The prominence of the knuckles is formed by the heads of the metacarpals. Base is expanded and articulates with the distal row of the carpal bones. Shafts are concave on the palmar surface producing the concavity. Dorsal surface of the metacarpal present a triangular impression.

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

Clinical:

Bennett’s fracture-dislocation: It is the fracture of the base of the first metacarpal bone involving the articular surface. Shaft of the first metacarpal is pulled proximally by the abductor pollicis longus muscle which is inserted in the base of the first metacarpal bone. In fact it is a subluxation of the joint and not the dislocation.

INDIVIDUAL METACARPAL BONES First Metacarpal Bone (Figure U):

First metacarpal bone is placed laterally. It is the shortest and the strongest metacarpal bone. It has undergone medial rotation of 90°. Therefore, plane of the four metacarpal bones is at right angle to the plane of the first metacarpal bone. Its palmar surface gives origin to opponens policis on the lateral side. Its base is concavo-convex and articulates with the trapezium to form the important joint known as the carpometacarpal joint of the thumb. On the palmar side of the head, there are facets for the sesamoid bones. Radial aspect of the base provides insertion to abductor pollicis longus muscle.

Figure U Showing 1st metacarpal (A) Palmar view (B) Lateral view

Second Metacarpal It is the longest amongst of the metacarpals. The base is expanded and (Figure U-1): has a groove which articulates with the trapezoid (Second has grooved base). Figure U-1 Showing 2nd metacarpal

Third Metacarpal Bone (Figure U-2):

Head presents tubercles at the sides for the attachments of collateral ligaments of the metacarpophalangeal joints. It has a styloid process which helps in its identification. Its base articulates with the capitate. Palmar surface of the base gives attachment to flexor carpi radialis and dorsal surface gives attachment to extensor carpi radialis.

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Figure U-2 Showing (left) 3rd metacarpal note styloid process (A) Lateral view (B) Medial view

Fourth Metacarpal Bone (Figure U-3):

It can be identified by means of a small oval facet on the medial side of the base. Please remember that there are two separate oval facets on the base of its lateral surface. Proximally it articulates with hamate by means of quadrilateral facet (Quadrilateral base means fourth metacarpal bone).

Figure U-3 Showing 4th metacarpal (left) (A) Lateral view (B) Medial view

Fifth Metacarpal Bone (Figure U-4):

It is relatively slender. It is identified by the fact that it has no articular facet on the medial side of its base, where a tubercle can be seen. Proximally it articulates with hamate.

Figure U-4 Showing 5th (left) metacarpal (A) Lateral view (B) Medial view

Phalanges of Hand (Figure V):

The phalanges of the hand are 14 in number, thumb has 2 and 3 each for the remaining four fingers. Palmar surface is slightly concave. The bases of all the proximal phalanges have concave facets for the head of proximal phalanx. The joint between phalanges are known as proximal and distal inter-phalanges joints.

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

Figure V Showing articilated hand and phalanges (palmar view)

Ossification of the carpal bones proximal row Scaphoid - 5th year Lunate - 5th year Triquetral - 3rd year (tri for three) Pisiform - 12th year Ossification of the distal row Trapezium - 5th year Trapezoid - 5th year Capitate - 2nd month (1) – Head one Hamate - 3rd month (1) Hook 1-1 The most important fact regarding the ossification of the metacarpal bones which should be remembered is that the first metacarpal has a center at the base while all others have centers at the heads. Ossification Centers 1. Primary center—for shaft of Phalanges: 2. Secondary center for base of 1st and heads of 2, 3, 4, 5. Ossification occurs in the shaft in the 9th week of intrauterine life in the distal phalanges; 10th week in the proximal and 11th week in the middle. Comment on carpals 1. Scaphoid - like a boat 2. Lunate - like a moon 3. Triquetral - pyramidal or triangular 4. Pisiform - like a pea 5. Trapezium - has groove 6. Trapezoid - like a boot 7. Capitate - has a head 8. Hamate - has a hook Metacarpals First - Short and stout, concavo-convex at the base and grooves for the sesamoids on the head. Second - It has grooved base Third - It has styloid process at the base Fourth - It has quadrilateral base. Fifth - Slender, and has tubercle at the base on the medial side.

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SUPERIOR LIMB IN GENERAL It is needless to state that the superior limb has an overall superiority over the inferior. We do various jobs with the hands. It is possible for us to perform the skilled acts such as writing, drawing and painting due to the functional potentiality of the hand. Hand has contributed a lot in putting the man in the superior position. The hand has an extensive representation in the cerebral cortex. It is actively supported by the fact that the majority of pyramidal fibres go to the superior limb and most of them to the hand. Considering the role the limb has to perform, free mobility for the limb is a must. Wide range of movements at the shoulder are due to the movements at shoulder joint and also due to the scapular mobility. If the movements of the scapula are to be allowed freely, naturally it cannot afford to get fixed to the axial skeleton. The truth is appreciated more when we know that the scapula is kept hanging on the dorsal aspect of the thorax mainly by the muscles. It is connected to the clavicle at the acromioclavicular and the coracoid process at the coracoclavicular joint. The free mobility of the limb is mainly due to the structural peculiarities of the shoulder joint. The glenoid cavity of the scapula is shallow and the head of the humerus is relatively large. At the elbow joint, flexion and extension are permitted. Flexion, extension, adduction, abduction and circumduction are permitted at the wrist. Pronation and supination occur at the superior and inferior radioulnar joints. This helps us in adjusting the working hand without giving trouble to the shoulder or the arm. Coming to the hand, one must say that the joint between the first metacarpal and the trapezium is of an immense importance. All the movements of the thumb are projected here. The thumb is separated from the rest of the four fingers by a wide gap and also has undergone a rotation of 90°. It is said that thumb is equal to four fingers. If the thumb is lost, 50 percent value of the hand is lost. If the 50 percent value of the hand is taken as lost then the 50 percent value of the limb is lost. The lowered value of the superior limb brings down man from superior position to the inferior in the animal kingdom. Imagine the functional value of this small anatomical structure of the superior limb. No doubt the thumb and the hand with fingers deserve compliments, but not without the cooperation and coordination of the muscles, bones and joints provide proximal to it. The nerves innervate the muscles, and the arteries provide nourishment. Superior limb is attached to the body at the junction of the neck and the thorax. In normal anatomical position, the limb is by the side of the body with palm facing forwards and thumb laterally. The vessels and the nerves enter the root of the limb through the cervico-axillary canal. The cervicoaxillary canal is bound by the first rib medially, clavicle anteriorly and the upper border of the scapula posteriorly. It can be considered as the gate of entry and exit of superior limb (Figure 1). Immediately below and lateral to the gate lies the pyramidal space known as the axilla. In reality, the canal opens at the apex of the axilla. Axilla is the hollow pyramidal space between the side of the thorax and the upper part of the arm. The axillary hollow is made prominent by the anterior and posterior axillary folds, which are coming from anterior and

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Kadasne’s Textbook of Anatomy (Clinically Oriented) posterior aspects of the trunk. Posterior fold is more prominent as it descends downwards, more than the anterior fold (Figure 2).

Figure 1 Cervico-axillary canal

Figure 2 Anterior and posterior fold of axilla

Embryological Background:

The front of the thorax is known as the pectoral region. On the posterior part of the thorax is the scapular region. The shoulder region is located around the shoulder joint. The region between the shoulder and the elbow joints is termed branchium or the arm. Humerus is the bone of the arm. It articulates with the scapular glenoid cavity proximally and the radius and ulna distally, thus forming the shoulder and the elbow joints. Shoulder joint has wide range of movements, while the elbow joint, has flexion and extension. At the wrist the lower end of the radius articulates directly with the scaphoid and lunate bones. It must be remembered that the lower end of the ulna is prevented from taking part in the formation of wrist joint by the triangular articular disc. Thumb has two phalanges and the rest of the four fingers have three. The first metacarpal bone of the thumb can be considered as the modified phalanx. Movements of the other fingers occur at the metacarpophalangeal joint and the movements of the thumb occur at the carpometacarpal joint of the thumb (Figure 3). The superior limb develops as an outgrowth from the side of the trunk of the embryo at right angle. Superior limb develops a little before the inferior, thus marks its superiority over the inferior, even during the embryonic life. The limb presents flexor (ventral) and extensor (dorsal) surfaces. The border pointing towards the head is known as preaxial border and towards the tail is labelled as postaxial border. The free end of the limb gets divided into four fingers and the thumb. The thumb develops before the four fingers. Thus, the thumb marks its superiority over the four fingers even during the embryonic life. Two constrictions mark the sites of the wrist and elbow. Now the arm, forearm and hand can be differentiated. Later on the precursors of the bones appear and the flexor and the extensor compartments get their limits defined. The muscles of both the

Superior Limb in General

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compartments are derived from the ventral somites. Therefore, the nerves which supply them are the ventral rami of the spinal nerves. Nerves divide into anterior and posterior divisions, which go to the flexor and extensor compartments, respectively. The nerves do not stick to their own compartments, during their journey. The muscle mass of one compartment migrates to the other. During this migration the muscle carries its nerve with it, e.g. brachialis is the muscle of the flexor compartment of the arm. It is supplied by a nerve of the flexor compartment (musculocutaneous). However, the small part of the muscle gets nerve supply from the nerve of the extensor compartment (radial). This indicates that the part of the muscle has migrated from the extensor compartment (Figure 4). Figure 3 Functional thumb and functional finger

Figure 4 Flexor and extensor compartments with nerves

About the terminology Name of the muscle

Criteria for the Name

Meaning

Deltoid Biceps brachii

Shape of the muscle Structural peculiarity

Subscapularis

Site of origin

Coraco brachialis

Point of origin and Point of insertion

Supinator Interosseous membrane

Function Situation

Delta means a Triangle Brachium means arm, it is the muscle of the arm with two heads. Muscle arises from the subscapular fossa. Arises from coracoid process and gets inserted into the bone of the arm e.g. humerus. Muscle which supinates A membrane which lies between two bones.

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Kadasne’s Textbook of Anatomy (Clinically Oriented) Comparison between Superior and Inferior Limbs Superior Limb

Interior limb

Mobility is the main job. Pectoral girdle consists of scapula, and clavicle. Clavicle articulates with the sternum anteriorly scapulae are separated by a wide gap posteriorly.

Stability is the main job. Pelvic girdle consists of two hip bones.

Hand has fine discriminative sense. Hand is specially meant for prehension. Shoulder joint is synovial polyaxial. Elbow joint is synovial uniaxial-hinge. Wrist joint is synovial polyaxial condyloid. Arm presents two compartments. Forearm presents two compartments. Extensor aspect of elbow is pointing backwards. Hand is in line with the forearm.

Hip bones articulate with each other anteriorly. The gap between two hip bones is filled by the sacrum, posteriorly. Foot has less discriminative sense. Foot is meant for supporting the weight and locomotion. Hip joint is synovial polyaxial. Knee joint is synovial uniaxial. (modified hinge). Ankle joint is synovial uniaxial-hinge. Thigh presents three compartments. Leg presents three compartments. Extensor aspect of knee is pointing forwards. Foot makes an angle of about 90° with the leg.

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REGIONAL ANATOMY OF THE SUPERIOR LIMB PECTORAL REGION General Consideration:

It is the name given to the region, situated in front of the chest, on either side of the sternum. Here we see the ribs, costal cartilages and the intercostal spaces. The intercostal spaces are closed by the intercostal muscles. In each space there is an artery, vein and the nerve (intercostal artery, intercostal vein and the intercostal nerve). (VAN from above downwards). Lateral and anterior cutaneous nerves, make their appearance in this region. They are the branches of the intercostal nerves. Some nerves from the region of the neck cross the clavicle superficially and run downwards to supply the skin of the pectoral region up to the level of the second costal cartilage. Anterior cutaneous arteries accompany the anterior cutaneous nerves. They are the branches of internal thoracic, mammary artery. Internal thoracic mammary artery runs vertically downwards behind the costal cartilages. Beyond the subcostal arch is the region of the anterior abdominal wall. External oblique muscle of the abdomen is the superficial muscle presenting the wide aponeurosis (Figure 5).

Figure 5 Cutaneous nerves of the pictorial region and the aponeurosis of external oblique muscle

The region presents two pectoral muscles, larger and the small, known as pectoralis major and the minor. The third muscle lies below the clavicle. It is known as subclavius. The nerves which supply the pectoral muscles are known as pectoral nerves. They are two medial and the lateral pectoral nerves. The subclavius is supplied by the special nerve named as nerve to subclavius. It comes from the region of the neck. The fascia covering the pectoralis major is known as pectoral fascia. The fascia between the clavicle and the subclavius muscle above and the pectoralis minor below is known as clavi-pectoral fascia. The special thickened part of it is seen running from the first rib medially to the coracoid process laterally, it is known as costocoracoid membrane. The pectoralis major, pectoralis minor along with the subclavius form the anterior wall of the axilla. In female the pectoralis major muscle is related to major portion of the base of the mammary gland. Surface Landmarks Following landmarks are easily felt: (Figures 6A and B): Run your finger laterally along the spine of the scapula until you reach a point where the spine ends and the flat acromion begins. By reaching the acromion you reach the top of the shoulder. Carry the finger along the acromion. Follow the acromion and come to the acromion clavicular joint,

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Kadasne’s Textbook of Anatomy (Clinically Oriented) where the acromion and the clavicle meet. You need not follow the clavicle with finger, as it is clear and evident to the eyes. In other words follow the clavicle with eyes. It will be seen that the clavicle is concave anteriorly in its lateral 1/3 and convex in its medial 2/3. At the medial end of the clavicle the smooth curvature of the clavicular line becomes obscure by the sternomastoid muscle producing a skin fold running upward and laterally (Fig.6A).

Figure 6A Surface landmarks

Figure 6B Surface landmarks of the upper part of back

Put your finger in between the two sternomastoid folds and press downwards. The finger gets logged in the suprasternal notch. Carry the finger from the notch along the front of the sternum-downwards. You come across an elevated ridge two inches below the superior border of sternum. It is known as sternal angle (angle of Louis), where the manubrium and the body of the sternum make an angle. The site of an angle is marked by the transverse ridge, where, the second costal cartilage articulates with the sternum. The xiphoid process is felt in an angle between subcostal arches (It is mobile and behind it lies the liver, do not use force while palpating the xiphoid process). Coracoid process lies below the lateral end of the clavicle. It is covered with fibres of the deltoid muscle. Pectoralis major muscle becomes more prominent during the adduction of the arm against resistance. Ask the patient to put both the hands on the hips and press firmly the pectoralis major muscle stands out in permanence deltoid muscle gives rounded appearance to the shoulder.

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An interval between the deltoid and clavicular head of the pectoralis major is known as the delto-pectoral groove. The depression below the middle third of the clavicle is known as infraclavicular fossa. Nipple is located approximately at the center of the mammary gland and is surrounded by the areola. Nipple lies in the fourth intercoastals space away from the lateral border of the sternum. Position of the nipple is variable, hence should not be taken as a reliable surface landmark. Ribs are counted down from the sternal angle e.g. from the second costal cartilage as the first is under the clavicle. Skin and Cutaneous Platysma arises from the skin lying immediately below the clavicle and Vessels and Nerves: runs upwards towards the region of the neck. It is inserted into the lower border of the mandible. The same area of the skin is innervated by the supraclavicular nerves coming from the neck. If one tries to correlate two facts an interesting story emerges. It is like a game of give and take. The skin lying immediately below the clavicle takes supraclavicular nerves from the neck and gives the platysma to it in return. It borrows the supraclaviculars and repays the platysma. It can be explained on embryological grounds. The aforesaid region of the skin originally belonged to the neck and is secondarily brought down below the clavicle (Figures 7 and 8). Figure 7 The supraclavicular nerve and platysma

Figure 8 Showing sagittal section of clavicle to illustrate game of give and take

Nipple and the areola represent the modified part of the skin. Areola presents number of small sebaceous glands raised from the surface in the form of small tubercles. They are known as tubercles of Montgomery. Areola is pinkish in colour in virgins but gets pigmented during the third month of pregnancy. This change of colour is permanent. There are 15 to 20 ducts of the mammary gland which open on the top of the nipple. Normally the nipple is directed downwards and laterally. The abnormal direction of the nipple is suggestive of the underlying pathology in the breast such as malignancy (cancer).

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Flexure Line (Langer’s Lines) of the Skin of Pectoral Region:

Superficial Fascia:

Cutaneous Nerves:

These lines run horizontal on the trunk except over the skin of mammary gland where they are arranged circularly. An incision given along the flexure lines heals with minimum scarring and an incision given across the lines heals with excessive scarring or keloid formation. Keloid—It is an growth of the scar tissue and not the hypertrophy. Hypertrophy—Increase in the size of the scar. Scar—It is the residual visible mark of the wound. It lies under the skin. Fat is absent under the areola. Superficial fascia splits in two, to enclose the mammary gland and thus provides it with an ill defined capsule. Numerous septae run from these two layers to divide the mammary gland into compartments. The mammary gland is situated in the superficial fascia itself. Anterior cutaneous branches of the intercostal nerves are seen piercing the pectoralis major near the lateral border of the sternum. They supply the adjoining area of skin. These nerves are accompanied by the anterior cutaneous arteries which are the branches of the internal thoracic mammary artery. Lateral cutaneous nerves are the branches of the intercostals nerves. They leave the thorax between the digitations of the serratus anterior and the external oblique muscles. They divide in the anterior and posterior branches. The anterior branches run anteriorly and reach the pectoral region after winding round the lower border of the pectoralis major muscle. The nerves are accompanied by the small cutaneous branches of the intercostals arteries. Anterior perforating arteries of the second, third and the fourth intercostals spaces are important in female as they supply the mammary gland. The supraclavicular nerves supply the area of skin of the pectoral region up to the level of second costal cartilage. They are arranged in three sets, the anterior, middle and the posterior. They are known as the medial, intermediate and lateral supraclavicular nerves (Figure 9).

Figure 9 Cutaneous nerves and vessels of pectoral region

The first intercostal nerve usually fails to give an anterior cutaneous branch. The lateral cutaneous branch of the second intercostal nerve is long. It crosses the floor of the axilla and supplies the upper and the medial part of the arm. It is known as intercostobrachial nerve. Between the clavicular head of the pectoralis major and the deltoid, lies a groove known as the deltopectoral groove. Cephalic vein, deltoid branches of thoracoacromial artery and the deltopectoral lymph nodes are situated in the groove (Figure 10).

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Figure 10 Deltopectoral groove

It is of interest to know that during surgery for the cancer of breast of removal of the clavicular head can be spared with the sole object of preserving the cephalic vein (Victor Riddel, 1948, BJS 36 p. 113). If the cephalic vein is cut, the surgeon may have to repent when it becomes obligatory for him to sacrifice the axillary vein (Figure 11). Figure 11 Surgical anatomy of clavicular head of the pectoralis major

Pectoral Fascia (Figure 12):

It is the name given to the deep fascia covering the pectoralis major muscle. It is attached to the clavicle above and the sternum medially.

Figure 12 Pictorial fascia and its different subdivisions

From the inferior border of the pectoralis major the fascia runs posteriorly to reach the latissimus dorsi and encloses it. The portion of the fascia between the pectoralis major and the latissimus dorsi forms the deep fascia of the floor of axilla. It is known as the axillary fascia. An upward extension goes from the axillary fascia to the lower border of pectoralis minor. It splits at the lower border of the pectoralis minor muscle

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

Clavipectoral Fascia (Figure 13):

to enclose it. As it comes to the upper border of muscle it unites to form the clavi-pectoral fascia. Clavipectoral fascia runs upwards to enclose the subclavius muscle and gets attached to the clavicle. The fascia between the facia of floor of axilla and the lower border of pectoralis minor is known as the suspensory ligament of axilla. During abduction, the clavicle is raised and the suspensory ligament is also pulled up, thus making the hollow of the axilla more prominent. Laterally, pectoral fascia is continuous with the deep fascia covering the deltoid muscle. Lower down, it joins the fascia over the external oblique muscle of the abdomen. It is already mentioned that the clavipectoral fascia lies between the pectoralis minor below and the subclavius muscle above. Medially it is attached to the first rib and laterally it goes to the coracoid process and the coracoclavicular ligament. Part of this fascial septum is specially thickened just below the subclavius muscle. It is named as costocoracoid membrane. Medially it is attached to the first rib and laterally to the coracocoid process and the coracoclavicular ligament. Clavipectoral fascia is pierced by an artery, vein, nerve and the lymphatic channel.

Figrue 13 Clavipectoral fascia

(Artery: thoraco-acromial artery; vein: cephalic vein; Nerve: lateral pectoral nerve, lymphatic from back of breast). Small lymph nodes lie in front of the fascia, while the apical group of lymph nodes are behind the fascia. It is important to note that a lymph trunk from the deep aspect of the breast after passing through the pectoralis major muscle pierces the clavipectoral fascia and drains into the apical group of lymph nodes. (Backdoor exit of the lymph from the breast). Surgical (Figure 14): 1) Collection of pus between the pectoralis major and minor. It is a rare site. 2) Collection of pus behind the pectoralis minor comes from the region of the neck, through the cervico-axillary canal. Sometimes the pus may take the reverse course. In other words, the cervico-axillary canal is the gate of entry or exit for the pus. Situated over the fascia of the pectoralis major, is the deep lymphatic plexus draining the mammary gland.

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Figrue 14 Surgical anatomy of pectoral and axillary fascia

Muscles of the They are three in number; namely, the pectoralis major, pectoralis minor Anterior Wall of the and the subclavius. Axilla (Figure 15): Figure 15 Anterior wall of axilla

Pectoralis Major (Figure 16):

It is the largest muscle of the pectoral region. It is triangular in shape.

Figure 16 Origin of pectoralis major muscle

Origin: Clavicular Head:

The muscle presents two heads, namely the clavicular and the sternocostal. It arises from the anterior surface of the clavicle from its medial half to medial two thirds. Fibres run downwards and laterally.

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

Sternocostal Head:

Insertion (Figure 17):

It arises from the front of the manubrium and the body of the sternum reaching up to the sixth costal cartilage. It also arises from the second, third, fourth, fifth and sixth costal cartilages. Origin from the first being occasional. Small part of the muscle arises from the aponeurosis of the external oblique of abdomen. In general, fibers of the sternocostal head run upwards and laterally and are posterior to the clavicular fibres, near the insertion. Description of the insertion of this muscle has been made complicated. Description of bilaminar tendon given by many authors is more convincing. Fibres of the clavicular head run downwards and are superficial. Naturally, they get inserted into the lower part of the lateral lip of the bicipital groove. The lower group of fibres as they ascend upwards and laterally pass under cover of the clavicular head and get inserted into the upper part of the lateral lip of the bicipital groove. It must be remembered that these two heads form two laminae which are continuous with each other, lower down. The lower border of the muscle forms the anterior fold of the axilla.

Figure 17 Details of insertion of the bilaminar tendon of pectoralis major

Nerve Supply:

Action (Figure 18):

All the roots taking part in formation of the brachial plexus supply the muscle (C 5, 6, 7, 8 and T 1) through two pectoral nerves the medial and the lateral. It is the adductor and the medial rotator of the arm. Clavicular head helps in flexion of the shoulder alongwith the anterior fibres of the deltoid.

Figure 18 Action of pectoralis major muscle

When the flexed arm is brought back to normal position, the sternocostal head is seen contracting, against resistance. If the upper limbs are fixed by catching a rope, as in climbing, the trunk is lifted up. The pectoralis major alongwith the latissimus dorsi lift the trunk while climbing. It also acts during forced and deep inspiration. Medial rotation is mainly due to the clavicular fibres.

Regional Anatomy of the Superior Limb Clinical Major (Figure 19):

39

1. Sternocostal and the clavicular heads of the muscle are separated by means of deltoid groove which contains cephalic vein. The sternocostal head of the pectoralis major is removed during operation of radical mastectomy (complete removal of the breast). Clavicular head is kept intact with a view to preserve the cephalic vein. The chances of recurrence of cancer in the clavicular head are less (Victor Riddell, 1948). Moreover it is claimed that the innervation of the clavicular head is separate and is left undisturbed. Surprisingly the functional loss after removal of the sternocostal head alone is less and the cosmetic defect nil.

Figure 19 Observe the constractions of pectoralis major and latissimus dorsal

2. Damage to the musculocutaneous nerve leads to weakness of the flexion of the elbow. Pectoralis major can be attached to the biceps tendon in order to restore flexion of elbow (Figure 19A). Figure 19A Showing restoration of flexion of elbow by attaching the pectoralis major to the tendon of biceps brachii

Poland Syndrome:

Pectoralis major may be partially or completely absent. Nipple is normal but the glandular tissue of the mammary gland is missing partly or completely.

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

Pectoralis Minor (Figure 20):

It is possible to memories the relations of different structures of the region by the study of pectoralis minor. It is the landmark muscle of the region. It is triangular in shape. It arises from the second, third and fourth ribs or may arise from the third, fourth and fifth ribs and the corresponding external intercostal membranes. It gets inserted into the medial border and the upper surface of the coracoid process. The tendon of the pectoralis minor may continue to join the coraco-acromial and the coracohumeral ligaments. The direction of the muscle is upwards and laterally. It is supplied by the medial pectoral nerve. It may get innervation from the lateral pectoral too.

Figure 20 Pectoralis minor

Clinical:

For axillary clearance it is essential to cut the pectoralis minor muscle. It forms the landmark for the new classification of axillary lymph nodes which are divided in three levels. Level one is below, two is infront and behind and level three above the muscle. In case of damage to nerve to serratus anterior (nerve of Bell) serratus anterior muscle is paralysed leading to the winged scapula. Pectoralis minor muscle can be used to restore the function of the serratus anterior muscle. It is attached to the infero-medial part of the scapula for the purpose. Pectoralis Minimus: At times a slip from the first rib passes to the coracoid process. It is known as pectoralis minimus muscle. Action (Figure 21): It draws the scapula forwards and downwards. It helps the serratus anterior muscle in protraction of the shoulder. Pectoralis minor keeps the lateral angle of the scapula in contact with the chest wall and prevents the lateral shift of the scapula. It also acts during forced inspiration. Figure 21 Action of pectoralis minor alongwith serratus anterior

Regional Anatomy of the Superior Limb Relations (Figure 22):

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The muscle divides the axillary artery into three parts as it passes in front of it.

Figure 22 Relations of pectoralis minor to the axillary artery

Anterior Relations:

Posterior Relations (Figure 23):

Skin, superficial fascia, mammary gland, pectoralis major, branches of medial pectoral nerve, Rotter’s lymph nodes and the clavicular fibres of deltoid are the anterior relations. Ribs and intercostal muscles, axillary artery, axillary vein, nerves of brachial plexus (cords) and more posteriorly the posterior wall of the axilla itself form the posterior relations of the muscle.

Figure 23 Posterior relations of pectoralis minor

Superior Relations:

Inferior Relations (Figure 24):

Clavicle, sub-clavius muscle and its nerve, clavi-pectoral fascia with cephalic vein, thoraco-acromial artery, the lateral pectoral nerve and the lymph nodes infront and behind the clavipectoral fascia, from the superior relations. Suspensory ligament of axilla, lateral thoracic artery, fascia of the floor of the axilla and the short head of biceps and the corco-brachialis form the inferior relations.

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

Figure 24 Showing relations of pectoralis minor

Sub-clavius Muscle It arises from the first rib and the adjoining part of its costal cartilage and (Figure 25): is inserted in the groove on the under surface of the clavicle. The clavipectroal fascia splits to enclose the subclavius and gets attached to the lips of the groove for the insertion of the subclavius muscle. Figure 25 Relations of the pectoralis minor muscle

Nerve Supply:

It is supplied by a special nerve known as nerve to subclavius which arises from the upper trunk of the brachial plexus. “The accessory phrenic nerve, when present arises from the nerve to subclavius. The nerve to subclavius also gives an articular twing to the sternoclavicular joint. The muscle steadies the clavicle during the movements of the shoulder girdle. It protects the axillary vessels by preventing its direct contact with the clavicle.

Mammary Gland

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MAMMARY GLAND It is rudimentary in the male and well developed in female, after puberty. It is a common site of cancer in female. Abnormal development of the male breast is known as gynecomastia. The gland develops from the ectodermal ridge known as the milk-ridge in front of the chest. Many abnormalities of the breast are known (Figure 26). Figure 26 Showing milk ridge

1. Polymastia (Polymazia): More number of breast than normal, such as in axilla, groin and buttocks. 2. Amastia: Absence of breast. 3. Abnormal site: Such as in axilla or groin. 4. Athelia: Absence of nipple. 5. Polythelia: Supernumerary nipple. 6. Poland syndrome: Nipple is normal but the glandular tissue is partially or completely missing. It may be associated with the total absence of pectoralis major muscles. Surface Appearance It is rounded or hemispherical. Its apex is surmounted by a nipple which and the form: is directed downwards and laterally. Abnormal direction of the nipple is suggestive of pathology underneath such as cancer. The areola surrounds the nipple. Its colour is pinkish in virgins, but becomes dark due to pigmentation in the 2nd and 3rd month of pregnancy permanently. Present over it are the small tubercles known as tubercles of Montgomery. They are the modified sebaceous glands, which help in protection and lubrication of the nipple. They may give rise to sebaceous cysts. The word cyst is derived from the Greek, meaning ‘bladder’. Cyst means a swelling containing collection of fluid in a sac lined by epithelium or endothelium. A few smooth muscle fibres lie under the nipple and the areola. They run in different directions. Erection of nipple is due to their contraction. Fifteen to twenty ducts open on the top of the nipple. Extent (Figure 27): The base of the gland extends up to the second rib above, sixth rib below in the vertical extent. Horizontally it extends from lateral border of the sternum medially to the mid-axillary line laterally. From the upper and outer part of the gland the tail of the gland (Tail of Spence) goes up to the second rib in the mid-axillary line. Situation Whole of the gland except in tail of Spence lies superficial to the deep (Figure 28): fascia. The tail of Spence passes through the opening in the deep fascia known as foramen of Langer. The superficial fascia split to enclose the

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Kadasne’s Textbook of Anatomy (Clinically Oriented) gland. Numerous firous sepatae join the two layers and divide the gland into the number of compartments. These fibrous septae are attached to the skin and are known as suspensory ligaments of Cooper. They are well developed in the upper part of the breast.

Figure 27 Showing extent of the mammary gland

Figure 28 Relations of the mammary gland and its tail

Surfaces:

They are two, namely the superficial and the deep. 1. Superficial surface: It is convex and lies under the skin, superficial facia, cutaneous vessels and the nerves. The nipple is surrounded by the areola. 2. Deep surface: It forms the base of the gland and is concave. It lies over the pectoralis major, serratus anterior muscles and the external oblique aponeurosis. Two third of the area of the base is on the pectoralis major (major part of the base lies over the major). Between the pectoralis major and the base of the gland, there lies a potential space known as retromammary space. During the operation of removal of breast, the surgeon takes advantage of plane provided by the space. In addition to what has been mentioned, other relations of the deep surface are as under: Pectoralis minor, intercostal spaces, pleura, lung, internal thoracic mammary artery, veins, lateral thoracic artery and the Rotter’s glands. Relations of the Tail: Second rib in the mid-axillary line, nerve to serratus anterior, serratus anterior muscle and the lymph nodes are the relations of the tail. Comment: During ligation of the anterior perforating branches of the internal thoracic mammary artery with the tips of the artery forceps, the possibility of damage to the pleura cannot be ruled out, in the region of the second, third and the fourth intercostal spaces. During dissection of the axillary tail, surgeon

Mammary Gland

Gross Structure of the Gland:

Microscopic Structure:

Blood Supply (Figure 29):

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has to isolate the nerve to serratus anterior and keep it away from the edge of the knife. Probably this is the occasion when he has to recollect the anatomy of the axilla with care and concentration. The knowledge of the anatomy of the breast is, always half and incomplete without the knowledge of anatomy of the axilla”. The glandular, fibrous and the fatty tissues combine to form the breast. Gland has an ill defined capsule of superficial fascia. There are numerous fibrous septae running from the deep part to the skin. The fibrous septae which are connected to the skin are known as ligaments of Sir Astley Cooper. In cancer of the breast they contract and produce dimpling of the skin (Peu-d-orange, e.g. orange peel appearance). Vessels and the lymphatics travel among these fibrous septae. There are 15 to 20 lobes, each of them contains numerous lobules. The lobules present number of alveoli. A duct begins from the lobe and form a dilation known as lactiferous sinus under the nipple. Beyond the sinus the duct narrows and opens on the top of the nipple, along with others. Lactiferous ducts are lined by spirally arranged myoepithelial cells which have an ability to contract. The mammary gland is a compound tubulo alveolar type of gland having characters of an apocrine and the merocrine glands. Apical membrane of the cell is lost and the fat globule is released (Apocrine). Apical plasma membrane remains intact and the protein molecules come out of the cell. (Merocrine). Alveoli are lined with cuboidal or columnar cells. Peri-alveolar tissue contains blood vessels, nerves and the lymphatic plexus. Fatty tissue is in abundance. Ducts are lined with cuboidal cells. Associated skin piece is usually seen. Male mammary gland is made of ducts without alveoli, little fat and fibrous tissue. 1. Perforating branches of the internal thoracic mammary artery, in the second, third, fourth and fifth spaces, 2. External mammary of the lateral thoracic, 3. Pectoral branches of the thoraco-acromial and branches from the intercostal arteries supply the mammary gland.

Figure 29 Blood supply of mammary gland

Venous Drainage:

Go to the internal mammary and the axillary veins along the arteries supplying the gland. Veins are in communication with the intercostal veins which join the vertebral venous plexus, this explains the spread of secondaries in the ribs and the spine. Lymphatic Drainage Higher incidence of the cancer of the breast is the cause of its importance. (Figure 30): The lymphatics begin at the peri-alveolar region. The lymphatic sets are two, namely the superficial and the deep. However, both the sets are in free communication with each other, making their division is artificial.

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Figrue 30 Lymphatic drainage of the breast (Note: Quadrants 1 and 2 of mammary gland drain into pectoral group. Quadrant 3 upper and medial drain into internal thoracic mammary of both sides and supraclavicular nodes. Quadrant 4 drains into liver through falciform ligament and forms Krukenburg’s tumour of ovary)

Superficial Set:

Deep Group:

Lymphatics from the superficial part of the gland with those of the adjoining area of skin form a plexus under the nipple and areola (Subareolar plexus of Sappey) and drain into the pectoral group of nodes by means of two lymph trunks. The mammary gland is divided into four quadrants. Lymphatics from the outer two quadrants go to pectoral group of nodes and from there to the central group of nodes. Lymphatics from the lower medial quadrant go to the peritoneal cavity through the rectus sheath. By this route cancer cells are able to reach the liver along the falciform ligament. Cancer cells fall like snowfall from the surface of the liver and get implanted over the raw surface of the ovary. This gives rise to the tumour of the ovary (Krukenburg’s Tumour). Imagine the possible danger of cancer in the lower medial quadrant of the breast (Dangerous quandrant). Fortunately the incidence of cancer in this quadrant is relatively low. Lymphatics from the upper medial quadrant go to the internal thoracic mammary group of the same side and the other side. They may cross the clavicle and go to the supraclavicular group. As mentioned before, recollect that a solitary channel leaves from the back of the gland, pierces the pectoralis major, clavi-pectoral fascia and reaches the apical group (Back door exit). In view of the recent advances. It is proposed to discuss a few more points regarding the lymphatics of the breast. Riddle V has described the importance of internal thoracic mammary group of nodes. Two to three nodes are found near the internal thoracic mammary artery. It is observed that these nodes get enlarged in about thirty percent of the cases having no enlargement of the pectoral group. Some lymphatics from the deep part of the gland also go to nodes lying between the pectoralis major and minor muscles. These nodes are known as Rotter’s nodes. Some of the lymphatic channels go to the nodes behind the clavicle. These nodes are known as Helsted’s nodes. Some go to the sub-scapular nodes. As mentioned earlier, a rich lymphatic plexus lies in the deep fascia of pectoralis major. This explains the need of removal of the pectoral fascia. Blockage of the lymphatics of the skin by the cancer cells gives a typical appearance to the skin (Peau d’orange—skin, like peel of an orange).

Mammary Gland New Classification of the Axillary Lymph Nodes:

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This classification is convenient for the surgeons operating on the breast for the cancer, while removing the axillary nodes and clearing of the axilla. It is divided into three levels in relation to the pectoralis minor muscle which is taken as a landmark. Level-1: The nodes lie below the pectoralis minor muscle, it includes lateral anterior and the posterior groups of axillary nodes. Level-2: It lies infront or behind the pectoralis minor muscle and includes the Rotter’s lymph nodes.

Palpation of the Axillary Nodes:

Clinical:

Investigations:

Figures 30A and B Mammography showing lump

Level-3: It includes apical group of lymph nodes. Axillary nodes are palpated from the front with the fingers, keeping the arm adducted during the palpation. Anterior, lateral, central and the apical glands can be felt this way. For palpation of the posterior group of glands the examiner has to stand behind and palpate the posterior group. 1. Mammary abscesses: An abscess is a localized collection of pus caused by pus forming bacterias. According to site they are pre, intra and retro-mammary abscesses. Incision for the drainage of an abscess is given along the direction of the ducts to avoid injury to the ducts, and prevent formation of fistula (Fistula—means an abnormal communication between two surfaces or cavities.) Retromammary abscess is due to the tuberculosis of the rib or due to pus in the pleural cavity (Empyema). 2. Fibroadenoma: It is a common nonmalignant lump of the breast. 3. Carcinoma of the breast: Upper and outer quadrant of the breast is the commonest site for malignant lump of the breast. The lower and medial quadrant is dangerous as the cancer spreads to the lever and has transperitoneal transmission. Malignant cells fall on the raw surface of the ovary giving rise to Krukenberg’s tumor. 4. Methods of spread of cancer of breast: a. Local spread: As it gets attached to the chest wall b. Lymphatic spread: Involving axillary supraclavicular and the nodes on the other side. c. Through blood: Malignant cells of the cancer of breast reach the ribs and the vertebrae through the intercostals veins which are connected with the vertebral venous plexus. d. Transperitoneal spread: 1. Mammography: They are the soft tissue radiographs taken on the ultrasensitive film with high voltage and low amperage (Figures 30A and B). 2. Ultrasound: It differentiates between the cystic and the solid lump. 3. FNAC: Fine needle aspiration cytology. 4. Ductography: Injection of radio opaque material in the large lactferus duct. It demonstrates the anatomy of the ductal system.

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Surgical Treatment: 1. Simple mastectomy: It includes the removal of the breast and not the removal of the axillary nodes. 2. Radical mastectomy: Removal of the breast with clearance of axilla for removal of axillary nodes and the fat. During clearance of the axilla surgeon has to take care not to damage the nerve to serratus anterior and the nerve to latissimus dorsi. 3. Structures to be removed during radical mastectomy: a. Whole breast b. Skin and the nipple c. Fat and fascia from clavicle to the rectus sheath and from sternum to the mid axillary line. d. Fat, fascia and the lymphatics in axilla. e. Sternal head of the pectoralis major muscle with fascia and the pectoralis minor with fascia. Fat and fascia on the serratus anterior, external oblique and the latissimus dorsi muscles. f. Costocoracoid membrane. 4. For better exposure of axilla, pectoralis minor muscle is either cut or removed. 5. During radical mastectomy following structures are preserved A. Axillary vein B. Nerve to serratus anterior (nerve of Bell) and the C. Cephalic vein. Surgeon should not touch the ABC during radical mastectomy. As far the nerve to the latissimus dorsi is concerned even if it is cut accidently or otherwise surgeon need not feel sorry as the functional loss due to the loss of latissimus dorsi is almost nil. 6. Costocoracoid membrane: A specialized thickened band of the clavipectoral fascia is removed during radical mastectomy. 7. Enlargement of the axillary tail (tail of spence): It is mistaken for the enlarged axillary node or the lipoma. In spite of the abundant fatty tissue, lipoma of the mammary gland is extremely rare (Poverty in the land of plenty). Clinically diagnosed lipomas of the breast are in fact liposarcomas having thick fatty cover.

Axilla

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AXILLA

Anterior Wall of Axilla (Figure 31):

It is a pyramidal space situated between the upper part of the side of thorax and upper part of the arm. Base is directed downwards and laterally, and the apex is pointing upwards and medially towards the coracoid process. Apex communicates with the neck through the cervico-axillary canal, the gate of axilla. It presents anterior and posterior walls of which the posterior wall, descends more than the anterior wall. Medial wall is larger and broader, while the lateral wall is narrower and smaller, Lower limit of the anterior and posterior walls can be examined in the form of anterior and posterior axillary folds seen after abduction of the arm. Floor is formed by the deep fascia which runs posteriorly from the lower border of the pectoralis major to the latissimus dorsi. Large amount of fat lies over the floor. Intercostobrachial nerve, which is the lateral cutaneous branch of the second intercostal, crosses the floor. Contents of the axilla are: 1. Axillary artery, 2. Axillary vein, 3. Brachial plexus with its cords and branches 4. Fat and 5. The lymph nodes. Out of these, fat keeps the skin of the floor of axilla away from the axillary vessels. (Fat has proactive function). In dislocation of the shoulder, the head of the humerus encroaches upon the axillary space and may damage the axillary artery and the brachial plexus. It is formed by pectoralis major, pectoralis minor, subclavius muscles, clavipectoral fascia and the suspensory ligament of axilla.

Figure 31 Anterior wall of axilla

Posterior Wall (Figure 32):

Subscapularis (Figure 33A and B):

It is formed by the subscapularis, teres major and the latissimus dorsi muscles. Subscapularis occupies the major portion of the posterior wall. Below and lateral to it lies the teres major. Latissimus dorsi winds the lower border of the teres major and comes to lie in front of it. It is a large triangular muscle. It arises from the medial two thirds of the subscapular fossa of the scapula including the groove along the lateral border. Some of the fibres arise from the tendinous laminae attached to the ridges on the subscapular fossa and from the fascia covering the muscle. Subscapular bursa intervene between the muscle and the neck of the

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

Figure 32 Posterior wall of axilla

Figure 33A Subscapularis muscle

Figure 33B Relations of subscapularis with its origin and insertion (horizontal section)

Nerve Supply: Action:

Clinical:

Relations:

scapula. The subscapular bursa is of size of an hen’s egg and it communicates with shoulder joint. It is supplied by the upper and lower subscapular nerves from the posterior cord of the brachial plexus. It fixes the head of the humerus against the glenoid cavity during the movements and thus helps in stabilizing it. It is the medial rotator of the arm. It is the member of the rotator cuff along with the supraspinatus, infraspinatus and the teres minor muscles. In recurrent dislocation of the shoulder tendon of subscapularis is overlapped along with the capsule to strengthen the capsule of the shoulder joint (Putti-Platt’s procedure) The muscle is related to the second and the third parts of the axillary artery (Fig. 33B).

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Anterior Relations:

Serratus anterior, coracobrachialis, biceps, axillary artery, axillary vein, the cords and nerves of the brachial plexsus. Posterior Relations: Scapula, infraspinatus muscle, shoulder joint, subscapular bursa and the neck of the scapula. Near the medial border of the muscle is an insertion of the serratus anterior (Figs 33A and B), while at the lateral border, teres major and the latissimus dorsi muscles are related. Surgical: In the operation for the recurrent dislocation of the shoulder, tendon of the subscapularis and the anterior part of the capsule of the shoulder joint are overlapped to strengthen the anterior part of the capsule. (Putti, Platt operation). Teres Major It arises from the oval impression on the dorsal aspect of the lateral (Figure 34): border of the scapula above the inferior angle and also from the fibrous septum between it and teres minor. It is inserted into the medial lip of the bicipital groove. As the latissimus dorsi winds its lower border, it comes infront of it. The posterior axillary fold is lower than the anterior axillary fold. It consists of teres major and latissimus dorsi muscles. Figure 34 Teres major muscle

Nerve Supply: Action: Latissimus Dorsi (Figure 35): Figure 35 Latissimus dorsi muscle

It is supplied by the lower subscapular nerve, a branch of the posterior cord of brachial plexus. It is an adductor and the medial rotator of arm and also helps in bringing arm backwards. This is the only muscle of the limb which is attached to both the girdles the pectoral and the pelvic (scapula and hip bone).

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

Origin: Insertion:

Nerve Supply:

Action:

Lesion:

Medial Wall of Axilla: Serratus Anterior (Figure 36):

It arises from the lower six thoracic spines, lumbar fascia, iliac crest, lower 2 to 3 ribs and the dorsal aspects of inferior angle of the scapula. After winding the lower border of teres major, it runs in front of it. Near its insertion the tendon lies anterior to the tendon of teres major, and their lower borders are continuous with each other. It is inserted into the floor of bicipital groove (intertubercular sulcus) through the thin and flat tendon measuring 7 cm in length. It is supplied by the nerve to latissimus dorsi, a branch from the posterior cord of brachial plexus. Looking at the nerve supply it is evident that the muscle originally belonged to the limb and has acquired very extensive attachments to the trunk. Main segmental source comes of the muscle comes from C7. The contributions from C6 and 8 are doubted. The segmental supply is seven and the length of the tendon is also seven (cm). It is an adductor and the medial rotator of the arm. It also helps in depressing the arm. When the arms are fixed as in climbing, it lifts the trunk along with the pectoralis major. The nerve to tatissimus dorsi is to be saved during radical mastectomy. If it is cut accidentally the surgeon need not worry, as the functional loss is practically nil. It is longer, broader and convex. Serratus anterior muscle with its nerve form the medial wall. At a deeper plane are the intercostal spaces, pleural cavity and the lung. It arises from upper eight ribs. (There are eight alphabets in the word serratus). Lower fibres of the muscle interdigitate with the upper fibers of the external oblique muscle.

Figure 36 Serratus anterior

First Digitation:

Middle two Digitations:

It arises from the first and the second, and also from the fibrous arch between two ribs. It gets inserted into costal aspect of the medial border of the scapula. They take origin from the second and the third ribs and gets inserted on the costal aspect of vertebral border of scapula. The remaining lower five digitations after arising from the respective ribs run towards the costal aspect of inferior angle of scapula, for the insertion. Out of these five digitaions, lower three make a shake-hand with the digitations of external oblique muscle. In brief origin and insertion of the serratus anterior can be summarized as under: It arises from the upper eight ribs and gets inserted into the costal aspect of the vertebral (medial) border of the scapula from superior to the inferior angles.

Axilla Nerve Supply:

Surgical:

Action (Figure 37):

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Nerve to serratus anterior come directly from the roots of C 5, 6 and 7 anterior primary rami. As these fibres come from the roots directly, near intervertebral foramina, they are irreparable. In injury of the rest of the plexus nerve to serratus anterior may remain intact as the roots are not damaged. Nerve to serratus anterior may be injured in the operations of cancer of breast resulting in paralysis of serratus anterior muscle. Lunge stroke of fencing is based on the serratus anterior muscle (Lunge – sudden forward movement of the body) (Fencing- It is the sport in which blunt swords are used for fighting). In the serratus anterior muscle paralysis there is no rotation of the scapula as a result raising of the arm above 90° is impossible. It brings the scapula forwards and thus helps in protraction of the shoulder. It comes into action during pushing and punching movements. It helps in rotation of the scapula along with the trapezius during the act of raising the arm above the head. It also fixes the scapula during abduction of the arm. This helps the deltoid to act as an effective abductor. If the nerve to serratus anterior is damaged, the patient has difficulty in abduction. In such cases the medial border of scapula can be fixed to vertebral spines with wires or fascia lata. While pushing against the wall the medial border of the scapula leaves the chest like a wing of a bird, in serratus anterior muscle paralysis (Winged scapula).

Figure 37 Action of serratus anterior muscle (protraction)

Lateral wall: Coracobrachialis:

Clinical:

Nerve Supply:

Action: Short head of Biceps:

Note: The serratus anterior, latissimus dorsi and pectoralis minor try to keep the scapula in contact with the thoracic wall. Bicipital groove along with the long head of biceps and the coracobrachialis form the narrow lateral wall. It arises from the tip of coracoid process along with the short head of biceps and gets inserted into the middle of the antero medial surface of the shaft of the humerus. Brachial artery can be compressed against humerus at the insertion of the coracobrachialis muscle to stop hemorrhage from the injured palmar arches. It is supplied by the musculocutaneous nerve, a branch of the lateral cord of brachial plexus. The nerve passes through two heads of the muscle, and supplies it before its entry into the muscle. It is a flexor of the arm along with the anterior fibres of the deltoid and the clavicular head of pectoralis major. It does help in adduction of the arm. It arises from the tip of coracoid process along with coracobrachialis. It joins the long head of biceps to form the fusiform belly of biceps brachii in front of the arm. The muscle is supplied by the musculocutaneous nerve.

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

AXILLARY ARTERY (FIGURE 38) It begins as a continuation of the subclavian artery at the outer border of the first rib. It runs downwards and laterally with a bold convexity pointing towards the shoulder. It ends at the lower border of the teres major muscle, and continues as the brachial artery. As it enters the axilla, it is related to the medial wall and distally it comes in contact with the lateral wall of axilla. Pectoralis minor crosses the artery from the front and divides it in three parts. Figure 38 Course of axillary artery and its parts

Relations of First Part of Artery (Figure 39):

Figure 39 Relations of the first part of axillary artery

Anterior relations: 1. Skin, 2. Superficial fascia, 3. Platysma, 4. Supraclavicular nerves, 5. Clavicular head of pectoralis major, 6. Clavipectoral fascia, cephalic vein, thoracoacromial artery and lateral pectoral nerve, 7. Apical group of lymph nodes, 8. Lymph nodes in front of clavipectoral fascia, 9. A loop connecting the lateral and the medial pectoral nerves.

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Posterior relations: They are as follows: 1. First and second digitations of serratus anterior muscle, 2. Nerve to serratus anterior, 3. First intercostal space, 4. Medial cord of brachial plexus. Note: Relations of the first part of the axillary artery to the cords of brachial plexus are peculiar as under: Medial cord is posterior; posterior cord is lateral and the lateral cord is still lateral. Lateral relations: They are: 1. Lateral cord 2. Posterior cord of brachial plexus. Medial relations: 1. Axillary vein 2. Axillary sheath. Relations of Second Anterior relations: Part of Artery 1. Skin, (Figure 40): 2. Superficial fascia with cutaneous nerve and vessels 3. Pectoralis major, 4. Rotter’s glands 5. Pectoral branch of thoracoacromial artery 6. Pectoralis minor 7. Medial pectoral nerve as it pierces pectoralis minor. Figure 40 Relations of the second part of axillary artery

Relations of Third Part of Axillary Artery (Figure 41):

Comments: Three structure lie between pectoralis major and minor, 1. Pectoral branch of thoracoacromial artery, 2. Rotter’s nodes and 3. The medial pectoral nerve. Posterior relations: Subscapularis muscle and the posterior cord of brachial plexus. Lateral relations: Lateral cord of brachial plexus. Medial relations: Axillary vein and medial cord of brachial plexus. Pectoralis major covers the anterior part of the axillary artery partly while remaining is under cover of the skin and the superficial fascia. Posterior relations of third part of axillary artery: 1. Subscapularis, 2. Teres major muscles

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

Figure 41 Relations of third part of axillary artery

3. Latissimus dorsi 4. Radial nerve 5. Axillary nerve Medial relations: 1. Medial cutaneous nerve of the forearm 2. Ulnar nerve 3. Axillary vein 4. Medial cutaneous nerve of the arm. Lateral relations: 1. Coraco- brachialis 2. Biceps 3. Musculocutaneous nerve 4. Lateral root of median nerve. Branches of Axillary Axillary artery has three parts, first gives one, the second gives two and Artery (Figure 42): the third part gives three branches. Figrue 42 Course and situation of lateral thoracic artery. Note the origin of external mammary artery

Branches from the first part: 1. Superior thoracic artery. Branches from the second part: a. Thoracoacromial b. Lateral thoracic arteries. Branches from the third part: 1. Subscapular,

Axilla

Superior Thoracic Artery: Thoracoacromial Artery:

Lateral Thoracic Artery:

Subscapular Artery:

Anterior Circumflex Humeral Artery:

Posterior Circumflex Humeral Artery:

Surface Marking of the Axillary Artery (Figure 43):

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2. Anterior humeral circumflex 3. Posterior humeral circumflex. It is the small branch arising from the first part of the axillary artery. It passes between pectoralis major and minor muscles. It anastomoses with internal thoracic mammary artery and the branches of intercostals. It arises from the second part of axillary artery under cover of the pectoralis minor. It winds the upper border of the muscle, pierces clavipectoral fascia and immediately divides into four branches. They are: 1. Clavicular 2. Acromial 3. Pectoral 4. Deltoid. The clavicular branch supplies the subclavius muscle and sternoclavicular joint. The acromial branch passes under coracoid process, towards the acromion. The pectoral branch passes between pectoralis major and the minor muscle. It anastomoses with the lateral thoracic artery. The deltoid branch passes along the groove between the deltoid and the clavicular head of pectoralis major muscle (Deltopectoral groove). It arises from the second part of axillary artery under cover of the pectoralis minor at its lower border. It supplies the serratus anterior, the pectoralis major, pectoralis minor, subscapularis muscles. It also supplies the axillary lymph nodes. It anastomoses with subscapular, intercostal, internal thoracic mammary and the pectoral branch of thoracoacromial arteries. In case of the females it gives an external mammary artery. It is the largest branch of the third part of the axillary artery. It arises from the third part of axillary artery at the lower border of subscapularis. It gives a branch known as circumflex scapular artery, which grooves lateral border of the scapula between two heads of teres minor muscle. Next the subscapular artery runs towards the inferior angle of the scapula. Here it anastomoses with lateral thoracic, intercostal and the deep branch of the transverse cervical artery. Terminal part of the artery is accompanied by the nerve to latissimus dorsi. Both of them pierce the latissimus dorsi muscle at one point (Neurovascular Hilum). The common entry of the artery and the nerve is protected by the fibrous arch. Probably it is the only known example of the neurovascular hilum in the body. It arises from the third part of axillary artery near lower border of subscapularis muscle. It runs in front of the surgical neck of humerus where it lies behind the biceps and the coraco brachialis muscles. It gives an ascending and the descending branches in the bicipital groove. Out of these, the ascending branch supplies the shoulder joint, and head of the humerus as it occupies the bicipital groove. It anastomoses with the posterior circumflex humeral artery. It arises from the third part of axillary artery. It is larger, it runs behind the neck of humerus after passing through the quadrangular space along with the axillary nerve. Its descending branches anastomoses with the profunda brachii artery. It supplies the deltoid muscle and the shoulder joint. It anastomoses with anterior circumflex humeral, subscapular, thoracoacromial and the profunda brachii arteries. Arm is abducted to 90° and palm facing upwards. Point A is marked at the mid clavicular point. Point B is marked on the line joining the anterior and posterior axillary folds at the junction of anterior two thirds and the posterior one third of this line. Join these two points with a convexity

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Kadasne’s Textbook of Anatomy (Clinically Oriented) pointing towards the shoulder. In the living it is possible to feel pulsations of the axillary artery lower down.

Figure 43 Surface marking of axillary artery

Surgical Importance Relation of the axillary artery to the head of humerus and the shoulder (Figure 44): joint is important. The vessel is likely to get ruptured during reduction of an old dislocation of shoulder joint. Axillary artery can be compressed against the upper part of shaft of humerus. As the axillary artery lies anteromedial to the bone, compression force should be applied in the opposite direction (Fig. 44). Figrue 44 Direction of force of compression to be applied to axillary artery

Note: Thrombosis (clotting of blood) of the artery can cause obstruction to the blood flow leading to ischemia and subsequent death of the tissue (gangrene). To study the vascular pattern of the artery and the site of block, angiography can be done. Radio-opaque medium is injected into the artery and X-rays are taken. Trauma, atheroma and an embolus are the main causes of blocking the artery. Blood supply of the ischemic and the dying part of the limb can be vascularized by means of an autograft or artificial graft. In case of bilateral iliac artery obstruction, eight mm. graft is passed subcutaneously from the axillary artery to the femoral artery. Blood from the axillary artery reaches the femoral beyond the block. Thus the blood from the axillary artery from upper limb is brought to the femoral artery of the lower limb.

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AXILLARY VEIN Course and Termination (Figure 45):

It begins at the lower border of teres major muscle as the continuation of the basilic vein. It ends at the outer border of the first rib, beyond which it is known as the subclavian vein. It lies on the medial side of axillary artery but tries to overlap it in the upper part.

Figure 45 Cephalic and axillary veins. Note the formation of median cubital vein

Medial Relations: Tributaries:

Valves:

Sheath (Figure 46): Figrue 46 Attachment of axillary sheath to clavipectoral fascia

Following structures lie between vein and the artery: 1. Medial pectoral nerve. 2. Medial cutaneous nerve of forearm. 3. Medial cord of brachial plexus. 4. Ulnar nerve 1. Medial cutaneous nerve of the arm lies medial to the axillary vein. Brachial veins join it in the lower part and the cephalic vein in the upper part. Please note that thoracoacromial vein joins the cephalic vein near its termination. Other tributaries follow their respective arteries. They are situated: 1. At the lower border of subscapularis, 2. At the termination of cephalic vein, and 3. At the termination of subscapular vein. It is enclosed with axillary artery in the axillary sheath, which itself is attached to clavipectoral fascia.

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Clinical (Figure 47): In case of the block of the axillary vein, before it is joined by the cephalic vein the blood from the upper limb is carried further to the axillary vein beyond the block by the cephalic vein and thus provides a bypass. Relation of lymph nodes to the vein is of great practical importance, as the surgeon has to remove the nodes from the axilla during radical mastectomy. Thrombosis of the vein may occur due to the damage to the intima of the vein. Thrombosis of the vein is followed by oedema of the limb. In such cases superficial veins in the upper part of pectoral region and around the shoulder become prominent. An attempt is made to save the cephalic vein during radical mastectomy. Spontaneous thrombosis of axillary vein is known in those who paint high ceiling with brush. Compression of the vein occurs between the first digitation of serratus anterior and subclavius muscles and not directly between the clavicle and first rib. Excessive exercise and cervicalrib may lead to axillary vein thrombosis. Figure 47 Blood passes through the cephalic vein if axillary vein is blocked

Brachial Plexus (Figure 48):

It lies partly in the neck and partly in the axilla. Following anterior primary rami take part in its formation.

Figure 48 Formation of the brachial plexus and its branches

Branches from the Roots: Branches from the Trunk:

What is primary ramus? Ventral or the anterior division of a typical spinal nerve is known as anterior primary ramus. 1. Cervical—5, 6, 7, 8 2. Thoracic—1. 5 and 6 cervical roots unite to form the upper trunk, while the cervical eight and the first thoracic roots unite to form the lower trunk. The remaining root (C7) forms the middle trunk. Each of the trunk divides to form anterior and posterior divisions. Anterior division of upper and middle trunks unite to form the lateral cord. Anterior division of lower trunk forms medial cord. Posterior division of all the trunks unite to form the posterior cord. Root and trunks are in the neck while the divisions are under the clavicle, cords and the branches in the axilla. They are as follows: Nerve to scaleni, lower root of phrenic nerve, nerve to serratus anterior (C 5, 6, 7) and the nerve to rhomboideus. Suprascapular and the nerve to subclavius arise from upper trunk of the brachial plexus in the neck.

Axilla Branches from the Cords:

Description of Branches is given in Brief:

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They are as under: Please note that median nerve comes from the lateral and medial cords; the ulnar from the medial cord and the radial and the axillary from the posterior cord. Lateral Cord

Medial Cord

Posterior Cord

Lateral pectoral nerve C5, 6, 7

Medial pectoral nerve C8 T1

Upper subscapular nerve C5, 6

Lateral root of median C5, 6, 7

Medial root of median C8 T1

Lower subscapular nerve C5, 6

Musculocutaneous nerve C5, 6, 7

Medial cutaneous nerve of forearm. C8 T1

Nerve to latissimus dorsi (Thoracodorsal nerve) C6, 7, 8

Medial cutaneous nerve of the arm C8 T1

Radial nerve

Ulnar of arm nerve. C (7) 8, T1

(Axillary nerve) C5, 6

1. Suprascapular nerve: It is the highest branch coming from the upper trunk of the brachial plexus. It can be examined in the posterior triangle. It passes through suprascapular foramen under suprascapular ligament (Please appreciate how the nature has given more protection to the nerve). Once it comes to supraspinous fossa it supplies the supraspinatus muscle and comes down to infraspinous fossa through the spinoglenoid notch to supply the infraspinatus muscle. The nerve is involved in Erbs-paralysis. It supplies its two muscles, two joints and the scapula itself. 2. Nerve to subclavious: It arises from the upper trunk of brachial plexus in the posterior triangle of the neck and descends downwards in front of the third part of subclavian artery and vein to supply the subclavius. It may give an accessory phrenic nerve. 3. Nerve to serratus anterior: It arises from the roots of the plexus, C 5,6,7. It is also known as the nerve of Bell. The roots of the nerve run downwards behind the roots of brachial plexus and unite to form the nerve trunk. Damage to the nerve leads to winged scapula. In an injury of the brachial plexus, the nerve of Bell remains uninjured indicating that the roots of the brachial plexus are unaffected. During operation of radical mastectomy surgeon has to preserve axillary and cephalic veins, nerve of Bell (nerve to serratus anterior). This can be remembered as A B C during radical mastectomy (Preserve the ABC). A - Axillary artery B - Nerve of Bell C - Cephalic vein. 4. Upper and lower subscapular nerves and the nerve to latissimus dorsi: All the three nerves arise from the posterior cord. Nerve to latissimus dorsi arises between two subscapular nerves. Lowersubscapular nerve, apart from supplying the subscapularis also innervates teres major muscle. Upper subscapular nerve supplies the muscle subscapularis. The nerve to latissimus dorsi supplies the muscle, latissimus dorsi. 5. Pectoral nerves: They are two, the medial and the lateral, respectively arising from medial and lateral cords of brachial plexus. Pectoral nerves are connected together by a loop which run across the front of the first part of axillary artery. Lateral pectoral nerve pierces the clavipectoral fascia along with the thoracoacromial artery, cephalic vein and the lymphatic from the breast. It supplies pectoralis major muscle and gives branches to the pectoralis minor muscle. Medial pectoral nerve

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arises from the medial cord of the brachial plexus and supplies the pectoralis minor muscle. It gives a branch to the pectoralis major also. 6. Musculocutaneous nerve: Arises from the lateral cord of brachial plexus (C 5, 6, 7) and lies on the lateral side of the third part of axillary artery. It passes through the coracobrachialis after giving a branch to it. It passes between biceps and brachialis with a lateral inclination. A little below the elbow, it pierces the deep fascia on the lateral side of tendon of biceps and continues as lateral cutaneous nerve of the forearm. It is the nerve of the flexor compartment of the arm. 7. Median nerve: (6, 7, 8 and T1): It is formed on the lateral aspect of the third part of axillary artery by union of the lateral and the medial roots. Lateral root comes from the lateral cord which lies laterally and the medial root comes from the medial cord which lies medially. Hence the medial root crosses the third part of the axillary artery from the front, from medial to lateral side and joins the lateral root forming the median nerve. Ulnar Nerve (C 8, T1; It is the continuation of the medial cord. It lies between the axillary artery Contribution from and the axillary vein, the artery being lateral and the vein medial. C7 is Doubtful):

AXILLARY NERVE (C 5, 6) (FIGURES 49 AND 50) It is one of the two terminal branches of the posterior cord of the brachial plexus. It lies behind the third part of the axillary artery and in front of the subscapularis muscle. The axillary nerve lies lateral to radial nerve. At the lower border of subscapularis it leaves the axilla by passing through the quadrangular space along with posterior circumflex humeral artery. In the quadrangular space the nerve divides into anterior and the posterior divisions and gives a branch to the shoulder joint. Posterior division of the nerve supplies the teres minor muscle leaves the quadrangular space. It presents a small pseudoganglion. Posterior division supplies the posterior part of deltoid muscle and gives the upper lateral cutaneous nerve of the arm. Anterior division runs along with posterior circumflex humeral artery, encircling the surgical neck of the humerus. It gives branches to deltoid muscle. In brief, the following contributions of the nerve are summarized. 1. Supplies the deltoid and the teres minor. 2. The shoulder joint. 3. The area of skin over the deltoid in the lower part, area over the shoulder and the small area of the upper part of the arm. Figure 49 Axillary nerve (diagrammatic)

Axilla

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Figure 50 Axillary nerve: Quadrangular space viewed from behind

Surgical:

Radial Nerve:

Intercostobrachial Nerve:

Relations of Brachial Plexus:

Clinical:

By virtue of its relation with the surgical neck of the humerus, it is always in danger during fracture of the bone. It may get damaged during dislocation of the shoulder. Damage to the axillary nerve leads to paralysis and atrophy of the deltoid (Atrophy means wasting). Rounded appearance of shoulder is lost and it looks square. Loss of function of teres minor is clinically insignificant. However, the loss of sensation of skin on the lower half of the deltoid is significant. It is due to the damage of the upper lateral cutaneous nerve of the arm. It is known as Regimental badge anaesthesia. Testing the integrity of the axillary nerve by abduction is difficult. Therefore the sensory loss on the lower part of the deltoid is taken as the sign of injury of axillary nerve. It can be described clinically as the “Regimental badge anaesthesia test”. It is the branch of the posterior cord of brachial plexus. It lies behind the third part of the axillary artery medial to the axillary nerve. It lies on all the muscles of the posterior wall of axilla, namely the subscapularis, latissimus dorsi and teres major. In its upper part, the axillary nerve (axillary nerve) lies lateral to the radial nerve. Radial is the nerve of the extensor compartment of arm. It is the lateral cutaneous branch of the second intercostal nerve. It escapes through the digitations of the serratus anterior muscle and crosses the floor of axilla and reaches the upper part of the arm. It communicates with lateral cutaneous branch of third intercostal, medial cutaneous and posterior cutaneous nerves of the arm. In the neck, the plexus lies between scalenus anterior and the medius muscles. Roots lie in the posterior triangle while the divisions are under the clavicle; cords and branches are with first, second and the third parts of axillary artery in the axilla. Brachial plexus can be injured in trauma, caused by traction, stab injuries, compression, during operations of cervical rib and the cancer of the mammary gland. Clinically damage to the nerve is described in three types: 1. Neuropraxia: There is a loss of function and not the continuity. 2. Axonotmesis: Sheath of the nerve remains intact while the axon is cut. 3. Neurotmesis: There is an anatomical discontinuity of the nerve in which the axon and the sheath are cut. Such injuries must be explored and sutured directly or with the intervening nerve graft either from the superficial branch of the radial or the sural nerve. Injury due to traction can occur during delivery or during the motor cycle accident. During delivery forceps is applied to the head outside, while the shoulders are inside the womb of the mother (Birth trauma).

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Pre-fixation and Post-fixation of the brachial plexus:

Erb’s Paralysis: (Figure 51)

Preganglionic injury does not recover while the recovery of the postganglionic type depends on the degree of nerve damage. Associated vascular injury to the subclavian artery can occur due to compression between the clavicle and the first rib. Damage leads to ischemia of the muscles, is followed by contracture. (Volkmann ischemic contracture) In pre-fixation brachial plexus moves one segment higher because of the contribution from C4 is more and the T1 is reduced and the contribution from the T2 is totally absent. In post-fixed brachial plexus it moves one segment below hence the contribution from the T2 is more. In post fixed brachial plexus the lower trunk has to go up, hence it is angulated and stretched on the superior surface of the first rib. This results in symptoms of compression of the lower trunk of the brachial plexus. It is commonly, due to the stretch exerted on the upper trunk of the plexus, involving the fifth and sixth cervical ventral rami. This type of injury is met with in difficult labour where head of the baby is out and shoulders are in. In such cases, if the head is pulled with forceps, the upper trunk gets damaged. It can occur due to forceful downward pull of the arm during delivery. Similarly injury can result if a heavy object falls on the shoulder.

Figure 51 Erb’s paralysis

Following muscles are involved: 1. Deltoid 2. Biceps, brachialis, brachioradialis 3. Supinator, supraspinatus 4. Teres major and teres minor 5. Infraspinatus.

Klumpke’s Paralysis:

Injury to the Roots:

Position of limb in Erb’s paralysis: 1. Limb by the side of the body. 2. Extension at the elbow, 3. Forearm is pronated and 4. Medially rotated. This position is described as “Policeman’s Tip” or “Porters Tip” Policeman being the custodian of law can not accept bribe openly). When the lower trunk gets injured (mainly T1) it is the medial cord which suffers. There is wasting of the small muscles of the hand and associated sensory loss along the inner side of the forearm. As the ulnar and the medial root of the median are involved inner three and a half fingers lose sensations and the hand has a clawed appearance (Claw hand). It can be associated with the Horner’s syndrome. Injury to T1 results in Horner’s syndrome (Drooping eyelid, constriction of the pupil and absence of sweating on the affected side.)

Axilla Exposure of the Plexus: Figure 52 Incision for exposure of brachial plexus

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Incision is given along the posterior border of sternocleidomastoid muscle. If this exposure is not adequate, then the incision is extended lower down across the clavicle which is divided and plexus is exposed (Figure 52).

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STUDY OF THE BACK Landmarks (Figure 53):

Draw it yourself and try to feel the points. 1. External occipital protuberance 2. Nuchal furrow 3. Spine of the seventh cervical vertebra 4. Spines of all the twelve thoracic vertebrae 5. Iliac crest. 6. Posterior superior iliac spine 7. Spine of scapula 8. Inferior angle of scapula—it lies on seventh intercostal space. 9. Superior angle of scapula—lies on second rib.

Figure 53 Landmarks of the back

Superficial Fascia: Fat:

Cutaneous Nerves (Figure 54):

It contains fatty tissue located in fibrous compartments. Cutaneous vessels and nerves are present, as elsewhere. The amount of fat differs from individual to individual. The back and shoulders are amongst the popular sites for Lipomas (Tumour of fatty tissue). They are the branches of posterior rami of thoracic and lumbar nerves. They divide into medial and lateral branches. The medial branch of the second is longest and can be traced along the spine of scapula. It must be remembered that medial branches of the upper six thoracic nerves become cutaneous, while lateral branches muscular. In the lower six nerves it is just the reverse.

Figure 54 Cutaneous nerves of the back

Cutaneous Vessels: Arteries are branches of the posterior intercostal and the lumbar.

Study of the Back

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MUSCLES Muscles can be studied under two groups, namely the superficial and the deep. Trapezius and latissimus dorsi are members of the superficial group. Levator scapulae, rhomboideus major and minor, serratus posterior, superior and inferior, supraspinatus, infraspinatus, teres major and minor are members of the deep group. Out of the deep group supraspinatus, infraspinatus, teres major and teres minor are attached to the humerus. The teres major is attached to medial lip of bicipital groove and supraspinatus, infraspinatus and teres minor are attached to the greater tubercle of humerus. Subscapularis is attached to the lesser tubercle. At their insertions on the greater and the lesser tubercles the muscles fuse with the capsule of the shoulder joint and strengthen it and form the rotator cuff (Figure 55). Figure 55 Members of the rotator cuff (Musculotendinus cuff)

Rotator Cuff:

Trapezius Muscle (Figure 56):

It is the musculotendinous cuff formed by subscapularis, supraspinatus, infraspinatus and the teres minor muscles with the capsule of the shoulder joint for the head of the humerus. It deserves the name trapezius, as, in combination with the member of the opposite side it assumes a trapezoid shape. It is the triangular muscle of the back and belongs to the superficial group. There is a diamond shaped aponeurotic zone, opposite the upper two thoracic spines.

Figure 56 Trapezius muscle

Origin:

Insertion:

It arises from the following: 1. External occipital protuberance, 2. Medial third of superior nuchal line, 3. Ligamentum nuchae, 4. Spine of seventh cervical vertebra. 5. Spines of all the twelve thoracic vertebrae. 6. Corresponding supraspinous ligaments. Upper fibres descend; lower ascend and middle fibres run horizontally. This fact helps the student in imaging action of the muscle. The muscle is

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Nerve Supply: Action (Figure 57):

inserted as under: The upper group of fibres seek their insertion along the lateral third of the posterior border of clavicle. Middle group gains insertion into the medial border of acromion and the lower group of fibres into the upper lip of the crest spine of scapula. Lower fibres form a well defined tendon over the root of the spine of scapula. A small bursa is interposed between the bone and the so called tendon. It is supplied by the spinal root of accessory nerve. Branches from third and fourth cervicals are probably proprioceptive. Upper fibres elevate the shoulder, lower fibres depress and the middle fibres approximate the shoulder from the back. Its role in rotation of scapula is also well established. Lower cervical and upper thoracic fibres in combination with lower thoracic fibres help in the rotation of scapula. It must be noted that the upper cervical fibres are mainly going to the clavicle for their insertion and hence cannot be the effective rotator of the scapula. Trapezius muscle actively cooperates with serratus anterior and latissimus dorsi in the act of rotation of the scapula. The rotation of the scapula takes place during the process of taking the arm above head.

Figure 57 Origin and insertion of trapezius muscle

Latissimus Dorsi: Levator Scapulae (Figure 58):

It is already discussed. It arises from the posterior tubercles of transverse processes of upper four cervical vertebrae. It is inserted into the dorsal aspect of the medial border of the scapula between the superior angle and the root of the spine. Developmentally it is the muscle of the body wall. It is supplied by anterior primary rami of the third and the fourth cervical nerves. In addition it gets innervation from the nerve to rhomboid. It draws the scapula upwards and medially.

Figure 58 Levator scapulae and its relations to the nerve and artery. Note the rhomboideus major and minor

Relations:

The muscle forms the floor of the posterior triangle of the neck. Nerve to rhomboids and the deep or descending branch of transverse cervical artery run deep to it. Note: Levator scapulae arises from transverse processes while rhomboideus major and minor arise from the spines and supraspinous ligaments. Upwards pull is the most significant action of the levator, while

Study of the Back

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medial pull being most powerful action of rhomboideus major and minor muscles. The rhomboideus major and the minor are studied as under:

Supraspinatus Muscle (Figure 59):

Name

Rhomboideus major

Rhomboideus minor

Origin

2nd, 3rd, 4th and 5th thoracic spines.

Last cervical and first thoracic spines.

Insertion

Along the dorsal aspect of the medial border of scapula between the root of spine and inferior angle of scapula.

Opposite the root of spine of scapula on the dorsal aspect of the medial border same.

Nerve supply (Fig. 58)

Branch of the 5th cervical root. The nerve passes through scalenus medius and runs under cover of the levator scapulae with deep branch of the transverse cervical artery.

Same

Action

Pulls the scapula upwards and Same medially and steadies the shoulder

It arises from the medial two-thirds of supraspinous fossa and fascia covering the muscle. It is inserted into the top of greater tubercle of the humerus.

Figure 59 Supraspinatus muscle

At the insertion it fuses with capsule of the shoulder joint. It is supplied by the suprascapular nerve (C 5, 6). It steadies the head of humerus and actively helps in initial stages of abduction (15 to 20°). It is one of the important members of the rotator cuff. The tendon of supraspinatus is separated from scapula by means of a small bursa. The tendon lies under cover of the acromion from which it is separated by the large bursa known as the subacromial bursa. Subacromial bursa may extend under the deltoid and is known subacromial subdeltoid bursa. It is the largest bursa in the body. During abduction, supraspinatus tendon gets compressed under the acromion. Repeated compression may lead to inflammation of the tendon known as supraspinatus tendinitis. Patient complains of pain during the middle of abduction, obviously due to the anatomical fact that the tendon gets compressed against the acromion, during the middle of abduction. Patient having the inflammation of capsule of the shoulder joint, complains of pain during all the movements (Periarthritis of shoulder). Rupture of tendon of the supraspinatus is not uncommon. When the muscle is paralysed or its tendon ruptured, a patient is unable to abduct the arm up to 15 to 20°. If the patient is helped in abducting the arm up to first 15° to 20°, rest of the abduction is done by the deltoid muscle. A patient may take help of the other hand in initial abduction of

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Kadasne’s Textbook of Anatomy (Clinically Oriented) the arm up to 15° to 20° or he may swing towards the affected side. The arm goes away from the trunk, upto 15°-20° and allows the deltoid to act (Figure 60)

Figrue 60 How tilting allows the deltoid to act

Clinical:

Infraspinatus Muscle:

Teres Minor (Figure 61):

Painful arc syndrome is due reduced blood supply (ischaemia) of the supraspinatus tendon or due to wear and tear. In the middle of abduction supraspinatus is compressed against the coracoacromial arch producing pain. It arises from the infraspinous fossa and the fascia covering the muscle. It is inserted into the greater tubercle of the humerus below and behind the insertion of the supraspinatus muscle. It is supplied by the suprascapular nerve. It stabilizes the head of humerus and is also the lateral rotator of the arm in association with the teres minor and posterior fibres of the deltoid. Tendon fuses with the capsule of the shoulder joint and adds to its strength. A small bursa may exist between the tendon and the capsule of the shoulder joint. It arises from the upper two thirds of the dorsal aspect of the lateral border of the scapula and the fibrous septum. It is inserted into the greater tubercle of the humerus below the insertion of infraspinatus muscle. It extends lower down to reach the neck of humerus. It is supplied by the axillary nerve. It steadies the head of the humerus and is also the lateral rotator of the arm. Circumflex scapular artery lies between the two heads of the teres minor muscle on the lateral border of the scapula, where it produces a groove.

Figure 61 Infraspinatus and teres minor muscles

Comment on members of rotator cuff. Members are: (i) subscapularis, (ii) supraspinatus, (iii) infraspinatus, (iv) teres minor. The functions of these four muscles can be remembered by 4 ‘S’. S - Sits - Sitting on the tubercle. S - Sticks - Sticks to the capsule S - Steadies - Steadies the head of the humerus S - Strengthen - Strengthens the capsule.

Study of the Back Teres Major (Figure 62):

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It arises from an oval impression on the dorsal aspect of the lateral border of the scapula just above the inferior angle, and also from the strong fibrous septae between the teres minor and the infraspinatus.

Figure 62 Teres major

Insertion:

It is inserted into the medial lip of the bicipital groove by means of a flat tendon measuring about five cms. in length. It has already been mentioned that the tendon of latissimus dorsi winds the lower border of teres major and comes to lie in front of it. It is supplied by the lower subscapular nerve which is a branch of posterior cord of brachial plexus. It is the adductor and the medial rotator of the arm. It also helps in drawing the arm backwards. Clinical (Figure 63): In case of paralysis of the serratus anterior muscle, during protraction, medial border of the scapula leaves chest-wall like a wing of a bird. In such cases, teres major muscle can be detached from the humerus and fixed to the ribs in front. Now the teres major muscle acts as the serratus anterior by keeping the scapula in contact with the chest wall. (H.W. Wouterrs Jr.of Bones and Jt. Surgery, Vol. 44 B, 1965). Pectoralis minor can also be attached to inferomedial aspect of scapula as an alternate. Figrue 63 Shows how the teres major can be utilized in place of serratus anterior muscles

Serratus Posterior Superior:

It arises from the following structures: 1. Lower part of ligamentum nuchae, 2. Spine of seventh cervical vertebra, 3. Spines of first and second thoracic vertebrae, 4. Corresponding supraspinatus ligaments. It is inserted into the 2nd, 3rd, 4th, and 5th ribs just lateral to their posterior angles. The fibres are directed downwards and laterally. It is supplied by 2nd, 3rd and 4th intercostals nerves. It is the elevator of the ribs, and has no role in respiration.

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Serratus Posterior Inferior:

It arises from the lower two thoracic and the upper two lumbar spines. It is inserted into the lower borders of the last four ribs. Fibres are directed upwards and laterally. It is supplied by the 9th, 10th and the 11th intercostals nerves. It is the depressor of the lower four ribs. By fixing the ribs it helps the diaphragm to contract, during the phase of inspiration.

TRIANGLE OF AUSCULATION It is a small illdefined intermuscular space situated at the back on left side. It is bounded above by the trapezius, below by the latissimus dorsi and laterally by the medial border of the scapula. The rhomboideus major lies in the floor. It is significant to note that deep to the triangle of ausculation of left side, lies the cardiac orifice of the stomach. Before the invention of X-rays the sound of the fluid entering the stomach from the oesophagus was heard with a paper tube (Figure 64). Figure 64 Trapezius latissimus dorsi and medial border of scapula are shown on left side as seen from behind forming the triangle of ausculation. Note origin and insertion of serratus posterior superior and inferior muscles

Lumbar Triangle of It is a small interval situated at lower part of the back above the iliac crest. Petit (Figure 65): Base of the triangle is formed by the iliac crest. Anteriorly external oblique and posteriorly it is bounded by latissimus dorsi muscles. The internal oblique muscle lies in the floor. It is the site for lumbar hernia. Figure 65 Lumbar triangle of Petit

Note on Petit:

I cannot check the temptation of devoting a few lines for the great surgeon Petit. “Petit Jean Louis, a great surgeon of his own time, started learning anatomy, at the seven, started teaching of anatomy at the age of twelve and took knife in hand as a surgeon, when he was merely sixteen. He subsequently became the Director of Academy of Surgery of Paris. He died at the ripe age of eighty six.” Let his example inspires us !

Study of the Back Deltoid Muscle (Figure 66):

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It is a triangular muscle, which covers the shoulder joint from above, behind and from the front. Rounded shape of shoulder is due to the deltoid. It arises from the clavicle, acromian and the spine of scapula (CAS). It takes origin from the lateral one third of the anterior border of the clavicle, lateral border of the acromion and the lower lip of the crest spine of the scapula. Fibres arising from the acromion are multi-pennate which adds to the strength of the muscle.

Figure 66 Deltoid muscle (view from the back)

Insertion:

Nerve Supply: Action:

The muscle is inserted into the deltoid tuberosity of the humerus which lies in the middle of the anterolateral surface of the humerus. It is opposite the insertion of the coracobrachialis. Median nerve crosses the brachial artery from lateral to the medial on the brachialis and under the biceps at the level of insertion of coracobrachialis muscle. The basalic vein also pierces the deep fascia at this level. It is supplied by axillary nerve (root value C-5, C-6.) Middle multipennate fibres are the abductors, anterior fibres are flexors and the posterior fibres are extensors of the shoulder. In addition to this, anterior and posterior fibres also help in medial and the lateral rotation of the shoulder respectively (Figure 67).

Figure 67 Action of deltoid (diagrammatic)

Intermuscular Spaces (Figure 68):

There are two triangular and one quadrangular spaces.

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Figure 68 Intermuscular spaces (A) Quadriangular space, (B) Triangular spaces

Quadrangular Space:

It is an intermuscular space bounded medially by the long head of the triceps, laterally by the shaft of the humerus, below by the teres major and above by the subscapularis muscles, capsule of the shoulder joint and the teres minor muscle. Axillary nerve and posterior circumflex humeral artery pass through this space. Triangular Space: a. It is bounded by the long head of triceps medially, shaft of the humerus laterally and the teres major muscle above. Redial nerve with the profunda brachii artery pass through this space to reach the spiral or the radial groove on the humerus. b. It is bounded by the long head of triceps laterally, by teres major below and teres minor above. Apex of the triangle lies at the lateral border of scapula between the origins of teres major and the minor muscle. Anastomosis There is good anastomosis around the scapula, between branches of the Around the Scapula first part of subclavian and the third part of the axillary artery. Transverse (Figure 69): cervical artery gives a descending scapular artery which runs along the medial border of the scapula. Subscapular artery, the branch of the third part of the axillary artery runs along the lateral border of the scapula. Suprascapular artery branch of the thyro-cervical trunk reaches the superior border of the scapula and passes above the suprascapular ligament and the suprascapular nerve. Amongst these three branches there is a good anastomosis in front, behind and around the scapula. In case of block of the axillary artery between the first part of the subclavian Figure 69 Anastomosis around the scapula posterior view

Study of the Back

Suprascapular Artery: Descending Scapular Artery:

Surgical: Note:

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artery and the third part of the axillary blood bypasses from first part of the subclavian to the third part of the axillary artery through this collateral circulation. The anastomosing vessels increase in size and take the shape of the scapula and pulsate. This is known as pulsating scapula. It is a branch of the thyrocervical trunk. It passes above the suprascapular ligament and enters the supraspinous fossa. It supplies the supraspinatus muscle goes further through the spinoglenoid notch and enters the infraspinous fossa where it supplies the infraspinatus muscle. It is also known as the deep branch of the transverse cervical artery. It passes deep to the levator scapula muscle along with the nerve to rhomboids. It runs along the medial border of the scapula, deep to the rhomboids major and minor muscles. The artery lies medial to the nerve. At the inferior angle of scapula, it anastomoses with a branch of the circumflex scapular artery. Circumflex scapular artery is a branch of the subscapular artery given at the lateral border of the scapula. It grooves the lateral border of the scapula and passes between the two heads of the teres minor muscle. Ligation of the second part of subclavian artery, normally does not affect blood supply of the upper limb as blood passes along the vessels of the scapular anastomosis. Another site of anastomosis exists at the acromion process of the scapula. Following arteries takes part in it:1. Suprascapular artery through its acromial branch, 2. Deep branch of transverse cervical artery and 3. Thoracoacromial artery through its acromial branch.

STERNOCLAVICULAR JOINT (Figure 70) It is the synovial type of joint, where the sternal end of the clavicle articulates with the manubrium and the first costal cartilage. The capsule of the joint is not very strong, hence stability of the joint is due to articular disc, costoclavicular and the interclavicular ligaments. Articular disc is fibrocartilaginous structure having flat surfaces and circular shape. It is placed obliquely and divides the joint cavity into two. It is attached to the first costal cartilage and the sternal end of clavicle. The attachment at the sternal end is along the upper and the posterior borders. It is also attached to the capsule. The costoclavicular ligament runs from the first costal cartilage to the under surface of the sternal end of the clavicle. This ligament is very strong. Interclavicular ligament runs from the sternal ends of the clavicles. It is attached to the middle of the suprasternal notch. Great vessels of the neck lie behind the joint along with strap muscle of the neck. Figrue 70 Sternoclavicular joint

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Blood Supply: Nerve Supply: Movements:

Clinical:

Acromioclavicular Joint (Figures 71A and B):

Blood supply is from the internal thoracic mammary and the suprascapular arteries. It is supplied by the medial supraclavicular nerves and nerve to the subclavius. All movements of the shoulder girdle are projected and permitted at the joint. It acts as a fulcrum during movements. The movements between the clavicle and the disc is more than the movements between the disc and the sternum. Dislocation of the joint is not common. When it occurs, medial end of the clavicle gets displaced either forwards or downwards. Backward displacement is bound to cause compression of the trachea and the great vessels leading of respiratory obstruction and congestion of the head and limb of the affected side. Due to strong ligaments and the line of transmission of weight along the clavicle, dislocations are less and the fractures more. It is a synovial type of joint where acromion process of scapula and the acromial end of the clavicle articulate. The articular surfaces are obliquely placed. Capsule of the joint is thin (Fig. 71A). Coracoclavicular ligament can be considered as its accessory ligament, which adds to the stability of the joint. The ligament has two part. Lateral part is quadrilateral and the medial like an inverted triangle. The lateral part is known as trapezoid and the medial as the conoid part (Fig. 71B). There is a small bursa interposed between the two parts. Sliding type of movement occurs at the joint. It is supplied by the lateral supraclavicular and the suprascapular nerves.

Figure 71A Acromioclavicular joint/coracoclavicular joint with parts of coracoclavicular ligament (Note: Coracoclavicular ligament)

Figure 71B Coracoclavicular joint. Note part of coracoclavicular ligament

Surgical:

Direct fall on the shoulder displaces the acromial end of the clavicle upwards, which now lies over the acromion. The displacement is mainly due to obliquity of articular surfaces. During displacement, coracoclavicular ligament gets ruptured. The displacement is noted by sight and confirmed by palpation with fingers. Dislocations are more common than the fractures.

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SHOULDER JOINT Classification:

It is the synovial, polyaxial and the ball and socket type of joint (Figure 72).

Figure 72 The movements of shoulder joint

Bones Taking Part: Glenoid Cavity (Figure 73):

Figure 73 Glenoid cavity

Figure 74 Plane of the glenoid cavity

Glenoid cavity of the scapula and the head of humerus. It is pear shaped, shallow articular cavity situated at the lateral angle of the scapula. It is covered with the hyaline cartilage. A flattened impression is present at its periphery for attachment of fibrocartilaginous structure known as glenoidal labrum (Actually it is fibrous ring and not a fibrocartilaginous as described earlier). Immediately below the cavity lies a small rough tubercle. It is known as infraglenoid tubercle. A similar tubercle lies above the cavity and is known as supraglenoid tubercle. It is significant to note that the glenoid cavity is directed forwards and laterally (antero-laterally) (Figure 74). The movements of flexion and extension take place along this plane and bringing the flexed arm in front of the

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Head of Humerus (Figure 75):

chest. The size of the head of the humerus is grossly disproportionate to the size of the glenoid cavity which is smaller, which contributes the free mobility of the joint (It is a sacrifice of stability for the sake of motility). The head is hemispherical and is covered with hyaline cartilage. The layer of hyaline cartilage is thick in the center of the head and thin at the periphery. Reverse is the case with the glenoid cavity.

Figure 75 Head of humerus and capsular attachment

Figure 75A X-ray of right shoulder

Attachment of the Capsule:

Head of the humerus is protected above by coracoacromial arch, which is formed by the coracoid process, coracoacromial ligament and the acromion process (Figure 75A). The coracoacromial arch is considered as the secondary socket for the head of the humerus (Figure 76). This prevents upwards displacement of the head of humerus which impinges against the coraco-acromial arch. Proximally the capsule is attached to the rim of glenoid cavity beyond the glenoid labrum. Superiorly, it includes the supraglenoid tubercle which gives origin to the long head of biceps, and hence the long head of biceps is intracapsular but extrasynovial. Epiphyseal line of the upper end of humerus lies within the capsule. This results in involvement of the joint in case of osteomyelitis of the upper end of humerus. Distally, the capsule is attached to the anatomical neck of the humerus, immediately beyond the articular area of the head. However, capsular attachment descends 1 to 1.5 cm. below, on the medial aspect of the shaft. It is interrupted at the upper end of the bicipital groove, the long head of the biceps along with its synovial sheath. As a result descent of the capsular attachment of the joint on the medial side of the neck of humerus it becomes loose and weak. This allows abduction of the shoulder without

Shoulder Joint

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Figure 76 Coracoacromial arch

Ligaments of the Shoulder Joint:

Glenohumeral Ligaments (Figure 77):

much tension on the inferior part of the capsule. However, it helps osteomyelitis of the upper end of humerus to reach the shoulder joint. Following are the ligaments of the joint. 1. Capsular ligament 2. Glenohumeral ligaments 3. Coracohumeral ligament 4. Transverse ligament 5. Glenoidal labrum. Glenohumeral ligament is divided into three separate bands, i.e. superior, middle and the inferior glenohumeral ligaments. Members of the rotator cuff, i.e. subscapularis, supraspinatus, infraspinatus and the teres minor form the musculotendinous cuff alongwith the capsule of the shoulder joint. It is known as rotator cuff. There are three openings in the capsule; they are: 1. Opening for communication with subscapular bursa. It lies between the superior and middle glenohumeral ligaments. 2. Opening for the long head of biceps with its synovial membrane. 3. The third one is inconstant and when presents it communication with the bursa of the infraspinatus muscle. Opening between the superior and the middle glenohumeral ligaments is meant for the subscapular bursa. It provide the weak spot for escape of the head of humerus during dislocation. Subscapular bursa is of a size of an hen’s egg and is placed between the neck of the scapula and the subscapularis muscles. Ligaments are between glenoid cavity and the humerus. They are three in number, namely the superior, middle and the inferior. All the three can very well be examined from inside the capsule. Medially they are attached to the medial margin of glenoid cavity in its upper part. Here, they practically fused with the glenoidal labrum. Laterally, the superior and the middle ligaments gain their attachment on the lesser tubercle. The inferior glenohumeral ligament is attached to the lower part of the anatomical neck of the humerus. The part of the capsule near the attachment of the superior band of the inferior glenohumeral ligament is known as axillary pouch. In anterior dislocation of the shoulder joint the inferior glenohumeral ligament is torn along with the damage to the glenoidal labrum. The lesion is known as Bankart’s lesion. Damage to the superior band of the inferior glenohumeral ligament and the part of the glenoidal labrum helps recurrent dislocation of the shoulder. However recently absence or advancement of middle glenohumeral ligament, extending on the scapular neck, is considered as an important factor in recurrent dislocation of the shoulder.

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Figrue 77 Glenohumeral ligaments

Coracohumeral Ligaments:

It increases the strength of the upper part of the capsule. It runs from the root of coracoid process to the anterior part of the greater tubercle of the humerus. During its course it practically fuses with the supraspinatus tendon. Transverse Humeral It bridges the gap between the two tubercles of humerus converting the Ligaments: upper part of the bicipital groove into the canal. Its attachment lies above epiphyseal line. Functionally it acts as a retinaculum for retention of the tendon of the long head of biceps. Glenoidal Labrum: It is a fibrocartilaginous ring (according to some it is only fibrous in nature) situated along the margin of glenoid cavity. It presents a base, which is fixed to the flattened impression at the periphery of the glenoid cavity and the sharp free edge, is lying free, for the contact with the humeral head. Superiorly two fasciculi of the tendon of long head of biceps fuse with the anterior and the posterior parts of the glenoidal labrum. Functions of the glenoidal labrum are: (i) deepens the cavity, (ii) maintain the bony contact and protects the edges of the glenoid cavity (DMP). Synovial Membrane The synovial membrane of the joint covers the capsule from inside and (Figure 78): other structures except articular areas. There is a separate tubular sheath of synovial membrane for the long head of biceps. The synovial membrane of subscapular bursa is continuous with synovial membrane of the joint through the opening for subscapular bursa. Figure 78 Synovial membrane of shoulder joint

Bursae around the joint: 1. Subscapular bursa, 2. Infraspinatus bursa, 3. Subacromial bursa, 4. Supra-acromial bursa,

Shoulder Joint 5. 6. 7. 8.

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Subcoracoid bursa, Bursa between coracobrachialis and the capsule, Bursa between teres major and long head of triceps, Bursa in front behind the tendon of latissimus dorsi. Subscapular bursa is the only bursa which communicates with the joint cavity. Subacromial Bursa: It is situated between the supraspinatus tendon below and the coracoacromial arch above. This is the largest of the bursa in the body. When it extends below the deltoid muscle it is known as subacromial subdeltoid bursa. In subacromial bursitis patient experiences pain when pressed below the acromion. After abduction of the arm the pain disappears and the tenderness is missing (Dawbarn’s sign). Supra-acromial It is placed above the acromion while the subcorocoid bursa lies below the Bursa: corocoid process. Relation of the Joints Following are the relations of the joint. (Figures 79 and 80): Superior relations: 1. Deltoid 2. Coracoacromial arch 3. Subdeltoid subacromial bursa: It lies between the coracoacromial arch and the deltoid muscle. During hyperabduction the bursa changes its position and goes under the acromion. 4. Tendon of supraspinatus. Figure 79 Relations of the shoulder joint (sagittal section)

Figure 80 Relations of the shoulder joint

Anterior relations: 1. Deltoid 2. Subscapularis muscle 3. Subscapular bursa 4. Coracobrachialis

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Kadasne’s Textbook of Anatomy (Clinically Oriented) 5. Short head of biceps 6. Clavicular head of pectoralis major.

Inferior Relations:

Nerve Supply:

Blood Supply:

Movements: Abduction at the Shoulder:

Accessory Movements at Shoulder Joint: Scapulohumeral Shoulder Joint:

Posterior relations: 1. Deltoid 2. Infraspinatus 3. Teres minor. They are important as the axillary nerve along with the posterior circumflex humeral artery and long head of the triceps lie below the joint. Apart from these relation, axillary artery must be mentioned as the rupture of the artery is likely to occur, during dislocation of the shoulder and reduction of an old dislocation. Following nerves supply in the joint: 1. Axillary, 2. Suprascapular and 3. Lateral pectoral. Remember that lateral pectoral nerve supplies pectoralis major, the suprascapular nerve supplies supraspinatus and infraspinatus, and the axillary nerve supplies deltoid and the teres minor. “The joint and the skin over the joint obtain their nerve supply from the nerves of the muscles crossing the joint”. (Hilton’s Law). Three arteries supply in the joint. They are: 1. Anterior circumflex humeral, 2. Posterior circumflex humeral and 3 Suprascapular. It has already been mentioned that flexion, extension, adduction abduction, medial rotation, lateral and the curcumduction are permitted at the shoulder joint. Please refer (Figure 72). As described before, the initial movement of 15° to 20° degrees is by the supraspinatus muscle. Due to this, insertion of the deltoid is brought 15° to 20° degrees laterally, allowing the deltoid to act as an effective and powerful abductor. This phase continues up to 90° degrees. The upper limb can be abducted to 180° degrees even without rotation of humerus. In that case, after 90° degrees of abduction, there is a very little movement at the shoulder joint and the onward progress of the movement is mainly due to the rotation of the scapula. Abduction of the shoulder occurs in three phases in first phase it is abducted to 15° to 20° degrees by the supraspinatus muscle in the second stage abduction upto 90° is mainly due to the contracting fibres of the deltoid arising from the acromion. Further hyperabduction upto 180° occurs due to the action of the trapezius and the serratus anterior muscles, involving the sternoclavicular and the acromionclavicular joints. The movement of the hyperabduction is facilitated by subacromial bursa. A part from the movements mentioned, some degree of accessory movements do occur at the joint. It is exemplified by the movements of pronation and supination. It is possible due laxity of the capsule of the shoulder joint and occur when the elbow is fully extended. Scapula and the humerus move together during abduction at the same time and not separately. In early abduction the contribution of the shoulder joint is more while the contribution of the shoulder girdle is less. After 90° of abduction, movements of the scapula play an important role. In brief during phase one there is 15° to 20° of abduction due to supraspinatus muscle. In phase two deltoid muscle carries abduction upto 90° and in phase three upper fibres of the trapezius, lower fibres of the trapezius and the serratus anterior play an important part in rotation of the scapula.

Shoulder Joint Clinical:

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It gets commonly dislocated due to disproportionate sizes of the head of humerus and the glenoid cavity. The capsule of the joint is thin and lax in its anteroinferior part. Capsule being weak and unsupported by muscles, commonest dislocation of the shoulder is anterior (subglenoidsubcoracoid). Movements

Muscle

1. Flexion

Clavicular head of pectorails major. Anterior fibres of deltoid and coracobrachialis biceps, sternocostal part of pectoralis major.

2. Extension

Posterior fibres of deltoid, teres major, teres minor, latissimus dorsi.

3. Abduction

Supraspinatus and deltoid.

4. Adduction

Pectoralis major, latissimus dorsi. Teres major, coracobrachialis, biceps and Triceps.

5. Medial rotation Pectoralis major, anterior fibres of deltoid, latissimus dorsi, teres major and subscapularis. 6. Lateral rotation Infraspinatus, posterior fibres of deltoid, teres minor.

Recurrent Dislocation of the Shoulder: Clinical Appearance of dislocation:

Dislocation on Examination:

Kocher’s Method:

Due to the permanent damage to the capsule and the glenoidal labrum shoulder joint dislocates frequently. In such cases patient himself learns to reduce the dislocation without help and anaesthesia. 1. Dislocation: As the head of the humerus dislocates anteriorly it comes to lie under the coracoid process and is known as the subcoracoid dislocation of the shoulder. It is very common. It occurs due to forced extension and external rotation of the abducted arm. Head of the humerus impinges on the capsule of the shoulder joint. Rupture of the capsule and the avulsion of the glenoidal labrum results. Glenoidal labrum being avascular it does not heal. Head of the humerus leaves the glenoid cavity and comes to lie below the corocoid process. Due to muscles spasm the humerus is locked. It can damage the axillary artery and the nerve. 2. Periarthritis, frozen shoulder: Inflammation of the capsule of the shoulder joint is known as periarthritis and the capsulitis is known as frozen shoulder. Patient of frozen shoulder complains of pain in the shoulder joint and the stiffness. Pain and stiffness continues for three months and becomes static during further three months. It takes total nine months for the full recovery. In due course of time the pain is reduced and the patient feels comfortable. X-ray of the shoulder reveals no abnormality and this is probably the only condition where normal X-ray proves the diagnosis. Treatment—injections of steroid and physiotherapy. Dislocation of shoulder can cause damage to the axillary nerve and the axillary artery. The outer aspect of the shoulder looks flat and the arm looks as if it is arising from the clavicle and the greater tubercle of the humerus below the acromial process is missing. Patient supports the elbow of the injured hand with the normal hand. There is obliteration of the infraclavicular fossa and the greater tubercle of the humerus below the acromion is found missing. Flexed elbow is externally rotated and after full external rotation the elbow is brought in front of the chest and the flat of the hand on the top of the normal shoulder. Reduction occurs with a click.

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SURGICAL TREATMENT Puttiplatt Procedure: Overlapping of the capsule and the subscapularis muscle is done to limit the lateral rotation. Bankart Procedure: Damaged to the capsule and glenoidal labrum is repaired and is attached to the bony ring of the glenoid cavity. Painful Arc It is due to the impaired blood supply of the supraspinatus muscle in the Syndrome: middle aged persons. Supraspinatus muscle undergoes the wear and tear due to the friction against the coracoacromial arch. At times supraspinatus muscle gets ruptured. Initial 60° of abduction is painless, while the next 60° of abduction is painful. Further 60° of abduction of the shoulder is painless. While coming back from the abducted stage to the adducted stage, first descent of 60° is painless. Second descent of 60° is painful and third descent of 60° is again painless. Members of the rotator cuff namely subscapularis, supraspinatus, infraspinatus and teres minor are also involved. Involvement of the subscapularis is clinically tested by external rotation which gives rise to the pain and the pain is reduced by internal rotation. Involvement of the intraspinatus muscle is revealed by the fact that the internal rotation gives rise to the pain which is relieved by external rotation (Reverse of the subscapularis). Shoulder Pain When the shoulder joint is normal. Following conditions cause pain in the shoulder: 1. Diseases of the spinal cord 2. Disease of the vertebral Column 3. Cervical rib 4. Irritation of diaphragmatic pleura or peritoneum through phrenic and supraclavicular nerves. Stability of the Following are factors for the stability of the joint: Shoulder: 1. Ligaments, 2. Capsule, 3. Muscles of the rotator cuff, 4. Long head of biceps, it steadies the head of humerus during movements and prevents its upward displacement, (it acts like a tie rope) 5. Atmospheric pressure. Exposure of the Incision is given along the deltopectoral groove protecting the cephalic Shoulder Joint: vein. After retracting the deltoid and the pectoralis major, musculotendinus part of the subscapularis is exposed. After cutting the subscapularis muscle, the capsule of the shoulder joint is exposed. For better exposure, deltoid can be detached from its clavicular origin and the coracoid process cut. This approach is commonly is used for repair of the glenoidal labrum and the double breasting of the subscapularis muscle (Thompson’s approach). Deltoid Splitting It is ideal for exposure of the subacromial space. You have to be careful Approach: about the axillary nerve. The approach is good for repair of the injuries of the rotator cuff. Aspiration of the Needle is passed between the tip of the coracoid and anterolateral edge of Shoulder Joint: the acromion. Aspiration of the shoulder joint can also be done through the deltopectoral groove. Optimal Position 20° abduction, 38° forward flexion and 40°-50° lateral rotation. of Function:

The Arm

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THE ARM Landmarks (Figure 81):

The region of the arm extends from shoulder to the elbow. If the elbow is flexed against resistance a fusiform elevation can easily be seen in front of the arm. It is due to underlying contracting biceps brachii muscle. Resistance of the bicipital aponeurosis can be appreciated and confirmed by pressing the finger medial to the tendon of biceps. If the forearm is extended against resistance, muscle mass of triceps can be seen and felt under the skin on the back of the arm. If contour of the deltoid is followed from acromion downwards, deltoid tuberosity can be palpated on the middle of the lateral aspect of the arm. Medial and lateral epicondyles of the humerus can be felt by passing the flat of the hand respectively on the medial and the lateral sides of the arm from above downwards. Ulnar nerve can be palpated in the groove behind the medial epicondyle of the humerus. Thickened and tender nerve is an important sign of leprosy (Hansen disease). Pulsations of the brachial artery can be felt in the living on the medial aspect of the upper part of the arm.

Figure 81 The landmarks of the arm

General Description Bone of the arm is humerus. It is covered with skin, superficial fascia, of Arm (Figure 82): deep fascia and the muscles with the vessels and the nerves. The arm is divided in two compartments namely the flexor and extensor by medial and lateral intermuscular septae and the shaft of humerus itself. Lower part of the shaft of the humerus presents medial and the lateral supracondylar ridges. Brachialis, coracobrachialis and biceps brachii are the members of the flexor compartment with brachial artery and the musculocutaneous nerve. Motor part of the musculocutaneous nerve is devoted to the flexor compartment of the arm. Biceps brachii muscle, as it runs from scapula to the radius, crosses two joints from the front and hence is the flexor of shoulder and elbow. On the other hand coracobrachialis runs from the scapula to the humerus and thus acts only on the shoulder joint. The brachialis muscle runs from humerus to the upper end of the ulna and acts on the elbow alone as the flexor. In the middle of the arm, the median nerve crosses the brachial artery from lateral to the medial side on the brachialis under the biceps. The crossing of the median nerve from lateral to the medial side drives the ulnar out from the anterior compartment and invites the radial in from the posterior

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Kadasne’s Textbook of Anatomy (Clinically Oriented) compartment (Median nerve drives the ulnar out and invites the radial in).

Figrue 82 Compartments of the arm

Extensor Compartment:

Triceps is the muscle of the extensior compartment. Out of its three heads only one head arises from the scapula and the rest of the two head arise from the humerus. It’s insertion into the olecranon process of ulna can be confirmed externally. Profunda brachii artery and the radial nerve run in the radial groove obliquely from medial to lateral side.

Detailed Description of the Arm: Coracobrachialis: It arises from the tip of the coracoid process and gets inserted into the middle of the antero medical surface of the shaft of the humerus. It is supplied by the musculocutaneous nerve, which is a branch of the lateral cord of brachial plexus. The musculocutaneous nerve gives branch to the coracobrachialis before its entry into the muscle. Comment: It is the adductor of the arm and also the flexor of the shoulder. It will be learnt during study of the thigh that adductors of the thigh are pocketed in the separate compartment known as adductor. While in the arm, adductor component is included in the flexor compartment of the arm and is not provided with a special suite or room. Brachialis (Figure 83): It arises from the lower two thirds of the front of the shaft of humerus and the intermuscular septae. Its origin extends upwards upto the deltoid tuberosity and the lower part of spital groove. It crosses in front of elbow joint, fuses with the capsule and gets inserted infront of the coronoid process of the ulna. It is supplied by the musculocutaneous nerve and also by the radial nerve. However, the part supplied by radial is small. (Why not say? Mr Brachialis. M-Stands for musculocutaneous R-for radial). Action: It is the flexor of the elbow. Relations: Following structures lie anterior relations of the brachialis. The brachialis muscles forms the part of the floor of the cubital fossa. Anterior relations: 1. Tendon of biceps 2. Brachial artery 3. Median nerve. (TAN – Tendon, Artery, and the Nerve) Posterior Relations: Elbow joint. Biceps Brachii As the name indicated it is the muscle of the arm (Brachii) having two (Figure 84): heads (biceps) namely the long and the short. The long head arises from supraglenoid tubercle inside the shoulder joint and also from glenoidal labrum from its anterior and posterior parts. The tendon comes out of the

The Arm

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Figure 83 Coracobrachialis and brachialis muscles

capsule of the shoulder joint under the transverse humeral ligament at the upper part of bicipital groove. It is enclosed in a separate tube of synovial sheath. Short head of the muscle arises from the tip of the coracoid process along-with the coracobrachialis. Figrue 84 Biceps brachii muscle

Bicipital Aponeurosis:

Nerve Supply: Action:

Two heads unite in the lower part of the arm to form the fusiform muscular belly. The muscular belly is replaced by a very strong tendon in cubital fossa (The tendon of biceps). It gets inserted into the posterior part of the radial tuberosity. There lies a small bursa between tendon and anterior part of the radial tuberosity. From medial side of the tendon of biceps a strong quadrilateral fibrous expansion runs downward and medially and gets fused with the deep fasica of forearm. It is known as bicipital aponeurosis. The bicipital aponeurosis is a quadrilateral fibrous expansion running from the medial side of the tendon of the biceps, forms the roof of the cubital fossa and gets fused with the deep fascia of forearm. Brachial artery and the median nerve are posterior to the bicipital aponeurosis, and the median cubital anterior. Biceps brachii is supplied by the musculocutaneous nerve. Most important action of the muscle is on the forearm. It is the powerful flexor and supinator of the forearm. Short head of the muscle helps in flexion of the shoulder. The long head steadies the head of humerus during movements and prevents its upward displacement during contraction of

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Relations (Figure 85):

deltoid. In other words, long head acts as tie-rope for keeping head of humerus in contact with glenoid cavity. The structures under the biceps brachii are as under: Latissimus dorsi, teres major, coracobrachalis, brachialis, brachial artery, median and the musculocutaneous nerve. Upper part of the muscle lies under the pectoralis major and the deltoid.

Figrue 85 Relations of the biceps brachii muscle

Surgical:

Brachial Artery (Figure 86):

Figure 86 Course of brachial artery

1. During lifting of the heavy objects, long head of the biceps gets detached from the muscular belly and a swelling of a size of cricket ball appears in the lower part of the arm (Popye deformity). 2. Damage to the musculocutaneous nerve causes paralysis of the biceps brachii resulting in loss of flexion of elbow. In order to restore the function of flexion of the elbow pectoralis major is attached to the tendon of biceps brachii muscle. As the name suggests, it is the artery of the arm. It begins as continuation of the axillary artery at the lower border of the teres major muscle and successively lies on the long head of triceps, medial head of triceps, insertion of coracobrachialis the brachialis and the elbow joint. At the elbow it passes under cover of the bicipital aponeurosis and divides into two terminal branches namely, the radial and the ulnar, one cm. below the elbow at the level of the neck of radius. In the upper part of its course, it lies medial to the shaft of humerus, however as it comes down it lies infront of the humerus and occupies an interval between the two epicondyles of the humerus.

The Arm Anterior Relations of Branchial Artery (Figure 87):

89

Skin, superficial fascia, biceps brachii and the median nerve and the bicipital aponeurosis form the anterior relation. The median nerve crosses the brachial artery from the front in the middle of the arm, on the brachialis and under the biceps from lateral to medial side.

Figure 87 Anterior relations of brachial artery

Posterior Relations of Brachial Artery (Figure 88):

Long head of triceps, radial nerve, profunda brachii artery, medial head of triceps, insertion of coracobrachialis and the brachialis muscles forms the posterior relations.

Figure 88 Posterior relations of brachial artery

Lateral Relation (Figure 89): Medial Relations:

Branches

Figure 89 Lateral relations of brachial artery

In the upper part the median and in the lower part the radial nerves are related to the lateral aspect of the artery. It is related to medial cutaneous nerve of the forearm, ulnar nerve in the upper half, the median nerve in the lower half of the arm. Basalic vein also is medial to the artery. The artery is occompanied by two venae commitantes. Following are the branches: 1. Profunda brachii, 2. Nutrient artery to humerus,

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3. Superior ulnar collateral, 4. Inferior ulnar collateral, 5. Muscular and 6. Terminal branches the radial and the ulnar. Profunda Brachii It is the largest branch of the brachial artery. It arises from the posteromedial Artery aspect of the brachial a little below the lower border of the teres major. It (Figures 90 and 91): goes to the posterior compartment along with the radial nerve through the triangular space. On the back of the humerus it lies in the radial groove. As it reaches the lateral part of the spiral (radial) groove, it divides into two terminal branches, namely the: 1. Radial collateral and 2. Descending branch of the profunda (Posterior branch). Figure 90 Branches of brachial artery

Figure 91 Profunda brachii artery

Nutrient Artery:

Radial collateral branch passes through lateral intermuscular septum along with radial nerve and enters the flexor compartment. Here it lies between brachioradialis and brachialis. At the lateral epicondyle it anastomoses with radial recurrrentum artery branch of the radial. Descending branch runs in the posterior compartment to the back of lateral epicondyle. It anastomosis with interosseous recurrent and inferior ulnar collateral arteries. A small branch from profundus artery goes to the deltoid and anastomoses with posterior circumflex humeral artery. A similar branch comes along the medial head of triceps and takes part in the anastomosis above the olecranon. At times, the nutrient artery to humerus may come from the profunda. It arises from the brachial artery in the upper part of the arm and enteres the nutrient foramen near the insertion of coracobrachialis. The direction

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of this foramen is towards elbow (To the Elbow I Go.). The upper end of the humerus is the growing end. Superior Ulnar It arises from the brachial artery a little below the middle of the arm. It Collateral Artery: follows the ulnar nerve to the anterior compartment after piercing the medial intermuscular septum along with the ulnar nerve. It anastomoses with the posterior ulnar recurrent. Inferior Ulnar It springs from the brachial about 5 cm above the elbow. It pierces the Collateral artery medial intermuscular septum and runs across the back of lower part of (Supratrochlear): the shaft humerus and anastomoses with the descending branch of profunda brachii. Muscular Branches: Four arteries arise from the brachial and are distributed to the three muscles of the flexor compartment. Surgical: The artery can be compressed effectively against the insertion of coracobrachialis muscle in case of hemorrhage. Artery is selected for recording the blood pressure. It can be damage in the supracondylar fracture. During reduction of the supracondylar fracture finger is kept on the radial artery lateral to the tendon of flexor carpi radialis to check the compression of the brachial artery. Anastomosis Around Following branches of the brachial, profunda, radial and the ulnar arteries the Elbow (Figure 92): take part in the anastomosis. 1. Branches of brachial: Superior and inferior ulnar collateral. 2. Branches of profunda: Radial collateral and descending. 3. Branch of radial: Radial recurrent. 4. Branches of ulnar: Anterior and posterior ulnar recurrent and interosseous recurrent which is indirectly coming from ulnar. Figrue 92 Cubital anastomosis

Surface Markings of the Brachial Artery: Veins of the Arm (Figure 93):

Mark the point on line joining the anterior and the posterior folds of axilla at the junction of anterior two-thirds and the posterior one-third. Mark the second point at the neck of the radius, join these two points. The cephalic vein is lateral to the biceps and the basilic vein medial. The cephalic vein runs upwards to lie in the groove between deltoid and clavicular head of pectoralis major. Here, it pierces the clavi-pectoral fascia

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Kadasne’s Textbook of Anatomy (Clinically Oriented) and opens into the axillary vein. The basilic vein pierces deep fascia of the arm in the middle and continues as the axillary vein at the lower border of the teres major muscle.

Figure 93 Veins of the arm

Median Berve (C 5, 6, 7, 8; T) (Figures 94AandB to 97):

Figure 94A Median nerve upto the elbow

The cephalic and the basilic veins are connected by the median cubital vein, which lies, on the bicipital aponeurosis. It is formed in the axilla by union of the lateral root of the lateral cord and the medial root of the medial cord. The medial root of the median crosses the third part of axillary artery from medial to the lateral side. The median nerve is formed on the lateral aspect of the third part of the axillary artery and lies medial to the musculocutaneous nerve and coracobrachialis muscle. As it runs downwards it lies on the muscles of the posterior wall of the axilla, i.e. subscapularis, teres major and the latissimus dorsi.

The Arm Figure 94B Median nerve in arm and forearm

Figure 95 Section of the arm in the upper limb

Figure 96 Section of the arm in the middle third

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Figure 97 Section of the arm in the lower third

Musculocutaneous Nerve (Figure 98):

Figure 98 Musculocutaneous nerve

At the lower border of the teres major muscle the median nerve runs on the lateral side of the brachial artery. Median nerve crosses the brachial artery in the middle of the arm opposite the insertion of coracobrachialis muscle from lateral to medial side, on the brachialis and under the biceps. The ulnar nerve goes to the extensor compartment and the radial nerve enters the flexor (The medial nerve drives the ulnar out and invites the radial in). At the elbow, the nerve lies under the bicipital aponeurosis. The structures infront of the elbow joint are arranged as tendon, artery and the nerve from lateral to medial side (The relations can be remembered as TAN: T-Tendon of biceps, A-Artery: brachial and N-Nerve median). In the upper part, coracobrachialis, short head of biceps and the musculocutaneous nerve are lateral to the median nerve. In the lower part, the nerve lies on the brachialis muscle, which separates it from the capsule of the elbow joint. In the middle of the arm the nerve is overlapped by the biceps brachii muscle. The median nerve does not give branch in the arm. As the median nerve enters the forearm it passes between the two heads of the pronator teres muscle where it is separated from the ulnar artery by the deep head of the pronator teres muscle. Next it passes under the fibrous arch of the flexor digitorum sublimis muscle and runs its further course in the forearm sandwitch between the flexor digitorum profundus and the flexor digitorum sublimis. The flexor digitorum profundus is deep to the median nerve and the flexor digitorum sublimis being superficial. It is the branch of the lateral cord of brachial plexus and lies lateral to the median nerve and the third part of the axillary artery. It is devoted to the flexor compartment of the arm as it supplies all the flexor muscles of the arm. It gives branch to the coracobrachialis and then passes in between its two heads. Next it lies between biceps and the brachialis muscles, biceps being in front and brachialis behind. A little below the level of elbow it pierces the deep fascia lateral to tendon of the biceps and continues as the lateral cutaneous nerve of the forearm, which is entirely sensory. It is also known as lateral antebrachial cutaneous nerve.

The Arm Ulnar Nerve (Figure 99):

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It is the branch of the medial cord of the brachial plexus. In fact it is its continuation. It lies medial to axillary artery and runs further along the medial side of brachial artery up to the middle of the arm, beyond the border of the teres major muscle. In the middle of the arm it pierces the medial intermuscular septum along with the superior ulnar collateral artery and enters the extensor compartment and lies on the medial head of triceps. The ulnar nerve passes through a well marked groove on the posterior surface of the medial epicondyle of the humerus. Here it lies on the ulnar collateral ligament of the elbow joint and gives a branch to the elbow. Next it passes between the two heads of the flexor carpi ulnaris muscle, and enters the flexor compartment of the forearm. It runs its further course on the flexor digitorum profundus muscle and under the flexor carpi ulnaris. At times there is fibrous canal placed between the two heads of the flexor carpi ulnaris. It is known as Osborne’s canal. It can cause the entrapment of the ulnar nerve (entrapment means damage) (Figure 100).

Figure 99 Ulnar nerve upto the elbow

Figure 100 Showing how the median nerve crosses the brachial artery from lateral to median side and how the ulnar is driven out and the radial is invited in

Surgical:

Osborne’s Canal:

Fracture of the medial epicondyle of humerus causes damage to the ulnar nerve resulting in deformity of the hand known as “Claw Hand”. While examining case of leprosy (Hansen’s Disease) one looks for thickened and tender ulnar nerve. Ulnar nerve can be dislocated anteriorly around the medial epicondyle and it slips infront of it. It is like the running belt slipping from the pully of a sewing machine. During violent flexion of the elbow, the medial intermuscular septum gets turned which allows the ulnar to slip around the medial epicondyle. Poorly developed medial epicondyle may contribute to it. It is a fibrous canal present between the two heads of the flexor carpi ulnaris muscle. It can cause entrapment of the ulnar nerve.

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Extensor Compartment of Arm (Figure 101):

Following structures lie in this compartment: Triceps muscle, profunda brachii artery, its branches, radial and the ulnar nerves. Examination of the posterior surface of humerus gives us an idea of structural details of the posterior compartment. The spiral groove is seen running downwards and laterally on the back of the shaft of humerus. Lateral head of triceps arises from lateral aspect of the groove, while medial head arises from the rest of the surface lying medial and below the groove. Long head arises from the intraglenoid tubercle. Origin of anconeus can be examined on the posterior surface of the lateral epicondyle.

Figure 101 Posterior view of left humerus

Triceps Muscle (Figure 102):

Figure 102 Triceps muscle

The radial nerve and the profunda brachii artery run in the spiral groove between the lateral and the medial heads of the triceps. Below the medial head of the triceps lies the origin of the anconeus muscles, which is supplied by nerve to the medial head. Medial and lateral intermuscular septae are attached to the medial and the lateral supracondylar ridges respectively. It has three heads namely the long, medial and the lateral. Long head arises from the infraglenoid tubercle. Lateral head takes it origin form the lateral limit of the spiral groove while the medial one arises from the medial limit of the spiral groove and rest of the posterior surface of the bone. Three heads unite to form a muscular belly in the posterior compartment. The tendon gets inserted into the top of the olecranon and also into the capsule of elbow joint.

The Arm Nerve Supply:

Action: Radial nerve (C 5, 6, 7, 8 ; T 1) (Figure 103):

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It is supplied by the radial nerve. Branch to the long head of triceps comes from the radial nerve in axilla and the branches to lateral and medial heads are given in the spiral groove. It is an extensor of the forearm. Long head may help in adduction of the arm. Radial nerve is the largest branch of the brachial plexus. It is one of the two terminal branches of the posterior cord of the brachial plexus given behind the third part of the axillary artery, the other being axillary nerve which lies lateral to the radial. It successively lies on the suprascapular, teres major and latissimus dorsi muscles. It lies posterior to the third part of the axillary artery and also posterior to the proximal part of the brachial artery. Next it passes through the triangular space alongwith the profunda brachii artery. It lies between the long and the lateral heads of the triceps. In the groove it lies between lateral and medial heads of the triceps. It is the lateral head which overlaps the nerve from the lateral side.

Figure 103 Radial nerve in arm (viewed from behind left side)

Branches (Figure 104): Figure 104 Branches of the radial nerve in the arm (diagrammatic)

At the lateral side of the arm it pierces the lateral intermuscular septum and makes its entry into the flexor compartment, along with the radial collateral artery a branch of the profunda brachii Here it is placed between brachialis, brachio-radialis and the extensor carpi-radialis longus muscles. It passes in front of the lateral epicondyle, where it gives the posterior interosseous nerve (deep branch of radial nerve) and continues as the superficial branch of radial or the radial proper which is purely sensory. Radial nerve at the lateral epicondyle of the humerus gets divided into its two functional components the motor and the sensory, posterior interosseous nerve being motor and the radial nerve being purely sensory. Motor branches of the radial nerve are arranged in three groups.

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Kadasne’s Textbook of Anatomy (Clinically Oriented) 1. Medial group: They go to the long and the medial heads of the triceps. The branch to the medial head is long. It runs in close proximity with the ulnar collateral artery, hence is also known as ulnar collateral nerve. In fracture of the shaft of the humerus the radial nerve is injured, leading to the wrist drop. However, nerve to the long head of the triceps is not affected hence the extension of the elbow remains. 2. Lateral group: They arise in the anterior compartment and supplies brachialis, brachioradials, extensor carpi radialis longus muscles, please note that the lateral head of the triceps is not innervated by the branches from the posterior group.

3. Posterior group: Supplies the medial head of the triceps and the anconeus muscle. It may be noted that the medial head of the triceps is supplied by two groups namely the medial and posterior. In brief, the radial nerve supplies the two muscles on the back of the arm, namely triceps and anconeus and the three muscles in front of lateral intermuscular septum namely brachialis (in part), brachioradialis and the extensor carpi radialis longus. Cutaneous branches of the radial nerve: 1. Lower lateral cutaneous nerve of the arm, 2. Posterior cutaneous nerve of the arm, 3. The posterior cutaneous nerve of the forearm. Articular Branches The radial nerve supplies the elbow joint. Surgical Radial nerve injury results wrist drop. The radial nerve can get injured in (Figures 105 to 108): the axilla if it is pressed hard by a crutch (crutch palsy). If a person sleeps in the chair with his arm hanging over the back of the chair, the nerve can get compressed. No sensible person would do this unless he is under heavy effect of alcohol hence known as Saturday night paralysis. Fracture of the shaft of the humerus results in the injury of the main trunk of radial nerve resulting in the wrist drop. The posterior interosseous nerve can get injured during the fracture or dislocation of the head of the radius. In this case, extensor carpi radialis longus escapes, as it gets it nerve supply from the radial itself. Figure 105 Crutch and saturday night paralysis due to the injury to the radial nerve

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Figure 106 Wrist drop

Figure 107 How extensor carpi radialis longus is spared to perform extension of wrist

Figure 108 The cutaneous innervation of the front and the back of the arm

Surface Marking of Radial Nerve:

It is important to note that the extensor carpiradialis longus is strong enough to perform the extension at the wrist and thus it reduces the severity of wrist drop to a considerable extent. It is not uncommon to see a person with wrist drop who gives history of an injection in the arm around the radial nerve in the radial groove. As the long head of the triceps escapes, the injury of the radial nerve in the spiral groove, extension of the elbow is possible. For marking the radial nerve in the arm three points are marked, point one is the end of the axillary artery and the beginning of the brachial artery. Second point lies between the line, i.e. line between the deltoid tuberosity and the lateral epicondyle. Take the junction of upper one third and lower two thirds of this line. Point three is marked one centimeter lateral to the tendon of biceps. Line between the first two point indicates the radial

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nerve in the spiral groove and rest of the line shows its course in the flexor compartment of the arm. Surface Marking of It requires three points point one lies one centimeter lateral to the tendon Superficial Branch of the biceps. The second point is on the lateral border of the forearm of Radial Berve: between the junction of upper two-thirds and the lower one-thirds. Third point is the anatomical snuff box. Join all these lines which indicates the superficial branch of the radial nerve. Cutaneous Following nerves supply the arm from the front: Innervation of 1. Medial cutaneous nerve of the arm, the Arm: 2. Intercostobrachial nerve, 3. Upper lateral cutaneous nerve of the arm and 4. The lower lateral cutaneous nerve of the arm. Following nerves supply the back of the arm: 1. Upper lateral cutaneous nerve of the arm, 2. Posterior cutaneous nerve of the arm, 3. Medial cutaneous nerve of the arm, 4. Intercostobrachial nerve and 5. The posterior cutaneous nerve of the forearm to some extent.

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ELBOW JOINT

Bones Taking Part:

Lower End of Humerus (Figures 109A and B):

It is compound as humero-ulnar and humero-radial components form the joint. It is placed between the arm and the forearm. It is a synovial, uniaxial and hinge variety of joint. Only the flexion and the extension are permitted in the joint. 1. Lower end of the humerus, 2. The upper end of the radius 3. Upper end of the ulna The head of radius participates in two joints, the elbow and the superior radioulnar. The capsule of the joint cavities of the two articulations is continuous with each other. At times two joints are collectively labelled as cubital articulation. It present the following named structures from lateral to medial side. 1. Lateral epicondyle, 2. Capitulum, 3. Trochela and , 4. The medial epicondyle.

Figure 109A: Lower end of humerus

Figure 109B: X-ray of elbow

Capitulum articulates with the head of radius and the trochlea with the trochlear notch of the ulna. Their articular surfaces are covered with articular cartilage. The medial flange of the trochlea projects lower down more than the lateral flange of the trochlea (6 mm). It creates an angle between the long axis of the arm and the long axis of the forearm known as carrying angle.

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Head of Radius (Figure 110):

The axis of the elbow joint runs downwards and medially instead of running transversely. Above the capitulum lies the radial fossa and the trochlear fossa is above the coronoid. Posterior aspect of the lower end of the humerus presents the olecranon fossa. During the flexion of the forearm radial head occupies the radial fossa and the coronoid process occupies the coronoid fossa. The olecranon fossa is occupied by the olecranon process during extension of the forearm. These fossae are non articular and contain pads of fat covered with synovial membrane (Haversian Pads). The head of radius presents a shallow articular depression for capitulum. Circumference of the head of radius is encircled by the annular (Ringlike) ligament except on the medial side where it articulates with radial notch on the ulna.

Figure 110 Upper end of radius

Upper End of Ulna (Figure 111):

The trochlear notch is formed by coronoid and olecranon processes. It is covered with articular cartilage. However, a small strip of monarticular area is present at the constricted junctional zone of these processes.

Figure 111 Upper end of ulna

Attachment of Capsule (Figure 112):

To the Humerus: It is attached to the lower end of humerus beyond the articular areas and includes the three fossae namely the radial, coronoid, and olecranon.

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Figure 112 Capsular attachment of posterior aspect of lower end of humerus

To the Ulna (Figure 113):

Capsular ligament is attached to the upper end of the ulna beyond the articular area.

Figure 113 Annular ligament (partially cut anteriorly)

Capsule:

Ligaments (Figure 114):

To the radius: It is attached to annular ligament. Capsule is not thick in front and behind. Anteriorly the capsule is continuous with the capsule of the superior radioulnar joint. On the radial and ulnar sides the capsule is strongly re-enforced by the radial and the ulnar collateral ligaments. They are as under: 1. Capsular ligament, 2. Medial or ulnar collateral ligament, 3. Lateral or radial collateral ligament.

Figure 114 Ligaments of the elbow joint

Medial Ligament:

It is triangular in shape and presents three parts namely the anterior, posterior and the middle. The anterior part is attached to medial epicondyle of humerus above and to upper part of the medial border of coronoid process below. The posterior one is attached to medial epicondyle of humerus above and the medial aspect of olecranon below. The middle one runs in between the coronoid and the olecranon processes.

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Figure 115 Synovial membrane of elbow joint (sagittal section)

Relations of Medial After emerging from the back of medial epicondyle, the ulnar nerve lies on Ligament: this ligament. Here it gives an articular branch to the elbow joint. Lateral Ligament: Above it is attached to the lateral epicondyle of the humerus and lower down it fans out and gets attached to the annular ligament. It is not attached to the radius which grants free mobility to head of the radius during movements of pronation and supination. Synovial Membrane It covers capsule from inside except the articular areas. (Figure 115): Pads of Fat:

Nerve Supply:

Blood Supply: Movements:

There are three in number: 1. In the radial fossa, 2. In the coronoid fossa and 3. In the olecranon fossa. The olecranon pad of fat is pushed inside by triceps muscle during extension. 1. Ulnar, 2. Median 3. Radial and 4. The musculocutaneous. Comes from the anastomosis around the elbow joint. Flexion and extension occur along the axis which runs obliquely downward and medially. Some degree of movements of upper end of ulna occur during pronation and supination. When the forearm is fully extended, long axis of the arm and the forearm do not lie in the same plane, but make an angle of 167° in female and 173° in male. It is open outside and is known as carrying angle. During pronation, the arm and the forearm lie in the same plane. The best working position, for the hand is obtained when the forearm is kept in a semi-prone position. Biceps brachii, brachialis, brachio-radialis and common flexors are flexors of the elbow joint, and the triceps and anconeus are the extensors.

Relations (Figure 116): Anterior relations: 1. Brachialis, 2. Median nerve, 3. Brachial artery or its two terminal branches, the radial and the ulnar. 4. Tendon of biceps, 5. Bicipital aponeurosis and 6. Median cubital vein. Posterior relations: Triceps with a bursa.

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Figure 116 Relations of elbow joint

Lateral Relations:

Anconeus, common extensors, radial nerve, brachio-radialis and the extensor carpi radialis longus. Medial Relations: Ulnar nerve, flexor carpi ulnaris and the common flexors. Surgical (Figures 117 In case of an abnormal collection of fluid in the joint (effusion), it can be and 118): aspirated by inserting a needle from the posterior side, medial or lateral to olecranon. Due to sudden and forceful fall on the hand the elbow joint can get dislocated. Dislocation of elbow is common in children than in adults as the bony elements which take part in the formation of the joint are poorly developed. The upper end of ulna goes backward with the olecranon process There is bursa between skin and the olecranon. It is known as olecranon bursa. Chronic inflammation of the bursa produces swelling on the olecranon. It is known as “Student’s elbow”. When the elbow is extended epicondyles of the humerus and the tip of the olecranon are in one line. When the elbow is flexed two epicondyles and the tip of the olecranon form an equilateral triangle. In dislocation of the elbow this relationship is disturbed due to the shift of the tip of the Figure 117 Bony points in dislocation of elbow joint are disturbed

Figure 118 Bony points in supracondylar fracture of humerus are not disturbed

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olecranon process posteriorly. In supracondylar fracture there is no distortion of the equilateral triangle. Exposure of the It is good for old dislocations and TY fracture of the humerus and orthoElbow Joint Postero- plasty. Olecranon osteotomy or VY plasty of the triceps tendon can be lateral Approach: done. Optimal position of fixation of elbow: 1. If unilateral 90° of flexion. 2. If bilateral 110 ° of flexion for the right elbow (good for food). 3. and 65° for the left (Personal hygiene).

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FOREARM General Plan (Figure 119):

Radius and the ulna are the bones of the forearm of which radius is laterally and the ulna is medial. The gap between the bones is filled up by an interosseous membrane which is attached to the interosseous borders of the radius and the ulna. The function of interosseous membrane is to keep the two bones in position and provides an extra surface for the origin of flexor and extensor groups of muscles. Radius and ulna articulate at their upper and lower ends forming superior and the inferior radioulnar joints. The head of the radius is at the upper end of the radius and the head of the ulna is at the lower end of the ulna. The movements of the pronation and supination are allowed in these joints. The axis of the pronation and supination runs from center of the head of the radius to the base of the styloid process of ulna. Forearm is capable of getting flexed, extended, pronated and supinated. Accordingly the forearm is provided with muscles responsible for producing the above mentioned actions.

Figure 119 Note direction of oblique cord and interosseous membrane. Posterior interosseous artery enters extensor compartment in between two

Forearm is divided into two compartments, e.g. flexor and the extensor by the partition formed by radius, ulna and interosseous membrane, anterior being flexor and the posterior extensor. Posterior interosseous nerve, (deep branch of the radial nerve) supplies all the muscles of the extensor compartment of the forearm except the brachio radialis and the extensor carpi radialis longus which are directly supplied by the radial above the elbow. Median and ulnar nerves are the nerves of the flexor compartment of the forearm. The branch of the median nerve which runs anterior to the interosseous membrane is known as anterior interosseous nerve. The radial, ulnar and the interosseous arteries run in flexor compartment. As the posterior interosseous artery in the extensor compartment gets exhausted lower down, and the anterior interosseous artery pierces the interosseous membrane at the upper border of the pronator quadratus and enters the extensor compartment. Instead of sending a branch for the help of the posterior interosseous artery, the anterior interosseus artery itself goes for the help. The ulnar artery gives the common interosseous branch which divides into the anterior and the posterior interosseous arteries. Out of these, posterior interosseous artery enters extensor compartment through the gap between the interosseous membrane below and the oblique cord above. The direction of fibres of

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interosseous membrane is downwards and medially, while that of the oblique cord is upwards, and medial. The extensor compartment consists of extensor group of muscle, the supinator, the posterior interosseous nerve and posterior interosseous artery. The forearm is connected to the hand by means of junctional zone known as the wrist joint. Eight carpal bones lie in this zone. They are arranged in proximal and distal rows. Their arrangements is such that they present concavity anteriorly obviously for accommodating the flexor tendons. For the retention of the tendons concavity is closed anteriorly by the flexor retinaculum. On the dorsal aspect of wrist there is convexity produced by carpal bones. The extensor tendons, instead of passing enmasse in one group, are placed wide-apart under the extensor retinaculum. The flexor and the extensor retinaculi are the thickened, specialized bands of the deep fascia of the forearm. I propose to put before you plan for simplification of complicated terminology of the muscles of the forearm. Let us concentrate on the fingers and the thumb. The thumb is known as pollex, hence the muscle acting on pollex always has the word pollicis. Fingers are the digits and the muscles acting on them always has the word digitorum. I would like to give an example. Let us consider the muscle named as flexor pollicis longus, the word flexor indicated the action, pollicis stands for the thumb and longus is suggestive of the length. Now let us consider the name flexor digitorum sublimis. From the name we know that the muscle is superficially placed and is the flexor of the digits. If the word profundus is put in place of sublimis we know that the muscle is the deep flexor of the digits as profundus means deep. Pronator stands for pronation and the supinator for supination. The names of the muscle reveal the action. Forearm has investing tube of the deep fascia. A small fossa in front of the elbow (Cubital region) is known as cubital fossa. Muscles of the Before study of these muscles please note that common flexors of the flexor Compartment forearm have common site of origin from the front of medial epicondyle of of the Forearm humerus. Now examine the front of radius and note its anterior oblique (Figure 120): border which gives origin to the flexor digitorum sublimis muscle. The origin of flexor digitorum sublimis also extends on the coronoid process of the ulna and to the medial epicondyle of humerus. Space of Parona lies in the lower one third of the flexor compartment of the forearm in front of the pronator quadratus muscle and behind the long flexor tendon. Pus can accumulate in the space in infection of the synovial sheaths of the hand. Upward extension of pus is prevented by the origin of the flexor digitorum sublimis muscle. Figure 120 Showing attachment of front of radius and ulna

Forearm

Pronator Teres (Figure 121):

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Following are the members of the superficial group. 1. Pronator teres. 2. Flexor carpi radialis. 3. Flexor digitorum sublimis, 4. Palmaris longus, 5. Flexor carpi ulnaris. It has two heads the humeral and the ulnar. The humeral head (Superficial) arises from the lower part of the medial supracondylar ridge and the medial epicondyle of the humerus. The ulnar head (deep head) arises from the medial border of the coronoid process of the ulna immediately below the origin of flexor digitorum sublimis. The median nerve enters the forearm passes between the two heads of pronator teres. The muscle runs downwards and laterally for its insertion into the middle of the lateral surface of the radius at the maximum point of convexity.

Figure 121 Pronator teres, muscle

Nerve Supply:

Action: Relations:

Surgical:

Flexor Carpi Radialis:

It is supplied by the median nerve before its entry between the two heads, and also gives the branch to the muscle as it passes between the two heads of the pronator teres muscle. It is the pronator and the weak flexor of the forearm. The pronator teres forms the medial border of the cubital fossa. As the median nerve passes between the two heads of pronator teres it is the ulnar head of the muscle which separates the median nerve from the ulnar artery. 1. Median nerve can be damaged (entrapment) between the two heads of pronator teres muscle. 2. In the fracture of radius above the insertion of the pronator teres the distal fragment is pronated. Such fracture should splinted in the position of supination. 3. In fracture of the radius below the insertion of pronator, pronation action of the pronator teres is opposed by the action of supination action of the biceps brachii. Such a fracture should be splinted in midprone mid-supine position (Nutral). 4. Robert Jones transfer of pronator teres to the extensor carpi-radialis longus can be done to improve extension of the wrist. It takes origin from medial epicondyle of humerus, the deep fascia of the forearm and the intermuscular septa. The muscle runs along the medial side of pronator teres. The tendon begins in the middle of the forearm which passes through the groove situated on the trapezium between the superficial and the deep part of the flexor retinaculum attached to the margins of the groove. It carries synovial tube along with it. The tendon of

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Nerve Supply: Action:

Relations:

Palmaris Longus (Figure 122):

flexor carpi radialis is considered as a Royal tendon as it passes through the separate tunnel. It is supplied by the median nerve. It is the flexor of the wrist joint along with the flexor carpi ulnaris. As it lies on the radial side it also acts as an abductor of the wrist along with extensor carpi radialis longus and brevis. The tendon of the flexor carpi radialis is related to radial artery laterally. Try to feel the tendon of flexor carpi radialis and pulsations of radial artery lateral to it . It lies medial to the flexor carpi radialis. It arises from the medial epicondyle of the humerus, deep fascia of the forearm and the intermuscular septa. The tendon of the muscle beings higher up in the forearm and runs on the medial side of the flexor carpi radialis tendon. It passes in front of the flexor retinaculum and gets inserted into the palmar aponeurosis. Part of it is also inserted into the distal half of the flexor retinaculum. This muscle is known for its variations and the absence.

Figure 122 Showing some of the tendons and the radial artery in front of the wrist

Nerve Supply: Action: Clinical:

It is supplied by the median nerve. It is the flexor of the wrist and may help in flexion of the elbow. Palmaris longus can be attached to the extensor pollicis longus in case of wrist drop due to radial nerve damage. Flexor Digitorum Although it belongs to the superficial group it lies relatively at the deeper Sublimis level under cover of the members of its own group. It is the largest muscle. (Figures 123 and 124): Figure 123 Flexor digitorum sublimis muscle origin and insertion

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Figure 124 Relation of flexor digitorum sublimis (schematic)

Humeroulnar Head: Arises from the medial epicondyle of the humerus, ulnar collateral ligament of the elbow joint, intermuscular septa and the coronoid process, a little above the origin of the pronator teres. Radial Head: It arises from the anterior border of radius extending from the radial tuberosity to the insertion of pronator teres. Comment: In brief the origin of the flexor digitorum sublimis muscle can be described as under: 1. Medial epicondyle of the humerus. 2. Coronoid process of the ulna. 3. Fibrous arch between the coronoid process and the radius. 4. Anterior border of the radius. Muscle: The broad sheet of the muscle gets divided into two stratas, the superficial and the deep. Tendons to the middle and ring fingers lie superficial while those for the index and the little finger are deep. All the tendons lie superficial to tendons of the flexor digitorum profundus. They pass alongwith profundus tendons under the flexor retinaculum and enter the palm. In the palm they go to the four fingers. Tendon of flexor digitorum sublimis lies superficial to the tendon of flexor digitorum profundus at the proximal phalanx. Sublimis surrenders and stops at the base of the middle phalanx to get attached to its base. Tendon of flexor digitorum profundus perforates the sublimis tendon and passes further to get attached to the base of the distal phalanx. SUBLIMIS STOPS AND SURRENDERS. PROFUNDUS PERFORATES AND PASSES. Nerve Supply: It is supplied by the median nerve (C7, 8; T I) Action: It is the flexor of the middle and the proximal phalanges. It can also help in the flexion of the wrist. Relations: Anterior Relations: Palmaris longus, flexor carpi radialis, radial nerve and radial artery. Posterior Relations: Median nerve, ulnar artery, flexor digitorum profundus and the flexor pollices longus muscle. It must be remembered that the median nerve passes between the two heads of the pronator teres and disappears under the fibrous arch of flexor digitorum sublimis muscle. It is intimately related to the under surface of the flexor digitorum sublimis. In fact it is virtually plastered to its under surface. Flexor Carpi Ulnaris It arises by two heads, the humeral and the ulnar which we connected by (Figure 125): an arch under cover of which the ulnar nerve enters the forearm.

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Figure 125 Origin and insertion of flexor carpi ulnaris. Ulnar nerve passing between two heads of flexor carpi ulnaris

Humeral Head: Ulnar Head:

Nerve Supply: Action:

Relations: Surgical:

Arises from the medial epicondyle of humerus. Arises from the medial margin of the olecranon process, upper two thirds of the posterior border of the ulna and the intermuscular septa. The two heads join together to form the muscular belly. The tendon of the flexor carpi ulnaris is inserted into the pisiform bone. However, its extension into the hook of hamate and the base of the fifth metacarpal bone can be traced through the piso-hamate and the pisometacarpal ligaments. The tendon gives a few slips to the flexor retinaculum. Note: Fibrous canal may exists between the two heads of the flexor carpiulnaris through which the ulnar nerve escapes and enteres the forearm. The canal is known as the Osborne’s canal. Entrapment of the ulnar nerve in the Osborne’s canal can lead to paresis or paralysis of the ulnar nerve and results in deformity of the hand which is known as “Claw Hand”. It is supplied by the ulnar nerve. It is the flexor of the wrist along with flexor carpi radialis. As it lies on the ulnar side it also acts as a powerful adductor of the hand alongwith the extensor carpi ulnaris. (Ulnar deviation). The muscle fixes the pisiform bone during abduction of the little finger. The ulnar nerve and the artery lie under cover of the muscle. Further it lies lateral to the flexor carpi ulnaris. 1. Osborne’s canal is the fibrous (canal) between the two heads of flexor carpi-ulnaris. It is widened during transposition of the ulnar nerve. (S. Palazzi and et all I. S. 65,6,1980). 2. In case of injury of the radial nerve, flexor carpi-ulnaris can be attached to the extensor digitorum tendon.

DEEP GROUP OF MUSCLES OF FOREARM

Flexor Pollicis Longus:

Following are members of the deep group: 1. Flexor pollicis longus 2. Flexor digitorum profundus 3. Pronator quadratus. The deep group consists of flexors of the fingers, a flexor of thumb and pronator of the forearm. Origin and insertion of pronator quadratus lie in the lower fourth of the forearm, therefore the flexor digitorum profundus and the flexor pollicis longus muscles are superficial to the pronator quadratus. The anterior interosseous nerve and vessels are between the flexor pollicis longus and the flexor digitorum profundus muscles in front of the interosseous membrane. It arises from the upper two thirds of the anterior surface of the shaft of the radius and from the adjacent part of the interosseous membrane. Some fibres arise from the medial border of coronoid process. Muscular belly is

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replaced by strong and thick tendon which passes under the flexor retinaculum. It is enclosed in a separate synovial sheath. It passes between the oblique head of the adductor pollicis and the opponens pollicis muscles. It runs in the fibrous flexor sheath of the thumb and gets inserted into the base of the distal phalanx of the thumb (Figure 126). Figure 126 Flexor pollicis longus and flexor digitorum profundus

Nerve Supply:

It is supplied by the anterior interosseous nerve, the branch of the median nerve. Action: It is the flexor of the thumb. It also flexes the wrist joint. Flexor Digitorum It arises from the upper three-fourths posterior border of the ulna, medial Profundus: and anterior surfaces of the ulna and the interosseous membrane. Some part of it takes origin from the medial aspect of the coronoid process. The muscle has four tendons which pass under the flexor retinaculum deep to the tendons of flexor digitorum sublimis. The tendon for the index finger is separate while other tendons are interconnected. Lumbrical muscles arise from the tendons of flexor digitorum profundus muscle, in the region of the palm and are four in number. The tendons of the flexor digitorum sublimis and the profundus are in the fibrous flexor sheath. Sublimis lies superficial and the profundus deep. The tendon of flexor digitorum profundus perforates the sublimis at the middle phalanx and passes for its insertion into the base of the terminal phalanx. The tendon of flexor digitorum sublimis gets attached to the base of the middle phalanx. Nerve Supply: Radial half of the flexor digitorum muscle is supplied by the median nerve through its anterior interosseous branch. Ulnar half of the flexor digitorum profundus muscle is supplied by the ulnar nerve. Two medial lumbricals get their nerve supply from the ulnar while the lateral two lumbricals are supplied by the median nerve. Action: It is the flexor of the fingers and the wrist. Action on the fingers is more powerful than the action on the wrist. Pronator Quadratus It is a quadrilateral muscle running from the ulna to the radius (Pronate (Figure 127): the forearm and see that the radius moves more as compared to the ulna. If this fact is kept in mind the student shall have no difficulty in remembering that the muscle has its origin on ulna and insertion on the radius). Normally the insertion moves and the origin remains static.

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Figure 127 Pronator quadratus muscle

Origin: Insertion: Nerve Supply:

It arises from the oblique ridge on the anterior surface, of the lower one fourth of the ulna. It is inserted into the lower one fourth of the anterior of the radius. By the anterior interosseous nerve.

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NERVES AND VESSELS OF THE FOREARM Radial Artery:

Figure 128 General plan of vessels and nerves of the forearm

Figure 129 Relations of the median nerve and the ulnar artery

Figure 130 Course of the radial artery

It is one of the two terminal branches of the brachial. It begins one cm below the elbow and runs laterally and downwards to gain the lateral aspect of the forearm. Lower down, it passes under the tendons of abductor policis longus and the extensor pollicis brevis muscles and goes to the back of the wrist. Its pulsations can be felt lateral to the tendon of flexor carpi radialis muscle. During its further course, it passes between the two heads of the first dorsal interosseous muscle and continues as the deep palmar arch. While in the front of the forearm, it gives superficial palmar branch, which forms part of the superficial palmar arch along with the ulnar artery (Figures 128 to 130).

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Relation:

Posterior relations (Figure 131)

Figure 131 Front of the right radius

Medial Relation: Lateral Relation:

Anterior Relations:

Branches of Radial Artery (Figures 132 and 133):

Anterior Carpal Branch:

It can be remembered if the front of the radius is kept before your eyes, with its attachments. The artery successively lies on the following structures: 1. Tendon of the biceps, 2. Superior, 3. Insertion of the pronator teres, 4. Flexor digitorum sublimis, 5. Flexor pollicis longus, 6. Pronator quadratus, 7. The radius itself. In short one can say that the artery lies on all the muscles attached to the front of the radius. Pronator teres in the upper part and the tendon of flexor carpi radialis in the lower part are the medial to the artery. Brachio-radialis, radial nerve and the lateral cutaneous nerve of the forearm form the lateral relations. The radial nerve lies away from the artery in the upper part however it comes near the artery in the lower part. Skin superficial fascia belly of the brachioradialis, tendons of the abductor pollicis longus and the extensor pollicis brevis, cephalic vein and the digital branches of the radial nerve are the anterior relations. Please note that the cephalic vein lies anterior or superficial to the artery in the region of the snuff box. They are: 1. Radial recurrent, 2. Muscular, 3. Palmar carpal branch, 4. Superficial palmar branch, 5. Dorsal carpal branch, 6. First dorsal metacarpal artery, 7. Princeps pollicis and 8. The radialis indices. The radial recurrent artery arises near the origin of the radial artery and passes between radial and posterior interosseous nerves. It anastomoses with the descending branch of profunda brachii artery. The muscular branches are given to the muscles. Arises near the lower border of pronator quadratus and joins the similar branch of the ulnar artery. Anterior carpal branches of the radial and ulnar artery form the anterior carpal arch. Anterior interosseous artery and recurrent branch from the deep palmar arch join the anterior carpal arch.

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Figure 132 Branches of the radial artery

Figure 133 Radial artery

Superficial Palmar Branch: Dorsal Carpal Branch: Clinical:

Arises from the radial artery at the point where it turns dorsally. It runs in front of the flexor retinaculum enters the palm and joins the ulnar artery to form the superficial palmar arch. Arises on the dorsal aspect and anastomoses with a similar branch of the ulnar artery under the extensor tendons. It is joined by the anterior and the posterior interosseous arteries to form the dorsal carpal arch. 1. Radial pulse is felt by keeping fingers on the lateral side of the flexor carpi radialis tendon at the wrist. 2. It is used for passing a catheter for angiography as the artery lies superficially and is easily accessible. Post cardiac catheterization bleeding from the radial artery can be controlled by pressing it against the radius for a short time. In case of femoral cardiac catheterization bleeding continues for long and the incidence of formation of hematoma is more. 3. Blood for gas analysis is obtained from radial artery. 4. Allen’s test: It is done to test the patency of the radial artery. The ulnar artery is compressed against the ulna and then the patient is asked to

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make a fist. The circulation in the palmar arches is stopped. Now ask the patient to open the fist. The circulation returns with change of colour of the palm if the radial artery is patent. 5. Radioulnar loop: The cardiac catheter returns after forming a loop due to anomaly. Anomalies of the radial artery are classified into three A. Radial artery arises from the axillary artery. AB. Radial artery arises from both the axillary and the brachial. aB. Radial artery arises mainly from the brachial artery and the contribution from the axillary artery is least. The anomalies can be remembered as A, AB, and aB 6. Arteriovenous fistula: Before renal dialysis, radial artery is anastomosed to the cephalic vein, creating an artificial arteriovenous fistula. Increased pressure in the cephalic vein causes thickening of the venous wall (arterialization). Thick walled cephalic vein can be utilized for passing arterial and venous lines through the canula. Venous line carries impure blood to the dialysis machine and the arterial line returns pure blood to the cephalic vein. Surface Marking of Mark a point one cm below the midpoint of the interepicondylar line at the Radial Artery: the elbow and the second point is radial pulse itself or the point lateral to the tendon of flexor carpi radialis. A curved line from this point is drawn across the wrist reaching the first intermetacarpal space. It represents the radial artery at the wrist. Four centimeter long horizontal line on the palm at the distal border of hook of hamate is the surface marking of the radial artery in the palm.

RADIAL NERVE Figure 134 Radial nerve

Radial Nerve in the After entering the flexor compartment the radial nerve lies in front of Forearm: lateral epicondyle of humerus. It gives branches to the brachioradialis, extensor carpi radialis longus and the brachialis muscles. It gives posterior interosseous nerve and continues as radial. Posterior interosseous nerve is known as deep branch of radial nerve. Deep branch of the radial is motor and the superficial branch being sensory (Figure 134). In brief the radial nerve separates at the level of the lateral epicondyle of the humerus in its two components the motor and the sensory. The

Nerves and Vessels of the Forearm

Ulnar Artery (Figure 135):

Figure 135 Ulnar artery

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radial nerve runs along the lateral part of the front of forearm. In its upper two thirds, it is accompanied by the radial artery on its medial side. In the lower third it shifts laterally away from the radial nerve and divides in the region of snuff box. In the upper part, the nerve is anteriorly overlapped by the belly of brachio-radialis. Lower down the nerve passes deep to the tendon of brachio-radialis about 7 cm above wrist to reach the dorsum of the hand. It successively lies on the following muscles. 1. Supinator, 2. Pronator teres, 3. Flexor digitorum sublimis, 4. Flexor pollicis longus. Radial nerve has no relations to the tendon of biceps and the front of the lower fourth of the radius. While the radial artery is related to the tendon of biceps above and the lower one forth of the radius below. Radial nerve crosses the lateral aspect of the radius as it goes to the dorsum. On the dorsum of the hand the nerve gives four to five digital branches, after piercing deep fascia. It is one of the two terminal branches of the brachial artery given at the level of the neck of the radius. It leaves the cubital fossa by passing under the ulnar head of the pronator teres, which separates it from the median nerve. It runs downwards and medially to reach the medial side of the forearm. In the upper third of the forearm it lies well away from the ulnar nerve which lies on its medial side. In the rest of its course it lies close to the ulnar nerve. Ulnar artery and nerve pass superficial to the flexor retinaculum and enter the palm. Posteriorly it lies on the brachialis and the flexor digitorum profundus muscles. Anteriorly the artery is deep seated in the upper part of forearm. Following muscles cover it (i) Pronator teres, (ii) Flexor carpi radialis, (iii) Palmaris longus, (iv) Flexor digitorum sublimis and the (v) Flexor carpi ulnaris. In the lower part, the artery is relatively superficial as it is covered by the skin, superficial fascia and deep fascia. Tendon of the flexor carpi ulnaris is medial and the tendons of flexor digitorum sublimis and profundus are lateral to the artery. It is accompanied by the venae comitantes.

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Branches (Figures 136 and 137):

Following are the branches of the ulnar artery: 1. Anterior ulnar recurrent, 2. Posterior ulnar recurrent, 3. Common interosseous—which gives anterior and the posterior interosseous branches, 4. Muscular, 5. Palmar carpal artery, 6. Dorsal carpal artery, 7. Deep branch and 8. The superficial palmar arch.

Figure 136 Branches of ulnar artery

Figure 137 Branches of ulnar artery

1. Anterior ulnar recurrent: It arises from the ulnar immediately below the elbow and passes in front of the medial epicondyle and anastomoses with the inferior ulnar collateral artery. 2. Posterior ulnar recurrent: It arises from the ulnar artery below the origin of the anterior ulnar recurrent artery. It passes behind the medial epicondyle and anastomoses with the superior ulnar collateral.

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3. Common interosseous: It takes its origin from the ulnar artery a little below the level of radial tuberosity and divides after a short one cm. course into the anterior and the posterior interosseous branches at the upper border of the interosseous membrane. Anterior Interosseous It runs in front of the interosseous membrane with the anterior interosseous Artery (Figure 138): nerve. They lie between flexor pollicis longus and flexor digitorum profundus. It gives muscular branches and nutrient vessels to the radius and the ulna. At the upper border of pronator quadratus it pierces the interosseous membrane and enters the extensor compartment to join the dorsal carpal arch. At its origin, arteria mediana arises from it, which runs along median nerve and supplies it. At times, arteria mediana is large and may go to the palm to join the superficial palmar arch. Figure 138 Interosseous arteries (diagrammatic)

Posterior It enters the extensor compartment between the interosseous membrane Interosseous Artery: below and the oblique cord above. On the back of the forearm it comes out between the supinator and the deep group of muscle of extensor compartment. Lower down it anastomoses with anterior interosseous artery and also with the dorsal carpal arch. The interosseous recurrent artery arises from it near the origin, and joins the posterior descending branch of profunda brachii, posterior ulnar recurrent and the ulnar collateral arteries. 4. Muscular branches: They are distributed to the muscles along the ulnar border of the forearm. 5. Palmar carpal branch: It runs in front of the carpus and unites with the similar branch of the radial artery to form the palmar carpal arch. 6. Dorsal carpal branch: It arises proximal to the pisiform bone, runs dorsally to anastomoses with the dorsal carpal branch of the radial artery and helps in forming the dorsal carpal arch. 7. Deep branch: It unites with the radial artery in the palm to form the deep palmar arch. 8. Superficial palmar arch: It is formed by the continuation of the ulnar artery in the palm. Surface Marking of Mark a point one centimeter below the middle of the interepicondylar Ulnar Artery: line at the elbow. Second point is at the junction of upper one third and lower two thirds of a line joining the medial epicondyle and the pisiform.

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Median Nerve (Figure 139) (In the Forearm):

The third point is the pisiform itself. The line joining the first and the second point indicates the oblique course of the artery. Now join the lower end of this line and carry it to the pisiform. It enters the forearm by passing between the two heads of pronator teres muscle. The deep head of pronator teres separates median nerve from the ulnar artery. Next it passes under the fibrous arch of the flexor digitorum sublimis muscle. It runs under the flexor digitorum sublimis muscle and on the flexor digitorum profundus. About five cm above the wrist the nerve winds the lateral aspect of the tendons of the flexor digitorum sublims. Tendon of the palmaris longus lies in front of the nerve. During its further course, it runs behind the flexor retinaculum through the carpal tunnel and makes its entry into the palm. Throughout its course in the forearm it is accompanied by the median artery which is the branch of the anterior interosseous.

Figure 139 Median nerve in the forearm

Branches (Figure 140): Figure 140 Median and anterior interosseous nerves (diagrammatic)

In the arm it gives a branch to the pronator teres muscle, to the elbow joint and vascular branches to the brachial artery.

Nerves and Vessels of the Forearm Branches in the Forearm:

Clinical:

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1. 2. 3. 1.

Muscular, Anterior interosseous, The palmar cutaneous. Muscular branches: They are distributed to all the superficial flexors of the forearm excluding the flexor carpi ulnaris. Muscular branches arise from the median nerve in the cubital fossa below the elbow joint. Apart from giving a branch to the pronator teres in the arm it does give a branch to the pronator teres muscle during its passage through its two heads. All these nerves come from the medial side of the median nerve while the anterior interosseous nerve arises from lateral side. 2. Anterior interosseous branch: It takes origin from the median nerve during its course in between the two heads of the pronator teres. It is accompanied by the anterior interosseous artery. It runs in front of the interosseous membrane in between the flexor pollicis longus laterally and flexor digitorum profundus medially. It supplies the flexor pollicis longus, radial half of the flexor digitorum profundus and the pronator quadratus muscles. It supplies the interosseous membrane, the radius, ulna and the wrist joint where it ends. 3. Palmar cutaneous branch: It arises from the median nerve in the lower part of the forearm, pierces deep fascia and runs in front of the flexor retinaculum. It divides into two branches, the medial and the lateral. The lateral branch supplies the skin over the thenar eminence while the medial is distributed to the skin of the palm. The nerve can be injured at two levels. 1. At the elbow: All the muscles supplied by the median nerve and the anterior interosseous nerve are paralysed. Only the medial half of the flexor digitorum profundus and the flexor carpi ulnaris remain unaffected as they are supplied by the ulnar nerve. Index finger cannot be flexed and this is known as pointing index. In the middle of the forearm, part of the flexor digitorum sublimis muscle going to the index finger receives a special branch from the median. Flexion of the terminal phalanx of the thumb does not occur due to paralysis of the flexor pollicis longus. Thenar eminence gets flattened due to wasting of the muscles of the thenar eminence. Thumb lies in the plane with other fingers. (Ape hand, Simian hand or Monkey hand) (Figures 141 to 143).

Figure 141 Pointing index

The results of injury: (i) Loss of pronation and (ii) Loss of powerful flexion. The wrist gets deviated towards the ulnar side. (Obviously because of the fact that the ulnar half of the flexor digitorum profundus and flexor carpi ulnaris retain their innervation as they are supplied by the ulnar nerve). 2. At the wrist: Apart from the motor loss, the sensory loss is significant. When the nerve is divided at the wrist, the thenar muscles except

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Figure 142 Median nerve in forearm. Note: The tendon of flexor digitorum profundus for index

Figure 143 Ape hand, simian hand or monkey hand

Surgical:

adductor pollicis, are paralysed. Abduction and opposition of the thumb with tip of the little finger to the thumb results in flexion and the adduction of the thumb (Please remember that the adductor pollicis is supplied by the ulnar nerve). Lateral two lumbricals are also paralysed. Eminence of the thenar muscles becomes less prominent due to atrophy of the muscles underneath. There is loss of sensation of the lateral half of the palm and lateral two and half fingers. The sensory loss is much more disability due to loss of tactile sense. The median nerve, gets compressed in the carpal tunnel leading to paresis of the nerve. However, its palmar cutaneous branch escapes as it passes superficial to the flexor retinaculum and does not choose to travel through already crowded tunnel. 1. Median nerve supplies the long and strong flexors of the forearm. It is known as “Labourer’s nerve”. While carrying a bag, weight of the bag is mainly shared by the middle phalanx, involving the flexor digitorum profundus muscle.

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2. In the supracondylar fracture median nerve gets damaged and all the superficial group of flexor muscles of forearm are paralysed except the flexor carpi ulnaris and the medial half of the profundus. 3. Due to paralysis of the flexor pollicis longus patient is unable to bend the terminal phalanx of the thumb. Patient is unable to bend index and the ring fingers due to paralysis of the lateral half of the flexor digitorum profundus. 4. As the pronator teres and pronator quadratus are paralysed there is no pronation. 5. The muscles responsible for the pronation are paralysed and the long flexors of the fingers specially the index and the middle are affected, the hand assumes a position of Benediction. (Benediction means a prayer asking for divine blessings) (Figure 144). Figure 144 Hand of Benediction

Carpal Tunnel:

6. Injury at the elbow can result due to the tight tourniquet, venipuncture, entrapment between the two heads of the pronator teres and also due to the fibrous arch of the flexor digitorum sublimis. There is paralysis of the pronator teres, flexor digitorum sublimis, flexor carpi radialis, palmaris longus, flexor pollicis longus, pronator quadratus and the lateral half of the digitorum profundus. As a result there is loss of pronation and there is a hand of Benediction deformity which is due to paralysis of both the superficial and deep flexors of the middle and index finger (Benediction means a prayer asking for divine blessings), Ape hand deformity is due to the paralysis of the thenar muscles. Thumb comes to lie in line with the other fingers (Semian hand, Monkey hand). Injury of the median nerve in the middle of the forearm leads to Pointing Index. The median nerve passes through the carpal tunnel which is bounded by eight carpal bones behind and the flexor retinaculum infront. The median nerve is surrounded by the crowd of tendons with their synovial sheaths. Increased pressure in the carpal tunnel leads to sensory loss of the lateral part of the palm. However the area near the base of the thumb escapes as it is supplied by the palmar cutaneous branch of the median nerve which passes superficial to the flexor retinaculum. May be that the slender and weaker nerve prefers not to go through the already crowded carpal tunnel and runs infront of the flexor retinaculum to retain the sensory supply of the base of the thumb.

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Causes of Carpal Tunnel Syndrome:

Injury at the Wrist:

Ulnar Nerve (Figures 145A and B):

1. Tubercular tenosynovitis of the flexor fingers 2. Rheumatoid arthritis of the wrist 3. Hypothyroidism 4. Hypertrophy of the flexor retinaculum 5. As the late complication of colles. The median nerve being superficial in the region it is likely to get injured or cut. Due to damage to the recurrent branch of the median nerve there is paralysis of the thenar muscles and the hand assumes the deformity of Ape hand. As it leaves the groove on the back of the medial epicondyle of the humerus, it enters the forearm by passing, between the two heads of the flexor carpi ulnaris (Osborne’s canal). Here it lies on the medial ligament of the elbow joint. During its further course, it runs along the medial side of the front of the forearm. It lies on the flexor digitorum profundus and is under cover of the flexor carpi ulnaris in its upper half. In the lower half the nerve lies superficial, as muscular belly of flexor carpi ulnaris is replaced by the tendon which lies medial to the nerve. In the upper third of the forearm the ulnar artery lies away from the nerve and in the lower two thirds it is close to the ulnar nerve. The artery is lateral to the nerve. Approximately five cm, above the wrist dorsal branch arises from the nerve. Ulnar nerve continues in front of flexor retinaculum along with the ulnar artery. The pisiform bone lies medial to the nerve. Ulnar nerve and the artery has a fascial cover on the flexor retinaculum forming a so called canal, it is known as Guyon’s canal. The nerve divides into superficial and deep branches.

Figure 145A Ulnar nerve in forearm

Branches:

Following are branched of the ulnar nerve: 1. Articular, 2. Muscular, 3. Palmar cutaneous, 4. Dorsal, 5. Superficial terminal and the 6. Deep terminal. 1. Articular: They are distributed to the elbow joint. They arise from the nerve as it lies on the medial ligament of the elbow joint.

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Figure 145B Ulnar nerve from axilla to forearm

2. Muscular branch: They come from the nerve near the elbow. They are two in number a. To flexor carpi ulnaris and b. To medial half of flexor digitorum profundus. 3. Palmar cutaneous branch: It arises from the ulnar as it lies in the middle of the forearm. It runs downwards along with ulnar artery. It gives a filaments to the artery. It passes in front of flexor retinaculum and supplies skin of the palm and may supply palmaris brevis muscle. 4. Dorsal branch: It passes deep to flexor carpi ulnaris and goes to the medial side of the back of the wrist and the hand. It further divides in two or three branches and supply the dorsal aspect of the one and half finger. 5. Superficial terminal branch: It gives branches to palmaris brevis and supplies the medial one and half fingers. 6. Deep terminal branch: It accompanies the deep branch of the ulnar artery and runs between the flexor digiti minimi, and the abductor digiti minimi muscles. Next it passes through the substance of the opponens digiti minimi. It supplies muscles of the hypothenar eminence, adductor pollicis, all the interossei and the medial (ulnar) two lumbricals. It also gives a branch to the wrist joint.

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Surgical:

It may get damaged at two sites: (i) At the elbow and (ii) At the wrist. i. At the elbow: As the nerve lies in a groove on the back of the medial epicondyle of the humerus it may get damaged during fracture of the medial epicondyle. Dislocation of the elbow can damage the ulnar. Combined lesion of the ulnar and median nerves results in true claw hand. There is extension of metacarpal phalangeal joints and the flexion of the interphalangeal joints. There is radial deviation of the hand as the flexor carpi ulnaris is paralysed. ii. Transposition of ulnar nerve (bringing of ulnar nerve in front of the medial epicondyle) is done after medial intramuscular septum is rected. ( S. Palazziet. All I.S.65, 6:1980). iii. At the wrist (Figure 146): As all the intrinsic muscles of the fingers excepting the lateral two lumbricals are paralysed, the deformity is a typical claw hand. The deformity (Clawing) is not so pronounced in second and third fingers as their lumbricals are supplied by the median nerve. The sensory loss over the medial one and half fingers is noted in injury at the above mentioned sites. Adduction and abduction of the fingers are lost, due to paralysis of interossei. Adduction of the thumb becomes impossible, as adductor pollicis is paralysed.

Figrue 146 Claw hand

Surgical:

Froment Sign:

Action of Paradox:

1. Pressure on the ulnar nerve given at the site of the groove on the back of the medial epicondyle gives rise to tingling sensation (Funny bone). 2. In leprosy thickened and tender ulnar nerve is an important sign. 3. Entrapment of the ulnar nerve in the two heads of the flexor carpi ulnaris is known as cubital tunnel syndrome. 4. In supracondylar fracture producing cubitus valgus deformity increases the carrying angle and puts pressure on the ulnar nerve. As a result the ulnar nerve gets stretched. It is known as tardy ulnar palsy (Tardy means late). As the ulnar half of the flexor digitorum profundus is paralysed the ring and the little fingers cannot be flexed. The interossei and the two ulnar lumbricals are paralysed, resulting in claw hand. The dorsum of the hand present grooves or gutters between the metacarpals due to the wasting of the interossei. The deep branch of the ulnar may get compressed by malet while working. If person is asked to press the card or a book with both the thumbs, the thumb on the side of lesion gets flexed due to the flexor pollicis longus pollicis muscle, being supplied by the median nerve is not affected. The adductor pollicis is paralysed as it is supplied by the deep branch of the ulnar nerve. An attempt to adduct the thumb results in the flexion of the thumb due to the action of the flexor pollicis longus muscle. Ulnar nerve injury at the elbow produces less clawing of the hand as the medial half of the profundus is paralysed affecting the ring and the little

Nerves and Vessels of the Forearm

Ulnar Paradox:

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finger, which is supplied by the ulnar nerve. The middle and the index finger is not affected as the lateral half of the flexor digitorum profundus is supplied by the median nerve. It is known as ‘action of paradox’. Even if the ulnar nerve is cut the hand remains surprisingly efficient, as the long flexors provides a good grip and the sensory supply of the palm is fairly maintained. It is difficult to diagnose injury of the ulnar clinically. A patient is made to put his palm on the table and ask to do adduction and abduction. Inability of adduction and abduction is sure sign of ulnar nerve damage.

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CUBITAL FOSSA Figrue 147 Cubital fossa

Contents:

It is the triangular depression in front of the elbow. The base is formed by an imaginary line joining the two epicondyles of the humerus. Its lateral border is formed by the brachioradialis and the medial by the pronator teres muscles. Apex is directed downwards and laterally where the pronator teres is overlapped by the brachioradialis. Its roof is formed by the deep fascia of the forearm and the bicipital aponeurosis. Lateral cutaneous nerve of the forearm lies on the roof and it pierces the deep fascia lateral to the tendon of the biceps brachii. The bicipital aponeurosis is the quadrilateral fibrous expansion from the medial side of the tendon of the biceps brachii. Over the bicipital aponeurosis lies the medial cubital vein. The floor of the cubital fossa is formed by brachialis and the supinator muscles. The contents of the cubital fossa are as under from the lateral to the medial side (Figure 147): 1. Tendon of the biceps brachii 2. Brachial artery with its two terminal branches namely the radial and the ulnar, lies in the cubital fossa medial to the tendon of the biceps. 3. Median nerve lies medial to the brachial artery and leaves the fossa by passing between the two heads of the pronator teres muscle. The median nerve is separated from the ulnar artery by the deep head of the pronator teres. 4. As the median nerve passes between the two heads of the pronator teres muscle it gives anterior interosseous nerve. Branches to the common flexor muscles are given from the median nerve in the cubital fossa below the elbow. 5. The arrangement of the contents of the cubital fossa are Tendon, artery and the nerve from lateral to median side, T—Tendon of biceps , A – Brachial artery, N—Median nerve (TAN). Radial nerve lies in the superolateral part of the cubital fossa under cover of the brachioradialis muscle. Brachial artery divides into the radial and the ulnar at the level of the neck of radius. Radial artery gives the radial recurrent branch and leaves the fossa. Ulnar artery gives three branches in the cubital fossa, i.e. anterior ulnar recurrent, posterior ulnar recurrent and the common interosseous. The common interosseous artery divides into anterior and posterior interosseous arteries. Interosseous

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recurrent is the branch of posterior interosseous artery. Ulnar artery leaves the fossa under the deep head of the pronator teres which separates it from the median nerve anteriorly. Median nerve while in the cubital fossa supplies pronator teres, flexor carpi radialis, palmaris longus and the flexor digitorum sublimis (superficialis) muscles. It escapes from the fossa by passing between the two heads of the pronator teres muscle. The radial nerve lies between the brachioradialis and brachialis muscles. It divides into superficial and the deep branches, deep branch is known as posterior interosseous nerve. The posterior interosseous nerve supplies the extensor carpi radialis brevis and the supinator before its entry in to the supinator. The superficial branch of radial nerve runs in the forearm under cover of the brachioradialis. Median cubital vein which lies on the flat and firm background of bicipital aponeurosis can be fixed between the thumb and the index for veni puncture. Bicipital aponeurosis separates the median cubital vein from the underline important structures like brachial artery and the median nerve. These days dorsal veins of the hand are preferred for the purpose of venipuncture.

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SUPERIOR RADIOULNAR JOINT It is synovial uniaxial pivot variety of joint (Pivot-joint – When the axis of the uniaxial lies along the long axis of the body it is known as pivot) (Figure 148). Figrue 148 Superior radioulnar joint and annular ligament

Bones Taking Part:

1. Head of the radius. 2. Upper end of the ulna. Head of the radius articulates with the capitulum of the lower end of the humerus on one hand and with the radial notch of the ulna on the other. It is surrounded by the annular ligament. Annular ligament is attached to the anterior and the posterior borders of the radial notch of the ulna. Thus the head of the radius is free to rotate and is also kept in position. In adults the annular ligament is wider above and narrow below, like a funnel. It is tubular or cylindrical in case of children, its upper and lower ends being equal in diameter. It is due to this fact, the dislocation of the head of the radius is common in children (Pulled Elbow). Anterior and lateral ligaments of the elbow are attached to the annular ligament. The lower border of the annular ligament is loosely attached to the neck of the radius. A small ligament runs from the neck of the radius to the lower border of radial notch of the ulna, is known as quadrate ligament. Synovial Synovial membrane of this joint is continues with the synovial membrane Membrane: of the elbow joint. It covers the annular ligament, quadrate ligament and non-articular part of radius within the joint. The small part of annular ligament which comes in contact with the head of radius is covered with a thin layer of cartilage. Inferior Radioulnar It is a synovial, uniaxial and pivot. The head of ulna articulates with the Joint: notch on the radius. Capsule of the joint is loose superiorly where it is lined by synovial membrane. The synovial membrane extends upward in front of the lower part of interosseous membrane. Anterior and posterior parts of capsule are thick. Surgical Anatomy: Galezzi-fracture presents the fracture of the radius with the dislocation of the inferior radioulnar joint. Articular Disc It is a triangular fibrocartilaginous disc connecting the two bones at their (Figure 149): lower ends. The apex of the disc is attached to the area between the styloid process and the head of the ulna. The base is attached to the lower border of the ulnar notch on the radius. It prevents the head of ulna from taking part in the formation of the wrist joint. Lower surface of the disc takes part in the formation of the wrist joint by forming the part of the proximal

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articular surface along with the lower end of the radius. It articulates with the lunate bone, however, during adduction it comes in contact with the triquetral. Figure 149 Articular disc

Middle Radioulnar Joint (Figure 150):

Interosseous borders of the radius and the ulna are interconnected by the interosseous membrane of the forearm. The direction of the fibers of the interosseous membrane is directed downwards and medially towards the ulna. The thick fibrous cord known as oblique cord, runs from the lower part of the radial tuberosity to the ulnar tubercle. The direction of the oblique cord is at right angle to the fibers of the interosseous membrane. It runs upwards and medially to the ulnar tubercle. The gap between the oblique cord and the upper border of the interosseous membrane gives for the posterior interosseous artery, which enters the extensor compartment.

Figure 150 Middle radioulnar joint and axis of pronation and supination

Functions of Interosseous Membrane of the Forearm:

It can be described as under: 1. It connects 2. It forms 3. It divides 4. It provides 5. It transmits 6. It connects two bones, i.e. radius and the ulna 7. It forms the middle radioulnar joint which is of a fibrous variety. 8. It divides the forearm into two compartments the flexor and the extensor. 9. It provides additional area for the origin of the muscles of the forearm. 10. It transmits weight from the radius to the ulna. The anterior surface of the interosseous membranes gives origin to flexor pollicis longus, flexor digitorum profundus and the pronator

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Movements of Pronation and Supination (Figure 150):

Note:

Extensor Compartment of Forearm (Figure 151):

quadratus muscles. Anterior interosseous artery is the branch of the common interosseous artery. Common interosseous artery arises from the ulnar and divides into the anterior and the posterior interosseous arteries. The anterior interosseous artery runs infront of the interosseous membrane between the flexor pollicis longus laterally and the flexor digitorum profundus medially. It passes through the interosseous membrane at the upper border of pronator quadratus muscle, enters the extensor compartment joins the posterior interosseous artery (which is virtually fading) and the dorsal carpal arch. Posterior relations of the interosseous membrane are the supinator, abductor pollicis longus, extensor pollicis brevis, and the extensor indicis. In addition to these the posterior interosseous nerve and the artery are related to the posterior surface of the interosseous membrane. In normal anatomical position the flexor surface of the forearm is facing anteriorly and the thumb laterally. This is the position of supination. When the flexor surface of the forearm faces posteriorly and the thumb medially it is known as the position of the pronation. The movement of the pronation and supination occur in the superior and the inferior radio ulnar joints. The axis of the movement runs downwards and medially from the center of the radius to the base of the styloid process of the ulna below. When the elbow is flexed at right angle the flexor surface of the forearm faces the roof and the thumb outside. This is the position of the supination. In the same position of the forearm if the flexor surface of the forearm is faces towards the floor and the thumb medially. It is known as position of pronation. (I remember the days of my anatomical years when we were taught that the supination is the position of begging and the pronation is the position of blessings.) The upper end of the ulna undergoes the slight abduction during pronation which is by anconeus muscle. It is only during full extension of the elbow, movements of pronation and supination are accompanied by some degree of movements at elbow and shoulder. Movements of supination is more powerful than that of pronation. We do supination while unlocking and pronation while locking the lock. Following are the pronators and the supinators. Ponators

Supinators

1. Pronator teres and pronator quadratus. 2. Palmaris longus. 3. Flexor carpi radialis. 4. Brachio-radialis 5. Other common flexor

Biceps brachii. Supinator. Brachioradialis. Other common extensors.

Brachio-radialis being a border line muscle helps in initiation of the pronation and supination movement in early phase. Recent study has shown that it has no role in pronation or supination. The muscles of extensor compartment of the forearm are arranged into the superficial and the deep groups. It is easier to remember muscles of the deep group as their number is small as compared to the superficial. Following are muscles of the deep group: 1. Supinator 2. Abductor pollicis longus 3. Extensor pollicis longus 4. Extensor pollicis brevis 5. Extensor indicis.

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Figure 151 Back of radius and ulna

Extensor Retinaculum (Figure 152):

Figure 152 Extensor retinaculum and the tendons passing under it

Following are muscles of the superficial group: 1. Brachio-radialis 2. Extensor carpi radialis longus 3. Extensor carpi radialis brevis 4. Extensor digitorum 5. Extensor digiti minimi 6. Extensor carpi ulnaris and the 7. Anconeus. Nine tendons pass under the extensor retinaculum through the sixth compartments having eight synovial sheath. It is an inch wide thickened fibrous band of the deep fascia on the dorsum of the wrist. It is placed obliquely across the back at junction of the forearm and the wrist. Medially it is attached to the triquetral and the styloid process of the ulna. On the radius it is attached to the ridge between anterior and lateral surfaces of the radius, at its lower end. It is due to this peculiar attachment of the extensor retinaculum, the movements of pronation and supination are free. Superficial to retinaculum cephalic vein lies on the lateral side and the basilic vein on the medial.

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Comment:

Anconeous (Figure 153):

There are six compartments under the retinaculum from lateral to medial side as under (i.e. radial to ulnar side). 1. First compartment: Contains abductor pollicis longus and extensor pollicis brevis. 2. Second compartment: Contains extensor carpi radialis longus and brevis. 3. Third compartment: Contains abductor pollicis longus. 4. Fourth compartment: Contains four structures namely extensor digitorum and extensor indicis tendons, anterior interosseous artery and the posterior interosseous nerve. 5. Fifth compartment: Contains extensor digiti minimi. This compartment lies between the lower end of radius and the lower end of ulna. While the first four compartments are on the dorsal aspect of the lower end of radius. 6. Sixth compartment: Contains extensor carpi ulnaris. This compartment lies on the groove at the lower end of ulna, between the head of the ulna and its styloid process. The fourth compartment has four structures namely the extensor digitorum, extensor indicis, posterior interosseous nerve and the anterior interosseous artery. The extensor digitorum goes to the four fingers and amongst the four is the index. In brief it can be said that the fourth compartment under the extensor retinaculum contains four structures, i.e. two tendons of the muscles, posterior interosseous nerve and the anterior interosseous artery. Let us consider the muscles of the superficial group. Actually this muscle belongs to the extensor compartment of the arm. It is triangular in shape. It arises from the posterior surface of lateral epicondyle of the humerus and gets inserted into the lateral aspect of olecranon process and the upper fourth of the posterior surface of the ulna. It is supplied by the radial nerve through the branch which passes through substance of the medial head of triceps. The muscle is an extensor of the elbow. It helps in abduction of the upper end of ulna during pronation.

Figure 153 Anconeous muscle

Brachioradialis (Figure 154):

It is the border line muscle and can be examined from the front and the back. It arises from the upper two thirds of lateral supracondylar ridge above the origin extensor carpi radialis longus and is inserted into the lateral surface of radius above styloid process. (Please recollect that the lateral surface provides insertions to three muscles, namely the supinator, pronator teres and brachioradialis. The conventional colour of the insertion

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is blue, therefore it can be said that the lateral surface of the radius is blue. It can be remembered as under “Say: Please, Blue”, S-supinator, P-Pronator teres, B-Brachioradialis). Figure 154 Brachioradialis muscle

Nerve Supply: Action:

Surgical:

Supinator Jerk Reflex: Extensor Carpi Radialis Longus (Figure 155):

Insertion: Nerve Supply: Action:

Extensor Carpi Radialis Brevis:

Insertion: Nerve Supply:

Brachioradialis is supplied by the radial nerve. It is the flexor of the forearm in mid-prone and the mid-supine position. It initiates the pronation and supination. However, this action of the muscle is not supported by electromyographic studies. Flex your forearm in midprone position against resistance and see that the muscular belly of the brachioradialis stands out in prominence. Damage to the musculocutaneous nerve flexors of the elbow are paralysed. To restore the flexion of the elbow brachio-radialis is detached and advanced proximally on the humerus. It works as the flexor of elbow. Tapping of the distal end of the radius causes flexion of the forearm. The reflex is through the cervical 7th and cervical 8th segments. It is due the contraction of the brachioradialis muscle and not the supinator. It arises from the lower part of the lateral supracondylar ridge below the origin of brachioradialis muscle. It gets inserted into the second metacarpal bone. The tendon of the of the extensor carpi radialis longus runs through the second compartment under the extensor retinaculum along with the tendon of extensor digitorum brevis. It is inserted into the base of the second metacarpal. It is supplied by the radial nerve. It is the extensor of the wrist. It is the radial deviator of the hand along with the extensor carpi radialis brevis and the flexor carpi radialis. As regards remaining muscles of the superficial group have their origin from the common extensor source, e.g. front of the lateral epicondyle of humerus. Other members of the extensor group have a common origin from the front of the lateral epicondyle of the humerus. It arises from the front of the lateral epicondyle of the humerus and gets inserted into the base of the third metacarpal bone. Its tendon passes under the extensor retinaculum through the second compartment, alongwith the extensor carpi radialis longus. It is inserted into the base of the third metacarpal. It supplied by the posterior interosseous nerve which gives a branch to the muscle just before its entry into the substance of supinator muscle.

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Figure 155 Extensor carpi radialis longus and brevis

Action:

It is an extensor of the wrist and also the radial deviator along with the extensor carpi radialis longus and the flexor carpi radialis muscles. Extensor Digitorum It arises from the lateral epicondyle of the humerus through the common (Figure 156): extensor origin, also from the deep intermuscular septa and the deep fascia of forearm. The muscle belly gives rise to the four tendons which pass through the fourth compartment under the extensor retinaculum alongwith the extensor indicis. Here, it is enclosed in a common synovial sheath. On the dorsum of the hand the tendons run towards the fingers. The tendons for the middle, ring and the little fingers are interconnected through the fibrous bands. On the dorsum of the proximal phalanx the tendon forms an extensor expansion. The extensor expansion divides into three slips. The middle slip goes to the base of middle phalanx while the two collateral slips unite and get attached to the base of the terminal phalanx. Figure 156 Extensor digitorum and extensor digiti minimi muscle

Nerve Supply: Action:

It is supplied by the posterior interosseous nerve. It is an extensor of the fingers. It helps in the extension of the wrist. It is important to note that it can act as an abductor of index, ring and little fingers.

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Extensor Digiti Minimi (Figure 156):

It arises from the common extensor origin, intermuscular septa and the deep fascia. It passes under the extensor retinaculum through the fifth compartment and hence is related to the dorsal aspect of the inferior radioulnar joint. It divides into two parts but soon unites near the head of the fifth metacarpal bone. It is joined by the tendon of extensor digitorum for the little finger. The method of insertion is similar to the method of insertion in other fingers. Nerve Supply: It is supplied by the posterior interosseous nerve. Action: It is an extensor of the little finger and helps in the extension of the wrist. Extensor Carpi It is the medial most member of the extensor group. It arises from the Ulnaris (Figure 157): common extensor origin, posterior border of ulna and the deep fascia of the forearm. Its tendon passes through the sixth compartment under the extensor retinaculum where it lies in the groove on the back of lower end of the ulna. It is inserted into the medial aspect of the base of fifth metacarpal bone on a small tubercle. Figure 157 Extensor carpi ulnaris muscle

Nerve Supply: Action:

Clinical: Tennis Elbow:

Comment:

Treatment:

Golfer’s Elbow:

By the posterior interosseous nerve (and not by the ulnar). It is an extensor of the wrist and also helps in ulnar deviation of the hand alongwith the flexor carpi ulnaris.

It causes localized pain on gripping of the hand. Pathology is not known, it may be due to enthesopathy, osteophyte of the radial head, capsulitis, bursitis or the entrapment of the posterior interosseous nerve. In capsulitis there is tenderness on the radial head. It is increased during rotation of the forearm. In compression of the posterior interosseous nerve. (PIN – SYNDROME), there is vague pain radiating to the dorsum of the wrist. It increases and becomes more intense by resisted extension of the straight middle finger. It may be due the injury to the radial collateral ligament and stretching of the fibres of the common extensor group of muscles. It is really a paradox as the Tennis elbow is not seen in those who play tennis. In India it is seen in middle aged women engaged in house hold work like washing of cloths and cleaning of utensils and carrying of heavy buckets. 1. Injection of hydrocortisone at the site (front of the lateral epicondyle) 2. Detachment and sliding of the common extensor origin from the lateral epicondyle. It is the enthesopathy of the common flexors origin which arise from the front of the medial epicondyle.

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Kadasne’s Textbook of Anatomy (Clinically Oriented) Tennis and the Golfer’s elbow are shown in the following table: Tennis elbow

Golfer’s elbow

Site

Lateral epicondyle of 0 the humerus

Medial epicondyle of the humerus

Muscles

Common extensors Extensor carpi radialis brevis Extensor digitorum, Extensor digiti minimi, Extensor carpi ulnaris.

Common flexors Peroneous tertius, Flexor carpi radialis, Palmaris longus, Flexor digitorum sublimis

Nerve Supply

Posterior interosseous nerve except extensor carpi ulnaris.

All the muscles are supplied by the median nerve except the medial half of flexor digitorum profundus and the flexor carpi ulnaris.

Etiology

Entheopathy (damage) Entheopathy (damage) Radial osteophytes, capsulitis, entrapment of the posterior interosseous nerve.

Signs

Well localized tenderness on the common extensor origin.

Well localized tenderness on the common flexor origin. Ulnar irritation in the groove, produces paresthesia of little and ring fingers. Pressure on the ulnar nerve leads to the diagnosis.

Treatment

Injection of hydrocortisone Surgical detachment of common extensors release of posterior interosseous nerve from the fibrous arch.

Injection of hydrocortisone Surgical detachment of common flexors

Note: By the Tennis elbow and the Golfer’s elbow have no relevance to the etiology of the disease. It certainly helps a medical student to remember the common flexors and the common extensors origin.

MUSCLE OF THE DEEP GROUP (FIGURE 158) Supinator:

It arises from the following (Figure 158): 1. Lateral epicondyle of humerus, 2. Lateral ligament of elbow joint, 3. Annular ligament, 4. supinator crest of ulna, 5. Area in front of the supinator crest and deep fascia. 6. The part of the muscle which is arising from the supinator crest and the area in front of it lies in close contact with the radius encircling it and it forms the deep head of the muscle. While the superficial head which arises from lateral epicondyle of humerus, lateral ligament of elbow joint, annular ligament forms the superficial strata or the superficial head. The posterior interosseous nerve is seen passing in between the two stratas of the supinator muscle.

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Figure 158 Supinator muscle and main branches of radial nerve

The muscles are inserted into the upper one third of the lateral surface of radius almost extending up to the anterior and the posterior borders of the radius, which are obliquely placed. Muscle has two stratas, the superficial and the deep The posterior interosseous nerve (deep branch of the radial passes in between the two stratas and comes out of the muscle on the back of forearm.) Nerve Supply: It is supplied by the posterior interosseous nerve. The posterior interosseous nerve gives a branch to supinator before passing through it. Therefore, if posterior interosseous nerve is cut close to supinator, the nerve supply of the muscle remains intact. Abductor Pollicis This is the only muscle of the extensor compartment of the forearm, which Longus (Figure 159): arises from both the bones of the forearm and the interosseous membrane. It arises from the posterior surface of the radius, lateral part of posterior surface of the ulna and from the posterior aspect of the interosseous membrane. Its tendon passes downwards and laterally alongwith tendon of extensor pollicis brevis through the first compartment under the extensor retinaculum. The tendon is inserted into the radial side of the base of first metacarpal bone. Figure 159 Abductor pollicis longus, extensor pollicis longus and extensor indicis

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Nerve Supply: Action: Surgical:

Extensor Pollicis Longus:

Nerve Supply: Action: Extensor Pollicis Brevis (Figure 160)

It is supplied by the posterior interosseous nerve. It is an abductor of the thumb. Stenosing tenovaginitis in which the sheath of the tendon thickens which gives pain and limitation of movement with a local sound (crepitus). This condition commonly affects the common sheath of the abductor pollicis longus and the extensor pollicis brevis at the wrist. It is known as de Quervain’s disease. If not treated the tendons can get ruptured. It takes origin from the lateral part of posterior surface of the ulna below the origin of the abductor pollicis longus and also from the posterior aspect of the interosseous membrane. It passes under extensor retinaculum through the third compartment all alone having no companion. It gets inserted into the base of the terminal phalanx of the thumb. By the posterior interosseous nerve. It is an extensor of the thumb and also helps in abduction. It can act as an extensor of the wrist. It arises from posterior surface of the radius below the origin of abductor pollicis longus and also from interosseous membrane. Its tendon runs with the tendon of the abductor pollicis longus. The tendon of abductor pollicis longus is lateral to the tendon of extensor pollicis brevis. Both the tendons pass through the first compartment under the extensor retinaculum. The tendons of abductor pollicis longus and the extensor pollicis brevis form the lateral limit of the snuff box, while the tendon of extensor pollicis longus forms the medial limit of the snuff box. Radial artery passes under the tendons of abductor pollicis longus and the extensor pollicis brevis. Extensor pollicis brevis muscle is inserted into the base of the proximal phalanx of the thumb. Abductor pollicis longus muscle is inserted into the base of the first metacarpal bones.

Figure 160 Extensor pollicis brevis and extensor indicis

Nerve Supply: Action: Extensor Indicis:

Nerve Supply:

It is supplied by the posterior interosseous nerve. It is an extensor of the thumb. It arises from the lateral part of posterior surface of ulna and the posterior surface of the interosseous membrane. Its tendon runs in company with the tendons of extensor digitorum through the fourth compartment under the extensor retinaculum. It is inserted into the extensor expansion of the index finger. It is supplied by the posterior interosseous nerve.

Superior Radioulnar Joint Action:

Comment:

143

It is an extensor of the index finger. It also helps in extension of the wrist. Account of the synovial sheaths of the flexor and extensor tendons. Flex. tendons

Sy. sheaths

Ext. tendons

Sy. sheaths

Flex. dig. sublimis

Common

Abd. poll. longus

Separate.

Flex. dig. profundus

Common

Ext. poll. brevis

Separate.

Flex. carpi. radialis

Separate

Ext. carpi rad. long.

Separate.

Flex. carpi . ulnaris

No sheath

Ext. carpi rad. bre

Separate.

Flex. poll. longus

Separate

Ext. poll. longus

Separate.

Ext. dig. minimi

Separate.

Ext. carpi ulnaris

Separate.

Ext. digitorum

Common.

Ext. indicis

Common.

Please note that there is no synovial sheath for the flexor carpi ulnaris as opposed to this the extensor carpi ulnaris which has a separate synovial sheath. Posterior Interosseous It is the branch of the radial nerve given in front of lateral epicondyle of the Nerve (Figures humerus. It gives a branch to the extensor carpi radialis brevis and the 161 to 163): supinator, before its entry in the supinator muscle. It passes between the two stratas of the supinator muscle. As it comes out as the supinator muscle it lies on the abductor pollicis longus muscle. At the lower border of the abductor pollicis longus muscle it lies on the interosseous membrane along with the posterior interosseous artery. The nerve is devoted to the muscles of the posterior compartment as it supplies all the muscles of the extensor compartment of the forearm except the brachioradialis and the extensor carpi radialis longus muscles which are supplied by the radial nerve directly. It passes through the forth compartment under the extensor retinaculum along with the extensor digitorum, extensor indicis, anterior interosseous artery and the posterior interosseous nerve. It reaches the dorsum of the wrist where it is present a small ganglion having no nerve cells. (Pseudo-ganglion). Number branches arise from the ganglion which are distributed to the wrist and the intercarpal joints. It gives a sensory branch to the interosseous membrane, periosteum of the radius and the ulna. Wrist and the intercarpal joints are supplied by the posterior interosseous nerve. (Posterior interosseous nerve is also known as the deep branch of the radial and the radial itself in the forearm is known as the superficial branch of the radial. Figure 161 Posterior interosseous nerve

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Figure 162 Posterior interosseous nerve (deep branch of radial) highly schematic. Note passing hrough the fourth compartment under the extensor retinaculum

Figure 163 Showing radial and posterior interosseous nerve in front of lateral epicondyle of humerus and relation of posterior interosseous nerve with two heads of supinator muscle

Surgical:

Posterior Interosseous Artery:

Orthopaedic surgeon is required to expose the head of the radius for fracture or dislocation. In the flexed elbow, i.e. 90° the forearm is kept supine and the incision is given three fingers distal from the head of the radius and not beyond that. The posterior interosseous nerve lies in the supinator muscle below this level (Henry’s method). It is the branch of the common interosseous. It enters the extensor compartment through the gap between the interosseous membrane and the oblique cord. It is accompanied by the posterior interosseous nerve. Lower down the artery fades away and the anterior interosseous artery from the anterior compartment is asked for. Anterior interosseous artery pierces interosseous membrane at the upper border of pronator quadratus muscle and enters the extensor compartment. It anastomoses with the posterior interosseous artery and the dorsal carpal arch.

Superior Radioulnar Joint Cutaneous Innervation of the Forearm (Figures 164 and 165):

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Following nerves supply the front of the forearm: 1. Lateral ante brachial nerve. 2. Anterior branch of medial cutaneous nerve of the forearm. 3. Medial branch of the medial cutaneous nerve of the forearm. In addition of these a small area of the skin of the distal part of the front of forearm is supplied by the palmar cutaneous branches of the median and the ulnar nerves.

Figure 164 Showing cutaneous innervation of the flexor surface of the upper limb

Figure 165 Cutaneous innervation front of forearm

Following nerves supply the back of forearm: 1. Posterior cutaneous nerve of forearm, 2. Lateral cutaneous nerve of forearm, 3. Posterior branch of medial cutaneous nerve of forearm.

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Venous Drainage of Forearm (Figure 166):

The veins of forearm are arranged in the superficial and the deep groups. Superficial group lies superficial to the deep fascia and the deep is placed deep to the deep fascia.

Figure 166 Venous drainage of forearm viewed from the front

Superficial Veins:

Tributaries of the Cephalic Vein:

It consists of cephalic vein on the radial and the basilic on the ulnar side. The median vein of the forearm lies in the middle of the front of the forearm. The cephalic and the basilic veins arise from the dorsal venous arch, respectively from the radial and ulnar sides. The cephalic vein crosses lateral border of forearm and comes to lie in front at a lower level. The basilic vein runs along posterior aspect of the medial border of forearm. It crosses the medial border in the upper part of the forearm and comes to lie anterior. It has already been seen that cephalic and basilic veins are interconnected through the median cubital vein. Median cubital vein lies on bicipital aponeurosis which provides a good platform for the vein. Median cubital vein was common used for veni puncture. However veins on the dorsum of the hand have gained more popularity for the purpose veni puncture. Basilic vein is used for introducing the cardiac catheter. Cephalic vein is not selected for the purpose as it has a curvature and the valve. Cephalic vein after its origin from the radial end of the dorsal venous arch passes over the roof of the snuff box. Here it is accompanied by the superficial branch of radial. The median vein of the forearm joins median cubital vein or cephalic or the basilic. It mainly drains blood from the front of the palm. Before renal dialysis a fistula is created between the radial artery and the cephalic vein. This leads to increase pressure inside the cephalic vein resulting in the thickening of the wall. It is known as arterialisation of the vein. The cephalic vein can be used for passing a wide bore needle. Cephalic vein is exposed in the delto-pectoral groove for giving infusions in the superior vena cava after veni section. Cephalic vein has an intimate relation with the lateral cutaneous nerve of forearm. Next the cephalic ascends towards the delto-pectoral groove and runs lateral side of the biceps brachii muscle and pierces the clavi-pectoral fascia to join the axillary vein. Number of tributaries collecting blood from hand, forearm and the arm join the cephalic vein. At times a small communication passes from cephalic vein to the external jugular vein which lies superficial to the clavicle. The median cubital vein is also the tributary of the cephalic vein. It runs upwards and medially from cephalic to the basalic carrying blood from cephalic to the basalic. The arrangement of venous pattern infront of

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the elbow is either ‘H’ shaped or ‘M’ shaped character. The median cubital vein is connected to the deep veins associated with the brachial artery through a connection which passes through an opening in the fascial covering of the elbow joint. Median Vein of the It is also known as antibrachial vein. It runs in front of the middle of the Forearm: forearm and drains superficial palmar plexus. It joins the medial cubital vein at the elbow. Deep Group: They are venae comitantes of the radial and the ulnar arteries. They drain blood from the deep and superficial palmar venous arches. They join together at the level of the elbow to form the brachial veins. The radial veins receive deep veins of the dorsum of the hand. The ulnar veins receive blood from the deep palmar venous arch. They are also in communication with the superficial veins of the wrist. In addition to this anterior and posterior interosseous veins join ulnar veins. There exists a large communication between ulnar veins and median cubital vein.

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WRIST AND THE HAND Wrist is the junctional zone between the hand and the forearm. The anatomical name for the wrist is carpus. Eight carpal bones, arranged in two rows are responsible for its skeletal foundation. The arrangement of these bones is such that they form a concavity in front and the convexity at the back. Immediately, distal to region of the wrist lies the region of the hand. Five metacarpal bones constitute bony foundation and again their arrangement is such that they present concavity in the front and convexity at the back. Beyond the region of the palm lies the thumb and the four fingers. All the four fingers lie in one plane while the plane of the thumb is entirely different. It can be said that the thumb is isolated from the fingers. This isolation is achieved by rotation of the first metacarpal bone and also by the deep and wide cleft between the index finger and the thumb. The thumb is required to work more, hence the movements are free, powerful as compared to that of the four fingers. If the size and the areas of origin of the muscles acting on the thumb are considered it will be seen that most of these muscles are larger in size and respective areas of their origin are also wider. Observe the elevation on the lateral side of the palm. (Thenar eminence). It is more prominent than its counterpart on the medial side, the hypothenar eminence. These eminences are produced due to underlying thenar and hypothenar muscles, thenar being lateral and hypothenar being medial. Surface Landmarks Try to feel the following bony points: of the Wrist and 1. Styloid process of the radius. Hand (Figure 167 ): 2. Styloid process of the ulna. Both the styloid processes can be felt simultaneously with the index fingers. Please observe that the radial styloid is lower than the ulnar. Figure 167 The landmarks of hand (palmar and dorsal view of left hand)

3. Head of ulna: Can be seen and felt on the dorsal aspect. 4. Pisiform bone: Follow the tendon of flexor carpi ulnaris towards the base of the hypothenar eminence, the first obstruction you meet is the pisiform bone. 5. Hook of hamate lies immediately distal to the pisiform. It can be felt only on deep pressure. Dorsal tubercle of Lister: lies on the back of lower end of the radius. If a line is projected distally along the hand, form the tubercle it runs along the long axis of the index finger.

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Figure 167A X-ray of wrist and hand

How to Examine Structures of the Front of the Wrist (Figure 168):

6. Heads of the metacarpal bones: They are easily seen from the dorsum. Please note that the flexor line of metacarpophalangeal joint lies actually distal to the true joint line. Please make a firm fist and observe the following structures: 1. Tendon of the palmaris longus stands out in prominence in the middle. Lateral to it is the tendon of flexor carpi radialis, and lateral to the flexor carpi radialis, pulsation of the radial artery can be felt. Immediately medial to the palmaris longus tendon, the resistance of tendons of flexor digitorum sublimis is felt. Still medial to it lies the tendon of flexor carpi ulnaris.

Figure 168 Front of the wrist of the left hand

How to Examine Structures on the Dorsum of the Wrist and Hand (Figure 169):

Spread out the fingers of the left hand with a firm extension. The most prominent tendon is the tendon of extensor pollicis longus. On radial side of it lies the snuff box. Still radial to it, the tip of styloid process of the radius and the tendons of abductor pollicis longus and extensor pollicis brevis can be seen and felt. On the ulnar side of the tendon of extensor pollicis longus lies a depression. Put the tip of the index of the right hand into and extend the wrist still further. You will feel the resistance of the tendons of extensor carpi radialis longus and the brevis. The tendons of extensor digitorum can be seen without any difficulty on the dorsum of the hand.

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Figure 169 Snuff box (dorsal view of hand)

Skin of the Hand:

The Palmar Aponeurosis (Figures 170 and 171):

The skin of the hand is thinner than the skin of the sole of the foot. Superficially it is attached to the underlying structures. This fact helps to improve the grip of the hand. Papillary ridges and the flexure lines of the hand, do help in bettering the grip. Over the radial side of the hand, number of fine lines are seen running towards the base of the thumb. Approximately they are arranged into the horizontal (transverse) and oblique sets, as if they are suggestive of the transverse and oblique heads of the adductor pollicis muscle of the hand underneath. The flexure lines at the bases of four fingers are a finger’s breadth distal to the plane of the metacarpophalangeal joints. However, this is not true in case of the flexor line of the base of the thumb as it corresponds to the plane of metacarpophalangeal joint of the thumb. No veins shine through the skin of the front of the hand as all are on the dorsum. Abduction of the little finger produces contraction of the skin on the ulnar side of the hand (due to palmaris brevis muscle which gets inserted into the skin). The skin on the dorsum is mobile and lax. Veins shine though the skin of the dorsum and the tissue under the skin of the dorsum is loose areolar type hence, the dorsum of the hand is freely mobile. The presence of these veins on the dorsum is due to fact that: 1. This surface is not subjected to pressure, 2. Lax skin of the dorsum allows their free dilation. It is important to note the following facts about the hand: 1. Hand is a prehensile structure, 2. Discriminative sense of the skin of the hand is acute, 3. It is specially constructed for skilled movements, 4. For free mobility of the thumb, the first metacarpal has undergone a rotation of ninety degrees and there is a wide and deep cleft (Web) between the thumb and the index. 5. The wide and deep web between the thumb and the index finger and can acts as a pen-rest. 6. Flexor crease at interphalangeal joints of fingers do not correspond to the joint underneath. All the lymphatics of the hand crowd on the dorsum of the hand, hence, infection of the hand presents with oedema on the dorsum of the hand and not on the palmar. It is the triangular fibrous structure situated in the middle of the palm, with its base directed towards the fingers and apex towards flexor retinaculum (In brief it is the flattened tendon of the palmaris longus muscle). It receives the tendon of palmaris longus at its apex. Four slips go towards the four fingers from the base of palmar aponeurosis. These slips

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further unite with the fibrous flexor sheaths of the respective fingers and deep transverse ligaments of the palm. Figure 170 Palmar aponeurosis (right hand)

Figure 171 Palmar aponeurosis in cross section and attachments of lateral, medial and midplamar septae

Surgical (Figure 172):

On the radial and ulnar sides it is continuous with the deep fascia covering the thenar and the hypothenar muscles. This part of the deep fascia on the radial and the ulnar sides is considered as lateral and medial parts of palmar aponeurosis. Palmaris brevis muscle arise from the medial border of the aponeurosis near the flexor retinaculum. In between the slips going to four fingers lie the digital vessels, nerves and the tendons of lumbrical muscles. The medial palmar, lateral palmar and the mid palmar septae arise from the under surface of the palmar aponeurosis. Mid palmar septum is placed in the midline of the palmar aponeurosis at its undersurface and is carried to the front of the third metacarpal bone. Relation: Anterior: It is firmly fixed to skin and fibrofatty tissue. Posterior: Superficial palmar arch, tendons of the flexor digitorum sublimis, tendons of the digitorum profundus, branches of the median and the superficial branch of the ulnar nerve form the posterior relations. It acts as a protective shield for these underlying delicate structures. Dupuytren’s contracture is due to contracture of the medial part of the palmar aponeurosis. It affects the middle and the ring finger. The proximal and middle interphalangeal joints are flexed and the distal phalangeal joints are hyper extended. Dupuytren’s contracture is seen in the foot and also over the penis (Peyronies). Hard plates of fibrosis are formed on the dorsum of the penis.

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Figure 172 Dupuytren’s contracture (Coachman’s hand)

Flexor Retinaculum It is a quadrilateral thickened specialized band of the deep fascia of the (Figure 173): forearm situated in front of the wrist. Medially, it is attached to the pisiform and the hook of hamate and laterally, to the tubercle of scaphoid and the crest of the trapezium. With eight carpal bones behind the flexor retinaculum and the carpal bones forms an osseo-fibrous tunnel known as carpal tunnel. The flexor retinaculum has two parts, the superficial and the deep. The superficial part is attached to the lateral lip of the groove on the trapezium meant for the flexor carpi radialis muscle. The deep part of the retinaculum is attached to the medial lip of the groove for the flexor carpi radialis. The groove on the trapezium and two parts of the flexor retinaculum form an additional osseofibrous tunnel for the tendon of flexor carpi radialis muscle. (As it passes through a special tunnel specially provided for it, it can be called as the Royal tendons.) Muscles of the thenar and the hypothenar eminences arise from it. Figure 173 Structures in front of flexor retinaculum

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Relations of Flexor Retinaculum (Figures 174 and 175): Figure 174 Flexor retinaculum with Guyon’s canal

Figure 175 Flexor retinaculum with Guyon’s canal and osseous fibrous tunnel for flexor carpi radialis in transverse section

Anterior:

The following structures lie in front of the flexor retinaculum from medial to lateral side: 1. Ulnar nerve, in Guyon’s canal 2. Ulnar artery, in Guyon’s canal 3. Palmar cutaneous branch of the ulnar, 4. Tendon of palmaris longus, 5. Palmar cutaneous branch of the median nerve and 6. The superficial branch of the radial artery. Posterior Relations: Following structures pass under the retinaculum through the carpal tunnel. 1. Tendon of the flexor digitorum sublimis and the profundus with their common synovial sheath. 2. Tendon of the flexor pollicis longus with its synovial sheath. 3. Median nerve. 4. Tendon of the flexor carpi radialis. The tendon of the flexor carpi radialis passes through a special tunnel and gets inserted into the base of second metacarpal bone. Under the retinaculum three tendons of profundus are fused together while the tendons for the index is separate. The tendons of the sublimis lie in front of the profundus tendons. Out of four sublimis, tendons for middle and ring fingers lie in front (MR infront) of those for the little and the index. The tendon of the flexor pollicis longus is lateral. The median nerve is lateral to the sublimis tendons. Common synovial sheath under cover of retinaculum encloses the flexor digitorum sublimis and profundus tendons from the ulnar side. In other words, it can be said that the sublimis and profundus tendons invaginate the synovial sheath from the radial side. Therefore, the radial side of tendons is not well covered with synovial sheath. Sometimes

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Kadasne’s Textbook of Anatomy (Clinically Oriented) synovial sheath of the flexor pollicis longus is in communication with the common flexor synovial sheath (Figures 176 and 177).

Figure 176 Showing carpal tunnel and structure passing through (deep relations of flexor retinaculum)

Figure 177 Showing how common flexor tendons invaginate common synovial sheath. Note that the tendons invaginate from radial side

Surgical:

Due to inflammation of common flexor synovial sheath under the flexor retinaculum the median nerve gets compressed. However, its palmar cutaneous branch as it passes in front of the retinaculum escapes, leaving cutaneous innervation of the skin of thenar eminence is intact. In addition to this, cutaneous sensation of the lateral three and half fingers is lost. The loss of sensation is more important as the loss of tactile sense seriously interferes with the fine and skilled adjustment. Adductor pollicis and flexor pollicis longus are not paralysed as the adductor pollicis is supplied by the deep branch of the ulnar and the flexor pollicis longus by the anterior interosseous nerve a branch of median in the forearm proximal to the carpal tunnel. Median nerve is surrounded by the crowd of tendons with their synovial sheaths. Due to inflammation of the synovial sheath the pressure inside the carpal tunnel increases and the median nerve gets compressed, leading to sensory loss of lateral three and half fingers however, the area near the base of the thumb escapes as the palmar cutaneous branch of the median passes superficial to flexor retinaculum. May be that the slender and the delicate nerve could not have managed to pave its way through the already crowded tunnel. Compression of the median nerve results in paresis of three muscles of the thenar eminence, namely the abductor pollicis brevis, flexor pollicis brevis and the opponens pollicis. Muscular branch to the thenar muscles may perforate the flexor retinaculum and come out of the crowded tunnel. Following are the causes of carpal tunnel: 1. Tubercular synovitis of the flexor tendon sheaths 2. Rheumatoid arthritis of the wrist 3. Hypothyroidism—(Myxoedema) 4. Pregnancy 5. Hypertrophy of flexor retinaculum.

Wrist and the Hand Muscles of the Thenar Eminence (Figure 178):

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There are three muscles of the thenar eminence namely the abductor pollicis brevis, flexor pollicis brevis and the opponens pollicis. The opponens lies deep to the flexor and the abductor. 1. Abductor pollicis brevis: It arises form flexor retinaculum, tubercle of scaphoid crest of trapezium and also from the tendon of the abductor pollicis longus. It is inserted into the radial aspect of the base of proximal phalanx of the thumb. However, some fibres join the dorsal expansion of the thumb.

Figure 178 Muscles of thenar eminence

Nerve Supply: Action:

Nerve Supply: Action:

Nerve Supply:

By lateral terminal branch of the median (C 8, T I). It is an abductor of the thumb. It also helps in medial rotation of the thumb. 2. Flexor pollicis brevis: It arises form the crest of trapezium and the flexor retinaculum. It is inserted into the radial side of the base of proximal phalanx of the thumb. Near its insertion it contains sesamoid bone. It is supplied by the lateral terminal branch of the median nerve. It is flexor of thumb. 3. Opponens pollicis: It arises from the crest of trapezium and the flexor retinaculum. It is inserted into the radial aspect of the shaft of first metacarpal bone. It is supplied by the lateral terminal branch of the median nerve (Figure179).

Figure 179 Median nerve entering the hand under flexor retinaculum (Note: Nerve to the thenar muscles)

Action:

Action:

It acts during opponens of the thumb. It is also a medial rotator of thumb. In contrast to other two muscles it acts mainly on carpometacarpal joint of the thumb. The branch of the median nerve to the thenar muscle winds round the lower border (distal border) of flexor the retinaculum and passes over the tendon of flexor pollicis longus muscle. The nerve must be protected during incisions in the region. Its most important action is to keep the two bones in position during movements. It is the pronator of the forearm, however, it does not enjoy the mechanical advantage which pronator teres has, as it is attached to maximum point of convexity of the lateral surface of the radius.

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Movement of the Before the study of the movements you must recall that the first metacarpal Thumb (Figure 180): has undergone a rotation of ninety degrees. Therefore the extensor surface of thumb is pointing laterally and the flexor surface medially while the flexor surface of the finger is pointing towards roofs and extensor surface towards the floor. Plane of the thumb makes an angle of 90 with the plane of the fingers. Movement towards the extensor surface is extension and the movement towards the flexor surface is flexion. The movement away from the plane of the four fingers and the palm is abduction and movement towards the plane of the palm is adduction. Touching of tip of the thumb to tips of the fingers is the movement of opposition (Opponens). Figure 180A Movements of the thumb and the plane (thick lines indicate extensor surface)

Figure 180B Movements of opponens of thumb to fingers

Adductor Pollicis This muscle lies at the deeper level almost in front of metacarpal bones Muscle (Figure 181): and interossei. It has two heads namely the transverse and the oblique. Figure 181 Adductor pollicis

Origin of the Transverse Head:

It arises from the distal two thirds of the palmar surface of the shaft of third metacarpal bone.

Wrist and the Hand Origin of Oblique Head: Insertion: Nerve Supply: Action: Sesamoid Bone: Comment:

Muscles of Hypothenar Eminence:

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It takes origin from the bases of second and the third metacarpal bones and also from the trapezoid, capitate, palmar carpal ligaments and the sheath of flexor carpi radialis muscle. Two parts of the muscle run in company with each other and get inserted into the medial aspect of the base of the proximal phalanx of the thumb. It is supplied by the deep branch of the ulnar nerve. It is an adductor of the thumb. Note: The muscle is enclosed in a fascial space known as adductor space. A small sesamoid bone lies in the tendon near its insertion. Considering the mode of termination of the deep branch of ulnar nerve in the substance of adductor pollicis, it can be said that the adductor pollicis muscle is the graveyard of the deep branch of ulnar nerve. They are three in number. (Figure 182).

Figure 182 Hypothenar muscles of right side

Abductor Digiti Minimi:

It lies on the medial (ulnar) side of the palm. To its radial side is the flexor digiti minimi, while the opponens lies deep. It arises from the pisiform, the tendon of flexor carpi ulnaris and the piso-hamate ligament. The tendon gets divided into two slips. One slip goes to medial side of the base of first phalanx of the little finger while the other slip goes to dorsal digital expansion of the extensor digiti minimi muscle. Nerve Supply: It is supplied by the deep branch of ulnar nerve. Action: It is an abductor of the little finger. Flexor Digiti Minimi: It takes origin from the hook of hamate and the flexor retinaculum. It is inserted into the medial (ulnar) side of the base of proximal phalanx of the little finger. At its origin the deep branch of ulnar nerve and ulnar artery lie between flexor digiti minimi and the abductor digiti minimi. Nerve Supply: It is supplied by the deep branch of ulnar nerve. Action: It is the flexor of the little finger. Opponens It lies deep to the abductor digiti minimi and the flexor digiti minimi Digiti Minimi: muscles. It arises from the hook of hamate and the flexor retinaculum and gets inserted into the ulnar half of the shaft of the fifth metacarpal bone. Many times the muscle is divided into two strata by the deep branch of ulnar nerve. Nerve Supply: It is supplied by the deep branch of ulnar nerve. Action: It draws the fifth metacarpal towards the palm and helps in its rotation towards palm. This obviously deepens the concavity of the palm.

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Superficial Palmar Arch (Figure 183):

It is an arched continuation of the ulnar artery which is completed by the superficial branch of the radial artery on the lateral side. Ulnar artery passes in front of the flexor retinaculum along with the ulnar nerve on its radial side. It passes lateral to the pisiform and medial to the hook of hamate. It lies in front of the flexor tendons and behind the palmar aponeurosis. It is concave towards the wrist and convex towards the fingers. It lies along the line projected form the distal border of the fully outstretched thumb. The composition of superficial palmar arch is as under: a. One third by the ulnar artery, b. One third by the radial artery and c. One third by the radialis indicis artery.

Figure 183 Superficial palmar arch

Relation:

Branches of the Superficial Palmar Arch:

Surgical:

Skin, palmaris brevis and the palmar aponeurosis are superficial to it. All flexor tendons, lumbricals, flexor digiti minimi and the branches of median nerve lie deep to it. Please note that the nerves lie between the arch in front and the tendons behind (ANT). From superficial to deep the sequence of structures is: Arch, Nerve, Tendons. From the convexity branches go to the fingers. They are four in number. 1. First branch goes to the ulnar side of the little finger. 2. Second branch goes to the web between the little and ring fingers. Here it divides into two branches which go to adjacent sides of the little and the ring fingers. 3. Third branch goes to the web between the ring and middle fingers. Here it divides and goes to the adjacent sides of the middle and ring fingers. 4. Fourth branch goes to the web between the middle and index, divides and goes to adjacent sides of the middle and index fingers. All the branches receive communications from the palmar metacarpal arteries. The branches to the thumb and radial side of the index, arise from the radial artery and not from the superficial palmar arch. Digital arteries supply the joints of the finger and also give nutrient arteries to the phalanges. Anastomosis between the radial and the ulnar is at three places (a) at the wrist, (b) in the palm and (c) at the digits. There is free anastomosis between the radial and ulnar arteries at two places (1) At the wrist and (2) In the hand. In case of the injury of the palmar arches ligation of either ulnar or the radial artery in the forearm

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Surface Marking of the Superficial Palmar Arch: Deep Palmar Arch (Figure 184):

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does not help. The bleeding continues due to intercarpal anastomosis. Compression of the brachial artery against the shaft of the humerus helps in arresting the hemorrhage temporarily. A curved line is drawn from the distal border of the extended thumb to the hook of hamate. It represent the superficial palmar arch. It is formed by the continuation of the terminal part of the radial artery in the palm (Figures 184A and B, Angiogram showing radial artery in hand). As the artery passes in between the heads of dorsal interossei of the first space and appears on the palmar surface between the transverse and the oblique heads of the adductor pollicis, it forms an arch. The deep arch lies a finger’s breadth proximal to the line of superficial palmar arch. It presents a concavity towards the wrist and convexity towards the digits. It gives three palmar metacarpal arteries. These arteries are in communication with palmar digital branches of the superficial palmar arch, at the level of the heads of metacarpal bones. As already mentioned the arch is in communication with the anterior carpal arch.

Figure 184A Deep palmar arch

Figure 184B Angiogram showing palmar arches with occluded ulnar artery and normal radial artery

Radialis Indicis Artery:

It arises form the radial artery as soon as it comes out between two the heads of first dorsal interosseous muscle. It runs along radial side of the index. The princeps pollicis arises from the radial artery near the origin of the radialis indicis. At the base of the thumb it divides into two branches which respectively run on the ulnar and the radial sides of the thumb.

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Surface Markings of Deep Palmar arch: Lumbrical Muscles:

Nerve Supply:

Action:

Interossei (Figure 185):

Four centimeter long horizontal line is drawn across the palm from a point distal to the hook of hamate. The line lies 1 to 1.5 centimeter proximal to the superficial palmar arch. They are four in number. They are numbered as 1, 2, 3, 4 from lateral to the medial side. Each of them arises from the radial side of the flexor digitorum profundus tendon of the respective fingers. After its origin the tendon passes in front of the deep palmar metacarpal ligament, and joins the extensor expansion on the dorsum of proximal phalanx. The tendon of lumbrical muscle is enclosed in a small facial compartment known as lumbrical space or canal. Two ulnar lumbricals are double headed, while the two radial lumbrical are uniheaded. Two ulnar lumbricals (3, 4) are supplied by ulnar nerve while the radial two lumbricals (1, 2) are supplied by median nerve. Nerve supply of the lumbrical reflects the nerve supply of the flexor digitorum profundus muscle, medial half being supplied by the ulnar and the lateral half by the median nerve. Tendons run from palmar to dorsal aspect across the sides of the fingers at metacarpophalangeal joints. Due to their attachments into the extensor expansions, they are the flexors of metatarsophalangeal and extensors of the interphalangeal joints. They are situated in between the metacarpal bones. They are eight interossei, four palmar and the four dorsal. All the interossei are supplied by the deep branch of ulnar. Palmar surface is for reception and the dorsal for refusal. 1. The palmar interossei are adductors, and 2. The dorsal interossei are abductors.

Figure 185 Palmar and dorsal interossei

Palmar Interossei:

Central axis of the hand passes through the middle finger. In adduction finger moves towards middle finger, in the plane of hand. Abduction is the movement of the finger away from the middle finger. As the middle finger can be abducted, it has two abductors and no adductors as it is already in the midline. Palmar (Adductors)

Dorsal (Abductors)

Four in number. (First is very small as the thumb is provided with a special powerful adductor known as adductor pollicis)

Four in number.

Arise form the metacarpal bone of corresponding finger.

Arise form the adjoining metacarpal bones.

Middle finger has no adductor

Middle finger has two abductors. All five metacarpals give origin to dorsal interossei. Between the two head of the first dorsal interosseous muscle, radial artery passes. Contd...

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Contd...

Ulnar Nerve in the hand (C7, 8 T1) (Figure 186):

Figure 186 Ulnar nerve in hand with its superficial and deep branches (Highly schematic)

Figure 186A Branches of ulnar and the median nerves in hand (Palmar view)

Palmar (Adductors)

Dorsal (Abductors)

They are relatively weak.

They are stronger.

Pass in front of the deep transverse metacarpal ligament.

Pass in front of deep transverse metacarpal ligament.

Inserted into dorsal digital expansions also into the bases of proximal phalanges of respective fingers.

Inserted into dorsal digital expansions and also into the bases of proximal phalanges of respective fingers.

They are with one head.

They are with two heads.

They are adductors.

They are abductors.

By virtue of their insertion into the extensor expansion the interossei and the lumbricals are the flexors of the metatarsophalangeal and the extensors of the interphalangeal joints.

By virtue of their insertion into the extensor expansion the interossei and the lumbricals are the flexors of the metatarsophalangeal and the extensors of the interphalangeal joints.

It passes superficial to the flexor retinaculum along with the ulnar artery on the radial side and enters the hand. Ulnar nerve divides at the distal border of flexor retinaculum into superficial and the deep branches. The superficial branch supplies palmaris brevis muscle and divides into two digital branches for cutaneous innervations of the medial one and half fingers. The digital branches lie in front of digital arteries in the region of the fingers. However, branches lie deep to the arteries in the palm. Digital branches can be pressed against the hook of the hamate.

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Surgical:

Surface Marking of the Ulnar Nerve:

Median Nerve in the Hand (C7 8 T1) (Figure 187):

Synovial Sheaths of Tendons in the Hand (Figure 188):

The deep branch of the ulnar nerve (Musician’s neve) passes between the flexor digiti minimi and the abductor digiti minimi muscles. It passes through the substance of the opponens digiti minimi muscle and runs across the palm under the long flexor tendons. It is accompanied by the deep branch of the ulnar artery. The nerve is proximal to the deep palmar arch and it ends in the adductor pollicis muscle (Adductor pollicis muscle can be considered as the graveyard of the deep branch of ulnar nerve). Deep branch of the ulnar supplies muscles of the hypothenar eminence i.e. abductor digiti minimi, the flexor digiti minimi and the opponens digiti minimi. It supplies all the interossei, two ulnar lumbricals and finally ends in the adductor pollicis muscle and supplies it. It also gives a branch to the wrist joint, and may supply the flexor pollicis brevis muscle. Even after the division of the ulnar nerve the efficiency of the hand is surprisingly good. (Ulnar Paradox). It becomes difficult to diagnose the ulnar damage clinically. Loss of abduction and adduction of the fingers is the sign of ulnar nerve paralysis. Patient is asked to put flat of the hand on the table and ask to do the adduction and abduction. Inability to perform the movement of adduction and abduction is an indication of the ulnar nerve damage. You require three points for marking the ulnar nerve. Point one lies at the junction of anterior two thirds and posterior one third on the line joining the axillary folds. Arm should be abducted and laterally rotated. Second point is at the middle of the medial margin of the arm and the third point is at the back of the medial epicondyle. In the forearm the ulnar nerve is marked from the back of the medial epicondyle to a point lateral to the pisiform bone. The median nerve comes out of flexor retinaculum and enters the palm. Immediately after its emergence from the carpal tunnel, it presents an enlargement and divides into medial and the lateral divisions. From the lateral division all the thenar muscles are innervated by a thick muscular branch. The lateral division gives three digital branches, first two for the thumb, and the third for the radial side of index finger. The third branch gives a twig to the first lumbrical muscle. Digital branches supply the skin of the thumb and fingers and their joints. Medial division divides into two palmar digital branches. The first one (radial one) gives branch to the second lumbrical and goes to the web between the index and the middle fingers. Here it divides to supply the adjacent sides of these fingers. The second goes to the web between middle and the ring finger, divides into two and supplies adjacent sides of fingers. It receives a communication form the ulnar nerve. In the fingers, digital nerves lie superficial to digital arteries. Near the terminal part of the finger each divides into two, for the pulp of the digit and for the nail bed. At the level of proximal phalanx it receives communication from digital branches of radial nerve. Knowledge of anatomy of synovial sheaths of tendons in fingers and the hand is of immense surgical importance. The common sheath extends above flexor retinaculum proximally while it runs into the palm distally. The common sheath provides sheath for the little finger in continuity. Common synovial sheath is interrupted in the middle of the palm. As a result tendons of the index, middle and the ring fingers are devoid of synovial sheaths. Flexor tendons for the index, middle and the ring fingers acquire synovial sheaths in the region of the fingers (Figures 188 and 189). There is a separate synovial sheath for the tendon of flexor pollicis

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Figure 187 Median nerve in the hand (Palmar view)

Figure 188 Synovial sheaths of common flexor tendons and flexor pollicis longus

longus extending from the proximal border of flexor retinaculum to the site of insertion on the distal phalanx of the thumb. Chances of spread of infection is more in case of the thumb and the little finger. Under the flexor retinaculum the common flexor synovial sheath and the sheath of flexor pollicis longus are in communication fifty percent of the cases. Common synovial sheath is also known as the ulnar bursa and the synovial sheath for the flexor pollicis longus as the radial bursa. Fibrous Flexor The long tendons to the fingers and the thumb are covered with the tough Sheaths (Figure 190): fibrous plate known as fibrous flexor sheath. It is thin opposite the interphalangeal joints, and thick over the phalanges. It is attached to sides of phalanges. Together with phalanges they form osseofibrous tunnel. In case of the fingers, tendons of flexor digitorum profundus and the flexor digitorum sublimis are the occupants. In case of the thumb,

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Figure 189 Synovial sheaths ulnar and radial bursae

Figure 190 Fibrous flexor sheath

Clinical:

Acute suppurative tenosynovitis of the flexor sheath: Infection of the flexor tendon sheaths of the finger is rarely from the pulp space. It occurs due to injury of the flexor sheath by needle or knife. The proximal part of the sheath is closed thus converting it into the close compartment. Pus inside the sheath does not allow gliding movements. It is followed by adhesion and loss of function of the tendons. Affected finger is held in position of flexion is known as ”hook sign”. Extension of the finger is accompanied by extreme degree of pain. Transverse incisions are given at the ends of the sheath, pus is drained and the cavity of the sheath is irrigated with normal saline. Mallet Finger: It is due to rupture or avulsion fracture of the extensor tendon slip attached to the base of terminal phalanx. It occurs when the terminal phalanx is held in flexion at the same time there is sudden extension of the fingers. The terminal phalanx remains flexed like a Mallet. On extension it falls back. Due to the action of the long flexor tendons the finger is flexed to 30°. It can be treated with a splint given to the finger in full extension. (Mallet means a hammer with a wooden head.) de Querain’s It is the tenovaginatis of the tendon sheath of the abductor pollicis longus Disease: and the extensor pollicis brevis muscles passing through the first compartment under the extensor retinaculum on the dorsum of the wrist. Trigger Finger: As tendon sheath gets thickened and the tendon is entrapped which causes pain and crepitus. The finger gets locked in flexion and can be extended with a forceful jerk. The extension of the finger can be automatic or forced. As a part of the treatment, the thickened sheath of the tendon is cut to release the tendon. Extensor Expansions The extensor tendons as they reach dorsum of proximal phalanges expand (Figure 191): to form fibrous expansions. The interossei and the lumbrical joins the extensor expansion. The proximal contribution of fibres from the interossei

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and the lumbricals is transversely placed across the dorsum of proximal phalanges. Distal fibres from the interossei and the lumbricals run almost along the long axis of the fingers. The extensor expansion divides into three slips. The middle slip is attached to base of the middle phalanx and two collateral slips unite together and get attached to the base of distal phalanx. By virtue of their insertion into the extensor expansion the interossei and lumbricals are flexors of the metatarsophalangeal joint and the extensors of the interphalangeal joints. Figure 191 Extensor expansion

The Palmar Spaces The knowledge of anatomy of palmar spaces is of surgical importance as in infections, pus gets localized to the particular space. Surgeon is required to recall the anatomy of palmar spaces when it becomes obligatory for him to drain the pus. Surgically Important • Thenar space Spaces (Figure 192): • Mid-palmar space • Adductor space • Lumbrical spaces • Pulp space • Dorsal space • Web space: They are triangular spaces between the palmar and the dorsal skin of the web. It is filled with fatty tissue. Though the pus is present on the palmar aspect the abscess points dorsally. Abscess can be drained by a transverse incision on the palmar side cutting the edges of the wound and leaving it open. Figure 192 Cross section of the right hand showing palmar spaces

Thenar Space (see Figure 192):

It occupies the lateral part of the palm. Anteriorly it is bounded by the palmar aponeurosis, posteriorly by the adductor pollicis and the first and second interosseous spaces. Medially it is limited by mid-palmar septum and laterally by the lateral palmar septum. Distally the space is continuous with the web between index, and thumb. Proximally it is closed under the flexor retinaculum. It contains the first lumbrical muscle and the long

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Mid-Palmar Space (Figure 193):

flexor tendons for index. The midpalmar septum runs posteriorly and joins adductor pollicis to reach the third metacarpal. Anteriorly it is bounded by palmar aponeurosis, posteriorly by third and fourth interosseous spaces, and transverse head of the adductor pollicis muscle, medially by medial palmar septum and laterally by midpalmar septum. Distally it is continuous with lumbrical spaces of second, third and the fourth leading to the respective webs. Proximally it is closed by attachment of synovial sheath to the walls of carpal tunnel. The space contains flexor tendons for the little, ring and the middle fingers. Superficial palmar arch and companion nerve occupy this compartment.

Figure 193 Palmar spaces

Adductor Space: Lumbrical Spaces or Canals: Surgical Anatomy (Figure 194):

The adductor pollicis muscles lies in the fascial pocket provided by the fascia, forming the adductor space. They are the spaces in which lumbrical tendons travel. They are continuous with the mid-palmar and the thenar spaces. First communicates with the thenar space and the rest with the mid-palmar space. The thenar space, being continuous with the first web space between the thumb and the index, can be opened through the first web. Similarly, midpalmar space can be opened, through the web space between the ring and the middle finger (MR).

Figure 194 Arrow shows the course of pus entering the space of Parona from hand. Note: Black arrows indicate the sites for drainage of thenar of thenar and and midpalmar space

Flexor Tendons of As mentioned earlier flexor digitorum sublimis and the flexor digitorum Fingers (Figure 195): profundus tendons run in the osseo-fibrous tunnels of the fingers. They are provided with the synovial sheaths which present visceral and parietal layers. The tendons are connected to phalanges by means of long and short synovial folds containing blood vessels. These folds are known as

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vincula longa and brevia (Figure 195). Each of the tendons has one long and one short vincula (tendium). The short one is at insertion and the long one is at proximal phalanx. The tendons get blood supply form the bones through these folds. Figure 195 Flexor tendons and vincula

Surgical (Figure 196):

Figure 196 Pulp space

It is situated at the tip of the finger in front of the distal phalanx. The fibrous flexor sheath ends at the base of distal phalanx, therefore the pulp space infection is not the source of, flexor tendons sheaths infections. There are number of fibrous septae, running form the skin to phalanx. The blood vessels to phalanx pass through the septae. In case of pulp space infection, the vessels get thrombosed leading to necrosis of distal phalanx. However, the epiphysis of the phalanx (base) escapes as the vessel for it comes from the digital artery before entering the pulp space. Pulp spaces of the index and the thumb are the commonest spaces to be infected.

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WRIST JOINT Bones Taking Part (Figure 197):

The joint is situated at the junction of the hand and the forearm. It is synovial, ellipsoid and biaxial type of joint. (1) Lower end of radius, (2) Triangular articular disc. Please note with care and concentration that lower end of ulna does not take part in the formation of this joint. It is prevented from taking part in the joint formation by the triangular articular disc. The distal articular surface is formed by the scaphoid, lunate and the triquetral bones from lateral to medial side. The proximal articular surface of the joint is concave and distal is convex. The styloid process of radius is also covered with articular surface, and projects lower than the ulnar styloid process. This anatomical fact is important and should be remember while examining the case of Colles fracture in which the radial and the ulnar styloid processes are at the same level.

Figure 197 Wrist joint on right shows proximal articular surface seem from below

Attachment of Capsule:

Ligaments (Figure 198):

Proximally it is attached to radius beyond the articular surface and the anterior and posterior borders of triangular articular disc. Distally it is attached to scaphoid, lunate and the triquetral bones. Some part of capsule is also attached to the lower end of ulna and its styloid process. They are four in number: 1. Anterior radiocarpal, 2. Posterior radiocarpal, 3. Radial collateral and 4. The ulnar collateral.

Figure 198 Showing ligaments of wrist joint

Out of these radial and ulnar collateral ligaments are attached to the styloid processes of the radius and the ulna respectively.

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Articular Disc:

It is triangular in shape. Its apex is attached to the styloid process of the ulna while the base is attached to lower end of the radius at the lower limit of the ulnar notch of the radius. Sometimes the disc has perforation through which synovial membrane of the joint· is continuous with the synovial membrane of the inferior radioulnar joint. Proximal Articular It is formed by the lower end of radius and the articular disc. The lower Surface: end of radius presents the triangular area laterally for scaphoid and the quadrilateral area for the lunate medially. Distal Articular From lateral to medial side, it is formed by the proximal surfaces of the Surface: scaphoid, lunate and the triquetral bones with their interosseous ligaments. The articular surface is convex and extends more downwards and posteriorly than anteriorly. Synovial Membrane: It covers the capsule from inside and other structures except the articular areas. As mentioned before it is continuous with synovial membrane of the inferior radioulnar joint where the articular disc has an opening. Nerve Supply: It is supplied by anterior and posterior interosseous nerves and also by the deep branch of ulnar. Blood Supply: Comes from the anterior and the posterior carpal arches. Movements: They are: 1. Flexion, 2. Extension, 3. Abduction, 4. Adduction and 5. Circumduction. The extension is more powerful than flexion. However flexion appears greater than extension mainly due to movements of midcarpal joints. The range of adduction is more than the range of abduction. The abduction is limited to some degrees by the styloid process of radius. It is of great importance to note that firm grip of hand is possible when the wrist is dorsiflexed. The knife held in dorsiflexed position falls as soon as the wrist is palmar flexed. Following are flexors: 1. Flexor carpi radialis, 2. Flexor carpi ulnaris and 3. Palmaris longus. Following are extensors: 1. Extensor carpi radialis longus, 2. Extensor carpi radialis brevis and 3. Abductor pollicis longus and extensor pollicis brevis.

Relations (Figure 199):

Following are adductors: 1. Extensor carpi ulnaris 2. Flexor carpi ulnaris. Muscles in front, are flexors, muscles at the behind are extensors, muscles on the medial side of the wrist are ulnar deviators and on the radial side are the abductors. Combination of all movements leads to rotation. Relations of the flexor retinaculum anteriorly and the extensor retinaculum posteriorly, complete the relations of the wrist joint infront and behind.

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Figure 199 Relations of wrist joint

Ganglia:

They are the localized tense cystic swellings with gelatinous fluid inside. They are commonly seen on the dorsum of the wrist and the foot. They are connected to the tendon or the capsule of the joint. Surgical removal of the ganglion gives an unsightly scar which is worst than the ganglionic swelling.

SURGICAL APPROACHES Dorsal Approach:

It is through the dorsal approach and the incision lies between the extensor tendons of the wrist and the fingers. This approach is used for the removal of dislocated lunate.

Volar Approach (anterior): Aspiration of the It is done through the dorsum of the joint between the first and the second Joint: extensor compartments at the radiocarpal level. Position of Function: 10°-20° of extension (fingers flexed at 90° at the MP Joints, minimally flexed at the IP Joints with thumb abducted and wrist dorsiflexed 10° to 20°). Inter Carpal Joints 1. The pisiform bone articulates with palmar surface of triquetral bone (Figure 200): by means of a small synovial joint. As mentioned before the flexor carpi ulnaris is attached to the pisiform bone. Two ligaments run distallyfrom the pisiform, respectively going to the hook of hamate (piso-hamate) and the base of the fifth metacarpal (piso-metacarpal ligament). Figure 200 Intercarpal joint

Wrist Joint

Carpometacarpal Joint of the Thumb (Figure 201):

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2. The joints between the other carpal bones are in the form of a cavity. The bones are connected by means of interosseous ligaments. The movements of intercarpal joints are mainly supplemental to the movements of the wrist joint. In midcarpal joint some degree of flexion and extension occur, while gliding type of movements take place during adduction and abduction at the wrist. All movements of the thumb are projected in this joint. It is the synovial saddle shaped joint. The base of first metacarpal and corresponding the distal surface of the trapezium take part. Their articular surfaces are reciprocally concavo-convex. The capsule is attached to the bone beyond the articular area. The capsule is lined by the synovial membrane from inside except the articular area. Carpometacarpal joint has an independent joint cavity.

Figure 201 Carpometacarpal joint of thumb

Movements:

Relations Carpometacarpal Joints of 2nd, 3rd, 4th and 5th:

There are three ligaments for the joint, i.e. 1. The anterior 2. The Posterior and 3. The lateral. The lateral ligament is stronger. It is attached to the radial side of the base of first metacarpal and radial aspect of trapezium. Anterior and posterior ligaments run from trapezium to the base of first metacarpal. They are obliquely arranged and go to the medial side of the base of the first metacarpal bone. This joint enjoys free mobility due to the shape of articular surfaces and the lax capsule. Following movements occur: 1. Flexion, 2. Extension, 3. Adduction, 4. Abduction, 5. Circumduction, 6. And some degree of medial and lateral rotation and opponens. The medial rotation takes place during flexion while lateral rotation occurs during extension. Radial artery lies medial to the joint. They are synovial plane variety of joints. Each is provided with a capsule, dorsal palmar and interosseous ligaments. Synovial membrane is continuous with that of other intercarpal joints. Sometimes the joints between fifth metacarpal and capitate and hamate have a separate synovial membrane. It has relatively free mobility next to that of carpometacarpal joint of the thumb.

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Intercarpal Joints:

Metacarpophalangeal Joints (Figures 202 and 203):

Intercarpal joints are arranged in two rows proximal and the distal by means of interosseous ligaments. In addition to these there is a complex joint between the proximal and the distal carpal bones it is known as midcarpal joint. Articular surfaces of the carpal bones are either sellar, ellipsoid or spheroidal. Flexor retinaculum is considered as an accessory ligament of the intercarpal joints. They are joints between rounded heads of the metacarpal bones and the concave bases of proximal phalanges. They are synovial condyloid type of joints. They are also known as ellipsoid joints. They are provided with the palmar, deep transverse and the collateral ligaments. The deep transverse ligament is attached to the palmar ligaments of adjoining joints and are three in number. Dorsal ligament is the part of extensor expansion. Tendons of lumbricals and digital vessels and nerves pass in front of these ligaments. The ligament connects heads of metacarpal bones.

Figure 202 Interphalangeal and metacarpophalangeal joints

Figure 203 Interphalangeal and metacarpophalangeal joints

Collateral Ligaments:

Each joint is provided with two collateral ligaments, one on radial and the other on ulnar side. It is attached to the posterior tubercle near the head of the metacarpal on the one hand and to the base of proximal phalanx on the other. Movements: They are flexion, extension adduction, abduction and circumduction. Interphalangeal joints. These joints are between the proximal, middle and the distal phalanges. They are uniaxial hinge and are of synovial type. They are provided with palmar and the collateral ligaments. The collateral ligaments run obliquely. The movements of flexion and extension take place in these joints. Lymphatic Drainage It is arranged in two groups, namely superficial and the deep. The of Upper Limb superficial group lies superficial to the deep fascia, while the deep group (Figure 204): lies deep. The lymph vessels mainly follow the veins and drain into the axillary group of lymph nodes. Although lymph vessels run on the front,

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it must be noted that majority prefer to go along the dorsal aspect. The general tendency is to crowd along medial aspect of the arm. (A tendency for posteromedial grouping). The lymphatics begin in the skin of the digits. Lymphatic channel go to dorsal aspect of the finger. Lymphatics from the proximal part of palmar plexus run anterior to the wrist, some prefer to go to back of the wrist after winding round the sides. Majority of the lymphatic channels start from distal end of palmar plexus and unite with lymphatic plexus of the digits, which themselves run upwards from dorsal aspect of the hand. The lymphatics from lateral and medial sides of palmar plexus also go to dorsum of the hand. Figure 204 Lymphatic drainage of superior limb

Clinical:

Deep Lymphatic Channels: Lymph nodes of the Upper Limb:

Lymph Nodes of Axilla (Figure 205):

Now all the lymph channels incline towards the medial side of the arm on their way to the axillary group of nodes. A small number of vessels from the medial side of the hand drain into the superficial cubital nodes. (epitrochlear). The superficial cubital nodes send their afferents, which pierce the deep fascia in proximity with the basilic vein. A few lymph channels follow the course of cephalic vein and directly drain into the pectoral or apical group. Skin of the palm is fixed to the palmar aponeurosis and there is hardly any loose areolar space in the palmar aspect of the hand. Therefore infections of the hand are not associated with oedema of the palmar surface. The oedema is observed on the dorsal surface as there is a space under the skin which is freely mobile and is not attached to the underlying extensor tendons. If one finds an oedema on the dorsum, hectic attempt should be made to search the source of infection on the palmar. Run deep to the deep fascia, travel in company with the main channels (Blood vessels) and ultimately drain into the axillary nodes. 1. Superficial-delto-pectoral, infraclavicular and superficial cubital, 2. Deep with arteries of the limb and axilla. (a) With brachial artery, (b) At the termination of brachial artery. 3. With radial artery, 4. With ulnar artery and 5. With interosseous arteries. Account of lymphatic drainage is incomplete without description of lymphatics of the axilla. A surgeon is required to remove the nodes of axilla during the removal of the breast for cancer. Following five groups are there: i.e. two are associated with the vein and two with arteries the remaining one lies at the center of the floor of axilla.

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Figure 205 Groups of lymph nodes in the axilla

1. Anterior: Pectoral group, 2. Posterior: Subscapular group, 3. Lateral: with axillary vein, 4. Central: In the central part of axillary space. 5. Apical: At the apex of axilla with the axillary vein. Anterior or Lies along the lower border of pectoralis minor with lateral thoracic artery. Pectoral Group: It receives lymph form the skin and muscles of anterior and lateral wall of the trunk up to the level of umbilicus. Central portion and majority of lateral part of the mammary gland also drain into this group. Its afferents go to the central and apical group. Posterior or It lies along subscapular vessels with the lower border of subscapularis Subscapular Group: muscle. It drains the posterior part of the trunk up to the level of iliac crest and also lower part of the neck. It can be stated that the group lies along posterior wall of axilla and drains posterior part of the trunk. Its afferents go to the central and apical groups. Lateral Group: It lies along posteromedial aspect of axillary vein. It receives lymphatics from the whole of the limb except the few, which go along the cephalic vein. Its efferents go to the central and apical groups. Central Group: Lies in the floor of axilla embedded in the fatty tissue. It has already been mentioned that pectoral, sub-scapular and lateral groups of nodes send their efferents to central group. All the efferents from the central groups go to the apical. Apical Group: Lies at the apex of axilla along the axillary vein. This group is situated behind the clavi-pectoral fascia. Direct channels coming to it are channels from deep part of mammary gland and those which accompany the cephalic vein. It is the final station for receiving lymph from all the nodes mentioned above. Out of the efferents of apical group, the subclavian lymph trunk is formed which drains into jugulo-subclavian junction or into jugular lymph trunk. Some of the channels do go to the lower members of the deep cervical group. Infraclavicular Though not included in the axillary nodes, it is convenient to study them Group: at this stage. They lie immediately below the clavicle and are placed between deltoid and pectoralis major. They lie in contact with the cephalic vein. Efferents from this group pierce clavi-pectoral fascia and drain into the apical group. A. few channels may go across the clavicle to the deep cervical group. Summary of Lymph There are five groups. Two are associated with the vein and two with the Nodes of Axillary: arteries. The remaining one lies at the floor. With the vein: 1. Lateral group, 2. Apical group.

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Clinical:

Lymphangitis:

Innervation of the Limb (Figures 206 and 207):

Figure 206 Cutaneous nerve supply of superior limb

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With the arteries: 1. Pectoral group, 2. Subscapular group. Lateral, pectoral and subscapular groups have similar arms, namely going to the central and apical groups. Pectoral group receives lymphatics from the front of the trunk, subscapular group from the back and the lateral group receives lymph from the limb. Central group receives contribution from all the three above mentioned groups. (Pectoral, Subscapular and Lateral) from where the efferents go to the apical group. The efferents from the apical group form subclavian lymph trunk which opens into jugulo-subclavian junction. Modern classification of lymph nodes of axilla: They are divided in three planes I, plane II, plane III Plane I: It includes lateral, anterior and central. Plane II: It includes the nodes infront and behind the pectoralis minor. Plane III: It includes the nodes above the pectoralis minor. It is the infection of the lymphatics by the streptococci. Superficial lymphatics of the hand prefers a shortcut by turning to dorsum of the hand. This explains the appearance of oedema on the dorsum of the hand. Infection of the ulnar side of hand drain into the epitrochlear node. The lymphatics from the thumb and the index finger drained into the axillary group of lymph nodes. The lymphatics from the middle finger drains into the supraclavicular group of lymph nodes. This facilitates the entry of infection into the circulation leading to septicaemia. We know that the C 5,6,7,8 and T1 supply the superior limb. As the limb bud appears in the region of the C 5,6,7 ,8,and T1, skin of the limb will be supplied by the same. Imagine a wire which shows the markings as 5,6,7,8, 1. Fix the upper end near 5 and bend it in such a way that apex of the loop remains at 7. The apical region forms the hand, hence cutaneous innervation of the hand is by the 7. Lateral limb lies laterally and medial limb lies medially, approximately the markings of 5 and 6 come to the· region of lateral sides of the arm and forearm and the 8 and T1 come to the medial side of the forearm and the arm. Small part of the top of the shoulder is supplied by C 4, a small part of the skin of the axilla by the T2.

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Figure 207 Showing segmental innervation from C5 to T8 of superior limb

Dermatome: Axial line:

The part of the skin supplied by one spinal nerve is known as dermatome. A line that lies between two or more dermatomes is known as “axial line”. The axial line of the front begins at the sternal angle and reaches the area of wrist, while posterior axial line ends on the back of the middle of the arm.

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OSTEOLOGY OF THE INFERIOR LIMB Hip Bone (Figures 208 and 209):

It is an irregular bone. It is made up of three components, the ilium, ischium and the pubis. The ilium is above, pubis is anteroinferior and the ischium is posteroinferior. These elements are joined by the Y shaped line cartilage which disappears at the age of 12 years. Conjoint ramii of the pubis and ischium unite at the age of 8 years. Both hip bones articulate anteriorly to form symphysis pubis. Posteriorly they articulate indirectly as the sacrum is interposed between hip bones. It presents a cavity which is deep, meant for the head of the femur. The cavity is known as acetabular cavity. It is broken below and the gap is covered by the transverse acetabular ligament. Below the acetabulum there is a triangular opening known as obturator foramen. Iliac crest lies above and it is concavo-convex. At its anterior end is the anterior superior iliac spine and the posterior superior iliac spine occupies the posterior end. It is marked by the dimple on the gluteal region which lies at the level of second sacral vertebra.

Figure 208 Showing hip bone lateral surface

Pubis:

Anterior border of the hip bone starts from the anterior superior iliac spine followed by a notch and the anterior inferior iliac spine from above downwards. Next to this is a raised part known as iliopubic eminence. Below the ilio-pubic eminence there is triangular area which is known as pectineal surface of the superior ramus of the pubis. Base of it is pointing laterally towards iliopubic eminence and the apex is located medially at the pubic tubercle. Medial to the pubic tubercle lies the pubic crest. Body of the pubis is placed anteroinferiorly and presents two ramii the superior and the inferior. The body of the pubis and the two ramii form the boundaries of the obturator foramen, body of the pubis being in front the superior ramus above and the inferior ramus below. Inferior ramus of the pubis meets the ramus at the ischium and forms the inferior boundry of the obturator foramen. Posterior to the obturator foramen is the ischium. It has a body and the tuberosity known as the ischial tuberosity. Above the

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Figure 209 Showing hip bone medial surface

Clinical:

ischial tuberosity there is a small notch known as lesser sciatic notch which is followed by the spine of ischium. Above the spine of ischium is the beginning of the greater sciatic notch. Greater sciatic notch ends at the posterior inferior iliac spine. Above the posterior inferior iliac spine lies the posterior superior iliac spine. Iliac crest lies between the anterior superior and the posterior superior iliac spines. It is divided into anterior two thirds and the posterior one third. Anterior two thirds are convex laterally. It presents lateral lip, medial lip and the intermediate zone. Five cms. behind the anterior superior iliac spine, lies the tubercle of the iliac crest. It gives attachment to the ilio-tibial tract. Anterior superior iliac spine gives attachment to the lateral end of the inguinal ligament. Below the attachment of the inguinal ligament is the origin of the sartorius muscle. Origin of the sartorius muscle also extends below the anterior superior iliac spine and covers the part of the anterior border of the ilium. Anterior inferior iliac spine gives origin to the straight head of the rectus femoris muscle above and the ilio-femoral ligament of the hip joint below. The sequence of attachments at the anterior border of the ilium is as under: • Ligament • Muscle • Muscle • Ligament Superior border of the pubis is known as pubic crest and the lateral end is known as pubic tubercle. Anterior surface of the superior ramus is triangular with apex medially and base laterally. At the apex is the pubic tubercle and at the base is the acetabulum. It gives origin to the pectineus muscle. Pecten pubis is the sharp superior edge of the pectineal surface of the superior ramus of pubis. It gives attachment to the lacular ligament and the pectineal ligament. (Ligament of Sir Astley Cooper). Medial surface of the inferior ramus of the pubis gives attachment to the crura of the penis and the perieneal membrane. It also provides origin to the muscle deep transverse perinei. Pelvic surface of the body of the pubis is related to the urinary bladder. As a result in fractures of the pelvis involving the pubis, injury to the urinary

Osteology of the Inferior Limb

Ischium:

Ischial Tuberosity:

Attachments of the Iliac Crest:

Clinical:

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bladder is common. Lower part of the pelvic surface of the pubis gives attachment to pubo-prostatic ligaments in males and pubo-vasical ligaments in females. The space behind the pubis is known as retro-pubic space. (Cave of Retzius). It is drained after surgery of the urinary bladder with a corrugated rubber sheet. Anterior to the pubic tubercles lies the spermatic cord in male and the round ligament of uterus in female. It forms the postero-inferior part of the hip bone and has a body, inferior ramus and the ischial tuberosity. Ischial tuberosity is located at 5 cm from midline or 5 cms from the gluteal fold. Normally it is not palpable when the hip is extended as it is covered by the fibers of the gluteus maximus. However it is palpable when the hip is flexed. It is because of the fact that the fibres of the gluteus maximus muscle slips away from the ischial tuberosity. Body of the ischium lateral to the ischial tuberosity gives origin to the quadratus femoris muscle. It forms the larger part of the ischium and is located five cms from the midline. It is divided into the upper and the lower parts by the transverse ridge. Upper part is further divided into supero-lateral and the inferomedial by an oblique ridge. Supero-lateral part of the tuberosity gives orgin to the semi-membranosus muscle. While the infero-medial part gives origin to the biceps femoris (long head) and the semi-tendinosus muscles. Lower part of the ischial tuberosity gives origin to the adductor magnus muscle laterally and provides attachment to the sacro-tuberous ligament medially. Ventral two thirds of the iliac crest provides insertion for the external oblique muscle of abdomen at its outer lip. Medially gives origin to the transverses abdominis muscle and the middle part of the crest provides origin for the internal oblique muscle of the abdomen. Behind the insertion of the external oblique muscle of the abdomen is the origin of latisimus dorsi muscle. It must be mentioned here that the iliac crest below the external oblique anteriorly and the latisimus dorsi posteriorly form a triangular space known as triangle of Petit which is the site for the lumbar hernia. Posterior one third of the iliac crest provides origin to the muscle gluteus maximus muscle laterally and the erector spini medially. Origin of the tensor fascia latae muscle is anterior to the tubercle of the iliac crest. The reflected head of the rectus femoris arises from the depression above the acetabulum. The adductor group of muscles namely the adductor longus, adductor brevis, adductor magnus and the gracilis arise from the pubis and ischium with their ramii. Adductor longus arises from the body of the pubis between the superior and the medial borders. Below it lies the origin of the adductor brevis. The adductor magnus muscle arises from the lower lateral part of the ischial tuberosity, body of the ischium, the ramus of ischium and the inferior ramus of the pubis. Below it lies a origin of the gracilis muscle along with the conjoint ramii of the ischium and the pubis. Anterior superior iliac spine and the greater trochanter form the important landmarks while examining the hip pathology. The length of the lower limb is measured from the anterior superior iliac spine to the medial malleolus. Distance of the greater trochanter from the iliac crest can be assessed with the fingers alone and can be compared with the other side. Anterior superior iliac spine is used as a landmark for drawing the Neleton’s line, Shoe-maker’s line and also measuring the upward shift of the greater trochanter. This is done with the help of Braynt’s triangle.

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Neleton’s Line:

It is the line drawn from the ischial tuberosity to the anterior superior iliac spine. Normally the greater trochanter lies below the line. In the dislocation of the hip the greater trochanter is pushed above the line. Shoe-maker’s Line: It is the line drawn from the tip of the greater trochanter to the anterior superior iliac spine and extended further on the anterior abdominal wall. Umbilicus is situated below the line. Braynt’s Triangle: When the patient is in a supine position a vertical line is drawn from the anterior superior iliac spine towards the bed. The second line is drawn from the tip of the greater trochanter to join the vertical line already drawn from the anterior superior iliac spine. The distance between the two lines is measured. A third line can also be drawn from the anterior superior iliac spine to the tip of the greater trochanter, thus completing the Braynt’s triangle although drawing of the third line is not mandatory. Clinical (Ischial Ureter is related to the pelvic surface of the ischial spine near its tip. In Spine): intravenous pyelography the course of the ureter is traced upto the ischial spine where it changes its course along the pelvic floor. A radio-opaque object along this line is indicative of a ureteric stone. While giving the pudendal block by vaginal approach, the ischial spine becomes an important landmark as the pudendal nerve crosses the dorsal aspect of the tip of the spine and the sacrotuberos ligament. Clinical (Ischial Hamstring muscles – muscles arising from the ischial tuberosity and going Tuberosity): to the bones of the leg for insertions except the adductor magnus, are known as hamstring muscles. Hamstring pull is suffered during the games is due to tearing or the injury of the hamstrings. Clinical Part of the iliac crest can be used for bone grafting as it is superficial and (Iliac Crest): easily accessible. Line running across the highest points of the iliac crest is known as supra-cristal plane. It lies at the level of the fourth lumbar vertebra or may lie between the third and the fourth lumbar vertebrae. While doing lumbar puncture this plane is referred to by the anesthetics. Inter-tubercular plane is at the level of the fifth lumbar vertebra. Obturator foramen is closed by the obturator membrane leaving small gap for the formation of the obturator canal. Obturator externus muscle arises from the obturator membrane and the bone around. While the obturator internus muscle arises from the obturator membrane from inside and the walls of the true pelvic cavity. Gluteal Surface of It presents three gluteal lines, the anterior, middle and the posterior. Gluteus the Ilium: minimus muscle arises from the gluteal surface of the ilium between the anterior and the middle gluteal lines. Gluteus medius muscle arises from the gluteal surface of the ilium between the middle and the posterior gluteal line. The gluteus maximus muscle arises from the gluteal surface of the ilium posterior to the posterior gluteal line, sacrum, coccyx and the sacrotuberous ligament. Iliac Fossa: Upper two thirds of the iliac fossa gives origin to the iliac muscle. Posterior to the iliac fossa lies the articular surface for the sacrum, which looks like an auricle hence, it is known as the auricular surface. Anterior to the auricular surface is the attachment of dorsal and the interosseous ligaments of the sacro-iliac joint. Acetabulum: It is deep cup placed in the middle of the lateral surface of the hip bone. It has an inverted horse-shoe shaped articular area. The rest of the area is non-articular. Edge of the acetabulum provides attachment to the labrum acetabulare, which is a fibro-cartilaginous ring. Levator ani muscle arises from the pelvic surface of the body of the pubis and the pelvic surface of the ischial spine and also from the obturator fascia covering the obturator

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internus muscle in between. Tip of the spine of the ischium gives attachment to the sacrospinus ligament and coccygeus muscle. From the lower part of the auricular surface runs the arcuate line downwards and forwards. It lies between the true pelvis below and the false pelvis above. Middle of the arcuate line provides insertion to the psoas minor muscle when present. Below the auricular surface there is a groove known as preauricular sulcus. Pectineal surface of the superior ramus of the pubis is bounded in front by the obturator crest and behind by the pecten pubis. It has 3 centers of ossification which are primary, each for ilium, pubis and ischium. • Center of Ilium appears at 2nd month • Center of Ischium appears at 4th month • Center of Pubis appears at 5th month Conjoint rami of ischium and pubis are united at 8th year and Y shaped cartilage ossifies at the age of 12 years.

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FEMUR Femur is the long bone of the thigh. It has shaft, upper and the lower ends. Shaft is convex in front. Upper end has head which is directed medially. On the posterior surface of the shaft there is a ridge known as linea aspira. This information is enough to decide the side of bone (Figures 210 and 211). Head of the femur which is spherical articulates with the acetabulum to form, the hip joint. Lower end has two condyles of which medial is larger as it takes part in weight transmission. Condyles are continuous with each other anteriorly but separated by means of the notch posteriorly known as inter-condylar notch. Lower end has two articular surfaces (1) for the patella, and (2) for the upper end of tibia. The patellar articular surface extends more laterally on the lateral condyle of the femur. Therefore patella has a natural tendency to go laterally. Dislocation of the patella is in the lateral direction, which is prevented by anterior projection of the lateral condyle of the femur. Vastus medialis muscle extends lower down than the vastus lateralis. This counteracts the movements of the patella laterally. The angle between the femur and the tibia which is open outside promotes lateral dislocation of the patella. Figure 210 Showing femur viewed from front

Femur 183 Figure 211 Showing right femur viewed from back

Upper End: Head:

Neck of Femur:

Clinical:

Greater Trochanter:

The upper end of femur presents the head, neck, greater and the lesser trochanters. It is spherical as against the head of the humerus which is hemispherical. It is directed forwards and medially. It is covered with articular cartilage and presents a small pit for attachment of ligamentum teres femoris a little below and behind its center. The depression for the ligament teres femoris is known as fovea. The junction of shaft and the neck is marked anteriorly by the intertrochanteric line. Posteriorly the junction of the neck and the shaft is marked by the inter trochanteric crest. It is important to remember that the capsule of the hip joint is attached to the inter-tronchanteric line anteriorly and the neck of the femur posteriorly and not to the inter-trochantric crest. Trans-cervical fracture of the femur is intracapsular. Fracture line breaks the retinaculi under which blood vessels go to the head of the femur resulting in avascular necrosis of the femoral head. It is the most important lateral bony prominence of the femur felt on the lateral aspect of the upper part of the thigh. Medial to the greater trochanter lies the trochanteric fossa which gives insertion to the obturator externus muscle. A line drawn from the upper border of the trochanteric fossa passes through the center of the head of femur. Four fingers above the greater trochanter is the iliac crest or vice versa. Lateral surface of the

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Intertrochanteric Line:

Intertrochanteric Crest:

Shaft:

Posterior Surface:

greater trochanter is divided by an oblique line. Anterior surface of the greater trochanter gives insertion to the gluteus minimus muscle, while the lateral surface provides insertion for the gluteus medius muscle. There is a bursa which is interposed between the glueus medius muscle and the greater trochanter. Gluteus maximus muscle is attached to the gluteal tubercle which is much below the posterior surface of the greater trochanter. Lesser trochanter is situated medially at the junction of the shaft and the neck. It can be divided into 3 zones: 1. Upper-zone gives insertion to psoas major 2. Middle one gives insertion to iliacus and the 3. Lower zone-provides an area for bursa which lies between it and the adductor magnus. As already mentioned it gives attachment to the capsule and two limbs of the Y shaped ilio-femoral ligament which is one of the strongest ligament of the body. Upper fibres of vastus lateralis takes origin from the upper part of the intertrochanteric line while the fibres of the vastus medialis take origin from the lower part of the line. It is situated at the junction of the posterior surface of the shaft and the neck. It runs from greater trochanter to lesser trochanter. It presents the quadrate tubercle in the middle. Quadrate tubercle provides insertion to quadratus femoris muscle. It has three borders and three surfaces. Posterior border is sharp and is known as linea aspera, while the lateral and the medial borders are ill defined. It has three surfaces the anterior, medial and lateral. Anterior surface is broader and lies between medial and lateral borders. Lateral surface lies between lateral border and linea aspera while the medial surface lies between medial border and the Iinea-aspera. It’s upper one third is upright V shaped which is limited by the spiral line medially and the gluteal tuberosity laterally. In the lower one third there is inverted V shaped area bounded medially by the medial supra-condylar ridge and laterally by lateral supracondylar ridge. Medial supra-condylar ridge ends in an adductor tubercle at the lower end. Supra-condylar ridges are continuous above with respective lips of the linea aspera. The upper part of the medial supra-condylar ridge is smooth as the femoral artery lies in contact. Adductor tubercle gives attachment to the tendon of adductor magnus muscle. Upper one third of the posterior surface of the femur provides insertion for the muscles, pectinius and the adductor brevis. Attachment of the linea aspera from medial to lateral side: 1. Vastus medialis 2. Medial intermuscular septum 3. Adductor longus 4. Adductor brevis 5. Adductor mangus 6. Short head of biceps femoris 7. Lateral intermuscular septum 8. Vastus lateralis. Immediately above the medial condyle is the origin of gastrocnemius medial head. On the upper part of the lateral condyle is the origin of lateral head of gastrocnemius Lowest part of the lateral supra-condylar ridge gives origin to the plantaris muscle.

Femur 185 Articular surface of the lower end of the femur is continuous with each other anteriorly while it is interrupted posteriorly by the inter-condylar notch. Articular area on the lower end of the femur articulates with the upper end of the tibia posteriorly and the patella anteriorly. The tibial and the patelar articular areas are separated by means of the faint groove. Popliteus muscle arises from the groove situated on the lateral surface of the lateral condyle of the femur below and the behind the lateral epicondyle and is intracapsular (Figure 212). Figure 212 Showing lateral surface of lateral condyle of femur

Intercondylar Notch:

Calcar Femorale:

Ossification:

Semilunar area is placed on the lateral part of the medial condyle of the femur. It comes in contact with medial vertical facet on the posterior surface of the patella during extreme flexion. Lateral wall of the inter-condylar notch gives attachment to anterior cruciate ligament and the medial wall gives attachment to the posterior cruciate ligament. It must be remembered that the cruciate ligaments are covered with synovial membrane only from the front and sides and not from the back, hence, they are extra-synovial but intracapsular. It is the compact plate of bone situated inside the femur running from the linea aspera to the postero-medial part of the neck of the femur. As it is made of a compact plate of bone it gives strength to the neck of the femur. In old age calcar femorale is absorbed. Indirect trauma can lead to the fracture neck of femur. Calcar femorale during life acts as the living nail for the neck of the femur. There is one primary center for the shaft. The upper end presents three secondary centers one each for the head of the greater and the lesser trochanters. Along with the clavicle the femur is the first bone to ossify in the body. Center for the shaft appears in the 8th week of intrauterine life. The secondary center for the lower end appears at birth. This fact can be confirmed by cutting the lower end of a dead foetus brought for examination by the police wanting to know the age of the new born. The secondary center for the head appears during the first year, for greater trochanter during fourth year and for lesser during fourteenth year. Upper end unites at the age of 16 and the lower end at 18 years. Lower end of the femur is the growing end. I would like to stress the importance of adductor tubercle for three things. 1. It is easily palpable landmark felt by passing the flat of hand on the medial side of thigh. 2. It gives attachment to the tendon of adductor magnus. 3. The lower epiphyseal line of the femur lies at the level of adductor tubercle.

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Kadasne’s Textbook of Anatomy (Clinically Oriented) Attachment of the capsule at the lower end. The capsule of the knee joint is attached to the lower end of the femur beyond the articular areas. 1. Anteriorly it presents an inverted V shaped attachment which forms the suprapatellar bursa. It is pulled up by fibres of articularies genu muscle which takes origin hardly two fingers above, from the anterior surface of the shaft of femur. 2. The groove on the lateral condyle of the femur is meant for the origin for popliteus muscle which is intracapsular. 3. On the posterior aspect of the knee joint semi-membranous bursa communicates with the synovial membrane of knee joint through a gap. In the posterolateral part of the back of the knee joint lies an opening for the tendon of popliteus muscle under the arcuate ligament.

Patella

187

PATELLA Patella is situated in front of the lower end of the femur and articulates with it. It must be mentioned that it takes part in the formation of the knee joint. It is considered as the largest sesamoid bone of the body. Sesamoid bone is a bone which develops in tendon, of a muscle. It is triangular in shape having its base above and the apex below. It has two borders the medial and the lateral. Being flat, it presents anterior and posterior surfaces. Anterior surface is rough and marked by ridges produced by the tendon of quadriceps femoris. It is subcutaneous. There is bursa between the skin and anterior surface of patella. Chronic inflammation of the bursa leads to the House-maid’s knee. Posterior surface is divided into large oval area and small non-articular area. The large articular area is sub-divided into two. Larger lateral and the smaller medial corresponding to the articular areas on the femur. Medially the medial vertical facet, comes in contact with the semilunar area of the medial condyle of the femur. The remaining articular area which is oval in shape is divided into 3 by two transverse lines (Figures 213 and 214). Figure 213 Showing anterior view of patella

Figure 214 Showing posterior view of patella

• Area 1 comes into contact with the femoral articular area during extension. • Area 2 comes into contact with the femoral articular area during partial flexion. • Area 3 comes into contact with the femoral articular area in mid flexion. The rough posterior surface below the articular area gives attachment to the ligamentum patellae which is attached to the tubercle of tibia below.

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Ossification:

Surgical:

Superior border of the patella gives attachment to the quadratus femoris which is formed by four muscles namely the rectus femoris and the three vastai. Rectus femoris and the vastus intermedius are attached to the upper border of patella. Medial border gives attachment to the vastus medialis which extends more downward than the lateral. This attachment helps in medial pull of the patella and counteracts the natural tendency of the patella dislocate laterally. It has several centers of ossification which appear during the third to sixth year and join at puberty. Accessory marginal center appears afterwards and fuse with the patella. These centers of ossification which appear as the supero-lateral angle of the patella form a separate piece of bone. It is known as bipartite or tripartite patella. This condition is bilateral and symmetrical. In multiple fractures, patella is removed (excised). Surprisingly removal of the patella does not interfere with normal functioning of the knee joint. The persons who are born without patella are leading normal life. (Patellar Paradox). In multiple fracture of the patella, the bony fragments stick to the tendon of quadriceps femoris. It is like a broken windscreen of a car where pieces of glass remain glued to the windscreen. It is autosomal dominent condition in which there is displasia of nail and hypoplasia or absence of patella.

Nailpatella Syndrome (Fong’s Syndrome): Bipartite or Tripartite There are additional one or two centers of ossification located at the Patella: superolateral angle of the patella may give rise to separate patellar pieces. It is known as bipartite or tripartite patella depending upon the number of bones. Dislocation of Due to angle between the thigh and the extensive patellar articular area Patella: on the lateral condyle of the femur, the patella has tendancy to go laterally it is counteracted by the anterior projection of the lateral condyle and pull of the vastus medialis muscles. Poor development of the patella leads to lateral dislocation frequently (recurrent patellar dislocation). Surgical correction is carried out by detachment of ligament of patellae from the tubercle and attaching it to the point inferior and medial to the tubercle. (detachment and reattachment of ligamental patellae) This procedure gives good results in the adults but not in children. Tendon of semitendinosus can be passed through patella by drilling it and fixed by suturing as required.

Tibia

189

TIBIA Tibia is the medial bone of the leg. It has a shaft and two ends. Upper end is bigger and presents medial and the lateral condyles. Medial condyle is bigger than the lateral condyle and they articulate respectively with the medial and lateral condyles of the femur. Just in front of the condyles 1.5 cm below is a tubercle known as tibial tubercle. It gives attachment to ligamentum patellae. A stout process projecting downwards from medial side of the lower end known as medial malleolus. The lateral surface of the medial malleolus articulates with the comma shaped articular surface of the talus. Tip of the medial malleolus gives attachment to the deltoid ligament. Anterior border of the tibia is subcutaneous. It is not straight but curved and ends in front of the medial malleolus. “This information is enough to decide the side of the bone (Figures 215 to 217). Figure 215 Showing borders and surfaces of tibia and fibula in cross section

Figure 216 Showing anterior view of tibia and fibula

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Figure 217 Showing posterior view of tibia and fibula

Upper end:

Medial condyle is larger than the lateral. At the periphery of the articular surfaces of the condyles, semilunar strips meant for the semilunar cartilages are placed. Medial semilunar cartilage being border, its anterior and posterior ends lie in front and behind the anterior and posterior ends of lateral semilunar cartilage. In other words medial semilunar cartilage tries to catch the two ends of lateral semilunar cartilage. In between the tibial articular areas there is rough area in front and behind with tibial spines in between. Tibial spines can be seen in X-rays. The attachments of the upper end of the tibia are as under from before backward. 1. 2. 3. 4. 5. 6.

Medial semilunar cartilage Anterior cruciate ligament Lateral semilunar cartilage Lateral semilunar cartilage Medial semilunar cartilage Posterior cruciate ligament. Around the periphery of the condyles is the attachment of short series of coronary ligaments except’ at the posterior border of the lateral condyle of tibia where the tendon of the politeus glides. In front of the lateral condyle there is a comma shaped facet for the attachment of the ilio-tibial tract. There is a grove on the posterior surface of the medial condyle of tibia for the semi-membranous muscle. Posterolateral aspect of lateral condyle of tibia presents a facet for upper end of the fibula. Tubercle of the tibia is divided into upper smooth and the lower rough areas or parts indicating the site of epiphyseal line between

Tibia

Shaft:

Capsular Attachment:

Ossification:

Surgical:

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the upper epiphysis and the shaft. Ligamentum patellae is attached to the smooth area of the tubercle. It has three borders namely the anterior, medial and the interosseous. It has three surfaces, medial, lateral and the posterior. Medial surface gives insertions to three muscle in the upper part. These muscles are sartorius, gracilis and semitendinosus. Rest of the medial surface is devoid of any muscular attachment and deep fascia of the leg is fused with its periosteum. Lateral surface in its upper three fourth gives origin to the tibialis anterior muscle. Lying in front of the medial malleolus is the long saphenous vein. Posterior surface is divided into three distinct areas. Its upper one fourth is triangular in shape which is limited by the soleal line, below which it is divided into the lateral and the medial areas by the vertical line. The triangular area gives insertion to the popliteus muscle. Medial part medial to the vertical line gives origin to the flexor digitorum longus in its upper two third, while the lateral part lateral to the vertical gives origin to the tibialis posterior muscle. Tibialis anterior muscle arises from the tibia alone while the tibialis posterior arises from both the bones of the leg the tibia and the fibula. This origin is similar to the origin of the muscle abductor pollicis longus of the superior limb. The posterior surface of medial malleolus presents groove for the tendon of the tibialis posterior. Capsule at the upper end is attached in a V shaped manner anteriorly and posteriorly the capsule is attached beyond the articular area. At the posterior border of the lateral condyle, capsule presents a gap for tendon of the popliteus muscle. It has three centers of ossification one for the shaft and one for each end. Primary center of ossification for the shaft appears at seventh week of intrauterine life. The center for the upper end appears at birth and fuses with the shaft at 16-18 years. Center for the lower end appears during first year of life and unites with the shaft at 16-18 years. Lower end is the growing end. The upper epiphysis includes the tuberosity of the tibia. Tuberosity of the tibia and the medial malleolus may have separate centers. Shaft of the tibia is weak at the junction of upper two thirds and lower one third. Lower part of the tibia has no muscular attachments as it is covered with tendons alone. Absence of muscular attachments in the lower part of the tibia results in relatively poor vascular supply to the bone. It is the reason for the delayed union of the fractures in the lower part of the tibia.

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FIBULA

Upper end:

How to Trace the Anterior Border:

Anterior Surface of the Fibula:

Fibula is the lateral bone of the leg. It has shaft, upper and the lower end. Upper end present head, neck and the styloid process. It has an articular area for the lateral condyle of the tibia. 1. It provides attachment to the number of muscles therefore has rich blood supply. 2. It forms the tibiofibular mortoise at its lower end where it articulates with the lower end of tibia by means of fibrous joint. The joint is known as syndesmosis. Tibio-fibular mortise is formed by the lower end of the tibia and the fibula with the help of the inferior transverse tibio-fibular ligament. Upper end of the fibula articulates with the lateral condyle of the tibia and forms the superior tibia-fibular joint. Biceps femoris muscle is inserted into the head of the fibula. Styloid process gives attachment to the lateral collateral ligament of the knee joint. Immediately below the head lies the neck which is related to the common peroneal nerve (lateral popliteal nerve). In order to understand the borders, the side and surfaces we have to go to lower end. Lower end presents the lateral malleolus which is compressed from side to side. Lateral surface of the lateral malleolus presents a subcutaneous triangular area with an apex directed upwards. Medial surface of the lateral malleolus presents three zones from above downwards. a. Rough surface for interosseous ligament. b. Presents inverted articular triangular area for the similar area on the lateral surface of the talus. c. Immediately below and behind it lies the malleolar fossa. The lateral malleolus gives attachment to the anterior and the posterior talofibular ligaments and the caleaneofibular ligament. The malleolar fossa gives attachment to the inferior transverse tibia-fibular ligament. If the apex of the subcutaneous triangular area on the lateral malleolus is followed upwards one comes to the anterior border of the fibula. Interosseous border is situated medially. It gives attachment to interosseous membrane and does not go upto the head of fibula leaving a gap for the passage of anterior tibial vessels. Medial to the interosseous border is the vertical crest and medial to the vertical crest is the posterior border. Vertical crest is situated on the posterior surface and divides it into the medial and the lateral areas. Fibula has three borders and three surfaces which can be seen by the study of the figure. As it is difficult to show the muscle attachments of the bone as the fibula is almost like a stick. Therefore, it is proposed to give a schematic representation of the origin of the muscles from anterior, lateral and the posterior surfaces of the fibula. Is divided into four equal parts. Upper one fourth and the middle twofourth gives origin to the extensor digitorum longus muscle. Now the middle two-fourth gives origin to the external hallusis muscles and the remaining one-fourth is for the origin of the peroneous tertius muscles.

Fibula

How to Decide the Side of Fibula (Figure 218):

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Posterior surface of the fibula in its upper one-forth gives origin to the soleus muscle. While the rest of the posterior surface is divided into the medial and the lateral areas by means of the vertical crest. Area lateral to the vertical crest gives origin to the flexor hallusis longus muscle and the area medial to the vertical crest gives origin to the tibialis posterior muscle. Identify the lateral malleolus, the triangular articular facet, malleolar fossa and the triangular subcutaneous area on the lateral aspect of the lateral malleolus. Put the tip of the thumb in the malleolar fossa and the index on the lateral triangular area of the lateral malleolus. You can hold only right fibula in the right hand and the left one in the left hand.

Figures 218 Showing how to decide the side of fibula. Thumb in the malleolar fossa and index on lateral malleolus. One can hold the right fibula only in the right hand

Ossification of Fibula:

Skeleton of the Foot (Figure 219):

Tarsal Bones:

It has three centers of ossification, one for the shaft and one for each end. The center for the shaft appears in the 8th week of intra-uterine life. The center for the lower end appears in the first year and unites between the 16-17 years. Center for the upper end appears in the 4th year and units with the shaft at the age of 18 years. Fibula does not follow the normal pattern of ossification. (appear first fuses last) Its arrangement is divided into three zones namely A,B,C from behind forwards. In the first is the zone of tarsals, second is the zone of the metatarsals, and the third is the phalanges. In normal anatomical position thumb of the superior limb is directed laterally while the great toe of the inferior limb is directed medially. During embryonic life the lower limb has undergone a rotation of 90° medially. In the upper limb the third metacarpal bone forms the middle axis of the hand, while the second metatarsal forms the middle axis of the foot. They are seven in number, while the carpal bones of the upper limb are eight. They support the weight of the body, hence are stronger and larger than the carpals. Tarsal bones are arranged in two rows, proximal and the distal. In the proximal row there are two bones, largest being the calcaneum which lies below the talus. The second row is made up of bones from lateral to medial side. They are cuboid, lateral cuneiform, intermediate cuneiform and medial cuneiform. Navicular is situated on the medial side in between the two rows.

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Figuer 219 Showing ossification of some of the bones of foot

Calcaneum is the largest bone on which sits the talus. Its long axis is directed laterally. Calcaneum ariticulates with cuboid and talus articulates with navicular. Cuboid articulates with lateral cuneiform. Five metatarsals articulate with this distal row of four bones and phalanges. There are two phalanges for the great toe. Thumb too has two phalanges.

Talus

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TALUS It has head, neck, and body, superior surface, inferior surface and the lateral surfaces. Talus is a bone of ligaments as no muscle is attached to it (Figures 220 to 222). Figure 220 Showing medial surface of left talus

Head:

Medial Surface:

Figure 221 Showing inferior surface of left talus

Head is directed antero-medially and articulates with navicular bone. On the plantar surface of talus there are three articular surfaces. Two are for calcaneum situated anteriorly and the posterior most is larger, is meant for similar articular surface of the calcaneum. On the lateral side there is a triangular articular facet for lateral malleolus of fibula. Medial surface presents a comma shaped articular facet for the medial malleolus of the tibia. On the postero-medial aspect there is a tubercle for the deltoid ligament (Figures 218). The groove on the posterior aspect of the talus is meant for flexor hallucis longus which lies between the medial and the posterior tubercles. Anteriorly, lower part of the head of talus is in contact with or supported by the plantarcalcaneonavicular ligament (spring ligament) (Medial tubercle gives attachment to the medial talo-calcaneal ligament and also to the deltoid ligament) . Inferior surface presents sulcus tali in the middle of the articular areas (Figures 221).

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Superior Surface:

Superior aspect presents the head, neck and the trochlear surface for the lower end of the tibia. The groove for the flexor hallucis longus can easily be seen form superior surface which lies between the medial and posterior tubercles. Note that lateral margin of trochlear surface is flattened posteriorly like a strip. It is due to the contact with inferior transverse tibia-fibular ligament in dorsiflexion of the foot (Figures 222).

Figure 222 Showing superior surface of left talus

Clinical:

1. Avascular Necrosis: In fracture neck of the talus head of the talus undergoes avascular necrosis as the blood supply of the head is from the body of the talus. 2. Vertical Talus: It is seen in rocker bottom foot type of deformity of foot where concavity of the foot is replaced by the convexity.

Calcaneus

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CALCANEUS

Posterior Surface:

Calcaneus is the largest bone and lies below the talus and extends at least three fingers behind the lower end of the tibia. This helps in walking as it provide leverage. Calcaneum is directed antero-laterally and it articulates with the cuboid. It can be divided into A, B, C from above downwards. A - for bursa. B - gives attachment to tendon tendo-calcaneus. C - Subcutaneous. Its dorsal surface is divided into three and can be labelled as A, B, C from behind forwards (Figures 223).

Figure 223 Left calcaneus dorsal view

A - It is rough in contact with fibro-fatty tissue. B - for posterior facet of talus. C - Presents two oval articular facets for the talus. Between B and C is a groove known as sulcus calcanei. When it articulates with the talus of the same side they form the sinus tarsi. Medial surface presents the shelf like projection with a groove on underneath (Figures 224). Figure 224 Left calcaneus medial view

This shelf is known as sustetaculum tali. The groove is meant for flexor hallucis, longus tendon.

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Plantar Surface: Lateral Surface: Calcaneum Plantar Surface:

It has tubercles which are three is number. The medial, lateral and the anterior almost forming the triangle. Lateral surface presents peroneal tubercle in the anterior one third and tubercle for the calcaneo-fibular ligament above and behind it. Medial process of the tuberosity gives origin to the abductor hallucis brevis and to the flexor retinaculum. Plantar aponeurosis is attached in front of them. Lateral process gives origin to abductor digitiminimi muscle (Figures 225).

Figure 225 Left calcaneus inferior or plantar view

Clinical:

Area lateral to the posterior articular facet for the talus gives origin to extensor digitorum brevis the only muscle on dorsum rest of them being tendons (It is like an oasis in the desert of tendons). Part of sustentaculum tali gives attachment to the planter calcaneonavicular ligament (spring ligament). Medial surface below the sustentaculum tali gives origin to the medial head of flexor digitorum accessorius. Lateral head of the flexor digitorum accessorius arises from the area in front of the lateral tubercle. Due to the fall from height on the feet, it is the calcaneum which gets fractured and it breaks like an egg shell.

Navicular Bone

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NAVICULAR BONE Figure 226 Left navicular bone proximal surface

Figure 227 Left navicular bone distal view

Cuneiform Bones (Figures 228 to 233):

Figure 228 Left medial cuneiform bone medial view

Navicular bone articulates with the head of talus proximally and the three cuneiforms distally. Proximal surface has single facet for the head of talus. Medial surface is important as it presents the tuberosity. Facets for all the cuneiforms are triangular. The apex of the facet for the medial cuneifom facet is directed medially and the apices of other two are directed down-wards. Tuberosity of the navicular gives insertion to the tibialis posterior muscle and the groove on the lateral side of the tuberosity gives passage to the rest of the tendon of the tibialis posterior (Figures 226 and 227). They are three in number. They are wedge-like. Proximally they articulate with navicular and distally with 1st, 2nd and 3rd metatarsal bones. 1. Medial cuneiform 2. Intermediate cuneiform 3. Lateral cuneiform.

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Figure 229 Left lateral view of medial cuneiform bone

Figure 230 Left intermediate cuneiform bone distal medial view

Figure 231 Left intermediate cuneiform bone proximal and lateral view

Figure 232 Left lateral cuneiform bone distal and lateral view

Figure 233 Left lateral cuneiform bone proximal and medial view

Note: The tibialis posterior tendon is inserted into the tuberosity of the navicular bone, all the metatarsals except first and all the tarsals except talus. (Talus is a bone of ligament and no muscle is attached to it).

Navicular Bone Cuboid (Figures 234 and 235):

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It is the large bone placed between calcaneum posteriorly and the base of the 4th and 5th metatarsals anteriorly. Posterior surface of the cuboid articulates with calcaneum to form a joint known as calcaneo-cuboid joint.

Figure 234 Left cuboid bone proximal and lateral view

Figure 235 Medial view of left cuboid bone

Metatarsals:

Plantar surface of the cuboid presents a groove which begins from the lateral side. It is bounded by two ridges the anterior and the posterior. Long plantar ligament is attached to the anterior while the short plantar ligament to the posterior ridge. This converts the groove into a canal for the passage of a tendon of peroneus longus. The peroneus longus muscle arises from the lateral surface of the fibula and goes medially to get attached to the base of the first metatarsal and the adjoining part of the medial cuneiform bone. Medial surface has the single oval facet which is meant for the lateral caneifom bone, Distal surface has 2 facets, medial quadrilateral and lateral which is triangular. Medial quadrilateral facet is for the base of 4th metatarsal, and the lateral is meant for the base of the fifth metatarsal bone. They are five in number and are miniature long bones. They are longer and stronger. They are counted from medial to lateral side, great toe being the medial most. Middle axis of the foot passes through the second metatarsal bone. The base of the second metatarsal projects proximally between the medial and the lateral cuneiform bones. 1. First metatarsal (Figure 236): It is short, thick and the strongest. Its size indicates its role in transmission of body weight. It has a kidney shaped facet at the proximal aspect of the base, having hilum pointing laterally. 2. Second metatarsal (Figure 237): It is long and has a wedge like base. Base has two facets on the lateral side and one on the medial. It being the longest bone is subjected to strain. Interference of its blood supply by micro-trauma to the epiphysis leads to apophysitis. It is known as Freiberg disease. 3. Third metatarsal (Figure 238): There is one facet on the lateral side of base and two on the medial side. 4. Fourth metatarsal (Figure 239): Presents with quadrangular base, similar to the base of the fourth metatarsal. It has one facet on lateral and one on medial sides. 5. Fifth metatarsal (Figure 240): Base presents a tuberosity directed laterally. Groove at the base is for abductor digitiminimi.

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Figure 236 Showing left 1st metatarsal A. Medial view B. Lateral view

Figure 237 Left second metatarsal A. Medial view B. Lateral view

Figure 238 Showing left 3rd metatarsal A. Medial view B. Lateral view

Figure 239 Left fourth metatarsal A. Medial view B. Lateral view

Navicular Bone

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Figure 240 Showing left 5th metatarsal A. Medial view B. Lateral view

Attachment:

Ossification:

Clinical:

Phalanges

Peroneus longus and tibial anterior are attached to the base of the first metatarsal forming a sling. Peroneus brevis and the tertius is attached to the base of the fifth metatarsal near the tuberosity. Base of the fifth metatarsal gives origin to the flexor digitiminimi muscle. First metatarsal has one primary centre for the shaft, which appear in the ninth week of intrauterine life. The secondary center for the head appears in the third year of life. In rest of the metatarsals the primary centre appears in the tenth week and secondary center for the head between the third and the fourth year. Tuberosity of the fifth metatarsal has a separate centre. March fracture: It results due to fatigue following the excessive walking at the neck of the second or the third metatarsal. Congenital short first metatarsal, foot strain on the second and the third metatarsal necks. This is commonly seen in soldier taking part in the long march. Each toe consists of 3 phalanges except the great toe which has only two, like that of the thumb in the upper limb. Phalanges ossify from two centers one for the shaft and the other for the base. In the great toe the epiphyseal center appears in the 3rd year and gets united with the shaft at 18th year. Long axis of the neck of the talus runs downwards, forwards and medially it makes an angle of 150° with the body at birth it is 130° to 140° being smaller it explains the inversion of foot in young children. A dorsolateral facet known as sqatting facet occurs on the neck of the talus of the Indians and is not seen in the Europeans. Ossification of bones foot 1. Calcaneus 2. Talus 3. Cuboid

Os trigonum:

Ossification of Metatarsal Bones:

3rd month of intrauterine life 6th month of intrauterine life Center of ossification can be seen at 5th month of extra uterine life 4. Medial cuneiform 2 centers - 2nd year 5. Intermediate cuneiform 3rd year 6. Navicular 3rd year 7. Lateral cuneiform 1st year Note: Scale like epiphysis is for the calcaneus begins to ossify at 6th year in females and 8th year in males. It unites with the calcaneus at 14 years in female and 16th years in the male. Sometimes posterior part of the talus has a separate center of ossification which is connected with a cartilage or even may be separate. It should not be confused with the picture of a fracture. It is known as Os trigonum. First metatarsal, one center for shift and one for the base. 2, 3, 4, 5 metatarsals each has one center for the shaft and one for the head and not for the base. Union of the head of the first with !he shaft and bases of the four metatarsals with the respective shaft take place at 18 to 29 years.

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FRONT OF THIGH Introduction:

Surface Iand-marks (Figure 241):

Lower limb it is meant for support of weight. Hence, the bones, muscles and the joints are built-up accordingly. The girth of the limb is more than the girth of the superior limb. The limb is indispensable for locomotion. The limb undergoes the medial rotation during embryonic life. This results in two changes: (1) The knee points in front instead of backwards, (2) The great toe is situated medially. The inferior limb develops later than the superior. The foot presents arched appearance. It is a due to these arches, we enjoy elasticity and resilience and efficiency. The arches of foot are the springs of the human body. Corresponding to the movements of pronation and supination of superior limb. the movements of eversion and inversion occur in the inferior limb. At the ankle only flexion and extension movements are permitted in contrast to the wrist, where more movements are permitted such as palmar flexion, dorsi flexion, ulnar deviation, radial deviation, and the circumduction. The skin of the sole is thicker and has a less discriminative sense than the skin of the hand. There are only seven tarsal bones as compared to eight carpal bones of superior limb. The hip bone consists of three elements, namely ilium, ischium and pubis. The region between the hip and the knee is known as thigh. Anteriorly its junction is marked with the trunk by means of the inguinal furrow. The inguinal ligament runs obliquely from the pubic tubercle medially to the anterior superior iliac spine laterally. The inguinal furrow marks the site of inguinal ligament. A short distance below iliac crest lies the greater trochanter on the lateral aspect. If a horizontal line is drawn from top of greater trochanter medially, it runs along pubic tubercle and crest. Five centimeters behind anterior superior iliac spine, lies tubercle of iliac crest. A line joining the highest points of iliac crests runs across the fourth lumbar vertebra. The midpoint between anterior superior iliac spine and symphysis pubis is known as mid-inguinal point. The midpoint between anterior superior iliac spine and public tubercle is known as mid-point of inguinal ligament. Please note the difference between these names with care and concentration, as it is found that commonly a student says just the reverse when asked about one or the other. If the finger is pressed firmly on midinguinal point in the living, pulsations of femoral artery can be felt against the head of femur. (Figure 241) If the flat of the hand is passed downwards along the medial side of the thigh, the first obstruction you meet is the adductor tubercle Epiphyseal line of the lower end of femur lies at the level of adductor tubercle. The patella can be moved from side to side during complete extension. During flexion popliteal fossa becomes prominent on the back of knee. The tendon of biceps femoris can be felt along the supero-lateral limit of the fossa (Figure 242). The gluteal fold does not indicate lower limit of gluteus maximus muscle. The posterior superior iliac spine is indicated by a slight depression or a dimple on the gluteal region. It lies at the level of second sacral spine. The gluteal tuberosity can be felt with maximum ease only during flexion of the hip and not during the extension.

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Figure 241 Surface landmarks of front

General Account (Figures 242 to 244):

Figure 242 Landmarks of gluteal region and back of knee

Figure 243 Compartments of thigh and course of femoral artery

The thigh is wider above and narrow below. Femur is the bone of the thigh. Profunda femoris is chief artery in the thigh. Muscles of the thigh are invested in a bag of deep fascia known as fascia lata. The thigh is divided into three compartments namely the extensor, or anterior flexor or posterior and the adductor or medial. They are supplied by femoral, sciatic and obturator nerves respectively. The femoral artery is required to pass through the opening in the adductor magnus muscle from the extensor to the flexor compartment. Beyond the opening, the artery enters the popliteal fossa, hence labeled as popliteal artery. A big vein follows the artery in the opposite direction very closely and is named as popliteal vein.

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Figure 244 Superficial fascia, its two layers and their relation to inguinal ligament and deep fascia of thigh

Cutaneous Nerves and Vessels: (Figures 245, 246 and 248 to 250)

The membranous layer of the superficial fascia lies deep. It is attached to inguinal Iigament medially but runs away from it as it proceeds laterally, where it is attached to deep fascia of the thigh. In other words. its attachment runs horizontally from the medial to the lateral side in contrast to the line of inguinal ligament, which is oblique (Figure 244). The line of attachment of the membranous layer of the superficial fascia to the deep fascia of thigh is known as Holden’s line. The fatty layer covers front of the thigh and is continuous with similar layer on the abdomen across inguinal ligament. Number of cutaneous nerves. superficial lymph nodes and vessels lie in the superficial fascia. The superficial fascia in the region of saphenous opening has a reticulated or perforated appearance, (Cribriform fascia) due to passage of the vessels and Iymphatics. Following cutaneous vessels are seen ;-. Arteries; They are superficial cutaneous branches of femoral artery. i. Superficial external pudendal, ii. Superficial epigastric, iii. Superficial circumflex iliac.

Figure 245 Superficial vessels and cutaneous nerves of the front of thigh

All of them either pass through cribriform fascia or deep fascia, nearby after their origin from the femoral artery. The superficial external pudendal crosses the spermatic cord or the round ligament of uterus from the front and goes towards genitalia and supplies the skin there. The superficial epigastric artery crosses the inguinal ligament and goes towards the lower

Front of Thigh

Veins:

Lymph Nodes: (Figure 246)

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part of the abdomen and supplies the skin there. The superficial circumflex iliac runs along the inguinal ligament and goes towards the anterior superior iliac spine. Please note that these vessels supply superficial inguinal group of nodes on their way. They are three corresponding to the above superficial arteries. They are seen joining the long saphenous vein. Please recollect that tributaries of cephalic vein in the superior limb also join cephalic vein and do not go directly to the axillary. Here, similar is the method of joining the tributaries of the long saphenous vein. They join the long saphenous and do not go to the femoral vein directly. They are arranged in two sets, namely the vertical and the horizontal. The members of vertical group are in association with long saphenous vein, while members of horizontal group are found below inguinal ligament. Most of the nodes of this group are placed below the attachment of membranous layer of superficial fascia to the deep (Holden’s line) (Figure 244). The Iymphatics from the superficial part of the limb and join these nodes. They drain following regions:- (1) superficial part of limb, (2) gluteal region, (3) perineum, terminal part of anal canal, external genitalia, (4) part of fundus of uterus along the round ligament of uterus in females. Therefore, an enlargement of these nodes could possibly be due to inflammation, injury or the tumor at these places apart from the limb. In other words, if no site of inflammation is found in the limb proper, the search at other places such as pelvic cavity and perineal region should be made. Efferent vessels from the nodes go to deep group of nodes lying by the sides of femoral, vein. While doing so they have to pass through deep fascia or cribriform fascia (Figure 246). Now the Iymphatics from deep nodes drain into external iliac group of nodes, which lie in association with external iliac vein (please remember that femoral vein continues into the abdomen, beyond inguinal ligament, as an external iliac vein).

Figure 246 Superficial inguinal lymph nodes

Long Saphenous Vein (Figures 247A and 247B):

It is the longest thick walled vein with the valves (18 to 20 in number) and is easily seen. The saphenous word is from Arabic which means ‘‘easily seen’’. It is comparable to cephalic vein of upper limb. It begins at the medial end of dorsal venous arch after receiving a vein from the medial side of the great toe, passes in front of medial malleolus and lies over tibia for a short while. This is the most important relation of medial malleolus clinically as this is the site where the vein can be cut for the purposes of intusions and transfusions particular when the other veins are collapsed. The vein ascends along the medial border of tibia and goes to the back of knee. It emerges from the back of the knee and enters the region of thigh on

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Kadasne’s Textbook of Anatomy (Clinically Oriented) its medial aspect. As it does so, it ascends obliquely upwards and laterally upto the point where it pierces the cribriform fascia and hooks the inferior margin of the saphenous opening. On its way, it is connected with underlying deep veins lying deep to the deep facia by means of short channels which are known as perforators. The perforators are provided with the valves, which allow blood from the superficial veins to the deep veins. Their incompetence leads to reversal of blood flow.

Figure 247 Long saphenous vein

Figure 247A Showing venous drainage of lower limb

Front of Thigh Figure 248 Cutaneous nerves of thigh

Figure 249 Showing cutaneus nerves of the flexor surface of the lower limb

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Figure 250 Showing cutaneus nerves of the posterior aspect of the lower limb

Tributaries:

Perforating Veins:

The saphenous vein, before it pierces cribriform fascia, is joined by 1. The superficial external pudendal 2. Superficial epigastric 3. Superficial circumflex iliac 4. The deep external pudendal join the long the saphenous vein before it pierces the femoral sheath. Superficial epigastric veins unites with the lateral thoracic vein and forms an anastomatic channel on the antero-lateral aspect of the trunk. It forms an important connection between the veins of the upper and the lower limbs. Apart from these number of veins join the long saphenous during its course, throughout the limb including that from the sole and the dorsum of the foot. In the leg it receives anterior vein of the leg and the posterior arch vein. Posterior arch vein begins at the medial malleolus ascends upwards on the medial aspect of the calf and joins the great saphenous vein. Posterior arch vein is connected to the posterior tibial vanae comitantes by means of three perforators. Posterior arch vein is also known as Leonardo da Vinci’s vein (Leonard). The antero-lateral and the posteromedial veins of the thigh join the great saphenous vein in the region of the thigh. The deep external pudendal vein joins the long saphenous vein before piercing the femoral sheath. Perforators are the venous channels connecting the superficial veins with the deep veins by perforating the deep fascia. They are provided with valves which allow blood flow from superficial to the deep and not from the deep to superficial in the normal physiological state. In the event of damage to the valves the blood can flow from deep to superficial leading to elongation, dilatation and the tortuosity of the superficial veins. This is known as varicose vein. Following three main perforators are seen in the leg one at the ankle, one in the midcalf and one in the adductor canal (Hunterian canal). The perforator near the medial malleolus is known as Cockett’s perforators.

Front of Thigh

Clinical:

Valves:

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They connect the posterior arch vein with the vena comitantes associated with the posterior tibial artery. Naturally these perforators are known as indirect perforators as they do not join the long saphenous vein directly. In the midcalf there is perforator known as Boyd’s perforator (Boyd – Sherman’s perforator) which again forms the connection between the posterior arch vein and the vanae comitantes of the posterior tibial artery. The third perforator which lies in the middle of the thigh is known as Hunterian perforator. It connects the great saphenous vein to the femoral vein in the adductor canal or the Hunter’s canal. There is an additional perforator at the Achilles known as Bassi’s perforator. 1. It is selected for venous cut in emergency when the other veins are collapsed. Incision is given in front of the medial malleolus for the exposure of the great saphenous vein. Care should be taken not to cut or injure the saphenous nerve which accompanies the long saphenous vein. 2. Being muscular the vein is used for the coronary arterial by-pass. Before the placement of the graft it is tested for the patency by reversing it. 3. Deep vein thrombosis: It is also known as phlebo-thrombosis which is the worst complication to occur postoperatively. Detachment of the thrombus can lead to the pulmonary embolism and death. 4. Varicose veins of the lower limb: In the early stages the patient complains of sense of tiredness and the pain in the calf. It may be associated with the itching of the skin in front of the medial malleolus. Factors for the occurrence of the varicose veins of the lower limb are attributed to (a) Prolonged standing (b) Cycle-riksha pullers (c) Incompetence of the perforators which allow reversal of the blood flow from the deep to the superficial veins. Incompetent sapheno-femoral valve allows blood to flow from the femoral to the saphenous vein leading to varicose veins. 5. Saphena varix: It is a sacular dialatation of the terminal part of the saphenous vein. The swelling disappears when the patient lies down but the sac of the femoral hernia does not disappear and remains palpable. 6. Varicose veins get inflamed commonly near the medial malleolus which results in pain, itching and tenderness. The area may ulcerate and produce varicose ulcer. Cause of the devitalisation of the skin at the midial malleolus is stasis leading to anoxia causing lipolysis. Cancer may develop in the varicose ulcer which is known as Marjolean’s ulcer. 7. Trendeleburg test: Patient is asked to lie down and raise his lower limb so that the veins of the lower limb get emptied. Thumb is placed at the sapheno-femoral junction and the patient is asked to standup. Instant filling of the great saphenous vein after release of the pressure indicates sapheno-femoral incompetence. If there is slow filling of the veins from below upwards even when the thumb is pressing indicates damage to the perforators. Both the tests are known as Trendeleburg test. 8. Perthes test: Patient is asked to walk with tourniquet around the upper part of the thigh. Varicose veins get collapsed if the deep veins and the perforators are normal. They get distended in case of the block. It is provided with eighteen to twenty valves, which act as shelves and support the column of blood. This helps pushing of the blood upwards against gravity. In case of pregnancy, the uterus presses on pelvic veins, leading to stasis of blood in the veins of the legs. Nowadays operation for varicose vein such as removal of (stripping of the long saphenous vein) is avoided as the long saphenous vein being muscular may be required in

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Physiological Varicose Veins: Diagnosis and Assessment of Varicose Veins:

Lumbar Plexus (Figure 251):

future for grafting in the coronary bypass surgery. Recently radial artery being superficial and easily accessible is used for the purpose of homograft in the coronary bypass surgery. Factors ensuring venous return towards the heart: 1. Valves: Damage to the valves leads to varicose veins. 2. Venous tone 3. Deep fascia 4. Calf muscle pump 5. Ankle joint movements: Its impairment of mobility is an important non-vascular cause. 6. Stretching of the plantar collecting vein with each step. 7. Respiration: negative pressure in the thorax. 8. Postural vasoconstriction. 9. Arterial pulsation of the nearby artery. It is seen that the combined action of the muscles and the joint of the lower limb play a significant role in physiology and patho-physiology of the venous return. In pregnancy uterus presses on the pelvic veins which lead to varicosity of the veins of the lower limb. It does not require treatment. With termination of pregnancy the condition returns to normal in about three months. Ultrasonography is done for assessment of the venous disease. It gives answer to the etiological diagnosis of the varicose veins. Doppler ultrasound and Duplex ultrasound are being used for the same purpose. Status of long saphenous vein in surgery: 1. Stripping of the long saphenous vein is no longer done. 2. It is not used for coronary bypass as the radial artery has replaced it on its own merits. 3. Its use as a autograft for the bypass in cases of the arterial blocks of the limbs. Use of long saphenous as a graft is still popular in spite of the availability of the artificial grafts. It is formed by the anterior primary rami of the upper four lumbar nerves. Following branches are given from it:

Figure 251 Lumbar plexus

1. lIio-hypogastric: from L-1. 2. Ilio-inguinal: from L-1. 3. Genito femoral from L-1 and L-2

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4. Lateral cutaneous nerve of thigh from L-2 and L-3. 5. Obturator from anterior division of L-2, L-3 and L-4. 6. Femoral from posterior division of L-2, L-3 and L-4. Following nerves are to be studied in the region (Figures 248 to 250): 1. Ilio-inguinal, 2. Femoral branch of genitofemoral, 3. Lateral cutaneous nerve of thigh, 4. Intermediate cutaneous nerve of thigh, 5. Medial cutaneous nerve of thigh, and 6. Saphenous: intermediate, cutaneous nerve, medial cutaneous nerve of thigh and saphenous nerve arise from the femoral. Ilio-inguinal (L-1):

It comes out of the inguinal canal through the superficial inguinal ring. It supplies skin of scrotum in male, labium majus in female and a small part of skin of the thigh.

Femoral Branch of Genito-femoral (L-1 and L-2):

It perforates the deep fascia lateral to saphenous opening and supplies the small part of skin below inguinal ligament. In the femoral sheath femoral branch of the genitor-femoral nerve lies anterior to the femoral artery.

Lateral Cutaneous Nerve of Thigh (L2 and L3):

It pierces the deep fascia immediately below the lateral end of the inguinal ligament. Due to the narrow fibrous tunnel, through which it passes, it is likely to get compressed. This gives rise to a condition known as meralgia paraesthetica. According to some authorities, the lateral cutaneous nerve actually passes through lateral end of inguinal ligament. Two to three fingers below the anterior superior iliac spine it gets divided into the anterior and the posterior divisions. The anterior division after piercing the deep fascia runs vertically downwards upto the knee. It supplies the skin of front and the lateral side of the thigh. The posterior branch pierces the deep fascia and supplies the skin over the greater trochanter and part of gluteal region.

Intermediate It perforates deep fascia at the junction of upper third and middle third of Cutaneous Nerve of the thigh, divides into two branches which go upto the patella. Thigh (L2 and L3): Medial Cutaneous Nerve of Thigh (L2 and L3):

It supplies medial aspect of the thigh. Its two branches lie respectively in front and behind long saphenous vein. The anterior branch goes upto knee joint. The posterior branch becomes superficial at the knee and runs still downwards to supply medial aspect of the leg.

Saphenous Nerve (L3 and L4):

It follows the great saphenous vein faithfully hence the name. It is the branch of the femoral. At the medial aspect of knee, it becomes superficial as it courses between sartorius and gracilis tendons. It is accompanied by the saphenous branch of the descending genicular artery. It gives the Infrapatellar branch which lies immediately below the patella.

Patellar Plexus (Figure 252):

Lateral cutaneous nerve of thigh, intermediate cutaneous nerve of thigh, medial cutaneous nerve of the thigh and the saphenous nerve take part in its formation. The plexus lies in front of ligamentum patellae and the tubercle of the tibia.

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Figure 252 Patellar plexus

Superficial Inguinal It is the triangular opening in the aponeurosis of the external oblique Ring (Figure 253): muscle. It lies just above the pubic tubercle and pubic crest. Spermatic cord in male and round ligament of uterus in the female comes out through it. As mentioned before the ilio-inguinal nerve also comes out through the opening. Figure 253 Superficial inguinal ring

Deep Fascia of Thigh:

Attachment in Detail:

It invests muscles of the thigh. It is attached to the hip bone above and the bones around the knee below. It is thickened on the lateral side to form a special band known as the ilia-tibial tract. As the name suggests the tract runs from iliac crest to the lateral condyle of tibia. Three fibrous septae run from the inner side of fascia to the linea aspera to divide the thigh in three compartments. One and half inch below and lateral to pubic tubercle the deep fascia presents an opening which is known as the saphenous opening. The fascia is continuous with gluteal fascia behind. In the region of popliteal fossa, it is known as popliteal fascia. 1. Proximal attachment. The line of attachment can be traced as the continuous line starting from the body of pubis, along the inguinal ligament, iliac crest, sacrum, coccyx, sacro-tuberous ligament, ischial tuberosity and the pubic arch so that you come back to the body of pubis completion the circle. In other words the line of attachment follows periphery of hip bone except in front and behind, where inguinal and sacro-tuberous ligaments give attachment to fascia. The fascia divides twice, (1) To enclose tensor fascia latae and (2) Gluteus maximus muscles.

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Distal Attachment:

It’s attachment to the prominent bony points around the knee. They are the condyles of femur, condyles of the tibia, head of the fibula, tubercle of the tibia, medial and lateral margins of the patella and the capsule of the knee joint. The deep fascia of thigh gives attachment to the membranous layer of superficial fascia below inguinal ligament along the line known as Holden’s line. Ilio-tibial tract receives insertions of the tensor fascia latae and the gluteus maximus muscles. Saphenous Opening It is a well defined gap in the deep fascia of thigh. The center of opening (Figure 254): lies 3.75 cm below and lateral to pubic tubercle. Its superior, lateral and lower margins are well defined. The medial margin slopes behind the upper and continues as fascia over pactineus muscle. The length of the opening is three times more than its breadth. Immediately behind the opening lies the femoral vein with the femoral sheath. Figure 254 Saphenous opening

Inguinal Ligament (Figure 255):

The opening is closed by the sieve like fascial septum known as cribriform fascia. (Sieve—means a piece mesh or net). Well defined edge of the opening is known as falciform margin. It is the lower, free, in-rolled lower margin of aponeurosis of the external oblique muscle of abdomen. It is attached to pubic tubercle medially and anterior superior iliac spine laterally. The lower convexity of the ligament is due to the firm pull of deep fascia of thigh.

Figure 255 Inguinal ligament

Following are parts of the ligament: 1. Pectineal part of inguinal ligament (Lacunar ligament), 2. Pectineal Iigament of Sir Astley cooper. 3. Reflected part of inguinal ligament runs from the lateral crust of the superficial inguinal ring to the linea alba. It passes behind the superficial inguinal ring in front of the conjoint tendon and decussates with the fibres of the opposite side near the linear alba.

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Femoral Sheath (Figure 256):

Pectineal part of inguinal ligament (Lacunar ligament): It lies horizontally and presents superior and inferior surfaces. It is triangular in shape with its apex at the pubic tubercle and the concave base towards the femoral ring forming the medial margin of the femoral ring. It has pelvic and the femoral surfaces. Pelvic surface is related to the spermatic cords in male and round ligament of uterus in female. Its upper and lower borders are attached to inguinal ligament and pectineal line, respectively. The femoral surface is pointing downwards and laterally. The inguinal ligament acts as the protective arch for the femoral vessels and the nerve. From medial to lateral side, following muscles occupy the gap: 1. Pectineus, 2. Psoas, 3. Iliacus. Femoral vein, femoral artery and the femoral nerve lie from medial to the lateral side. Funnel shaped fascial packet for the femoral vessels is known as the femoral sheath. (Similar to axillary sheath), Femoral nerve lies outside the sheath the lateral to the femoral artery. Let us consider the femoral sheath. It is the funnel shaped fascial pocket for the upper one and half inches of the femoral vessels situated at the base of the femoral triangle. Its anterior wall is formed by the fascia transversalis and the posterior by the fascia iliaca. Distally the layers fuse with the adventetia of the femoral vessels. On the medial and the lateral side, layers get fused, thus forming an enclosed space for the femoral vessels. Its length is one and half inch (3.75 cm.) at the lateral border and it is only half an inch (0.75 cm) at the medial border. Therefore its distal line is oblique. Femoral sheath is divided into three compartments by the fibrous septae. Medial most compartment is known as the femoral canal. The middle compartment is meant for the femoral vein and the lateral compartment for the femoral artery. It must be remembered the femoral nerve enters the femoral triangle under the inguinal ligament lateral to the femoral artery and outside the femoral sheath.

Figure 256 Femoral sheath

Femoral Canal (Figures 257 and 258):

It is the medial most, shortest and the relatively empty compartment of the femoral sheath. It has length of half an inch and contains a lymph node known as gland of Cloquet which drains the glans penis in the male and the clitoris in the female. It also provides passage for the lymph vessels. It opens into the abdomen by means of femoral ring which is closed by fatty areolar tissue known as femoral septum. The femoral ring is formed by inguinal ligament anteriorly, pectineal line posteriorly and the sharp concave margin of the lacunar ligament medially. Femoral ring is larger

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in female due to larger size of the pelvis. Hence the femoral hernia is common in the female. Sac of the femoral hernia enters the femoral canal through the femoral ring. It goes anteriorly and comes out through the saphenous opening. It may go towards the inguinal ligament and reach the anterior abdominal wall. Femoral hernia is prone for obstruction at the femoral ring which is narrow and rigid. During release of the femoral hernia surgeon has to cut the concave lateral margin of the lacunar ligament. In small percentage of the cases pubic branch of the inferior epigastric artery and the pubic branch of the obturator artery form an abnormal large vessel against the pelvic surface of the lacunar ligament. A Surgeon must be aware this anatomical fact before cutting the lacunar ligament for the release of the obstructed femoral hernia. Figure 257 Showing femoral sheath and canal

Femoral canal plays three roles as under: (Figure 257A) 1. Anatomical 2. Physiological 3. Surgical Figure 257A Showing dilatation of femoral vein during increased venous return

1. Anatomical: It provides room for the gland of the Cloquet and acts as the road for the passage of lymphatic. 2. Physiological: It allows dilatation of the femoral vein due to increase venous return during exercise. 3. Surgical: It is the site for femoral hernia.

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Abnormal Obturator It is the enlarged communication of the pubic branches of the inferior Artery (Figure 258): epigastric arteries and the obturator arteries. Sometimes it replaces the obturator artery completely. It may be related to the pelvic surface of the pectineal part of the inguinal ligament in small percentage of cases. (lacunar). Figure 258 Abnormal obturator artery seen from the back

Front of the Thigh (Figure 259):

Anterior compartment of thigh is an extensor. In the upper two thirds of the front of the thigh lies the femoral triangle. The base of the femoral triangle is above and the apex below. Base is formed by the inguinal ligament. Medial border is formed by the medial border of the adductor longus muscle and the lateral border by the medial border of the sartorius. The sartorius and the adductor longus overlap at the apex. Femoral triangle opens in the sub-sartorial canal which is situated in the lower one third of the medial aspect of the thigh.

Figure 259 Front of the thigh

The sartorius muscle runs from the anterior superior iliac spine obliquely down and medially to reach the upper part of the medial surface of the tibia for its insertion. It forms the lateral boundary of the femoral triangle and also the roof of the sub-sartorial canal. It is the key-muscle of the thigh. Medial to it are the iliacus, psoas, pectineus and the adductor longus muscles from lateral to medial side. While on the lateral side, the rectus femoris, vastas lateralis and part of the vastas medialis are seen. Tensor fascia latae muscle is placed in the upper and lateral part of the thigh running from the area lateral to the iliac crest to the ilio-tibial tract. Lateral boundary of the thigh is marked by a special thickened part of the deep fascia running from the iliac tubercle above to the comma shaped impression in front of the lateral condyle of the tibia below.

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Sartorius (Figure 260):

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If the adductor longus and the pectineus are separated the adductor brevis muscle and the anterior division of the obturator nerve are brought into the view. Vastus intermedius lies under the cover of the rectus femoris muscle. It is situated in front of the thigh and is the most superficial muscle. It runs from supero-lateral angle to the infero-medial angle of the thigh. Fibres of the muscle are running parallel in the direction of the muscle. The muscle forms the lateral border of femoral triangle and the roof of sub-sartorial canal. On the back of the thigh one comes across the muscle running from superomedial angle to infero-lateral angle of the thigh. It is known as the biceps femoris muscle (long head). The direction of this muscle is opposite to that of the of the sartorius. It is obvious from the directions of sartorius and biceps femoris, they must be playing a very important role in balancing the pelvis over the heads of femora.

Figure 260 Balancing action of sartorius and biceps femoris (Kadasne)

Origin: Insertion:

Nerve Supply: Action (Figure 261):

It takes origin from anterior superior iliac spine and the small part of the anterior border of the ilium immediately below. It is inserted into the upper part of medial surface of tibia. The tendon is flat and is separated from tendons of gracilis and semi-tendinosus by bursa. It is supplied by the femoral nerve (L 2,3,4). It is the flexor of the hip and the knee. In addition to this, it is the medial rotator of the leg. The peculiarity of the muscle lies in the fact that it is the flexor of both the joints, the hip and the knee (Tailor’s muscle) (Figure 261).

Figure 261 Action of sartorius (Tailor muscle)

Rectus Femoris: (Figure 262)

It lies in the middle of the front of thigh, in between vastus lateralis and vastus medialis. The vastus intermedius lies deep to it. It arises by two heads the straight and the reflected.

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Figure 262 Rectus femoris

Origin of Straight Head: Origin of Reflected Head: Insertion:

Action: Nerve Supply: Blood Supply: Clinical:

It arises from the upper part of the anterior inferior iliac spine immediately below the attachment of ilio-femoral ligament. It arises from the groove situated immediately above the acetabulum. Two heads join below the acetabulum to form the muscle belly. The flat tendon begins 7.5 cm. above the knee joint and gets inserted into the upper border of patella along with vastus medialis, lateralis, and intermedius muscles. Rectus femoris with three vasti (All together four muscles) from the quadriceps femoris muscle. The lower end of patella is attached to the tubercle of tibia by means of the strong ligament known as ligamentum patellae. It is the flexor of the hip and the extensor of the knee. It is supplied by femoral nerve. (L 1,2,3). By the branches of lateral femoral circumflex artery. Wasting and Quadriceps Drill: It is one of the important muscles of the body as its role in standing is invaluable. If the rectus femoris is paralysed and one makes an attempt to stand the knee gives way and the person falls. After an injury of the knee and surgery on the knee there is rapid wasting of the quadriceps muscle. Therefore quadriceps drill is taught to the patient. Dead Leg syndrome (Charley horse’s syndrome): Forceful injury on the front of the thigh can damage the rectus femoris muscle which leads to intermuscular or intramuscular bleeding. If the hemorrhage is intramuscular the pain and the limitation of movements are extreme. Continuous bleeding in the anterior compartment of the thigh leads to compartment syndrome. The thigh becomes painful swollen and the person is unable to move the leg. For localization of the injury, ultra-sonography can be done for detecting the site of injury and haematoma. The chronic haematoma gets fibrosed and may require excision (removal).

Fracture of Patella: Vastus Lateralis (Figure 263):

Q-Angle: (Quadriceps Angle): Line of quadriceps and the line of ligamentum patellae make an angle which is open laterally. This valgus angle is known as quadriceps angle or Q-angle. Normal value being between 10 to 12. Wider pelvis increases and promotes the natural tendency of patella to go laterally in female. Patient complains of pain (patellar pain if the Q-angle is more than 15° since the patella is pulled laterally against the lateral femoral condyles. Sudden and forceful contraction of the rectus femoris muscle can fracture the patella against the femoral condyle. It is one of the members of quadriceps femoris.

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Figure 263 Vastus lateralis and vastus medialis

Origin:

Insertion:

Nerve Supply: Action:

It arises from the upper part of inter-trochanteric line, base of greater trochanter, lateral aspect of gluteal tuberosity and upper two thirds of linea aspera. It is inserted into the lateral border of patella, where it helps to form the quadriceps tendon. Some of the fibres are inserted into the capsule of the knee joint. Fibrous extension of this muscle forms the lateral patellar retinaculum. Fibres go to lateral condyle of tibia and ilio-tibial tract. It is supplied by the femoral nerve (L 2,3,4). It is an extensor of the knee joint.

VASTUS MEDIALIS (Figure 264) Figure 264 Vastus medialis

Origin:

Insertion:

Nerve Supply:

It arises from the lower part of intertrochanteric line, spiral line, whole of linea aspera, upper two thirds of the medial supracondylar ridge and the medial intermuscular septum. It is inserted into the medial border of patella and takes active part in the formation of quadriceps tendon. The fibres descend more downwards than fibres of the vastus lateralis. As the fibres of, medialis descend more downwards at medial border of the patella, they exert more powerful medial pull on the patella. This acts as the constant check on the patella and prevents its lateral displacement. Some of the fibres of vastus medialis go to the capsule of knee joint and the medial condyle of tibia. Fibrous expansion from the muscle forms the medial patellar retinaculum. It is supplied by special nerve from femoral known as nerve to vastus medialis which lies in the sub-sartorial canal.

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Action:

It is the extensor of knee joint and also helps in keeping the patella in place by virtue of its strong medial pull. Role in Counteracting It plays an important part in counteracting the natural tendency of the Patellar Dislocation: patella to dislocate laterally. Attachment of the vastus medialis descends more downwards than the attachment of the vastus lateralis. The part which comes down is obliquely placed and is known as vastus medialis oblique and the remaining part of the muscle is known as vastus medialis longus.

VASTUS INTERMEDIUS (Figure 265) Figuer 265 Vastus intermedius

Origin: Insertion:

Nerve Supply: Action: Articularis Genu (Figure 266):

It arises from upper two third of the front and lateral surface of the shaft of femur. It also arises from lateral inter-muscular septum. It is inserted into the patella by means of the quadriceps femoris tendon. Please note that all the quadriceps femoris members gain indirect attachment into the tubercle of the tibia through the ligamentum patellae. It is supplied by the femoral nerve. (L 2,3,4) It is an extensor of knee joint. Rectus femoris muscle is the flexor of the hip and the extensor of the knee It arises from lower part of the front of the shaft of the femur and gets inserted into the synovial membrane of knee joint. It pulls the synovial membrane upwards and thus prevents its trapping between the condyles.

Figure 266 Articularis genu

Tensor Fascia Latae It arises from the outer lip of iliac crest in front of the tubercle of the iliac (Figure 267): crest, extending up to the anterior superior iliac spine. It is enclosed in deep fascia. It is inserted into the ilio-tibial tract at the level of junction of upper one third and the lower two third of thigh.

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Figuer 267 Tensor fascia latae

Nerve supply: Action:

Clinical:

Pectineus (Figure 268):

It is supplied by, superior gluteal nerve, (L-4 and 8-1). It is the tensor of illo-tibial tract. As the ilio-tibial tract runs from the iliac crest to the tibia, the muscle helps in keeping the ilio-tibial tract tense and thereby steadying the pelvis over femur and the femur over the upper end of tibia. As the ilio-tibial tract comes in front of knee joint, muscle is an extensor of the knee. The muscle does help in medial rotation of the leg by virtue of its attachment to ilio-tibial tract. Runner’s knee: It is commonly described as the site of fascial trouble. The fascial insertions of the tensor fascia lata muscle passes over the lateral condyle of the femur. Some runners complain of pain at the site, accompanied by local tenderness. The pain begins at the lateral condyle and stays there. Surgical release by cutting the ilio-tibial tract helps and the local injection of hydrocortisone gives relief. It forms the floor of femoral triangle. It arises from the pectineal surface of superior ramus of pubis, pubic crest and the fascia covering. It is inserted into the upper part of posterior surface of the shaft of femur immediately below the lesser trochanter extending up to the upper end of the linea aspera. The muscle runs downwards laterally and backwards.

Figure 268 Origin and insertion of pectineus muscle

Nerve Supply:

Action: Relations (Figure 269):

It is supplied by the femoral nerve and at times by the obturator. The nerve to the pectineus is the branch of femoral nerve, given above the inguinal ligament. It passes under the inguinal ligament and the femoral sheath to reach the pectineus. It is the flexor and adductor of the thigh. Anterior relations: i. Femoral canal, ii. Femoral vein, iii. Femoral artery,

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Figuer 269 Relations of pectineus

Posterior relations: i. Superior ramus of pubis, ii. Adductor brevis and anterior division of obturator, iii. Adductor magnus, iv. Quadratus femoris.

Medial Relations: Adductor Longus (Figure 270):

Lateral relations: i. Psoas major, ii. Iliacus, iii. Femoral nerve. Adductor longus, and profunda femoris artery as it lies between adductor longus and pectineus during its exit form femoral triangle. It forms part of the floor of femoral triangle and also part of the floor of sub sartorial canal. It arises from the body of pubis in an angle between pubic crest and symphyseal surface of the body of pubis. It is inserted into the lower part of linea aspera. On the linea aspera its insertion is placed between vastus medialis medially and the adductor brevis and the magnus laterally. Due to the narrow origin and the broad insertion the muscle has triangular shape.

Figure 270 Adductor longus

Nerve Supply: Action: Peculiarity:

By the anterior division of obturator. It is the adductor and lateral rotator of thigh. At times the strong tendinous origin of the muscle gets ossified. It is classically described as ‘Rider’s bone’.

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Anterior relations: 1. Femoral artery, 2. Femoral vein. Posterior relations: 1. Profunda femoris artery and vein, 2. Adductor brevis and anterior division of obturator nerve. Medial relations: Gracilis. Lateral relations: i. Pectineus, ii. Profunda femoris artery. Psoas Major: (Figure 271)

It arises from the last thoracic and all the lumbar vertebrae. Its origin is broad. As the muscle descends downwards. it comes out of the abdomen by passing under inguinal ligament and enters the femoral triangle, along with iliacus. Psoas major is inserted into the lesser trochanter of the femur along with the iliacus. Its tendon passes in front of the capsule of hip joint from which it is separated by the bursa (Psoas Bursa).

Figure 271 Psoas major

Clinical:

In fracture of the upper third of the shaft of femur, psoas and the iliacus cause flexion of the proximal fragment and possibly the lateral rotation.

Nerve Supply:

It is supplied by the lumbar plexus (L2 and 3). Remember that lumbar plexus lies in the substance of psoas major muscle. It is flexor of the thigh upon the trunk and flexor of the trunk upon the thigh. As regards its role in rotation of the thigh different views are expressed. (1) Medial rotator. (2) Lateral rotator. (3) No role in rotation.

Action:

Psoas Sheath:

The muscle is provided with the fascial sheath known as psoas sheath. Pus from tubercular vertebrae can come down along the sheath and appears as swelling on the upper part of the medial aspect of the thigh (Psoas abscess).

Relations:

It forms the floor of femoral triangle. Femoral artery lies anterior to the muscle, while iliacus muscle and femoral nerve lie lateral to it. Posteriorly it is related to the capsule of hip joint from which it is separated by the psoas bursa. The pectineus muscle is medial to it, with the medial circumflex femoral artery. Medial circumflex femoral artery leaves the femoral triangle, through the floor by passing between the pectineus and the psoas major muscles.

Iliacus (Figure 272):

It arises from the two-thirds of iliac fossa. It comes out of the abdomen by passing under the inguinal ligament and gets inserted into lesser trochanter and a small area of the back of upper part of the shaft of femur immediately below the lesser trochanter.

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Figure 272 Iliacus

Nerve Supply: Action: Femoral Triangle (Scarpa’s Triangle) (Figure 273):

It is supplied by the femoral nerve in the abdomen above the inguinal ligament. It is the flexor of the hip and the lateral rotator of thigh. Note: It forms part of the floor of femoral triangle. It is situated in front of the upper two third of the thigh with the base directed upwards and the apex downwards. At its apex it continues with the sub· sartorial canal. It contains femoral vein, femoral artery and the femoral nerve. It presents the base, an apex, medial border, lateral borders, the floor and the roof. The roof of the femoral triangle is formed by the deep fascia of the thigh. It presents the saphenous opening.

Figure 273 Femoral triangle and cross section of the floor

Roof:

Base: Is formed by the inguinal ligament Apex: It is the meeting point of the adductor longus and the sartorius muscles. The apex opens into sub-sartorial canal. Medial border: It is formed by the medial border of adductor longus. Lateral border: It is formed by the medial border of sartorius. Floor: It is formed by the following muscles. Adductor longus, pectineus psoas major and the iliacus from medial to lateral side. It must be noted that the adductor brevis does not come directly in the floor, since it lies deep. However, it can be examined if the adductor longus and the pectineus are separated. The floor is hollow in the center. Two arteries leave the femoral triangle through the floor (Figure 273B). 1. The medial circumflex femoral artery passes through the gap between the psoas and the pectineus muscle. 2. The profunda femoris artery passes through the gap between the adductor longus and the pectineus muscles (Figure 273B). It is formed by the skin, superficial fascia, deep fascia with saphenous opening and the cribriform fascia. Cutaneous vessels, nerves, superficial inguinal lymph nodes, long saphenous vein, femoral branch of genitofemoral and the ilio-inguinal nerve lie in the superficial fascia.

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Contents:

1. Femoral vein with circumflex veins, 2. Femoral artery with its branches, profunda femoris artery with its branches in the femoral triangle. 3. Femoral nerve, 4. Deep external pudendal artery, 5. Lateral cutaneous nerve of thigh, 6. Femoral branch of genito-femoral nerve, 7. Deep inguinal lymph nodes, 8. Femoral canal, 9. Femoral sheath, and the fat. General At the base, the relations of the structures from lateral to medial side are Arrangement of the the nerve, artery and the vein. The artery, vein and the saphenous branch Structures of the femoral run from the base to the apex of the triangle. Due to medial (Figure 274): rotation of leg the nerve passes in front of the artery and the vein passes behind the artery. Upper one and half inch of femoral vessels are within the femoral sheath. Figure 274 General arragement of structures in femoral triangle and subsartorial canal

Femoral Artery (Figures 275 to 277A)

It is the chief content of femoral triangle. It is the continuation of the external iliac artery. It runs from mid-inguinal point to the opening in adductor magnus. It is directed downwards and medially. The line of its direction can be marked on the surface, by joining the mid-linguinal point to adductor tubercle. Upper two thirds of the line indicates the course of femoral artery. Beyond the opening in the adductor magnus, the femoral artery continues as the popliteal artery.

Figure 275 Course and posterior relations of femoral artery

Relations with Femur:

The artery lies over the head; next on the medial aspect of the shaft of the femur and subsequently behind the shaft of the femur. The artery can be compressed over the head of the femur effectively to prevent bleeding in case of injury to the artery.

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RELATIONS IN FEMORAL TRIANGLE Anterior Relation (Figure 276):

Skin, superficial fascia, superficial inguinal nodes, superficial circumflex iliac vein, deep fascia of thigh (fascia lata) anterior wall of femoral sheath, femoral branch of genitor-femoral nerve, saphenous nerve, nerve to vastus medialis and medial cutaneous nerve of thigh.

Figure 276 Anterior relations in femoral triangle

Posterior Relations (see Figure 275):

Medial Relations Relations in Subsartorial Canal (Figure 277):

Figure 277 Relations in subsartorial canal (Hunter’s canal)

The artery lies on all muscles of the floor of the triangle except iliacus. It lies on the psoas, pectineus and the adductor longus, in the femoral triangle. During its course in the sub-sartorial canal it lies on the adductor magnus muscle. 1. In the region of psoas: Posterior wall of femoral sheath, nerve to pectineus, psoas major, psoas bursa and the capsule of hip joint. 2. In the region of pectineus: Profunda vessels and pectineus. 3. In the region of adductor longus: Adductor longus muscle intervenes between the femoral vessels in front and the profunda behind. Lateral relations: 1. Femoral nerve, 2. Lateral cutaneous nerve of thigh 1. Femoral vein, femoral canal in the upper part of the triangle. Before describing the course and relations of the femoral artery in the canal let us see the canal itself. It is a narrow inter-muscular space bounded by vastus medialis, sartorius, adductor, longus and the magnus. Sartorius forms roof of the canal while adductor longus and, magnus form the floor. Adductor magnus presents an opening through which the femoral artery disappears from the canal and becomes the popliteal at the back of the knee. Under the sartorius the thin fibrous roof is present on which lies the sub-sartorial plexus of nerve.

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Figure 277A Angiogram showing femoral artery

Contents:

Femoral Artery in the Canal (Figure 277A):

Branches of the Femoral Artery (Figure 278):

Figure 278 Branches of femoral artery

Femoral artery, femoral vein, saphenous nerve and the nerve to vastus medialis are the contents of the sub-sartorial canal. The arrangement of the structures in the sub-sartorial canal from lateral to medial side are VAN. V- vein, A – artery, N – Nerve. It lies on adductor longus and the adductor magnus muscles. It is covered with fibrous roof, sub-sartorial plexus of nerves and the sartorius muscle. Vastus medialis and the nerve to the vastus medialis lie antero-Iateral to artery. Femoral vein lies lateral and the saphenous nerve medial to femoral artery in the canal. Sub-sartorial canal is also known as adductor canal or Hunters canal. John Hunter found it safe and convenient to Iigate the femoral artery for treating the popliteal artery aneurysm. (Aneurysm means localised dilitation of an arterial wall). After ligation of the femoral artery, the collaterals around the knee joint open and continue the blood supply to the leg. This procedure is based on the sound knowledge of collateral circulation. They are divided into two (1) Superficial (2) Deep. Superficial branches- are three in number namely 1. Superficial Branches: 1. Superficial circumflex iliac, 2. Superficial epigastric and 3. Superficial external pudendal.

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Deep External Pudendal:

Figure 279 Relations of profunda femoris

Figure 280 Relations of profunda femoris

2. Deep Branches: 1. Deep external pudendal 2. Profunda femoris with medial and the lateral circumflex femoral arteries. 3. Descending genicular. It arises a finger’s breadth, below inguinal ligament and passes medially deep to spermatic cord in the male or round ligament of uterus in the female. It supplies the skin of the scrotum in the male and the labium majus in the female along with perineum. 3. Muscular Branches: To adductor muscles, sartorius and vastus medialis. 4. Profunda Femoris (Figures 279 and 280): It is the artery of the thigh. It is the largest branch of femoral artery given in femoral triangle approximately one and half inch (3.75 cm) below inguinal ligament. It arises from lateral aspect of femoral-artery, gradually turns behind the artery with a medial inclination. It leaves the triangle by passing through the gap between adductor longus and pectineus. Before doing so it goes deep to femoral vein. After leaving the femoral triangle it lies between adductor longus and brevis, longus being in front. In its further course it passes in front of the adductor magnus muscle. It’s termination is in the form of fourth perforating branch of the profunda femoris which takes part in the anastomosis around the knee.

Front of Thigh Relations of Profunda Femoris Artery (Figure 281):

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It lies on the pectineus, the adductor brevis and the adductor magnus muscles from above downwards. Anteriorly it is related to the femoral artery, femoral vein, profunda vein and adductor longus muscle. Vastus medialis lies lateral to the artery.

Figure 281 Course of lateral circumflex femoral artery

Branches of Profunda femoris artery: 1. Medial circumflex femoral, 2. Lateral circumflex femoral, 3. Muscular, 4. Perforating. 1. Medial circumflex femoral: Its origin is variable. It may arise from- (i) The femoral or (ii) the Profunda. It passes between the psoas major and pectineus muscles and leaves the femoral triangle. Next it passes between the adductor brevis and the obturator externus muscles and further appears between quadratus femoris and the upper border of adductor magnus. Here it divides into ascending and the transverse branches. Ascending branch goes to trochanteric fossa to anastomose with the superior gluteal artery while transverse branch takes part in the formation of cruciate anastomosis which is placed in the upper part of the thigh. The medial circumflex femoral artery gives an acetabular branch at the upper border of the adductor brevis (see Figure 280). This branch passes below transverse acetabular ligament and it supplies the hip joint. It sends small branch to the head of femur along with the ligamentum teres femoris. (Please note that the blood supply of head of femur also comes from the branch of the obturator artery). 2. Lateral Circumflex Femoral: It takes origin from the profunda femoris artery and leaves the triangle by passing under the sartorius muscle. It passes under the rectus femoris and divides into the ascending, transverse and the descending branches. The ascending branch follows inter-trochanteric line and anastomosis with the superior gluteal artery. It gives a small branch to the hip joint which passes between two parts of ilio-femoral ligament. The descending branch runs downwards behind the rectus femoris and supplies the vastus lateralis, rectus femoris and goes to the knee joint where it anastomoses with the lateral superior genicular artery a branch of poplitial. The transverse branch takes part in the cruciate anastomosis and joins the medial circumflex femoral. Superior gluteal artery and the first perforating branch of the profunda femoris artery also joins the cruciate anastomosis.

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Kadasne’s Textbook of Anatomy (Clinically Oriented) 3. Muscular branches: They are distributed to the adductor longus, brevis, magnus and the hamstring group of muscles. 4. Perforating branches of the profunda femoris (Figure 282): They are four in number: i. First branch arises at the level of the upper border of adductor brevis, ii. Second branch arises in front of adductor brevis, iii. Third arises at the lower border of adductor brevis and the iv. Forth is the continuation of profunda femoris itself (Figure 282).

Figure 282 Perforating branches of profunda

Surgical:

Femoral Vein (Figure 283A):

The perforating branches are closely related to the linea aspera, where they pass under cover of the fibrous arches at the insertion of the adductor magnus and the short head of biceps femoris. As mentioned before the first perforating branch takes part in the cruciate anastomosis. Usually the second perforating branch gives the nutrient artery to the femur. 5. Descending genicular artery: It arises from the femoral artery in the subsartorial canal and anastomoses with superior medial genicular branch of the popliteal. The descending genicular gives a small branch known as saphenous, which accompanies the saphenous nerve. The saphenous artery anastomoses with the medial inferior genicular artery. Being superficially placed in the femoral triangle (Scarpa’s triangle), and easily accessible, it is used for coronary angiography for passing the cardiac catheter. Femoral artery can be compressed against the head of the femur at the mid inguinal point for arresting the traumatic hemorrhage from the lower limb. It begins as the continuation of the popliteal vein at the opening of the adductor magnus muscle. It runs into sub-sartorial canal postero-lateral to the femoral artery and enters the apex of femoral triangle. At the apex of the triangle it lies behind femoral artery but gradually comes to lie on its medial side at the base of the triangle. Above the inguinal ligament, it continues as the external iliac vein. Femoral vein is placed in the special compartment of the femoral sheath lateral to the femoral canal. During increase venous return of lower limb femoral vein dialates on the medial side as the medial most compartment of the femoral sheath is relatively empty. In other words femoral canal allows dialatation of the femoral vein during increase venous return.

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Figure 283A Femoral vein

Anterior Relations of Femoral Vein:

Skin, superficial fascia, deep fascia (fascia lata), saphenous opening, cribriform fascia, anterior wall of femoral sheath, small part of femoral artery at the apex, saphenous nerve, medial cutaneous nerve of thigh, the nerve to vastus medialis and the long. saphenous vein with superficial inguinal lymph nodes, near its termination. Medial Relations: Femoral canal lies medial to the femoral vein at the base of the femoral triangle and the saphenous nerve lies medial to the femoral vein in the sub-sartorial canal. Lateral Relations: Femoral artery, femoral branch of genito the femoral and femoral nerve with its branches are the lateral relations. Nerve to vastus medialis is antero-lateral to the vein in the subsartorial canal. Posterior Relations: From below upwards, adductor magnus, adductor longus and the pectineus muscles are posterior to the femoral vein. Profunda femoris vessels also lies deep to the vein in the femoral triangle. Note: At the apex of femoral triangle the antero-posterior relations are: i. Saphenous nerve, nerve to vastus medialis, and medial cutaneous nerve of thigh, ii. Femoral artery, iii. Femoral vein, iv. Adductor longus, profunda femoris vein, v. Profunda femoris artery, vi. Two to three deep lymph nodes are associated with the upper part of femoral vein in the femoral triangle.

Valves: Clinical:

Tributaries: i. Profunda femoris vein, ii. Long saphenous vein, iii. Muscular tributaries, iv. Many times it receives lateral and medial circumflex femoral veins. They are at two places; (i) At the upper part of the vein near the base of femoral triangle and (ii) below the opening of profunda-femoris vein. 1. It can be used for taking blood samples, infusions and transfusions in children’s. 2. The cardiac catheter can be passed to reach the pulmonary trunk for obtaining the blood sample from the pulmonary veins.

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Profunda Femoris Vein: Femoral Nerve (Figure 283B):

3. In varicose veins long saphenous vein is ligated, flushed at the saphenofemoral junction to prevent the recurrence. It receives muscular and accompanying veins of perforating arteries. It lies in front of its own artery, enters the triangle and opens in the femoral vein, on the posterior aspect. It is the branch of the lumbar plexus, (L2, 3, and 4). Ventral rami of L2, L3 and L4 divide into anterior and posterior branches. The posterior branches of the ventral rami of L2, L3, L4, form the femoral nerve. It comes out of psoas major at its lateral border. Thereafter, it lies between the psoas major and the iliacus. It is under cover of the fascia iliaca. It occupies an interval between the psoas major medially and the iliacus laterally. It enters the femoral triangle by passing under the inguinal ligament lateral to the femoral artery and outside of the femoral sheath. One and half inch below inguinal ligament it divides into number of branches.

Figure 283B Femoral nerve (schematic)

Branches:

In the Thigh (Femoral Triangle):

In the abdomen: (1) Branch to the iliacus, (2) Nerve to the pectineus: which arises from the femoral either above, below or behind the inguinal ligament. However, it commonly arises above inguinal ligament, passes behind the ligament, and femoral artery on its way to pectineus muscle. Femoral nerve divides into two divisions namely the anterior and the posterior. Branches of these divisions are better summarised as under. Lateral femoral circumflex artery passes amongst the branches of femoral nerve. Type of branches

Branches of anterior division

Branches of posterior division

Muscular branches

To only one muscle e.g. Sartorius

To quadriceps femoris: 1. Rectus Femoris: Through it, it supplies the hip joint and knee joint. 2. Vastus Lateralis: Through it to knee joint. 3. Vastus Medialis: Through it to knee joint. Contd...

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Contd... Type of branches

Cutaneous branches

Branches of anterior division

Medial cutaneous nerve of thigh. Intermediate cutaneous nerve of thigh.

Branches of posterior division 4. Vastus Intermedius: Through it to the knee joint and articularis genu muscle. Saphenous nerve: It lies lateral to femoral artery in femoral triangle but crosses the artery from lateral to medial side anteriorly the front and comes to lie medial to it in sub-sartorial canal. It gives an infrapatellar branch after coming out of the canal. Saphenous nerve becomes superficial as it comes out on the medial aspect of the knee, between the sartorius and the gracilis tendons. Further it runs along with great saphenous vein upto the medial malleolus. It supplies the skin of medial side of the knee, leg and the foot, except the medial side of great toe which is supplied by the superficial peroneal nerve. It communicates with the deed peroneal (musculo-cutaneous) nerve.

Clinical:

Surgeon is called upon to expose the femoral triangle on many occasions. During incision in the region of groin three superficial vessels are met with. (Superficial circumflex iliac, superficial epigastric, superficial pudendal). During operative procedure for varicose veins surgeon has to ligate all the tributaries of long saphenous vein and long saphenous itself. During recent days the long saphenous vein is preserved as patient may require it for himself or herself for the coronary by-pass surgery. For block dissection of inguinal nodes (as done in case of carcinoma of penis) superficial fascia, deep fascia, fatty tissue and lymph nodes are to be removed along with the long saphenous vein. By detaching inguinal ligament, external iliac nodes can also be removed through the femoral triangle. Femoral hernia makes its way through femoral canal and further through saphenous opening into the upper part of the thigh. Next it points towards the abdomen and may even cross inguinal ligament. Differential Make the list of all the anatomical structures in the femoral triangle this Diagnosis of a Lump alone answers the question. in the Femoral Skin: Sebaceous cyst, Triangle: Superficial tissue: lipoma, sarcoma Artery: Aneurysum of the femoral artery. Vein: Varix of the long saphenous vein. Femoral canal: femoral hernia. Psoas muscle and the sheath: psoas abscess Cruciate Anastomosis (Figure 284):

Lymp nodes: It could be primary or secondary. It is the secondary arterial channel for the blood to pave its way to the leg when the femoral artery gets blocked or obstructed. It extends from gluteal region to popliteal fossa. The superior gluteal artery anastomoses with the inferior gluteal, inferior with the medial and lateral femoral circumflex and the circumflex with the first perforating branch of profunda. First perforating branch of the profunda joins the second, second joins the third and the third joins the fourth perforating arteries. Fourth perforating anastomose with the branches of the popliteal artery.

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Figure 284 Cruciate anastomosis (schematic)

MEDIAL SIDE OF THIGH Adductor Compartment (Figure 285):

It lies on the medial side of thigh. It is separated from extensor compartment by the medial inter-muscular septum. In addition to the above named adductors, gracilis muscle lies in this compartment. Above the adductor brevis lies obturator externus muscle. All the muscles of adductor compartment are supplied by the obturator nerve except the part of adductor magnus which arises from the ischial tuberosity. (Hamstring part) Obturator nerve, obturator artery, medial circumflex femoral artery and the profunda femoris are located in the adductor compartment.

Figure 285 Origin of adductors

General Arrangement of Muscles: Adductor Longus (Figure 286): Figure 286 Adductor longus

Adductor longus is anterior and the adductor magnus is posterior while adductor brevis is sandwiched between the two in the middle. Gracilis muscle covers adductors from the medial side. Obturator externus lies above upper border of the adductor brevis. It arises from the femoral surface of the body of the pubis between the pubic crest and symphyseal surface. It is inserted into the upper part of linea aspera.

Front of Thigh Nerve Supply: Action: Adductor Brevis (Figure 287):

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It is supplied by anterior division of obturator nerve. It is an adductor and lateral rotator of the thigh. It arises from the femoral surface of the body and the inferior ramus of the pubis, immediately below the origin of adductor longus. It is inserted into the upper part of linea aspera. Lower down its insertion lies between the insertions of the adductor magnus and the pectineus.

Figure 287 Adductor brevis

Nerve Supply: Action: Relations (Figure 288):

It is supplied by the anterior division of the obturator nerve. It is an adductor and lateral rotator of the thigh. It is considered to be a key muscle of adductor compartment.

Figure 288 Relations of adductor brevis

Anterior Relations:

Posterior relations: Relations of Upper Border: Relations of the Lower Border: Adductor Magnus (Figures 289 to 291):

Pectineus, adductor longus, obturator nerve (anterior division), profunda femoris artery with its 2 to 3 perforating branches and profunda femoris vein. Obturator nerve (Posterior division) and the adductor magnus muscle. Obturator externus muscle and the medial circumflex femoral artery, and tendons of iliacus and psoas near the insertion (Figures 285 to 289). Adductor magnus and gracilis are related to the small part of lower border of muscle. It is a triangular muscle. It arises from the following i. Inferior ramus of pubis, ii. Ramus of ischium, iii. Lateral aspect of the lower part of ischial tuberosity below the transverse ridge.

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Figure 289 Adductor magnus

Figure 290 Relation of adductor magnus

Figure 291 Anterior and posterior aspect of adductor magnus

Nerve Supply:

Fibers arising from inferior ramus of pubis run horizontally and get inserted into the area medial to gluteal tuberosity. Fibers arising from the ramus of ischium fan out and get inserted into linea aspera and upper part of medial supra-condylar ridge. Fibers arising from the ischial tuberosity go the adductor tubercle in the form of a strong tendon. In the upper part of supra-condylar ridge this expansion presents an opening for the passage of the femoral artery. It has double nerve supply. Fibers arising from the rami of pubis and ischium are supplied by the obturator nerve, which is the nerve of the adductor compartment. These fibers constitute the true adductor part. The fibers arising from the ischial tuberosity are supplied by the sciatic nerve (tibial element), which is the nerve of flexor compartment. Ischial part of the muscle is known as the hamstring part.

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Action:

It is an adductor and lateral rotator of the thigh. Its ischial part does not help in rotation but instead it is an extensor of hip joint. Along with the other adductors, the magnus also helps in flexion of the thigh to some extent. One has to use all adductors while riding the horse back. (Rider’s muscles). It is well known that the horse rider develops bone in the tendon of the adductor longus. It is known as the rider’s bone. Anterior Relations: Pectineus, adductor longus and the brevis muscles lie anterior to the adductor magnus. The obturator nerve divides into the anterior and the posterior divisions. The anterior division passes in front and posterior division passes behind the adductor brevis muscle. (Riding on the horse back as described in many textbooks). If you remember the horse do not forget the rider”. Other structures forming anterior relations are, femoral vessels, profunda vessels, lesser trochanter and the small bursa which intervenes between horizontal fibres of the muscle and the lesser trochanter. Posterior Relations: Biceps femoris, semi-membranosus, semi-tendinosus and the sciatic nerve. A smaller part of the muscle is under cover of gluteus maximum in the upper part. Relations of Upper Quadratus femoris and transverse branch of the medial femoral circumflex Border: artery. Relation of Medial Sartorius and the gracilis. Border: Gracilis It arises from lower part of the body of pubis and the lower part of the (Figure 292): conjoint rami of pubis and the ischium. Its origin is long and linear. At the insertion the narrow flattened tendon gets attached into the upper part of the medial surface of the tibia. Bursa anserine is placed between the three tendons separating from the tibial surface and the tibial collateral ligament. (Pes anserine means the foot of the goose) Figure 292 Gracilis

Nerve Supply: Action:

It is supplied by obturator nerve (Anterior division) It may help in adduction of thigh. The tendon passes behind the axis of knee, hence acts as the flexor and the medial rotator of the leg. Obturator Externus It arises from the outer two thirds of the obturator membrane and the bony (Figure 293): margins of obturator foramen. Upper part of obturator foramen presents an opening or a gap which is known as obturator canal. Obturator vessels and the nerves come out through this canal. Obturator nerve divides into two

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Kadasne’s Textbook of Anatomy (Clinically Oriented) divisions at the obturator foramen. The anterior division comes above the obturator externus while posterior division has to pierce externus muscle. The tendon is inserted into the trochanteric fossa. Considering the sites of origin and the insertion, the muscle has to go backwards, laterally and upwards. It lies on the back of the neck of the femur where it grooves the bone. The manner in which the tendon of the obturator externus winds round the femoral neck and by virtue of the fact it helps in supporting the femoral neck. (supporting muscular collar of the neck of femur). This support is of a great help during fractures of the neck of the femur as it prevents the displacement of the fragments of the neck.

Figure 293 Obturator externus

Nerve Supply: Action:

Relations:

Obturator Nerve (L2, L3, L 4) (Figure 294):

Anterior Division:

By posterior division of obturator nerve. It is the the flexor and lateral rotator of thigh. As described by Johnston, the more important action of this muscle and other short lateral rotators are: i. They help in controlling the direction of axis of the neck of femur during movements, ii. They act as a check for medial rotation, iii. When large muscles are relaxed they take the strain instead of troubling The capsule of the joint and ligaments. In short one can say that this muscle helps in stabilizing the upper end of femur during movements. (Almost similar to the action of the members of the rotator cuff of the shoulder). It lies under the pectineus and tendons of psoas and iliacus. At the lower border, obturator externus is related to pectineus, medial circumflex femoral artery and upper border of adductor brevis muscle. It passes under the lower part of the capsule of hip joint and subsequently lies on femoral neck. Anterior division of obturator nerve passes in front of the muscle while its posterior division comes out by piercing the muscle. Obturator artery lies under cover of the muscle. It arises from the anterior branches of anterior rami of the L2, L3 and L4. It passes through the substance of psoas major and appears at the brim of the pelvis, where it lies along the medial border of psoas major muscle. Next the nerve passes behind common iliac vessels and runs lateral to the internal iliac vessels. During its further course it passes towards obturator foramen along the lateral wall of the pelvis, where it lies on the obturator internus muscle. Here obturator vessels lie below obturator nerve. Near obturator foramen the nerve divides into the anterior and the posterior branches or divisions. It passes above obturator externus muscle and comes to lie in front of it. Next it gives a twig to the hip joint. It runs downwards in front of the adductor brevis and behind the pectineus and adductor longus. Branches to adductor longus and gracilis come during this course. Many times a branch is given to adductor brevis. Please note that very rarely a branch to pectineus may come from anterior division of the nerve. In such cases the

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Figure 294 Obturator nerve with its distribution (digrammatic)

Posterior Division:

Clinical:

pectineus has double nerve supply namely, from the femoral and anterior division of the obturator. At the lower border of adductor brevis it communicates with medial cutaneous nerve of the thigh and saphenous nerve. As noted before medial cutaneous nerve, saphenous nerve and communicating branch of the anterior division of obturator form the plexus is known as the sub-sartorial plexus. The remaining part of the nerve is distributed to the wall of the femoral artery and gets exhausted. It passes through the substance of the obturator externus. While doing so it supplies the muscle. Next it passes behind the adductor brevis and in front of the adductor magnus and gives a branch to brevis only when the anterior division fails. A branch to knee joint passes through the substance of the adductor magnus, but more commonly it passes through the opening in the adductor magnus msucle, follow popliteal artery and reaches the back of the knee joint. Here it pierces oblique posterior ligament of the knee joint and supplies the capsule. Popliteal artery receives few filaments from posterior division of obturator nerve. Distribution of obturator can be studied in brief as follows: Muscular Branches: To adductor longus, brevis and magnus; gracilis and obturator externus. Articular Branches: To hip and knee joints. Cutaneous Branches: Through sub-sartorial plexus to the skin on medial side of thigh. Vascular Branches: To femoral and popliteal arteries. i. Obturator nerve supplies both the joints, e.g. hip and the knee. Therefore, diseases of the hip joint may give referred pain at the knee joint and thus misleading the clinician. ii. Strangulated obturator hernia may produce compression of obturator nerve leading to referred pain on medial side of the thigh. (obturator supplies the skin on medial side of thigh). This helps tremendously in diagnosis, e.g. if a patient of intestinal obstruction comes with referred cutaneous pain on medial side of thigh, the possibility of the strangulated hernia can not be rolled out.

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Accessory Obturator Nerve (Figure 295):

iii. In cases of spastic paraplegia obturator nerve is cut in order to ensure better perineal care. It is present in thirty percent of cases. It is formed by anterior branches of anterior rami of the third and fourth, lumbar nerves. It runs in front of the superior ramus of pubis but under cover of the pectineus. It supplies the pectineus and gives an articular twig to the hip joint. A communication from accessory obturator joins the anterior division of the obturator nerve.

Figure 295 Accessory obturator nerve

Obturator Artery (Figure 296):

It arises from internal iliac artery inside the true pelvis. It runs along the lateral wall of pelvis on the obturator internus, lying all the time below the obturator nerve. It passes through the obturator canal in company with the obturator nerve. Immediately after its emergence from the canal it divides into anterior and the posterior branches which join to form an anastomotic circle, around the obturator foramen. This anastomotic circle lies under cover of the obturator externus muscle. An acetabular branch to the hip joint comes from the posterior branch. Acetabular branch of the obturator artery supplies the head of femur along with the branch of medial circumflex femoral artery. Posterior branch anastomoses with the anterior branch and also with inferior gluteal artery. Anterior branch anastomoses with posterior and also with the medial circumflex femoral artery.

Figure 296 Obturator artey

Branches:

Outside Pelvis: Obturator Vein:

Pubic branch is given from obturator as the obturator is just to enter obturator canal. Pubic branch goes to posterior aspect of the pubis and anastomoses with the pubic branch of inferior epigastric arteries. This connection between the obturator and the inferior epigastric is more prominent and well developed in thirty percent of the cases. (Abnormal obturator artery). It gives anterior and posterior branches of which the posterior branch gives an acetabular branch. Obturator vein accompanies obturator artery and the nerve and lies below the obturator artery.

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GLUTEAL REGION Surface LandMarks (Figure 297):

Following landmarks should be studied carefully and an attempt should be made to feel them on the body.

Figure 297 Surface landmarks of gluteal region

Superficial Fascia: Cutaneous Nerve:

Figure 298 Cutaneous innervation of gluteal region

1. Posterior Superior Iliac Spine: It lies at the level of the spine of the second sacral vertebra. It is marked on the gluteal surface by the small dimple. 2. Gluteal Tuberosity: It is felt on infero-medial part of gluteal region. 3. Greater Trochanter: It is felt on the infero-Iateral part of gluteal region. 4. Gluteal Fold: It lies in the lower part and runs from the medial to the lateral side with slight convexity downwards. Please note that the gluteal fold does not indicate the limit of lower border of the gluteus maximus. 5. Natal Cleft Lies Between Buttocks: In the posterior end of floor of the cleft lies tip of the coccy. 6. Sacrotuberous Ligament: If the fingers are firmly pressed between the ischial tuberosity and the dimple, resistance of the sacro-tuberous ligament is felt. 7. Rounded shape of gluteal region is due to the gluteus maximus and the overlying fat. 8. Quadrate Tubercle: Lies a fingers breadth medial to the greater trochanter. It is studded with a large amount of fat. There is greater amount of fibrous tissue and fat over the gluteal tuberosity. Cutaneous innervation of gluteal region (Figure 298) Following nerves supply the skin of gluteal region. 1. Lateral cutaneous branch of subcostal, 2. Lateral cutaneous branch of iliohypogastric, 3. Posterior branch of lateral cutaneous nerve, 4. Gluteal branches of posterior cutaneous nerve, 5. Perforating cutaneous nerve, 6. Upper perforating branches of three lumbar dorsal rami, 7. Upper three branches of sacral dorsal rami.

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Deep Fascia:

Gluteal Muscles:

Deep fascia over the small part of gluteus medius is thick. As the fascia comes to the gluteus maximus, it splits into two layers to enclose the gluteus maximus. Fascia covering the gluteus maximus muscle is thin. They are three in number, namely the gluteus maximus, the medius and the minimus (Figure 299). The gluteus maximus is superficial while minimus is the deepest and the medius is in between. All the muscles arise from gluteal surface of ilium and get inserted into the femur. Maximus goes to the back of the hip joint to reach the gluteal tuberosity. Gluteus medius muscle goes lateral to the hip joint for insertion into the lateral aspect of the greater trochanter. Gluteus minimus goes in front of the hip joint for insertion into the anterior surface of the great trochanter. The maximus is supplied by inferior gluteal nerve while medius and minimus are supplied by superior gluteal nerve. The medius and the minimus lie above and are supplied by the superior gluteal nerve. Gluteal muscles come from the gluteal surface of the ilium and are the members of one large gluteal muscular mass. In order to balance the pelvis over the heads of the femora, one goes in front; one goes laterally and the remaining goes posterior to the hip joint. They are acting like ropes running from the pelvis, going to the anterior, posterior and the lateral aspects of the hip joint. In fact this arrangement of the three muscles acts as the guy rope. (Guy means a rope fixed to the ground to secure a tent, etc.)

Figure 299 Gluteal guy rope

Gluteus Maximus: Figure 300 Gluteus maximus

It is a large muscle and hence deserves the name maximus.

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Origin:

It arises from the gluteal surface of ilium behind the posterior gluteal line; posterior surface of sacrum, coccyx and the sacro-tuberous ligament.

Insertion:

Fibres are directed downwards, laterally and also forwards for their insertion. One fourth of the muscle gets inserted into the gluteal tuberosity while the rest of the three fourth gets inserted into the ilio-tibial tract (Figure 300).

Nerve Supply:

Inferior gluteal nerve.

Action:

It is the powerful extensor of the hip joint. It comes into action when the trunk is straightened over the limbs such as during the act of standing from stooping position or sitting position. It does not help during normal walking. However, it is actively contracting during running, climbing and jumping.

Relations:

Maximus is a muscular curtain for structures of gluteal region. Deeper relations are important as their knowledge helps us in memorising further details. 1. Bony points under maximus: a. Ischial tuberosity, b. Greater trochanter, c. Gluteal tuberosity. 2. Muscles under maximus: a. Reflected head of rectus femoris, b. Gluteus minimus, c. Gluteus medius, d. Piriformis, e. Obturator internus and gemelli, f. Quadratus femoris, g. Long head of biceps femoris, semi-tendinosus, semi-membranosus and the adductor part of adductor magnus. (Hamstrings). Obturator externus lies deep to maximus (see Figure 300). 3. Ligaments under maximus: Sacro-tuberous and sacro-spinous. 4. Joint: Hip joint. 5. Nerve: Sciatic, the posterior cutaneous nerve of the thigh, nerve to the quadratus femoris, nerve to the obturator internus, pudendal nerve, superior gluteal and inferior gluteal nerves. 6. Vessels: Internal pudendal artery, superior gluteal artery, inferior gluteal artery and the medial circumflex femoral artery. 7. Foramina: Greater and lesser sciatic foramina. 8. Synovial bursae: a. Over ischial tuberosity, b. Over greater trochanter and c. Over upper part of vastus lateralis. Posterior border of the gluteus maximus forms posterior limit of the ischio-rectal fossa along with the sacro-tuberous ligament.

Gluteus Medius (Figure 301):

It lies partially under cover of the gluteus maximus. It arises from gluteal surface of ilium between posterior and the middle gluteal lines. It is inserted into an oblique impression on the lateral surface of the greater trochanter. A small bursa intervenes between the tendon of the gluteus medius and the lateral surface of the greater trochanter above the insertion of the muscle.

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Figure 301 Gluteus medius

Nerve Supply Action (Figure 302):

By the superior gluteal nerve. It is the main abductor of the hip along with tensor fascia latae and the anterior fibres of the gluteus minimus muscles. When one stands on one leg, pelvis on that side is depressed and that of the opposite side is raised (Figure 302).

Figure 302 Action of gluteus medius

Clinical:

Gluteus minimus (Figure 303):

On this basis Trendelenburg’s test in evolved. In poliomyelitis, dislocation of the hip and non-united fracture of the femoral neck, the gluteus medius being paralysed the pelvis on the opposite gets depressed instead of getting raised. This is known as positive Trendelenburg’s test. Person has a dipping gait. In intra-muscular injection in the upper and outer quadrant of the gluteal region needle passes through the skin, deep fascia and the gluteus medius muscle and not the maximus. It is the deepest muscle and lies under cover of the medius. It arises from the gluteal surface of ilium between the middle and inferior gluteal lines. It is inserted into the anterior surface of the greater trochanter (Figure 303). It is intimately related to capsule of the hip joint. At its insertion, the tendon is separated from the upper part of anterior surface of greater trochanter by means of bursa. Nerve Supply: It is supplied by the superior gluteal nerve. Action: It is the abductor and medial rotator of thigh. Relations: Following structures lie under cover of gluteus minimus: i. Capsule of hip joint, ii. Reflected head of rectus femoris, iii. Greater trochanter and iv. Bursa. Piriformis Muscle: (Figures 304 and 305) It is the key muscle of the gluteal region.

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Figure 303 Gluteus minimus (lateral view)

Figure 304 Piriformis

Figure 305 Relations of piriformis

Origin:

Insertion:

Relations in Gluteal Region: Upper Border:

Lower Border:

It arises from the pelvic surface of middle three pieces of the sacrum. It leaves the pelvic cavity through the greater sciatic notch and enters the gluteal region. It is inserted into the upper border of greater trochanter. Nerve Supply: It is supplied by the first and second sacral nerves. Action: It is the short lateral rotator of the thigh. It lies under cover of the gluteus maximus and partly under cover of the sacrotuberous ligament. It lies behind the hip joint. Following structures are related to it: i. Gluteus medius and minimus muscles, ii. Part of sacro-tuberous ligament near posterior inferior iliac spine, iii. Superior gluteal vessels and the nerve. i. Obturator internus with gemelli, ii. Spine of ischium with the sacro-spinous ligament and the sacrococcygeus muscle. iii. Sciatic nerve, nerve to the quadratus femoris, the posterior cutaneous nerve of thigh, the nerve to obturator internus and the pudendal nerve iv. Inferior gluteal vessels and the nerves and internal pudendal.

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Obturator Internus Muscle (Figure 306):

It arises from pelvic surface of the hip bone below the pectineal line. It also arises from obturator membrane and the part of the hip bone surrounding the obturator foramen. It leaves the pelvic cavity through the lesser sciatic foramen and gets inserted into the medial surface of the greater trochanter. Nerve Supply: It is supplied by the nerve to obturator internus. Action: It is the short lateral rotator of the hip.

Figure 306 Obturator internus with gemeli and quadratus femoris

Quadratus Femoris: It lies between the obturator internus above and upper border of the adductor magnus below. The gap between these two is occupied by the transverse branch of the medial circumflex femoral artery. It takes origin from lateral aspect of ischial tuberosity and gets inserted into the quadrate tubercle. Nerve Supply: It is supplied from the sacral plexus by the special nerve known as nerve to the quadratus femoris. It leaves pelvic cavity through the greater sciatic foramen below the piriformis and enters the deep surface of quadratus femoris muscle. Action: It is the short lateral rotator of the thigh. Obturator Externus: It is already described and is being repeated in view of its importance. Obturator externus muscle arises from the external surface of the obturator membrane and from the bone forming the borders of the obturator foramen. It is inserted into the trochantric fossa. It is closely related to the posterior aspect of the neck of the femur. In other words it forms the collar for the neck of femur and acts as a prop or support in the trans-cervical fracture of the femur. Superior Gemellus: It lies above obturator internus tendon. It arises from the upper part of lesser sciatic notch and gets inserted into the tendon of the obturator internus. Inferior Gemellus: It lies below the obturator internus tendon. It arises from the lower part of lesser sciatic notch and gets inserted into the obturator internus. Nerve Supply: Gemellus superior is supplied by the nerve to obturator internus muscle and the inferior gemellus is supplied by the nerve to quadratus femoris. Action: They may help in lateral rotation of thigh. Note: Sometimes the gemelli are well developed and are of a considerable size. Sacro-tuberous As the name indicate the ligament runs between the sacrum and the Ligament tuberosity of the ischium. Medially it is attached to superior and inferior (Figure 307): iliac spines, lateral margin of sacrum and the coccyx. Laterally it is attached to the medial aspect of the lower part of ischial tuberosity. Sharp edge of the ligament is attached to the line on the medial aspect of ischium. It is known as falciform process. The ligament is broad above and below. It is narrow in the middle. Sacrotuberous Iigament converts-sciatic notches into the sciatic foramina with the help of sacro-spinous ligament. The

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sacro-spinous ligament lies under sacro-tuberous ligament. Origin of the long head of biceps femoris may extend over sacrotuberous ligament. As mentioned before, perforating cutaneous branches pierce the ligament. The gluteus maximus muscle arises from the sacrotuberous ligament as mentioned before. Sacrotuberous ligament and the gluteus maximus form the posterior limit of the ischio-rectal fossa. Figure 307 Sacro-tuberous and sacro-spinous ligaments

Sacro-spinous Ligament (Figure 308):

It is the degenerated part of coccygeus muscle. The ligament lies under sacrotuberous ligament. Laterally it is narrow and medially it is broad. It is attached to the tip of the spine of ischium laterally and the last and the first piece of sacrum and coccyx, medially. Pudendal nerve lies over the ligament.

Figure 308 Showing sacrospinous lig.

Sciatic Foramina:

They are two namely the greater and the lesser. They are better studied as under: Particulars

Greater sciatic foramen

Lesser sciatic foramen

Boundaries

By greater sciatic notch, sacrotuberous and sacrospinous ligaments.

By lesser sciatic notch, sacro-tuberous and sacro-spinous ligaments.

Structures passing

Piriformis, superior gluteal vessels and the nerve, sciatic nerve, nerve to quadratus femoris, nerve to obturator internus, posterior cutaneous nerve of thigh, pudendal nerve, internal pudendal artery and the inferior gluteal

Obturator internus nerve to obturator internus, Internal pudendal artery and the pudendal nerve.

vessels and the nerves.

Sciatic Nerve (L4, 5, L 1,2, 3) (Figure 309):

It’s size is remarkable at it varies from the size of the little finger to the thumb. It is the terminal branch of sacral plexus. It comes out of pelvic cavity through greater sciatic foramen, below the lower border of piriformis muscle, and makes its entry into gluteal region. During its further course it subsequently lies on ischium, nerve to quadratus femoris obturator internus with gemelli, quadratus femoris and the adductor magnus muscles.

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Figure 309 Course and relations of sciatic nerve (A and B)

Branches:

Blood Supply: Surface Marking of Sciatic Nerve:

Clinical:

It passes mid-way between the ischial tuberosity medially and the greater trochanter laterally. Usually it divides in the middle of the back of the thigh into medial (tibial nerve) and lateral popliteal, common peroneal branches. It must be remembered that the site of division is variable. The nerve may divide inside pelvis or very close to level of the knee. When the division takes place inside the pelvis, the common peroneal pierces the piriformis muscles and the tibial passes below the lower border of piriformis. During its journey through gluteal region the nerve is provided with a tough fascial tube. In the gluteal region the nerve lies under cover of gluteus maximus muscle. However, beyond the lower border of gluteus maximus the nerve is superficial. On the back of the thigh it is covered by biceps femoris muscle, which crosses the nerve from the medial to the lateral side as it runs from the ischial tuberosity to the head of the fibula. The posterior cutaneous nerve of thigh lies on the medial side of sciatic all along its course but may overlap it. Origin of hamstring muscles lies medial to the nerve. The inferior gluteal artery also runs along medial side of the nerve. 1. Articular: To the hip joint, 2. Muscular: They are given to the long head of biceps femoris, semitendinosus, semimembranosus, hamstring part of adductor magnus and the short head of the biceps femoris (Please note that the branch to the short head of biceps femoris comes from the common peroneal element of sciatic and the rest of the branches come from the tibial element of the nerve. Nerve to short head of biceps femoris is the only nerve which comes from the lateral side of the nerve and all others arise from the medial side. The sciatic nerve is supplied by the branch of inferior gluteal artery. Join the ischial tuberosity to the posterior superior iliac spine. Mark the midpoint of the line. Join the ischial tuberosity and greater trochanter and mark the midpoint of the line. Mark the apex of the popliteal fossa. A thick line is drawn from the point, lateral to the midpoint of the line joining the ischial tuberosity and the posterior superior iliac spine. Connect the line to a point located at the midpoint of the line joining the ischial tuberosity and the greater trochanter and continue it to the apex of the popliteal fossa. 1. The nerve can get damaged due to hard edge of the chair, below the lower border of gluteus maximus muscle, where it lies superficial. 2. It can be damaged in the posterior dislocation of the hip. 3. It can be damaged when deep intramuscular injection in gluteal region if wrongly given. (Safest quadrant for injections supero-Iateral). 4. Artery of the sciatic nerve may bleed profusely in the above knee amputation. 5. In the damage of the sciatic nerve all the hamstring muscles and all the muscles supplied by the common peroneal and the tibial are paralysed.

Front of Thigh

Inferior Gluteal Nerve (L5, 51, 2): Inferior Gluteal Artery:

Internal Pudendal Artery:

Pudendal Nerve:

Nerve to Obturator Internus:

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This results in foot-drop. There is sensory loss below the knee, however. sensations on the medial aspect of the leg, ankle and the foot are normal as this area is supplied by saphenous nerve which is the branch of femoral. 1. Sciatica: Patient complains of severe pain along the line of sciatic nerve. Exact cause of this condition is not known. It could be due to partial damage of the nerve, pressure of inter-vertebral disc or due to ischaemia (reduced blood supply of the nerve itself) Sciatica is not the disease but a symptom. Clinical test for sciatica: SLR i.e Straight leg rising test. Patient is asked to lie supine with and the raise the leg with knee extended. Normally patient can carry the leg up to 90 degrees without pain. In case of the pathology in the lumbar spine such as trauma, tumour and the tuberculosis ( 3 T’s), the leg can be raised to the lessor degree and is accompanied by radiating pain along the sciatic line. It is expressed as SLR positive. 2. Sleeping foot: It is the concussion of the sciatic nerve when the nerve is pressed against the femur by the hard surface of the chair. In the dislocation of the hip the nerve is damaged which leads to paralysis of the muscles of the flexor compartment of the thigh, the leg and the foot. 3. Damage to the tibial element of the sciatic nerve leads to paralysis of the muscles of the posterior compartment of the leg and sole of foot. The patient is unable to do plantar flexion and he can not stand on toes. There is loss of Achillis tendon reflex. Trophic ulcers may develop in the sole of the foot due to loss of sensations. Injury of the common peroneal element causes paralysis of the muscles of the extensor and the peroneal compartments of the leg. There is a foot drop and patient is not able to stand on heel. Due to injury of the superficial peroneal nerve there is inability to evert the foot. There is loss of sensation on the dorsum of the foot except in the area supplied by the saphenous nerve. 4. Intra-gluteal injection: It is safely given in the upper and the lateral quadrant of the gluteal region, infero-medial quadrant being the dangerous due to the presence of a sciatic nerve. The needle passes through the gluteus medius muscle and not the gluteus maximus as it is commonly thought of. It is a branch of sacral plexus. It leaves pelvic cavity through the greater sciatic foramen below the lower border of piriformis muscle and enters gluteal regional. It supplies gluteus maximus muscle. It is the branch of anterior division of internal iliac artery. It leaves the pelvic cavity through greater sciatic foramen, below the lower border of the piriformis muscle and supplies gluteus maximus and also gives cutaneous branches to the skin of the thigh and the gluteal region. It gives a branch which runs with sciatic nerve to supply it (Companion artery of the sciatic). It is the branch of anterior division of internal iliac artery. It leaves pelvic cavity through greater sciatic foramen, below the lower border of the piriformis and supplies the gluteus maximus and also gives cutaneous branches to the skin of thigh and gluteal region. It is a branch of sacral plexus. It comes out of pelvic cavity through greater sciatic foramen below the piriformis muscle, crosses sacro-spinous ligament and disappears by passing into the lesser sciatic foramen. It is branch of the sacral plexus (L5, 51, 2). It comes out of pelvic cavity through greater sciatic foramen, below piriformis, crosses the base of spine

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of ischium, supplies superior gemellus and disappears by passing into the lesser sciatic foramen. It enters the pelvic cavity and supplies the obturator internus muscle. Nerve of Quadratus It is a branch of sacral plexus (L4, 5, 51). It comes out of pelvic cavity below Femoris: the lower border of piriformis and lies under sciatic nerve. During its further course it lies on ischium and hip joint under cover of obturator internus and gemelli. It enters the deeper surface of quadratus femoris. However before its entry it gives a branch to inferior gemellus. It also supplies the hip joint. Superior Gluteal It is the branch of the sacral plexus. (Dorsal branches of anterior primary Nerve (L4, 5, 51) rami of L4, 5 and S1). It leaves pelvic cavity through the greater sciatic (Figure 310): foramen above the upper border of piriformis muscles. Here it divides into two branches, namely the superior and inferior. The superior branch supplies the gluteus medius and inferior branch supplies the gluteus minimus and the tensor fascia latae. Figure 310 Superior gluteal nerve and artery

Superior Gluteal Artery:

It is the branch of posterior division of the internal iliac artery. It leaves the pelvic cavity through the greater sciatic foramen above the upper border of piriformis along with the superior gluteal nerve. The superior gluteal artery divides into two divisions, namely the superficial and the deep. Superficial division supplies the maximus. The deep division divides into the superior and the inferior branches. The inferior branch runs in company with the inferior branch of superior gluteal nerve, while the superior branch runs along middle gluteal line between medius and the minimus.

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HIP JOINT Figure 311 Bones taking part in the formation of hip joint and proximal and distal capsular attachment

Classification: Peculiarity:

Bones Taking Part: (Figure 311A)

It is a synovial, poly-axial and belongs to the ball and the socket variety. Built on strong structural foundation and therefore movements are not free as they are in shoulder joint. We have sacrificed mobility for the sake of stability. The joint is of paramount importance to the surgeons, practicing orthopedics, and also to the suffering patients. It is formed by the articulation of the head of the femur with the acetabular cavity of the hip bone.

Figure 311A X-ray of right hip joint

Acetabulum:

Head of Femur:

Ilium, ischium and the pubis contribute to the formation of the acetabulum. The line of union before ossification is Y shaped. It disappears at the age of twelfth year. It has an inverted horse shoe shaped articular area. Rest of the area of the cavity is non-articular. Inferior rim of the acetabulum is broken and is known as acetabular notch. The acetabular notch is converted into the foramen by the transverse acetabular ligament. Edge of the acetabulum and the transverse acetabular ligament provides attachment to the labrum acetabulare. Labrum acetabulare is a triangular fibrocartilagenous ring. Its function are (1) It deepens the cavity, (2) maintains the bony contact and (3) protects the edges of the acetabulum. It is spherical and is covered with the articular cartilage all over except in the region of small pit which lies little below and behind the center of the head. This pit is known as fovea capitis femoris. It gives attachment to ligamentum teres femoris. Articular surface of the head extends a little in front of femoral neck. The cartilage is thick in the center and thin at the periphery of the head.

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Attachment of Capsule:

Capsule:

Ligaments (Figure 312):

The capsule is attached to the periphery of the acetabulum beyond the labrum acetabular and also to the transverse acetabular ligament. Attachment of the capsule on the femur is along the inter-trochantric line anteriorly and the middle of the neck of the femur posteriorly. The neck of the femur is completely intracapsular while the neck of the femur is partly intracapsular and partly extra-capsular. Therefore, oblique fracture of the femoral neck will be intra as well as extra capsular (Figure 312). It is stronger as compared to capsule of the shoulder joint. The capsule is relatively thicker in front, above, below and behind. Capsular fibres are arranged in two sets namely the longitudinal and the circular. Longitudinal fibres are superficial and circular fibres are deeper. The circular fibres form a ring surrounding the neck of femur, which is known as zona orbicularis. Ilio-femoral, pubo-femoral and the ischio-femoral ligaments are specialised thickened fibrous capsular bands which add to the strength of the hip joint. They are as under: 1. Capsular ligament, 2. Iliofemoral, 3. Ischio-femoral, 4. Pubo-femoral, 5. Ligamentum teres femoris (Ligament of the head of femur), 6. Transverse acetabutar ligament, 7. Labrum acetabular 8. Retinacular ligaments.

Figure 312 Ligaments of hip joint

Ilio-femoral Ligament:

Functions of Ilio-femoral Ligament:

Pubo-femoral Ligament:

It lies in front of the hip joint and is one of the strongest ligament in the body. It is known as ligament of Bigelow. It is inverted ‘Y’ shaped. The apex of the Y is attached to the lower part of anterior inferior iliac spine. Immediately below the origin of straight head of rectus femoris. Lower down, its two limbs are attached to the upper and the lower part of the trochanteric line. Medial is vertical and the lateral is oblique. 1. Adds strength to the capsule, 2. It prevents excessive extension, 3. During erect posture, it helps to balance the pelvis over heads of the femora and counteracts natural tendency of pelvis to roll back as the center of gravity passes posterior to the hip joint. 4. Its lateral limb prevents excessive adduction and the medial limb prevents excessive abduction. It runs between the pubis and antero-inferior part of the capsule of the hip joint. Many times psoas bursa communicates with the joint cavity through the gap between the pubo-femoral and ilio-femoral ligaments. It prevents excessive abduction.

Hip Joint Ischio-femoral Ligament: Ligament of Head of Femur (Figure 313):

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It runs from ischium to posterior part of the capsule of the hip joint. It prevents excessive medial rotation. It is attached to the pit on the head of femur and the transverse acetabular ligament and the limits of acetabular notch. It is broad and flattened near acetabular attachment and narrow at the pit on the head of the femur. It also sends a slip to non-articular part of acetabulum (Kate BR.) It has a tube of synovial membrane of its own.

Figure 313 Ligament head of femur

Function: Transverse Ligament of Acetabulum:

Carries blood supply to the head of femur from the acetabular artery. It is attached to the margins of acetabular notch and converts the notch into the foramen. Acetabular branch of the obturator artery to the hip joint passes under this ligament.

Synovial Membrane (Figure 314):

Synovial membrane covers the capsule of hip joint inside and the non articular area of the femoral neck except the articular area. In other words synovial membrane does not cover the articular area. It is absent over the articular areas. The ligament of the head of femur is provided with the separate tube of synovial membrane. Over the neck of the femur the synovial membrane covers thin fibrous ridges running from peripheral attachment of the capsule towards head of femur. These fibrous ridges are known as retianiculi under which lies the blood vessels supplying the head of the femur.

Figure 314 Section of hip of joint showing capsule and synovial membrane

Nerve Supply:

(Now, we know that blood supply to head of femur comes from two sources:- (1) along the ligament of the head of femur, and (2) along the retinaculi. From the medial femoral circumflex, lateral femoral circumflex and the nutrient artery of the shaft of the femur. (All should read question often) (A S R Q O) A - Accessory obturator when present, S - Sciatic, R - Nerve to rectus femoris, Q - Nerve to quadratus femoris, O - Obturator. Note: Aids to the memory is no crime as one can not remember more than forty thousand words.

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Blood Supply: Relations (Figures 315 and 315A):

It is supplied by the superior gluteal artery, inferior gluteal artery, obturator artery, medial and the lateral femoral circumflex arteries. They are important from the point of view of surgical exposures. The joint can be opened from front, back and also from the lateral aspects.

Figure 315 Horizontal section of hip joint (diagrammatic)

Figure 315A Schematic sagittal section of the hip joint for surgical exposures

Anterior Relations:

Pectineus, psoas, iliacus, rectus femoris, tensor fascia latae, sartorius, femoral artery, vein and the nerve are the anterior relations. Posterior Relations: Gluteus maximus, sciatic nerve, obturator internus, gemelli, obturator externus, quadratus femoris and nerve to quadratus femoris. Lateral Relations: Gluteus minimus, gluteus medius and part of gluteus maximus forms the lateral relations. Medial: Adductor brevis, adductor magnus and medial circumflex femoral artery form the medial relations. Superior: Reflected head of rectus femoris and the gluteus minimus are the superior relations. Inferior: Quadratus femoris muscle is related to the hip joint inferiorly. Movements: 1. Adduction, 2. Abduction, 3. Flexion,

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Extension, Medial rotation, Lateral rotation and Circumduction.

Movements

Muscles

Adduction

: Adductor magnus, brevis, longus; gracilis and pectineus.

Abduction

: Gluteus medius, minimus and tensor fascia latae.

Flexion

: Psoas, iliacus, rectus femoris, sartorius and pectineus.

Extension

: Gluteus maximus, semitendinosus, semimembranosus, long head of biceps femoris and the hamstring part of the adductor magnus.

Medial rotation : Gluteus medius and minimus. Lateral rotation : Adductors, psoas and iliacus (action of psoas is doubtful) Circumduction : All combine to produce circumduction

Clinical:

1. Exposures: Joint can be exposed from the front, behind and the lateral side. Anteriorly the approach is made between sartorius medially and gluteus medius and minimus laterally. Lateral approach is made through fibres of tensor fascia latae and gluteus medius and minimus muscles. Posterior approach is made by cutting the lateral part of maximus, and this approach gives a wide exposure. The line of incision from the posterior approach extends from the posterior superior iliac spine to the greater trochanter. 2. Dislocation: Posterior dislocation of the hip is common. It may be associated with or without fracture of the acetabular rim. When the head of the femur is in the position of adduction chances of fracture of the acetabulum are minimum. If the force is applied in the position of the abduction the fracture of the acetabulum is invariably seen. In the central type of dislocation head of the femur perforates the acetabulum and encroaches the pelvic cavity. 3. Fracture neck of femur: It occurs in old age due to osteoporosis and the absorption of the calcar-femorle. Calcar-femorle acts as living nail of the neck of femur. Intra-capsular fracture of the neck of femur can be sub-capitulum or trans-cervical while the extra-capsular fractures are inter-tronchantric or per-trochantric. In transcervical fracture the retinaculi in front of the femoral neck are damaged it breaks the retinacular vessels supplying the head of the femur. It can lead to avascular necrosis of the head of the femur. In fracture neck femur the limb is abducted and laterally rotated as the shaft of the femur is free to move alone without the head of the femur. Lateral border of the sole touches the bed. Foot can not be held in extension or medial rotation as it falls back. Psoas major muscle becomes the lateral rotator of the proximal fragment. There is shortening of the limb. The length of the limb is measured from the anterior superior iliac spine to the medial malleolus (Figures 316 and 317).

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Figure 316 Showing blood supply of head of femur

Figure 317 Showing fracture sites of upper end of femur and difference cascular damage in both

4. Coxa vara (Figure 318): Normal neck shaft angle is 125° in adults and 150° in children. In coax vara it is decreased which limits the movement of abduction. It is seen in the fracture neck femur. Figure 318 Showing normal neck shaft angle of femur, decreased and increased

5. Coxa Valga: Increases the neck shaft angle and is called the coax valga. It limits the adduction. It is commonly seen in the congenital dislocation of the hip. 6. Congenital dislocation of hip (CDH): There is complete loss of contact between the acetabulum and the head of the femur. It is mainly due to the shallow acetabulum and is seen below the age of 5 and is more common in girls than boys. In CDH patient presents the lurching gait like a duck. It is mainly due to incomplete development of the upper part of the acetabulum which makes the head of the femur to slip upwards.

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7. Perthe’s disease: There is destruction and flattening of the head of the femur. It is commonly seen between the ages of 5 to 10 years. 8. Tuberculosis of the hip: Tuberculosis is commonly seen in the joints having extensive synovial membrane such as hip and the knee. It can involve the synovial membrane alone and is known as tubercular synovitis. If the diagnosis is made early the joint can return to the normal function without deformity or limitation of movements. In osseous type of tuberculosis the disease ends in deformities shortening and limitation of movements. 9. Osteoarthritis: It is seen in the age group of 45 to 55. It is due to the degenerative changes in the articular surfaces associated with formation of osteophytes. In severe degree of the osteoarthritis of the hip medicines and physiotherapy do not help. Recently total hip replacement can be done by using the prosthesis of polyethylene. 10. Irritable Hip: It is commonly seen in children due to inflammation of the synovial membrane. It responds to rest and medical line of treatment. 11. Metastasis: Cancer metastasis can occur in the neck of femur, primary site of the cancer is being the breast or the prostate. More than 50% of the cases are either patients of cancer breast or the cancer prostate. 12. Chiene’s test: The lines are drawn from anterior superior iliac spine and the greater trochanter across the pelvis. Normally they are parallel to each other. 13. Shenton’s Line: It is a continuous curved line joining upper border of obturator foramen and the lower border of the neck of femur. It is disturbed in dislocation of hip and the fracture neck of femur. It is also disturbed in the fracture of the superior border of the obturator foramen. (Superior ramus of pubis). 14. Exposure of Hip (see Figure 315A) a. Anterior approach (Smith Peterson): Between the tensor fascia latae laterally and the sartorious and the rectus femoris medially. Protect lateral femoral cutaneous nerve. b. Lateral approach (Watson Jones): Incision 2-5 cms. form anterior superior iliac spine to greater trochanter and shaft. The plane is between the tensor fascia latae laterally and the gluteus medius medially. c. Posterior approach (Moores): Incision 10 cms distal to posterior superior iliac spine and extending distally parallel to the fibers of the gluteus maximus upto the posterior margin of the greater trochanter and parallel to the shaft. Split the gluteus maximus and reflect the short lateral rotators from the greater trochanter. Protect the sciatic nerve. 15. Aspiration: Lateral – pass needle at 45° to the surface of the thigh inferior and the anterior to the greater trochanter and advance medially upto 5 to 10 cms. 16. Joint replacement surgery: Major surgical problems of the hip and the knee do not give satisfactory results treated by arthrodesis and osteotomy. Therefore the joint replacement surgery has come to forefront. The material used for the concave component of the joint is high density polyethelene and implantable metal for the convex surfaces. Replacement orthoplasty has many merits as the pain disappears, joint becomes mobile and also stable. The demerits of the procedure are:

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Kadasne’s Textbook of Anatomy (Clinically Oriented) 1. It is not simple to perform. 2. Components used for replacement may become loose or get infected 3. Cement reaction. However with modern replacement implants and non-reactive cement the replacement surgery of the joint has come as a boon for the patients of osteoarthritis particularly the rheumatoid type. 17. Position of function of hip joint: 30° flexon, 0°-5° adduction, 10°-15° external rotation.

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BACK OF THIGH Cutaneous Nerves (Figure 319):

1. Posterior cutaneous nerve of thigh: It lies in the center 2. Lateral cutaneous nerve of thigh lies laterally and 3. The posterior branch of medial cutaneous nerve of thigh lies medially.

Figure 319 Showing cutaneous innervation of gluteal region—back of the thigh and leg

Posterior Cutaneous It is the branch of sacral plexus (S, 1, 2, 3) It leaves the pelvic cavity through Nerve of Thigh: the greater sciatic notch, below the lower border of piriformis. It runs downwards all along sciatic nerve till it reaches long head of biceps femoris muscle. Here the sciatic nerve goes deep to long head of the biceps femoris and posterior cutaneous nerve of the thigh runs superficially. It runs downwards till it reaches the middle of the back of leg. Branches: 1. Gluteal: They wind round lower border of gluteus maximus and supply the skin of lower part of gluteal region. 2. Perineal branch: Comes out from posterior cutaneous nerve of thigh in the gluteal region. It passes medially immediately below the ischial and crosses the hamstrings superficially. The nerve supplies the skin of perineum and upper part of the medial aspect of thigh. 3. Branches to the skin of thigh: They are many and supply the skin of the back of thigh. 4. Branches to the skin of the leg: Supply upper part of the back of the leg. Muscles of Flexor They are members of the hamstring group. They are supplied by the sciatic Compartment nerve. The following muscles lie in this compartment (Figure 320). (Figure 320): 1. Biceps femoris, 2. Semitendinosus, 3. Semimembranosus.

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Kadasne’s Textbook of Anatomy (Clinically Oriented) All of them arise from ischial tuberosity. Out of them the biceps goes downwards and laterally and semitendinosus and membranosus go downwards and medially, thus forming an inverted ‘V’.

Figure 320 Muscles of the back of thigh and muscle arising from ischial tuberosity. Note attachment of sacrotuberous ligament

BICEPS FEMORIS Origin:

Insertion: Nerve Supply:

Action:

Arises by two heads namely the long and the short. (i) Long head arises from lower and medial part of ischial tuberosity above transverse ridge along with semitendinosus. The origin of long head can also be traced into sacrotuberous ligament. (ii) Short head arises from linea aspera and upper part of lateral supra-condylar ridge. The tendon gets inserted into the head of the fibula. Near the insertion the tendon is split into two by lateral ligament of the knee joint. Long head gets innervated from the tibial element of the sciatic, while the short head receives innervation from the common peroneal element of the sciatic. It is the flexor and the lateral rotator of the leg. In addition to these, the long head is extensor of the hip

SEMITENDINOSUS Origin: Insertion:

Nerve Supply: Action:

From the lower medial part of ischial tuberosity above transverse ridge along with the long head of the biceps femoris. Tendon of the muscle is cord like. It lies over semi-membranosus and gets inserted into upper part of the medial surface of the tibia below insertions of sartorius and the gracilis. The tendon is separated from medial ligament of knee joint by means of bursa. The bursa intervenes between semitendinosus and gracilis on the one hand and sartorius on the other. It is supplied by sciatic nerve from two sets of branches the upper and the lower. It is the flexor and medial rotator of the leg and extensor of the hip in other words it is the extensor of the hip and the flexor of the knee.

SEMI-MEMBRANOSUS Origin: Insertion:

It arises from upper and lateral part of ischial tuberosity above transverse ridge. As the muscle descends downwards and medially it lies deep to biceps femoris (long head) and semitendinosus. As mentioned before, the semitendinosus lies on the semi-membranosus muscle. The tendon of semimembranosus gets inserted into the groove on the back of medial condyle

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of tibia. At its insertion, tendon of membranosus, sends three fibrous expansions: (1) Oblique posterior ligament of the knee joint, (2) To deep fascia of the leg and (3) To the fascia covering the popliteus muscle. A bursa intervenes between the tendon of semi-membranosus and medial head of gastrocnemius (Semi-membranosus bursa). Enlargement of this bursa produces swelling in popliteal region (Morrant Baker’s Cyst). It becomes prominent during extension of the knee and disappears during the flexion of the hip. By sciatic nerve (Please note that branch to the semi-membranosus arises in common with the nerve to the adductor magnus.) It is flexor and medial rotator of the leg and extensor of the hip. Tendon of semitendinosus muscle is used in rupture of the anterior cruciate ligament for repair and replacement. It is the diamond shaped hollow situated at the back of knee. Popliteal surface of femur is covered with the popliteal fat. Popliteal fossa presents the floor, the roof, the supero-lateral, supero-medial, the infero-lateral and the infero-medial borders.

Figure 321 Boundaries of popliteal fossa

Floor: Roof:

Supero-medial Boundary (Figure 322): Figure 322 General arrangement of the structures in popliteal fossa

It is formed by popliteal surface of femur above; back of the capsule of knee joint in the middle and popliteus muscle with its fascia below. Is formed by deep fascia known as popliteal fascia. Posterior cutaneous nerve of thigh and short saphenous vein lie over the roof before piercing deep fascia. Is formed by semitendinosus, semimembranosus, sartorius, gracilis and adductor magnus.

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Supero-lateral Border:

Contents:

General Arrangement of Structure:

Popliteal Artery:

Relations (Figure 323):

By tendon of biceps femoris. Infero-Iateral Border: By lateral head of the gastrocnemius and plantaris. Infero-medial Border: By medial head of gastrocnemius. They are: i. Popliteal artery with branches, ii. Popliteal vein with tributaries, iii. Medal popliteal nerve with branches, iv. Lateral popliteal nerve with branches, v. Lymph nodes, vi. Popliteal fat. Popliteal artery runs obliquely from adductor opening to inferior corner of the fossa and disappears between two heads of gastrocnemius muscle. Popliteal vein follows the artery but lies superficial to it. The tibial nerve runs vertically downwards from superior corner of the fossa to the inferior. It lies superficial to the artery and vein. The common peroneal nerve follows tendon of biceps femoris along supero-lateral border of the fossa. It runs as a continuation of femoral artery beyond the opening of artery in adductor magnus and ends at the lower border of popliteus by dividing into terminal branches namely anterior and posterior tibial. For convenience of description we shall divide it into three, upper third, middle third and lower third.

Figure 323 Relations of popliteal artery in the popliteal fossa

Relation in the Upper Third: Relations in the Middle Third:

Relations in the Lower Third:

Here it lies under the semi-membranosus. Popliteal vein and tibial nerve lie lateral to the artery. This part lies on popliteal surface of the femur and fat. Here it lies between the condyles of femur. The capsule of knee joint lies anteriorly. Artery lies between heads of gastrocnemius. Lateral head of gastrocnemius and plantaris lie laterally white medial head of gastrocnemius lies medially. The artery is deepest, next lies vein and over it lies tibial nerve. Popliteal artery is most important posterior relation of the knee joint. Here it lies under cover of plantaris, lateral head of gastrocnemius and nerve to lateral head of gastrocnemius. At the division, popliteal artery lies under soleus muscle. Anteriorly lies popliteus with its fascia. Now popliteal vein and medial popliteal nerve lie medial to the artery (Figure 323).

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BRANCHES (FIGURE 324) Figure 324 Branches of popliteal artery in the popliteal region

Muscular: Cutaneous: Articular:

Surgical:

Popliteal Vein:

Tributaries:

Tibial Nerve (Figure 325):

It gives branches to the hamstrings and calf muscles. It gives cutaneous branches. They are five in number, namely, two superior, two inferior and one middle. They follow genicular nerves, which are branches of medial popliteal nerve Superior genicular arteries arise from popliteal when it lies between two condyles of femur. They respectively pass above lateral and medial condyles, in close contact with femur. The inferior genicular arteries arise from popliteal immediately below condyle of femur. Out of these lateral inferior genicular runs below lateral condyle and medial inferior genicular runs along the upper border of popliteus muscle. Middle genicular branch pierces the oblique posterior ligament of the knee joint and supplies cruciate ligaments which are intra-articular and extra-synovial in the knee joint. Localised dilatation of the arterial wall is known as an aneurysm. Its relation with popliteal vein it may cause its thrombosis. It may irritate the tibial nerve. It can be damaged in supra-condylar fracture of the femur and the posterior dislocation of the knee. True aneurysm means involvement of all the three constituent of the arterial wall i.e. adventia, media and the intima. It is formed at the lower border of popliteus muscle on the medial side of popliteal artery by union of venae comitantes of anterior and posterior tibial arteries. After its formation the vein runs upwards towards adductor opening to continue as femoral vein. While doing so popliteal vein crosses popliteal artery superficially from medial to lateral side and gets itself crosses by tibial nerve. At the adductor opening the vein lies posterolateral to the artery. 1. Veins accompanying branches of popliteal artery, and the 2. Short saphenous vein. Valves: Popliteal vein presents 3-4 valves. It is one of the two terminal branches of sciatic nerve given in the middle of the back of thigh, under cover of long head of biceps femoris. At the upper corner of popliteal fossa it comes out from undersurface of biceps and further runs downwards crossing popliteal artery and vein from lateral to medial side superficially. At the lower border of popliteus muscle it continues as posterior tibial nerve.

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Figure 325 Tibial nerve in the popliteal fossa

Relations:

Muscular:

Nerve to Popliteus (Figure 326):

Figure 326 Nerve to popliteus (Highly schematic)

It lies on adductor magnus, popliteal vessels and popliteus muscle from above downwards. In the upper part of the fossa the popliteal vessels are medial to the nerve while in the lower part of the fossa the popliteal vessels lie lateral to the nerve. In the middle of the fossa the nerve lies superficial to the vessels. In the lower part of the fossa heads of gastrocnemius muscle try to overlap the nerve. Branches: 1. Muscular, 2. Articular, 3. Cutaneous. Branches are given to plantaris, medial, and lateral heads of gastrocnemius and soleus. All branches arise from the nerve in the lower part of the fossa where it lies medial to popliteal vessels. Now it becomes obligatory for all these muscular branches to cross popliteal vessels from medial to lateral superficially. (As a matter of fact “we have to say behind” if anatomical positions is brought into view. However, dissection of fossa is done when the body is prone and hence the given description is applicable in that position). Please note that soleus gets second branch in the leg from the soleus. It under takes a peculiar course. It is the lowest branch of tibial nerve. It passes superficial to popliteal artery, reaches popliteus and after winding round its lower border comes to the anterior surface (deep surface) of the muscle. In addition to this, the nerve to popliteus gives branches to superior and inferior tibio-fibular joints and interosseous membrane.

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Articular Branches: They are three in number: 1. Superior medial genicular, 2. Middle genicular and 3. The inferior medial genicular. Superior medial genicular nerve passes above medial condyle of femur and supplies the capsule, ligaments and synovial membrane of knee joint. Middle genicular pierces oblique posterior ligament of knee joint and supplies cruciate ligaments inside the knee joint. Inferior medial genicular nerve follows upper border of popliteus goes below medial condyle of tibia. Here it passes deep to medial ligament of knee joint and supplies the capsule. Cutaneous Branch:

It arises from tibial nerve when it lies in the fossa. It runs downwards across gastrocnemius to reach back of the leg and lateral side of the foot as it runs further.

Common Peroneal Nerve (L4, 5, 81, 2) (Figures 327 to 329):

It is one of the two terminal branches of sciatic nerve given at the middle of the back the thigh on the adductor magnus and under the long head of the biceps femoris muscle. As it enters the popliteal fossa it runs downwards and laterally following tendon of biceps femoris and reaches the neck of fibula where it divides into superficial and the deep peroneal branches anterior tibial and musculocutaneous nerves. Please note that biceps femories tendon passes superficial to plantaris and lateral head of gastrocnemius, so the common peroneal nerve also has to pass superficial to plantaris and the lateral head of gastrocnemius muscle Hence the nerve lies relatively superficially in the popliteal fossa. It is related to the neck of fibula, and is damaged in the fracture neck fibula. In the tumor known as osteoclastoma of the head of the fibula, the common peroneal nerve is carefully separated during the excision of the tumor.

Figure 327 Branches of tibial nerve

Figure 328 Common peroneal nerve

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Figure 329 Common peroneal nerve with branches (Diagrammatic)

Branches:

It is important to remember that common peroneal nerve does not give any muscular branch in the popliteal fossa as all muscular branches in the fossa come from the tibial nerve alone. However, it gives articular and cutaneous branches. Articular Branches: They are three in number namely: Superior lateral genicular, inferior lateral genicular and recurrent genicular. Out of these superior and inferior lateral genicular are very small and they run in company with genicular arteries. The recurrent genicular nerve is thicker size and arises from common peroneal nerve near the neck of fibula. It passes through the substance of extensor digitorum longus and tibialis anterior and reaches capsule of the knee joint. It also gives the branch to the superior tibio-fibular joint. During most of its course it is accompanied by anterior tibial recurrent artery (Figure 329). Cutaneous They are: (1) Sural communicating and the (2) lateral cutaneous nerve of Branches: calf. The sural communicating arises higher up and join sural nerve at middle of the back of calf. The lateral cutaneous nerve of the calf arises lower down and supplies the skin of lateral and anterior aspect of the leg. Popliteal Lymph The deep group of lymph nodes are five to six in numbers and are placed Nodes: in the fat of popliteal fossa. One node is placed at the sapeno-popliteal junction the other is placed between the popliteal artery and the capsule. It drains the knee joint. In addition to the deep group there are superficial group of lymph nodes. Superficial nodes lie with small saphenous vein. They drain postero-Iateral aspect of leg and foot. Deep group of lymph nodes lie deep to deep fascia and are in close relation with popliteal vessels. They receive lymphatics from superficial nodes and also from the deep parts of the leg and foot. The popliteal nodes are palpated by the flexing of the knee which relaxes the deep fascia of the roof of the popliteal fossa. The popliteal nodes may form an abscess under the tough deep fascia, hence remains unnoticed. The abscess presses on the nerves and vessels of the popliteal fossa. The abscess is drained through an incision on the lateral aspect, anterior to the tendon of biceps femoris.

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KNEE JOINT Classification: It is a synovial modified hinge variety of joint. Bones Taking Part Lower end of femur, upper end of tibia and posterior surface of patella. (Figures 330 and 331): Figure 330 Lower end of femur (anterior and posterior view)

Figure 331 (A) Lateral veiw of lateral condyle of femur, (B) Lower end of femur seen from below

Lower End of Femur:

It presents medial and the lateral condyles. Medial condyle is larger than lateral. Anteriorly two condyles are connected together and presents an articular area for patella. Patellar articular area is larger over lateral condyle and smaller over medial. Rest of the articular area on medial and the lateral condyles, is meant for tibial articulation. However, a shallow groove marks the Iimit of patellar and tibial articular areas. These grooves are produced by anterior edges of medial and lateral semilunar cartilages. Patellar articular area appears to be continuous with the semilunar area on the lateral part of the medial condyle of the femur. The patellar articular area is known as medial vertical facet of patella. In extreme degree of flexion the medial vertical facet of patella comes in to contact with the semilunar area of the medial condyle of the femur. Patellar articular area in front of lateral condyle extends more laterally and upwards than its counterpart on the medial condyle. On the posterior aspect, condyles are separated from each other by means of a deep and wide notch known as inter-condylar notch. The notch presents medial and lateral walls. The tibial articular surface extends almost up to popliteal surface of the femur, posteriorly. Maximum point of convexity of each condyle is known as epicondyle. Immediately below the lateral epicondyle is the small groove anterior part of which gives origin to the popliteus muscle which is intracapsular.

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Upper End of Tibia Top of the upper end of tibia presents two condyles namely medial and (Figure 332): the lateral. Medial condyle is larger in size like the medial condyle of femur. Medial condyle presents a shallow articular area for medial condyle of femur. This area is oval. At its periphery the flattened impression is present, which is meant for the medial semilunar cartilage. Lateral condyle presents the circular articular area, for lateral condyle of femur. At its periphery a flattened impression is present, which is for the lateral semilunar cartilage. Two condylar areas are separated from each other by means of anterior and posterior inter-condylar areas and the tibial spines. Articular areas of the tibial condyles encroach the tibial spines to some extent (Figures 332 and 332A). Figure 332 Upper end of tibia and its attachments (Viewed from above)

Figure 332A X-ray of knee joint

Posterior Surface of It presents a large oval articular area above and small non articular area Patella (Figures 333 below. The articular area of the patella is divided into large lateral and the and 333A): small medial areas by means of the faint ridge. The medial most part of medial area presents the medial vertical facet which comes into contact with semilunar area of the medial condyle of the femur during extreme degree of flexion. In addition to this, two ill defined horizontal ridges are present which run across the whole of patellar articular area.

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Figure 333 Posterior surface of patella

Figure 333A Showing patella viewed from behind and sequential contact of femoral articular surface with patella

CAPSULAR ATTACHMENT (Figures 334 and 335) Figure 334 Capsular attachment of knee joint viewed from front and back

Figure 335 Showing fibular collateral ligament from front (A) oblique posterior ligament, popliteus muscle and arcuate ligament viewed from back (B)

To Lower End of Femur:

It is attached all along the periphery beyond articular area of the lower end of femur. On the lateral aspect of the lateral condyle of femur, capsular line includes the groove which gives origin to the popliteus muscle.

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To Upper End of Tibia:

Ligaments of Knee Joint

Capsular Ligament (Figure 335):

Medial Ligament (Tibial Collateral Ligament) of Knee Joint:

Anteriorly it descends downwards like an inverted ‘V’ up to the tubercle of tibia. At the sides and posteriorly it is attached to periphery of the condyles beyond the area for semilunar cartilages. However, it is broken (interrupted) at the posterior border of lateral condyle of tibia, for the passage of the tendon of popliteus muscle. 1. Capsular ligament, 2. Medial collateral ligament, (Tibial collateral ligament) 3. Lateral collateral ligament, (Fibular collateral ligament) 4. Oblique posterior ligament, 5. Coronary Ligaments 6. Transverse ligament, 7. Anterior cruciate ligament, 8. Posterior cruciate ligament, 9. Ligamentum patellae, 10. Arcuate ligament. Capsule is thick at the sides. It is deficient in front where patella and ligamentum patellae try to compensate anterior weakness of the capsule. Supra-patellar bursa communicates with joint cavity and tendon of popliteus comes out of the cavity on the posterior aspect. Here popliteus is protected from above by an arcuate ligament. Anteriorly capsule is supplemented by the medial and the lateral patellar retinaculi. The retinaculi are fibrous expansions from the vastus medialis and vastus lateralis muscles. Capsule is relatively thin on the posterior aspect. Above, it is attached to medial epicondyle of the femur and lower down it is attached to medial aspect of medial condyle of tibia and upper part of medial border of tibia. The ligament has two parts, namely superficial and deep. Deep parts of the ligament is attached to medial semilunar cartilage. It is due to this fixity to the tibial collateral ligament the medial semilunar cartilage gets ruptured often. Lateral ligament is not attached to lateral semilunar cartilage but it is attached to the tendon of the popliteus. It can be expressed in the following terms. Medial semilunar cartilage is attached to the static structure while the lateral semilunar cartilage is attached to the dynamic structure. Superficial to the tibial collateral ligament are the tendons of sartorius, gracilis and semi-tendinosus. The inferior medial genicular artery lies deep to the ligament (Figure 336).

Figure 336 Knee joint viewed from behind (Tibial collateral ligament and medial semilunar cartilage). Please note the inferior medial genicular artery below the ligament

Direction of Ligament: Lateral Ligament of Knee Joint (Fibular Collateral Ligament):

It is directed downwards and backwards. It is cord like and thick. Above, it is attached to lateral epicondyle of femur and lower down to styloid process and adjoining part of the head of fibula. It splits the tendon of biceps femoris into two parts. Deep to the ligament lie inferior lateral genicular artery and the nerve. Lateral ligament is not attached to lateral semilunar cartilage as opposed to medial ligament which is attached to medial semilunar cartilage (Figure 337).

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Figure 337 Lateral ligament of knee joint

Oblique Posterior Ligament of Knee Joint (Figure 338):

It is the membranous expansion from semi-membranosus muscle near its insertion. It runs upwards and laterally from the back of medial condyle of tibia to the back of lateral condyle of femur. On its way it fuses with capsule of the knee joint.

Figure 338 Oblique posterior ligament of knee joint

The ligament is pierced by i. Middle genicular nerve, ii. Middle genicular artery and iii. Genicular branch of the obturator nerve. Popliteal artery lies over the ligament. Coronary Ligaments: They are the short series of ligaments which connect the periphery of the semilunar cartilages to the top of tibia. They are absent at the back of lateral tibial condyle, where the tendon of popliteus lies in contact with the bone. Transverse Ligament: It is not always present. It connects anterior ends of the two semilunar cartilage. Anterior Cruciate Ligament (Figures 339A, 339B and 340):

It lies inside the joint. Please note that names of cruciate ligaments are in accordance with their tibial attachments and not femoral. Anterior cruciate ligament is attached to anterior inter-condylar area of the upper end of tibia on the one hand to the lateral wall of inter-condylar notch on the other (Figures 339A, 339B). It runs upwards and backwards and crosses the posterior cruciate ligament from lateral aspect. It prevents backwards dislocation of lower end of femur. Please note that its function is just opposite of its name e.g. anterior cruciate ligament prevents posterior displacement of the lower end of the femur. Naturally the posterior cruciate ligament prevents the anterior displacement of the lower end of the femur. Cruciate ligaments are covered with the synovial membrane from the front and sides (Figure 342B).

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Figure 339A Cruciate ligaments of knee joint. Anterior cruciate ligament prevents posterior displacement of lower end of femur and posterior cruciate ligament prevents anterior displacement of lower end of femur Figure 339B MRI of knee showing anterior cruciate ligament

Figure 340 Showing attachment of cruciate ligaments on the walls of intercondylar notch of the lower end of femur

Posterior Cruciate Ligament:

Ligamentum Patellae: Arcuate Ligament:

It lies inside the joint. It is attached to posterior inter-condylar area of upper end of tibia and goes to medial wall of inter-condylar area. It runs upwards and forwards and crosses anterior cruciate ligament from the medial side. It prevents anterior dislocation of lower end of femur, It is covered with synovial membrane from the front and sides (Figures 339A and 392B). Note: Anterior cruciate ligament prevents posterior dislocation of lower end of femur while posterior cruciate ligament prevents anterior dislocation. Thus antero-posterior stability of lower end of femur over upper end of tibia is achieved. As regards dislocation of the upper end of tibia, the function of the above ligaments can be described as under: 1. Anterior Cruciate ligament: Prevents anterior dislocation of upper end of tibia. 2. Posterior Cruciate ligament: Prevents posterior dislocation of upper end of tibia. It runs from the apex of patella to the tubercle of tibia. It represents tendon of quadriceps femoris as patella is the sesamoid bone developed in the tendon of quadriceps femoris. It runs from lateral condyle of femur and gets attached to back of capsule of knee joint and also to head of fibula. Tendon of popliteus escapes under the arch of the arcuate ligament.

Knee Joint Medial Semilunar Cartilage (Figures 341 and 341A):

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Rupture of the medial semilunar cartilage is seen more than the lateral semilunar cartilage. It is oval in shape. It is attached to anterior and posterior inter-condylar areas by means of the anterior and posterior horns, respectively. On the medial side it is attached to deep part of tibial collateral ligament of knee joint. Medial semilunar cartilage ruptures often as compared to the lateral, mainly due to its attachment to the deep part of the tibial collateral ligament of knee joint. (Bucket handle tear). Peripheral border is thick and the inner is thin almost like the sharp edge of the knife. It is fibro-cartilaginous in nature. The cartilage is broad posteriorly and narrow anteriorly.

Figure 341 Medial semilunar cartilage is attached to tibial collateral ligament which is a static structure while lateral semilunar is attached to the dynamic structure, e.g. popliteus muscle

Figure 341A Arthroscopic view of knee joint showing normal meniscus

Lateral Semilunar Cartilage (Figure 341B):

Functions of Medial Semilunar Cartilage: i. Deepens articular surface at the upper end of tibia, ii. Protects bony edges, iii. Helps in maintaining the bony contact of articular surface of tibia and femur. It is somewhat circular in shape as anterior and posterior ends come closer and lie in between anterior and posterior ends of medial semilunar cartilage. It is attached to anterior and posterior inter-condylar areas by means of the anterior and posterior horns. From posterior end of the cartilage a fibrous band goes to medial condyle of femur. Posterior end of the lateral semilunar cartilage provide to ligamentus slips one of which goes in front and the other behind the posterior cruciate ligament and get attached to the medial condyle of the femur. One in front is known as ligament of Humphrey and the posterior is known as ligament of Wrisberg. Outer border of the cartilage is thick and medial border is thin, almost like a sharp edge of a knife. Laterally it is attached to the tendon of popliteus and is related to the fibular collateral ligament of the knee joint. The functions of the lateral semilunar cartilage are similar to the functions of the medial semilunar cartilage.

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Figure 341B Arthroscopic view of knee joint showing intra-articular portion of popliteus

Figure 341C Injury of medial semilunar cartilage (bucket handle injury)

Figure 341D Showing arthroscopic view of interior of the knee showing discoid meniscus (lateral semilunar cartilage)

Figure 341E Showing arthroscopic view of interior of the knee showing reconstructed anterior cruciate ligament from tendon of semitendinosis

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Figure 341F Showing arthroscopic view of interior of the knee showing process of removal of foreign body

Nutrition of the Semi-lunar Cartilages (Menisci): Surgical:

Unhappy Triad’s of Knee:

Runner’s Knee:

Peripheral few millimeter part has blood supply while the major inner portion of the semilunar cartilages are avascular and are nourished by diffusion. Due to its fixity, the medial semilunar cartilage is commonly ruptured, when the fixed knee is forcibly abducted and laterally rotated. (Such as in the game of foot-ball). The broken fragments of the cartilage get wedged between the articular surfaces of the femur and the tibia and the knee gets locked. Locking of a joint after injury of the knee is suggestive of damage to the intra-articular cartilage. Medial semilunar cartilage when ruptured may presents the bucket handle deformity. This immensely helps in diagnosing the case of rupture of the semilunar cartilage. There are only two important things to be remembered about lateral semilunar cartilage. 1. Discoid cartilage: It is shaped like a disc. In this condition parents usually complain that the knee of their child gives way and he falls. This helps us in diagnosing the condition of discoid cartilage. It is due to the failure of mechanoreceptors from the joint surface. It requires excision of the cartilage. 2. Cyst of lateral semilunar cartilage: It appears in the form of a swelling on the lateral side of knee joint. It requires excision of the cartilage. 3. Lateral semilunar cartilage ruptures less often due to tendon of popliteus which keeps if mobile. I would like to repeat here the following sentence “MEDIAL SEMILUNAR CARTILAGE IS ATTACHED TO THE STATIC STRUCTURE AND THE LATERAL SEMILUNAR CARTILAGE IS ATTACHED TO THE DYNAMIC STRUCTURE.” It is the combination injury which involves medial semilunar cartilage, anterior cruciate ligament and the tibial collateral ligament. The triad is also described the triad of three “C” (Cartilage, Cruciate ligament and Collateral ligament). Damage to the intra-articular structures leads to synovitis and effusion in the joint. It is also known as patelo-femoral pain syndrome, commonly seen the athletes. There is the pain at the patella which increases after sitting for long time. Patella is not able to roll smoothly on the femoral surface. High patella, weak vastas medialis, wide pelvis and the genu valgum do contribute to the runner’s knee syndrome. 1. In spite of the shallow articular surfaces, dislocation of joint is less. Credit for this is to be given to the ligaments and muscles. 2. Medial semilunar cartilage gets ruptured, commonly than the lateral. 3. Anterior cruciate ligament ruptures in the extension position of the knee. If lower end of femur gets dislocated posteriorly the anterior

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cruciate ligament gets ruptured. In the event of the displacement of the upper end of tibia anteriorly the posterior cruciate ligament is ruptured. In the rupture of the anterior cruciate ligament the tibia can be drawn forwards which is known as positive anterior drawer sign. In the rupture of the posterior cruciate ligament the upper end of tibia can be drawn posteriorly. It is known as positive posterior drawer sign. 4. In posterior dislocation of knee popliteal artery is damaged along with the vein and the tibial nerve. 5. Genu-valgum: During erect posture the legs instead of being vertical, spread out at their lower ends. Thus, an angulation between femur and tibia is increased and is open laterally. This brings the knee still nearer and results in knock-knee. 6. Aspiration of the joint: It is done by inserting the needle either medial or lateral to the patella and it can also be done from lateral side. 7. Ideal position for fixation of joint (Optimal position of joint): Joint is fixed in semi-flexed position this being the position of rest. 8. Baker’s cyst: In rheumatoid arthritis effusion appears in the joint which pushes the synovial membrane through the posterior part of the capsule of the knee joint, containing the fluid. With regression of the effusion in the knee joint the swelling does not disappear. It may rupture in the calf muscles giving rise to pain, swelling and tenderness. It can be diagnosed by the orthrogram. 9. Morrant Baker’s cyst: it is the enlarged semi-membranosus bursa which appears as a swelling on the posterior aspect of the knee which becomes prominent in extension and disappears in flexion. It communicates with the knee joint cavity. (Trans-illumination is done with the help of the torch.) 10. Osgood Shlatter’s disease of the tubercle of the tibia: It is the traction apophysitis of the tubercle of tibia. Commonly seen in boys between the age of 13 to 14 years. It presents with pain and swelling at the tubercle of tibia. Synovial Membrane It covers the capsule from inside and other structures, except the articular (Figure 342): areas. Synovial membrane of supra-patellar bursa is in communication with synovial membrane of the joint. As mentioned earlier supra-patellar synovial bursa is pulled upwards by articularis genu muscle. Below patella the synovial membrane forms folds known as alar folds. Alar folds unite to form infra-ptellar fold, which gets attached to the area in front of intercondylar notch of femur. Between synovial folds and ligamentum patellae there is good amount of fat known as infra-patellar pad of fat. Synovial membrane of the joint gives a tube like synovial extension for tendon of popliteus muscle. Semilunar cartilages are not covered with synovial membrane. Cruciate ligaments are covered by synovial membrane from the front and sides only. Figure 342 Synovial membrane of knee joint in sagittal and horizontal section

Knee Joint Bursae Around The Knee (Figures 343 and 344):

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The knowledge of these bursae is desirable as on many occasions their positions are required to be recalled while examining the case of swelling in the region of knee. There are thirteen bursae around the knee joint. They are grouped into three, namely the anterior, the lateral and the medial. Anteriorly, there are four, laterally four and medially five bursae.

Figure 343 Some bursae around knee joint

Figure 344 Bursae associated with semimembranosis, semitendinosis and biceps femoris muscles serially 1, 2 and 3

Anterior Group:

Lateral Group:

Medial Group:

Clinical:

Here they are named in accordance with their positions in relation to patella i. Subcutaneous pre-patellar, ii. Subcutaneous infra-patellar iii. Deep infra-patellar and iv. Supra-patellar (Figure 343) They are four in number: i. Under lateral head of gastrocnemius - This usually communicates with joint cavity, ii. Between the tendon of biceps and the fibular colateral ligament, iii. Between fibular colateral ligament and popliteus tendon, iv. Between lateral condyle of femur and popliteus (Figure 344). They are five: i. Under medial head of gastrocnemius and the capsule (Brodie’s bursa), ii. Under sartorius, gracilis and semi-tendinosus tendons, (Pes anserius) iii. Under semi-membranosus and deep part of medial ligament, iv. Between tendon of semi-membranosus and medial condyle of tibia, v. Between semi-membranosus and semi-tendinosus tendon (Figure 344). It is better to remember them as under: i. With patella - 4 ii. With semimembranosus - 3 iii. With popliteus - 2 iv. With biceps femoris - 1 v. With gastrocnemius - 2 vi. With sartorius gracilis and semitendinosus - 1. Inflammation of the pre-patellar bursa is known as house maid’s knee or pre-patellar bursitis. Inflammation of the subcutaneous infra-patellar bursa is known as clergyman’s knee. During effusion of the knee there is a

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Nerve Supply: Blood Supply:

Movements:

Movements of Locking and Unlocking:

collection of fluid in the supra-patellar bursa which distends and gives rise to fullness on both sides of the quadriceps. It is described as water on the knee. If the patella is pressed down it gives sound which is known as patellar tap. It is supplied by the femoral, obturator, medial and lateral popliteal nerve supply this joint. It is supplied by the genicular branches of the popliteal, descending genicular branch of femoral, recurrent branches of anterior tibial and long descending branch of lateral circumflex femoral artery. Being synovial and uniaxial and the modified variety of the hinge type it has flexion, extension, medial rotation and the lateral rotation take place in this joint. It must be remembered that movement of flexion is accompanied by movement of medial rotation and movement of extension is accompanied by movement of lateral rotation. During flexion and extension axis of the joint does not remain fixed and changes. In extension the anterior ends of semilunar cartilages are forcibly flattened by condyles of the femur. When the foot is on the ground, in extreme degree of extension lower end of the femur rotates medially. It is known as locking. It is unlocked by the slight lateral rotation of the lower end of the femur over the upper end of the tibia. It is done by the popliteus muscle, hence known as the key of the knee joint. We are able to stand for hours due to movement of locking without putting strain on the quadratus femoris. Lateral rotation is the part of the flexion therefore it is conjugate rotation. In extension femur rotates medially on the tibia which is the part of extension. It is called conjugate rotation. Main cause of the rotation is the disparity between the articular surfaces of the femoral condyle. It is only in the extreme degree of extension medial vertical facet of patella comes in contact in the semilunar area of the medial condyle of the femur. Note: Flexion and extension occur in meniscofemoral compartment and the rotation in the meniscotibial compartment. Two types of rotations occur in the knee: (1) Conjunct and (2) the adjunct. Conjunct rotation occurs in locking and unlocking of the knee and it is between the 20 – 30 degrees. Adjunct rotation occurs in semiflexed knee which is 50 to 70 degrees (Conjunct means part of it and adjunct means additional). Muscles producing different movements

Accessory Movements:

Movements

Muscles

Flexion

Biceps, femoris semitendinosus Posteriorly related muscles are Semimembranosus, popliteus, flexors. sartorius, gracilis, gastrocnemius find plantaris.

Comment

Extension

Quadriceps femoris: Rectus femoris, Vastus lateralis, Vastus medialis, Vastus intermedius and tensor fascia latae.

Medial rotation

Sartorius, gracilis, semiMedially related muscles are tendinosus, semi-membranosus medial rotators, which is true and popliteus. for all except popliteus.

Lateral rotation

Biceps femoris

Anteriorly related muscles are extensors. Note that tensor fascia latae muscle is inserted into liotibial tract, which comes in front of the joint to some extent.

Laterally related muscle is the lateral rotator.

They occur when the knee is flexed at the right angle position. During this position slight amount of gliding movements occur and tibia can be pulled away from the lower end of femur to some extent.

Knee Joint Relations of the Knee Joint (Figure 345):

Figure 345 Relations of knee joint (Highly schematic)

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Posterior relations of the knee joints are important from before backwards they are (1) Popliteal artery (2) Popliteal vein and the (3) Tibial nerve. In addition to the above structures it is related to semi-membranosis, semitendinosis, medial head of gastrocnemius, plantaris and the fat (Figure 345). Horizontal Section through the knee.

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LEG The region between the knee and the ankle is known as the leg. Tibia and fibula are the bones of the leg, tibia being the medial and the fibula lateral. Deep fascia of the leg begins at the anterior border of the tibia surrounds the neck and ends at the medial border of the tibia. It is not attached to the fibula directly. However, anterior and the posterior borders of the fibula are attached to the fascial cover by means of anterior and posterior muscular septae. The deep fascia does not cross the periosteum of the bone hence, it is absent over the medial surface of the tibia. Interosseous borders of the tibia and the fibula are connected by means of the interosseous membrane. The leg is divided into three compartment (1) Anterior or extensor, (2) Posterior or flexor and (3) Lateral or the peroneal. Surface Landmarks Try to feel and note the following landmarks. (Figure 346): Figure 346 Surface landmarks of leg viewed from front

i. Head of Fibula: By following the tendon of biceps femoris muscle. ii. Neck of Fibula: Immediately below head of fibula. Feel for lateral popliteal nerve over the neck. iii. Tubercle or Tuberosity of Tibia: By following ligamentum patellae. iv. Anterior Border of Tibia: v. Lateral and Medial Malleoli: To be felt respectively on lateral and medial side of ankle. vi. Tendon of Tibialis Anterior: Dorsiflex the foot and note the prominent medial most tendon of the tibialis anterior. vii. Tendo Calcaneus: A strong tendon behind the ankle. viii.Long Saphenous Vein: Seen in front of medial malleolus and also over lower part of medial surface of tibia. ix. Make an attempt to see the short saphenous vein on the back of lateral malleolus. x. Try to feel for pulsation of posterior tibial artery on medial side of the ankle between medial malleolus and tendo-calcaneus. xi. Muscle mass of the calf becomes much more prominent as you stand on your toes.

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This muscle mass of calf is due to contracting gastrocnemius and soleus muscles. Anterior compartment of the leg contains four muscles, one artery and one nerve. The muscles are tibialis anterior, extensor digitorum longus, extensor hallusis longus and the peroneus tertius. The artery of the anterior compartment is known as anterior tibial artery which is one of the two terminal branches of the popliteal artery given at the lower border of the popliteus muscles at the back other being posterior tibial. The nerve of the anterior compartment is the deep peroneal nerve. It is one of the two terminal branches of the common peroneal nerve given at the level of the neck of the fibula in the peroneal compartment other being superficial peroneal nerve.

Figure 347 Cross section of the leg, please note how the extensor compartment borrows its artery from the flexor and the nerve from the peroneal compartments. Deep fascia of leg does not cover the medial surface of tibia

Comment:

Superficial Fascia: Superficial Veins:

Extensor compartment has no artery of its own. It borrows the artery from the flexor compartment and the nerve from the lateral compartment. This itself speaks of the relations of the anterior tibial artery and the deep peroneal nerve, the artery is the medial and the nerve lateral. However, in the lower one third of the leg, the deep peroneal nerve makes an half hearted attempt to cross the anterior tibial nerve from lateral to medial side. It fails to do so and just goes in front of the artery and returns to the lateral side. This is classically described as hesitation of the nerve to cross the artery. Compartments Muscles

Comment

Extensor

Tibialis anterior Extensor digitorum longus. Extensor hallucis longus. Peroneus tertius.

Four muscles, out of them one is tibial, two are extensors and one is peroneus.

Flexor

Gastrocnemius, soleus, plantaris, popliteus, tibialis posterior, flexor hallucis longus, and flexor digitorum longus.

Seven muscles, out of them first three lie in the superficial group and the rest of them are in the deep group.

Peroneal

Peroneus longus. Peroneus brevis.

Two muscles, one lies superficial and the other lies deep; longus being superficial and the brevis being deep. (Longer covers the shorter).

Amount of fat is relatively less. Mainly two: 1. Long saphenous and 2. Small (short saphenous) saphenous veins. The long saphenous vein begins by the union of medial end of dorsal venous arch and medial dorsal digital vein of the great toe. The long saphenous vein passes in front of medial malleolus and reaches lower part of medial surface of

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Small (short) Saphenous Vein:

tibia. Next it follows the medial border of the tibia and goes to the back of the knee. It begins by union of lateral end of dorsal venous arch and lateral dorsal digital vein of the little toe. After its formation the vein passes behind lateral malleolus and reaches the back of the leg, by passing on the lateral aspect of tendo-calcaneous. Thereafter, it reaches middle of the back of the leg in the mid-line. It ascends upwards and lies on the deep fascia of the lower part of popliteal fossa, where it pierces deep fascia and enters the popliteal vein. The small saphenous vein communicates with long saphenous (great saphenous) by means of cross channels. However, one channel is fairly big and it connect small saphenous vein with long saphenous vein approximately in the middle of thigh. Small saphenous vein drains blood from lateral aspect of foot, lateral aspect of ankle and back of the leg. Small saphenous vein is accompanied by sural nerve, which is a branch of tibial nerve. Cutaneous Nerves: Following nerves supply front of leg (Figure 348). 1. Infrapatellar branch of saphenous (L3 and 4). 2. Lateral cutaneous nerve of calf (L5, S1 and 2). 3. Musculo-cutaneous nerve (L4, 5, S1).

Figure 348 Cutaneous nerves of front and back of leg

Infra-patellar branch supplies the upper part of anterior aspect of the leg. Lateral cutaneous nerve which is the branch of lateral popliteal nerve, supplies skin of the middle third of the front of the leg. (e.g. the area between infrapatellar branch and musculo-cutaneous nerve). While the skin of the lower third of the front of the leg is innervated by musculocutaneous nerve. Following Nerves Supply Back of the Leg 1. Sural nerve, 2. Sural communicating nerve, 3. Posterior cutaneous nerve of thigh, 4. Medial cutaneous nerve of thigh, 5. Saphenous nerve. Sural communicating supplies the skin of upper two thirds of the back of the leg, while sural nerve, which runs in company with small saphenous vein, supplies the skin of infero-lateral aspect of the back of the leg. As described before, posterior cutaneous nerve of thigh reaches the middle of the back of the leg. Here it overlap the areas supplied by sural communicating and posterior cutaneous nerve of thigh. Small part of the leg is supplied by medial cutaneous nerve of thigh, however medial

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Deep Fascia (Figures 349 and 350):

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cutaneous nerve of thigh mainly supplies the skin of medial aspect of the leg in the upper part. For better understanding of deep fascia of leg and septa, one must look at the borders and ridges of tibia and fibula. Tibia presents three borders namely anterior, medial and interosseous, while fibula also presents three borders namely anterior, posterior and interosseous. It clearly shows that tibia does not have posterior border. However the fibula does have the posterior border on the posterior surface of the tibia is the vertical line and the posterior surface of the fibula is the vertical crest known as medial crest of fibula. The posterior surface of tibia also presents a vertical line. There is a well defined septum connecting medial crest of the fibula and the vertical line of the tibia. This septum lies over tibialis posterior muscle. This is the deeper septum or septum No. 2. There is another septum known as superficial septum (or posterior septum No. 1). It is attached to soleal line and medial border of tibia on the one hand and posterior border of fibula on the other. Lower down, this septum helps to form superior peroneal retinaculum. In the upper part it is attached to soleal line of tibia and also to the fibula. In between these two connections there is a fibrous arch from which the soleus muscle takes origin.

Figure 349 Showing septae of flexor compartment of leg

Figure 350 Deep fascia of leg and compartments

Deep fascia of the leg is absent over the medial surface of the tibia however it is attached to the anterior and the posterior limits of the triangular subcutaneous area on the lateral malleolus of fibula. The deep

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Compartments (see Figure 350):

Surgical Anatomy (Compartment Syndrome):

Muscles of the Extensor Compartment (Figure 351):

fascia is thick above and it becomes thin in the middle part of the leg. In the lower one third of the leg the fascia thickens to form the extensor retinaculi, the superior and the inferior. In the upper part of the leg, the fascia is thick and in the middle of the leg it becomes thin. However, at the lower part of the leg it again gains strength as it forms the superior, inferior and the peroneal retinaculum. (Please note that superior peroneal retinaculum is mainly formed by septum No. 1 (superficial septum) and flexor retinaculum is also formed by the same septum 1. Anterior: It runs from anterior part of deep fascia to anterior border of fibula. 2. Posterior: It runs from lateral part of deep fascia to posterior border of fibula. By virtue of these two septae the leg is divided into three compartments namely, extensor, flexor and peroneal. Extensor compartment is bounded by deep fascia anteriorly, lateral surface of tibia medially, interosseous membrane and extensor surface of fibula posteriorly and anterior intermuscular septum laterally. The peroneal compartment lies between anterior and posterior inter-muscular septae, deep fascia laterally and Peroneal surface of fibula medially. The flexor compartment is bounded by posterior inter-muscular septum, posterior surface of fibula, interosseous membrane and posterior surface of tibia from lateral to medial side. At the sides and behind, deep fascia bounds it. This compartment is further divided into three by septum No. 1 and septum No. 2. Flexor compartment as a whole is separated from peroneal compartment by posterior inter-muscular septum. Three facial compartments of the leg are of great surgical importance. In case of damage to muscles in the compartments, blood collects and presses on the vein and arteries. It produces ischiamia, pain and the necrosis of the muscles. Opening of the facial spaces with the help of knife can decompress and prevent complications. The particular compartment is open by incising the deep fascia. Three muscles arise from extensor surface of fibula: extensor digitorum longus, extensor hallucis longus and peroneus tertius. The tibialis anterior muscle arises from the lateral surface of tibia from its upper two thirds. All the muscles are supplied by the deep peroneal nerve.

Figure 351 Origin of extensor muscles from anterior surface of fibula and lateral surface of tibia (After Dr Y. Gopalrao)

Tibialis Anterior (Figure 352):

It is situated medially in the extensor compartment and runs from the tibia to bones of the foot, crossing ankle joint from the front.

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Figure 352 Tibialis anterior

Origin:

It arises from upper two thirds of lateral surface of tibia, interosseous membrane and deep fascia of leg. Insertion: Tendon is seen above the ankle. The tendon passes through superior and inferior extensor retinaculi. The tendon runs on medial aspect of dorsum of the foot to reach the medial cuneiform bone and the infero-medial aspect of the base of first metatarsal, where it is inserted. Synovial Sheath for It has an independent synovial sheath. It begins from the upper border of Tendon: the superior extensor retinaculum and extends up to the insertion of the tendon. Nerve Supply: It is supplied by two nerves: (1) deep peroneal and (2) the recurrent genicular nerve. Action: It is dorsiflexor (extensor) and inverter of the foot. (Please note that movements of inversion and eversion do not occur at ankle joint, but solely take place at mid-tarsal and the sub-taloid joints). It also helps in maintenance of medial longitudinal arch of foot. Extensor Hallucis It arises from extensor surface of fibula and goes up to the base of terminal Longus (Figure 353): phalanx of the great toe. In the upper part of the leg, the muscle is covered on medial side by tibialis anterior and on the lateral side by extensor digitorum longus. However, in the lower part of the leg, its tendon emerges out between the tendons of tibialis anterior medially and extensor digitorum longus laterally. Figure 353 Extensor hallucis longus

Origin: Insertion:

It arises from anterior part of the middle two fourths of fibula, interosseous membrane and deep fascia of the leg (Figure 353). The tendon passes behind superior and the two bands of the inferior extensor retinaculi, to reach the base of terminal phalanx of the great toe.

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Synovial Sheath:

It has a separate synovial sheath which runs from upper border of superior limb of inferior extensor retinaculum upto the proximal phalanx of the great toe. Nerve Supply: It is supplied by the deep peroneal nerve. Action: It is the dorsi-flexor (extensor) of the foot and also dorsi-flexor of the great toe. Extensor Digitorum It is situated in the lateral part of extensor compartment. Longus (Figure 354): Figure 354 Extensor digitorum longus

Origin:

Insertion:

Nerve Supply: Action: Synovial Sheath: Peroneus Tertius (see Figure 351):

Nerve Supply: Action:

From the whole of the upper fourth, anterior part of the middle two fourths of extensor surface of fibula and also from deep fascia of the leg (Figures 354 and 357). Tendon of this muscle passes behind superior extensor retinaculum and subsequently through the inferior extensor retinaculum (stem of inferior extensor retinaculum). It divides into four extensions for lateral four toes of the foot at the inferior extensor retinaculum. On the dorsum of each toe it forms the extensor expansion which divides into three slip the middle one is attached to the base of the middle phalanx and the two collateral slips unite and get attached to the base of the terminal phalanx. On the dorsum of the toes the interossei and the lumbrical muscles joints the dorsal digital expansion. It must be noted that the tendons of extensor digitorum brevis muscle for 2nd, 3rd and 4th join dorsal digital expansions. It is supplied by deep peroneal nerve. Dorsiflexor of foot and extensor of lateral four toes. It begins under lower border of superior extensor retinaculum and ends a finger’s breadth below the stem of inferior extensor retinaculum. It arises from lower fourth of extensor surface of fibula, lower part of interosseous membrane and anterior septum and gets inserted into the base of fifth metatarsal bone. (As a matter of fact this muscle is a part of extensor digitorum longus muscle). The tendon passes behind the superior extensor retinaculum and next, through inferior extensor retinaculum befor its insertion into the base of the fifth metatarsal. It is supplied by deep peroneal nerve. It is dorsiflexor of foot in spite of the small size, this muscle is of a great help in the act of dorsifiexion of the foot and eversion along with the peroneous longus and the brevis muscle.

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Superior Extensor Retinaculum (Figure 355):

289

Superior and the inferior retinaculi are the thickened bands of the deep fascia in front of the ankle. They are two in number (i) superior and the (ii) inferior. It is approximately three cm. in breadth and is situated above the ankle, as it runs from fibula to the tibia. It is attached to lower part of anterior border of fibula on the one hand and lower part of the anterior border of tibia on the other. Tibialis anterior tendon passes through medial most part of retinaculum while tendons of extensor hallucis longus, extensor digitorum longus and peroneus tertius pass behind retinaculum along with anterior tibial artery and the deep peroneal nerve. In addition to these structures, perforating branch of peroneal artery also passes under lateral most part of retinaculum.

Figure 355 Superior extensor retinaculum and structures below

Inferior Extensor Retinaculum (Figure 356):

It is ‘Y’ shaped and thus presents a stem and two limbs. It is situated in the proximal part of tile dorsum of foot and overlaps the front of ankle to some extent. Stem of the ‘Y’ is attached to small part of superior surface of calcaneus. Here, it is fused with interosseous ligament and also gives origin to extensor digitorum brevis muscle from its under surface. The superior limb of the ‘Y’ is attached to anterior border of medial malleolus of tibia, while the inferior band runs medially over the proximal part of dorsum of foot and further fuses with fascia of the sole of foot.

Figure 356 Inferior extensor retinaculum and structures below

Tendons of four muscles pass through retinaculum. They are: Tibialis anterior, Extensor hallucis longus, Extensor digitorum and Peroneus tertius, from medial to the lateral side. Tendons of tibialis anterior and extensor hallucis longus pass through superior and inferior limbs, while tendons of the extensor digitorium and peroneus tertius pass through the stem, through a common channel. It is important to note that anterior tibial artery and the deep peroneal nerve escape behind superior and inferior limbs of the inferior extensor retinaculum. 1. 2. 3. 4.

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Deep Peroneal Nerve (Figure 357):

It is one of the two terminal branches of the common peroneal nerve, given at the neck of fibula. Here, it lies under cover of peroneus longus muscle. Next, it passes across anterior inter-muscular septum and through the substance of extensor digitorum longus. The deep peroneal nerve runs downwards on the lateral side of anterior tibial artery. In the lower third of the leg the nerve makes a futile attempt to cross the artery from lateral to medial side. Therefore, in the lower third of the leg, anterior tibial nerve only overlaps artery from the front and again comes back to lateral side of it (classically described as hesitation of “the nerve to cross the artery), which has already been mentioned previously. Next it passes under the extensor retinaculum approximately midway between two malleoli. At the ankle the deep peroneal nerve divides into two branches namely the medial and the lateral.

Figure 357 Deep peroneal nerve

Relations:

It lies on interosseous membrane, with anterior tibial artery on its medial side. Here the nerve is deeply placed between extensor digitorum longus and extensor hallucis longus on the lateral side tibialis anterior on the medial side. In the lower part of the leg the tendon of the extensor hallucis longus crosses the deep peroneal nerve from lateral to the medial side. As the nerve comes down in the lower third of the leg it becomes superficial in position as muscular bellies of the muscles are now replaced by tendons. Therefore, deep peroneal nerve is in a position to peep through the gap between tendons of extensor digitorum longus on one hand and the extensor hallucis longus on the other. As noted above, the deep peroneal nerve lies along the lateral aspect of anterior tibial artery except in the lower third of the leg, where it overlaps the artery from the front. However, immediately above the ankle the nerve lies on the tibia with anterior tibial artery on its medial side. Lower down the nerve is placed on the talus. Relation in front of the ankle from medial to lateral side are: 1. Tibialis anterior, 2. Extensor hallucis longus, 3. Anterior tibial artery, 4. Deep peroneal nerve, 5. Extensor digitorurn longus, 6. Peroneus tertius and the 7. Perforating branch of peroneal artery. Why not keep in mind the following sentence and remember the relations (The Himalayas Are Never Dry Places).

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Branches: 1. Muscular, 2. Articular, and 3. Terminal. 1. Muscular: To four muscles, namely extensor digitorum longus, extensor hallucis longus, peroneus tertius and the tibialis anterior. 2. Articular: To ankle joint. 3. Terminal (Figures 358 and 359): They are two namely the medial and the lateral. The medial branch runs almost in line with the parent trunk (e.g. deep peroneal nerve). It reaches the cleft or web between the great toe medially and second toe laterally and thus supplies the skin of adjacent sides of great toe and the second toe. Major part of the nerve on the dorsum of the foot is under cover of the deep fascia of the foot. The extensor hallucis longus tendon, dorsalis, pedis artery and first metatarsal artery lie medial to the nerve while the tendons of extensor digitorum longus lie lateral to it. Please note that the nerve is crossed superficially from lateral to medial side by tendon of extensor digitorum brevis meant for the big toe. (For descriptive case one should remember that the deep peroneal nerve is crossed from lateral to medial side by the extensor hallucis longus in the leg but its medial branch is crossed by tendon of extensor digitorum brevis muscle meant for the big toe, from lateral to medial side on the dorsum of foot. The tendon of the extensor digitorum brevis for the great toe is known as extensor hallucis brevis. It supplies the joints of the great toe and the first dorsal interosseous muscle. Figure 358 Terminal branches of deep peroneal nerve and other structures of dorsum of foot

Lateral Branch (Figure 359):

Figure 359 Lateral terminal branch of deep peroneal nerve (Diagrammatic)

It runs laterally immediately after its origin and goes under cover of extensor digitorum brevis muscle. Under the extensor digitorum brevis it forms an enlargement (ganglion-like) which gives number of branches proceeding to the extensor digitorum brevis muscle. They supply the tarsal joints and also to metatarso-phalangeal joints of 2nd, 3rd and 4th toes. (Please recall that similar enlargement is present on the posterior interosseous nerve (deep peroneal nerve).

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Anterior Tibial Artery (Figures 360 and 361):

As commented earlier it is the borrowed vessel from posterior (flexor) compartment. It is one of the two terminal branches of popliteal artery given at lower border of popliteus muscle. Please note that the site of origin of the artery is approximately at the level of tuberosity of tibia. It makes its entry into extensor compartment by passing through a gap in the upper part of interosseous membrane. It runs downwards on the interosseous membrane, along with deep peroneal nerve. As the artery comes down it leaves interosseous membrane and lies over tibia.

Figure 360 Anterior tibial artery (observe hesitation of the nerve to cross the artery)

Figure 361 Branches anterior tibial and popliteal arteries

At the ankle it lies approximately between two malleoli and passes deep to superior and inferior extensor retinaculi. The continuation of anterior tibial artery beyond the ankle joint is known as dorsalis pedis artery.

RELATIONS Posterior Relations: Interosseous membrane in upper part and tibia and ankle joint in lower part. Medial Relations: Tibial origin of tibialis anterior in the upper part and tendons of the tibialis anterior and extensor hallucis longus in the lower part. Lateral Relations: Neck of fibula lies lateral, at tile entry of the artery in extensor compartment. In the upper third of the leg extensor digitorum and in the middle third of leg, the extensor hallucis lie lateral to the artery. In the lower third, the extensor hallucis longus crosses the artery from lateral to medial side and

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Anterior Relations:

Superior Relations:

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comes to lie on its medial side just above the ankle. In the lower part, the tendons of extensor digitorum and peroneus tertius lie lateral to artery. The artery is deep seated in the upper two thirds of the leg but becomes relatively superficial in the power third. The deep peroneal nerve lies lateral to the artery in the upper two third of leg but tries to cross it from the front in the lower third and again comes back to the lateral side at the ankle. (Hesitation of the nerve to cross the artery). As noted before extensor muscles overlap the artery in the two thirds of leg, the extensor hallucis muscle crosses the artery from the front and deep peroneal nerve overlap the artery, in the lower third of the leg. At the ankle the vessels pass deep to extensor retinaculi. At the lower border of the popliteus muscle, the anterior tibial artery leaves the flexor compartment and enters the extensor through a gap in interosseous membrane and the lower border of popliteus muscle. Superior tibia-fibular joint and the small upper part of interosseous membrane are related to the artery superiorly.

Branches: 1. Posterior tibial recurrent, 2. Anterior tibial recurrent, 3. Muscular, 4. Anterior medial malleolar, 5. Anterior lateral malleolar. 1. Posterior Tibial Recurrent: It is occasionally seen. It arises from anterior tibial artery when it lies in flexor compartment. It establishes communication with inferior genicular branches of popliteal artery. 2. Anterior Tibial Recurrent: It arises from anterior tibial artery immediately its entry into extensor compartment. It passes upwards through the tibialis anterior muscle and anastomose with genicular branches of the popliteal artery and also with the descending genicular branch of the femoral. 3. Muscular Branches: They are many - They supply muscles of extensor compartment However, some of them perforate interosseous membrane and anastomose with the branches of peroneal and the posterior tibial arteries. 4. Anterior Medial Malleolar: Arises from anterior tibial artery two inches above the ankle. It runs medially, passes deep to tendons of the extensor hallucis longus and the tibialis anterior. It anastomoses with the branches of the malleolar and the posterior tibial arteries. 5. Anterior Lateral Malleolar Branch: Runs laterally under the tendons of extensor digitorum longus and peroneus tertius. It anastomoses with perforating branch of the peroneal artery. Venae Comitantes: Two vanae comitantes run with the artery. They unite with vanae comitantes of posterior tibial artery at the lower border of popliteus muscle to form the popliteal vein. Clinical: The arteries of the leg are closely related to the bones of the leg. The anterior tibial artery in the lower third lies directly on the lateral surface of the tibia. In addition to this the superficial position of the artery makes it susceptible for injuries. Therefore in the fracture of the lower one third of the tibia, anterior tibial artery is damaged. However the bleeding is not severe and is not life threatening. Surface Marking of Mark a point one inch below the medial aspect of the head of fibula, or Anterior Tibial take a point one inch lateral to lower limit of the tubercle of tibia. Mark Artery: another point midway between the medial and the lateral malleoli. Join these two points and you get the surface marking of the anterior tibial artery.

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MUSCLES OF THE FLEXOR COMPARTMENT (FIGURE 362) Figure 362 Attachment of muscles of flexor compartment of leg

They are arranged in two groups, superficial and the deep. Members of the superficial Group: 1. Gastrocnemius, 2. Soleus, 3. Plantaris.

Popliteus (Figure 363):

Members of the deep group: 1. Popliteus, 2. Tibialis posterior, 3. Flexor digitorum longus. It is the key of the knee joint. It is obliquely placed on the posterior surface of the knee joint.

Figure 363 Popliteus muscle

Origin:·

Insertion:

Nerve Supply:

It arises from anterior part of the groove on the lateral surface of the lateral condyle of femur and from lateral semilunar cartilage. Its origin is intracapsular. The tendon of popliteus escapes from the joint cavity on posterior border of lateral condyle of tibia, through an opening in the capsule under the arcuate ligament. It is inserted into the upper part of the posterior surface of tibia above the soleal line. It gets inserted into the fascia covering it. It is supplied by the nerve known as nerve to the popliteus. It is the branch of tibial nerve. It runs across popliteal vessels and reaches the popliteus muscle. It winds round the popliteus muscle at its lower border and comes to lie in front of it and supplies it. Nerve to popliteus also supplies the superior, inferior tibio-fibular joints and the interosseous membrane of the leg.

Muscles of the Flexor Compartment Action:

Relations:

Inside the Joint:

Outside the Joint:

Flexor Digitorum Longus (Figure 364):

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It is the weak flexor of the knee. When the foot is on the ground during extreme degree of extension, there is a slight medial rotation of the lower end of the femur over the upper end of the tibia. Now the joint is locked. In order to undo this locking there must be lateral rotation of the lower end of the femur over the upper end of the tibia. It is done by the popliteus muscle. After the initial lateral rotation of the lower end of the femur, the flexion begins as the joint is unlocked. When the foot is off the ground and the leg is extended in the extreme degree of extension, there is a slight lateral rotation of the leg. This is known as locking when the foot is off the ground. To unlock the knee there is slight medial rotation of the leg. This cancels the lateral rotation of the leg and the flexion begins. Due to the attachment of the popliteus muscle to the lateral semilunar cartilage its wedging between the condyles of the femur and the tibia is prevented. It is because of the protective action of the popliteus the lateral semilunar cartilage enjoys relative freedom from injury. On the other hand the medial semilunar cartilage is attached to the tibia in front and behind and it is fixed in the middle by the tibial collateral ligament. It is commonly injured due to the fact that it is attached to the static structure. (Tibial collateral ligament). The lateral semilunar cartilage enjoys freedom from injury due to the fact that it is attached to the dynamic structure (Popliteus muscle). Almost similar to the function, it is the key muscle of popliteal region, as it forms lower part of the floor of the popliteal fossa. The relations are studied under two heads (1) inside the joint and (2) Outside the joint. Here it is related to fibular collateral ligament of the knee and the tendon of biceps femoris laterally. Lateral semilunar cartilage forms the medial relation. It escapes from the joint by passing through an opening at the back of the knee under the arcuate ligament. Here it is related to the posterior border of the lateral condyle of the tibia. Sometimes a shallow groove may be seen at the site of its escape from the joint cavity on the posterior border of the lateral condyle of the tibia. It forms floor of the popliteal fossa and is related to the popliteal artery, popliteal vein and the tibial nerve. They are superficial to the popliteus muscle. (Posterior surface in normal anatomical position). The nerve to popliteus forms the posterior, anterior and the lateral relations due to its peculiar course. At the lower border of muscle, popliteal artery divides and the popliteal vein is formed. Popliteal artery divides into the anterior and the posterior tibial arteries. The vena comitantes of the anterior and the posterior tibial arteries unit at the lower border popliteus muscle to form the popliteal vein. The tibial nerve continues its journey in the flexor compartment of the leg. Lower part of the popliteus muscles is important land-mark due to the changes. 1. Popliteal artery ends - and anterior and posterior tibial arteries begin. 2. Venae comitantes of arteries of leg unite and form the popliteal vein. 3. Tibial nerve continues as tibial in the flexor compartment. 4. Nerve to popliteus runs, from the posterior surface of the popliteus to the anterior surface and winds around the lower border. It runs from the posterior surface of tibia to the lateral four toes of the foot.

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Figure 364 Flexor digitorum longus

Origin:

From posterior surface of tibia below the soleal line and medial to vertical line. It also arises from deep fascia, over tibialis posterior. Course of the Tendon It is peculiar and very extensive. At the back of the leg it crosses tendon of and its Insertion tibialis posterior superficially and reaches the groove on back of medial (Figure 365): malleolus along with tendon of tibialis posterior. It runs in contact with medial aspect of sustentaculum tali of calcaneus. Here, it is undercover of flexor retinaculum. During its journey in the sole of foot the tendon runs forwards and laterally where it crosses tendon of flexor hallucis longus muscle from below. Many times the tendon gets a slip from flexor hallucis longus. In the middle of the sole of foot tendon of flexor digitorum longus gets flattened and immediately divides into four slips for lateral four toes of foot. The flexor digitorum accessorius gets inserted into flattened tendon of the muscle. Each slip passes through tendon of the flexor digitorum brevis and gets inserted into the base of terminal phalanx of respective toe. Four lumbrical muscles arise from four slip of extensor digitorum tendon. Figure 365 Crossing of tendons in the back of the leg in the sole of foot

Nerve Supply: Action:

Two facts remind us of flexor digitorum profundus muscle of forearm: 1. Passing of the tendinous slip of flexor digitorum longus through the tendons of flexor digitorum brevis, 2. Origin of lumbrical muscles. One can say that flexor digitorum longus of the Ieg is comparable to flexor digitorum profundus of the forearm. On the back of medial malleolus, the tendons of tibialis posterior and flexor digitorum longus are separated from each other by means of fibrous partition. The synovial sheath of tendon of flexor digitorum longus extends from upper part of flexor retinaculum to middle of the sole of foot. It is supplied by tibial nerve. It is the plantar flexor of foot and flexor of lateral four toes. It helps in inversion of the foot. By virtue of the insertion of flexor digitorum accessories, it helps in maintaining longitudinal arches of foot. The flexor digitorum accessories applies a strong backward pull on the tendons of flexor digitorum longus thus giving it the mechanical advantage for the action of flexion.

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Flexor Hallucis This muscle lies on lateral side of the back of the leg. Longus (Figures 366 and 367): Figure 366 Flexor hallucis longus

Figure 367 Flexor hallucis longus

Origin:

Course of Tendon and Insertion:

Nerve Supply: Action:

Tibialis Posterior (Figures 368 and 368A):

It arises from lower three fourths of posterior surface of fibula between the medial crest and the posterior border of fibula. In addition, small part of the muscle arises from the interosseous membrane, the posterior intermuscular septum and from deep seated septum of flexor compartment. It is the multi-pennate muscle which speaks of its strength. The tendon of flexor hallucis longus runs downwards (Figures 366 and 367) and reaches back of lower end of tibia. Next it passes between medial and posterior tubercles of talus where well-marked groove is present. Tendon runs in the antero-inferior direction and passes under the sustentaculum tali here it lies a well defined groove. In the sole, it turns medially and is crossed by the tendon of the flexor digitorum longus from below from medial to lateral side. In the sole flexor hallucis longus gives strong fibrous slip to the flexor digitorum longus tendon. The flexor hallucis longus and gets inserted into the base of distal phalanx of the big toe. At the ankle it is provided with a synovial sheath. The synovial sheath may extend upto the site of insertion. It is supplied by posterior tibial nerve. It is the plantar flexor of great toe and plantar flexor of foot. It helps in the movement of inversion and eversion of the foot. It plays an important role in maintaining the longitudinal arches of the foot. This muscle is deeply placed.

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Figure 368 Tibialis posterior muscle

Figure 368A Showing restoration of dorsi flexion of ankle by pulling the tibialis posterior from the flexor compartment through the interosseous membrane and attached to the tibialis anterior

Origin:

Course of Tendon and Insertion:

1. From the Fibula: The area on the posterior surface of fibula between the interosseous border and the medial crest. 2. From the Tibia: From the upper two thirds of lateral part of posterior surface of tibia lateral to vertical line. 3. From interosseous membrane. 4. Deep fascia-covering the muscle. Note: The tibialis posterior muscle is comparable to the abductor pollicis longus muscle of the extensor compartment of the forearm as it arises from both the bones of the forearm, radius, ulna and the interosseous membrane. Origin of the tibialis posterior can be described briefly as under: Tibialis posterior muscle arises from the posterior surface of the tibia, posterior surface of the fibula between the line and the crest and the interosseous membrane. The tendon is crossed by flexor digitorum longus tendon in the lower part of leg. As it reaches back of medial malleolus, it lies in well defined groove. The tendon runs along the medial aspect of the sustentaculum tali to reach the tuberosity of navicular, for its inserted. However, many slips of the tendon extend further through the groove on the under surface of the navicular and get inserted into all the metatarsals except first and all the tarsals except the talus. (Talus is known as the bone of ligaments). Nerve Supply: By the tibial nerve. Action: It is the plantar-flexor and invertor of the foot. It helps in maintaining medial longitudinal arch of foot.

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Note: The tibialis posterior muscle has an extensive origin in the leg and insertion in the foot. The muscle acts as the most powerful ligament which keep the bones of the foot bound down. The interosseous ligaments connecting the individual tarsal bones are important as a binding material, like the cement or mortar in between the bricks or stone. (Basu Ind Jr. of Surgery). Surgical Application In case of the common peroneal nerve damage dorsiflexion of the foot is of Tibialis Posterior lost. Tibialis posterior muscle is transferred to the extensor compartment (Robert Jone’s) through the interosseous membrane and is attached to the tibialis anterior. Classical Transfer: It restores dorsiflexion of the foot to a considerable extent. Superficial Muscles: i. Gastrocnemius (Figure 369): Two heads of the muscle form the inferolateral and infero-medial boundaries of the popliteal fossa, respectively. Both heads arise from the lower end of femur and join the soleus muscle to form the muscle mass of the calf. These muscles form the strong tendon lower-down and get inserted to the calcaneus (Tendocalcaneus). Tendocalcaneus is the thickest and the strongest tendon of the body. Figure 369 Gastrocnemius

Origin of the Medial Head:

Brodie’s Bursa: Origin of Lateral Head: Flabella: Insertion (Figure 370):

Figure 370 Insertion of soleus and gastrocnemius into the middle of the posterior surface of the calcaneus through tendocalcaneus

It arises form the lower part of popliteal surface of femur above medial condyle and also from the lower part of the medial supra-condylar ridge. Under cover of the medial head lies the bursa. It communicates with the cavity of the knee joint. It lies deep to the medial head of the gastrocnemius and deep to the semimebranosus. It may communicate with cavity of the knee joint. It arises from lateral aspect of lateral condyle of femur, from the flattened or pitted impression situated behind the lateral epicondyle, above the groove meant for the popliteus tendon. It is small sesamoid bone in the tendon of origin of the lateral head of gastrocnemius. The two heads unite together and join the soleus muscle. A combined tendon of the gastrocnemius and the soleus is the strongest tendon of the body. It gets inserted into the middle of the posterior surface of the calcaneous. It is separated from the calcaneus by means of a bursa. The tendo-calcaneus is accompanied by the thin tendon of plantaris on medial side which gets inserted with the tendo-calcaneus.

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Clinical:

As the tendo-achilles is involved in movements of knee and the ankle joints it is susceptible to ruptur. The rupture of the tendo-achilles is due to ischemia, wear and tear. Site of rupture is about 3 cm above the insertion. It can be diagnosed by feeling a gap between the two parts of the ruptured tendon (visible and palpable gap). Patient can not stand on toes, however this defect is never complete and the surgeon may conclude that the rupture is incomplete. This delays the timely repair of the tendon causes difficulty in repair and subsequent healing. Inflammation of the bursa between the tendo-achilles and calcaneum is known as Hugand syndrome. Achilles Tendonitis: Loose areolar tissue around the tendon gets thickened due to inflammation and gives rise to pain. If the relief is not obtained by the conservative methods, the thickened sheet is excised. Nerve Supply: Two heads are supplied separately by the tibial nerve in the lower part of popliteal fossa. Action (Figure 371): The muscles pass behind the knee and the ankle joints and are acting on both the joints. When acting from above it is a plantar flexor of the foot as seen in walking or when standing on toes. This action helps us in the propulsion. When acting from below it flexes the knee, however, this action is hardly required in normal condition. In case of the fracture of the lower third of femur (supra-condylar fracture) distal fragment of the femur is pulled backwards by both the heads of the gastrocnemius muscle, as a result the popliteal artery may get damaged. Figure 371 Action of gastrocnemius

Plantaris (Figure 372):

Figure 372 Plantaris

Note: Bursa under the medial head of the gastrocnemius is constant in its presence and communicates with the knee joint. The lateral head presents small sesamoid bone, near the origin. It is known as flabella. It arises from lower part of popliteal surface of femur and part of lateral supracondylar ridge, immediately above the lateral condyle of femur. The fleshy belly ends in a thin white shining tendon which runs along the soleus muscle, follows the tendo-calcaneus and get inserted into the posterior surface of the calcaneus medial to the insertion of tendo-calcaneus.

Muscles of the Flexor Compartment Clinical:

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Rupture of tendon of plantaris is commonly seen in players. It is more of an imagination than the reality. Even after the rupture of the tendon diagnosis is difficult. Nerve Supply: It is supplied by the tibial nerve. Action: Similar to the action of gastrocnemius. Soleus Muscle: It is the big muscle situated deep to gastrocnemius. It has large veins inside. Contraction of the muscle pushed the blood upwards towards the heart therefore the soleus muscle is known as the peripheral heart. Origin (Figure 373): 1. From the head of fibula, 2. Upper one fourth of the posterior surface of fibula, 3. Fibrous arch between tibia and the fibula, 4. Soleal line 5. The middle part of medial border of the tibia. Insertion: Big muscle belly is formed under cover of gastrocnemius which fuses with it to form the tendo-calcaneus. Tendo-calcaneus gets inserted into the middle of posterior surface of calcaneus. Action: It is plantar flexor of the foot. Its action is similar to action of gastrocnemius on ankle joint. Figure 373 Soleus muscle origin

Relations:

Figure 374 Relations of soleus muscle

Anterior (deep) Relations (Figures 374 and 375): 1. Flexor hallucis longus, 2. Flexor digitorum longus, 3. Tibialis posterior, 4. Posterior tibial artery and tibial nerve and 5. Peroneal artery.

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Figure 375 Relation of soleus muscle viewed from above

Tibial Nerve (Figure 376):

Posterior (superficial) Relations: 1. Gastrocnemius 2. Plantaris 3. Sural nerve 4. Small saphenous vein. Structures which lie under fibrous arch between tibia and fibula are: popliteal artery, popliteal vein and tibial nerve. It is one of the two terminal branches of the sciatic nerve even in the middle of the back of the thigh on the adductor magnus and under cover of the long head of the biceps femoris muscle. It enters the popliteal fossa at its superior angle and crosses the popliteal vein, popliteal artery and comes to the medial side of the artery and runs on the popliteus muscle and continues further in the flexor compartment of the leg. Lower down it descends it lies on the tibialis posterior, flexor digitorum longus, lower part of the posterior surface of the tibia and the posterior aspect of the ankle joint from above downwards. Superficially it is covered by the soleus, the gastrocnemius and the plantaris in the upper two third of leg. As it comes near the ankle it is covered with skin and the deep fascia of leg. Behind the ankle it lies between medial malleolus and the calcaneus and lies under the flexor retinaculum. under cover of the flexor retinaculum the tibial nerve divides into two terminal branches namely, the medial and the lateral plantar nerves. The nerve lies under cover of the first septum all along its course.

Figure 376 Tibial nerve

Relation with Posterior Tibial Vessels:

Branches:

Posterior tibial vessels lie lateral to nerve in the upper part of leg under cover of the fibrous arch of soleus muscle. Immediately distal to fibrous arch, vessels cross the nerve from lateral to medial side, from deeper aspect of (Anterior aspect) the nerve and lies medial to it during their further course. Hence, at the ankle, artery is medial and the nerve lateral. Muscular: They arise from upper part of the nerve and are distributed to the tibialis posterior, flexor digitorum longus and the upper part of soleus muscles. Articular Branches: Number of fine filaments arise from the tibial nerve near the ankle. They are distributed to posterior part of the capsule of ankle joint.

Muscles of the Flexor Compartment

Medial Plantar Nerve (Figure 377):

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Cutaneous Branches: Number of filaments arise from tibial nerve in the region of ankle under the flexor retinaculum. They perforate the flexor retinaculum and are distributed to the skin of posterior-inferior part of the heels. Terminal Branches: They are two in number the medial and the lateral plantar. They appear as the terminal branches of the tibial nerve under the flexor retinaculum. The medial plantar is larger than the lateral. It runs in the sole and gives branches: 1. Muscular 2. Cutaneous and 3. Digital.

Figure 377 Medial plantar nerve

Muscular branches are given to the following short muscle of sole i. Abductor hallucis, ii. Flexor hallucis brevis, iii. Flexor digitorum brevis and iv. First lumbrical muscle. Cutaneous branches are given to the skin of the medial aspect of sole. Digital branches are given to plantar aspect of medial three and half toes (Figure 378). Figure 378 Cross section of foot showing layers of foot seen from above (right)

Lateral Plantar It arises from tibial nerve as one of its two terminal branches under flexor Branch (Figure 379): retinaculum. It runs laterally towards base of fifth metatarsal bone where it divides into superficial and deep branches. During this course the nerve runs between the first and second layers of the sole (Figure 379). It gives: (1) Muscular (2) Cutaneous (3) Superficial terminal and (4) Deep terminal branches.

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Figure 379 Lateral plantar branch of tibial nerve

Superficial Terminal Branch: Deep Branches:

Posterior Tibial Artery (Figures 380 and 381):

Figure 380 Posterior tibial artery

Figure 381 Branches of posterior tibial artery

Muscular branches are given from the trunk of the nerve to the: (i) Abductor digiti minimi and (ii) Flexor digitorum accessories. Cutaneous branches from the trunk supply the skin of medial side of sole. It gives two digital branches which supply lateral one and half toes. It gives muscular branches to the flexor digiti minimi brevis, third plantar and fourth dorsal interosseous muscles. From the base of the fifth metatarsal the nerve runs medially towards first metatarsal. During this course it runs in between the third and fourth layers of foot. It supplies adductor hallucis, three lumbricals except first which is supplied by the medial plantar nerve and the remaining interossei except the third plantar and the fourth dorsal which are supplied by the superficial branch. It is one of the two terminal branches of popliteal artery given at lower border of popliteus muscle under cover of soleus muscle in the flexor compartment. Here, it is lateral to the tibial nerve, crosses the tibial nerve from lateral to the medial side and comes to lie on its medial side. It runs vertically downwards on the medial side of tibial nerve till it reaches the midpoint between the calcaneus and the medial malleolus where it lies under the flexor retinaculum. It divides into two terminal branches, namely the medial and the lateral plantar arteries.

Muscles of the Flexor Compartment Relations:

Branches (Figure 381):

Peroneal Artery (Figure 382):

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Tibial nerve and posterior tibial artery successively lie on following structures, tibialis posterior, flexor digitorum longus, lower end of tibia and the back of ankle joint from above downwards (Figures 380 and 381). Superficially it is covered with gastrocnemius, soleus and plantaris in upper three fourths of the leg. In the lower third of the leg artery becomes relatively superficial along the tibial nerve. At the back of ankle the relations from medial to lateral side are, tibialis posterior, flexor digitorum longus, posterior tibial artery, tibial nerve and flexor hallucis longus. 1. Circumflex fibular 2. Peroneal 3. Nutrient 4. Muscular 5. Medial calcanean 6. Terminal - namely medial and lateral plantar arteries. 1. Circumflex Fibular Branch: This branch sometimes arises from anterior tibial artery. It runs laterally and winds the neck of the fibula. It supplies the muscles and skin of the region. 2. Nutrient: It is the large branch of posterior tibial artery given near its origin. This branch runs downwards and medially to pass through the nutrient foramen of tibia. 3. Muscular Branches: They supply muscles of flexor compartment and also give branches to skin of the back of leg. 4. Medial Calcanean Branches: They arise from posterior tibial artery under flexor retinaculum and perforate the flexor retinaculum to supply the skin of postero-inferior aspect of the heel. 5. Terminal Branches: They arise under flexor retinaculum and pass to the sole in company with the nerves of the same name. Medial plantar artery runs on the medial side of the medial plantar nerve and lateral plantar artery runs on lateral side of lateral plantar nerve. It is the branch of the posterior tibial artery given one to one and half inches distal to lower border of the popliteus. It runs downwards and laterally towards medial crest of fibula, which it follows during its further course. In an attempt to do so the artery lies under cover of soleus and the flexor hallucis longus. It comes out of flexor hallucis longus above the ankle and then lies on the posterior aspect of the inferior tibio-fibular joint. At the ankle, the artery gets exhausted by giving lateral calcanean branches.

Figure 382 Peroneal artery

Relations of Peroneal Artery: Superficial Relations: Lateral Relation:

Tibialis posterior and fascia covering inferior tibio-fibular joint and ankle joint are the deep relations. Gastrocnemius, soleus and flexor hallucis longus, form superficial relations. Medial crest of fibula and tendons of peroneus longus and the brevis.

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Medial Relation:

Tibial nerve and posterior tibial artery. Branches: 1. Muscular, 2. Nutrient to fibula given near medial crest of fibula, 3. Perforating branch: It is given in the lower part of leg above inferior tibio-fibular joint. It pierces interosseous membrane and makes its entry into extensor compartment an inch above lateral malleolus. Sometimes this perforating branch is larger while the dorsalis pedis remains absent. In such cases perforating branch represents the dorsalis pedis artery. 4. Communicating branch: it communicates with the posterior tibial artery. Venae Comitantes: They are two, lying on sides of the artery. They are interconnected by series of small cross channels and which gives an appearance of a ladder. Blood Supply of Its knowledge is important for the surgeon who is required to amputate Skin Covering Heel the leg above the ankle (Syme’s amputation). He has to recall anatomy of (Figure 383): calcanean branches of peroneal and posterior tibial arteries. Medial aspect of heel is supplied by the large branch known as calcaneo-plantar branch which arises from lateral plantar or posterior tibial artery. Lateral aspect of heel is supplied by the lateral calcanean branches of peroneal artery. If the incision at the heel is extended posteriorly, the posterior tibial artery is cut and the blood supply of the heel by calcaneo-plantar branch is lost. This leads to necrosis of the skin flap. Please note that the heel will be deprived of its blood supply only in two cases, (i) if the posterior tibial trunk is cut above origin of calcaneo-plantar branch or (ii) if calcaneoplantar branch itself is cut. Figure 383 Blood supply of skin of heel

Anastomosis Around Knee Joint (Figure 384):

Figure 384 Anastomosis around the knee

Well developed vascular anastomosis is present in the front and the sides of knee. Number of arteries take part in the formation of this anastomosis. Out of these, four are genicular branches of popliteal artery one is, the recurrent genicular branch of the anterior tibial artery and the descending genicular branch of the femoral. There are three well developed cross channels. Out of these the superior one is situated over tendon of quadriceps femoris and the Iower two are under cover of ligamentum patellae.

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Other Arteries Are:

Circumflex fibular, descending branch of lateral femoral circumflex and the posterior fibular recurrent. Flexor Retinaculum It is the thickened part of the deep fascia, covering the strctures underneath. (Figure 385): It is attached to medial malleolus of the tibia and the medial tubercle of the calcaneus, in other words it forms an osseo-fibrous tunnel similar to the carpal tunnel of the superior limb. The structure passing under the flexor retinaculum are the tibialis posterior, flexor digitorum longus, posterior tibial artery, tibial nerve and the flexor hallucis longus tendons from medial to the lateral side. Branches of medial calcanean artery and nerves pierce the flexor retinaculum to supply the skin. The tendons pass through separate compartments and are lined with the separate synovial sheaths. Figure 385 Flexor retinaculum and structures passing under

Synovial Sheath of Tibialis Posterior: Synovial Sheath for Flexor Digitorum Longus: Synovial Sheath for Flexor Hallucis Longus: Lateral Compartment:

Peroneus Longus (Figure 386):

Nerve Supply:

It begins a finger’s breadth above flexor retinaculum and goes to site of insertion. Begins a finger’s breadth above flexor retinaculum and goes up to the middle of the sole of the foot. Begins a finger’s breadth above flexor retinaculum and goes to the site of its insertion. It is bounded by peroneal surface of fibula, deep fascia of leg and anterior and posterior inter-muscular septae. It contains peroneus longus and peroneus brevis muscles and superficial peroneal nerve. Common peroneal nerve lies in this compartment at the neck of fibula where it divides into two terminal branches namely deep and the superficial peroneal. Peroneus longus is superficial to the peroneus brevis muscle. It arises from the upper third and posterior half of middle third of peroneal surface (lateral surface) of fibula and also from deep fascia. Superiorly the origin of the muscles extends upto the lateral aspect of the head of fibula. The tendon of the peroneus longus lies in the groove on the posterior surface of the lateral malleolus, superficial to the tendon of peroneus brevis. They are provided with the separate synovial sheaths. Peroneus longus tendon passes on the lateral aspect of the calcaneus below the peroneal tubercle. (Peroneal trochlea). On the lateral aspect of calcaneus. It passes under inferior peroneal retinaculum through a separate compartment. Here, it is provided with a separate synovial tube, which is the inferior limb of common synovial sheath. Next, the tendon grooves the under surface of cuboid and runs medially across the sole of foot in close contact with the bones and ligaments. It is inserted into antero-inferior aspect of lateral surface of medial cuneiform and postero-inferior aspect of lateral side of the base of first matatarsal bone. Please note that the insertion of tibialis anterior and peroneus longus are in close proximity. By musculo-cutaneous nerve.

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Action:

Peroneus Brevis (Figure 387):

It is the plantar flexor and the evertor or foot. By virtue of its peculiar course in foot it helps in maintaining the lateral longitudinal and transverse arches of the foot. It arises from anterior half of the middle third and whole of lower third of lateral surface of fibula. Its tendon lies under peroneus longus tendon on the back of lateral malleolus under superior peroneal retinaculum. Here, it has a common synovial sheath with the longus tendon. On lateral side of calcaneus, the peroneus brevis tendon passes above the peroneal tubercle under inferior peroneal retinaculum through the separate compartment. Here it is provided with a separated synovial sheath, which is the superior limb of the common synovial sheath. The tendon gets inserted into the base of the fifth metatarsal on lateral side. Its insertion is marked by the well developed tubercle on lateral-aspect of the base of the fifth metatarsal bone.

Figure 386 Peroneus longus

Figure 387 Peroneus brevis

Nerve Supply: Action: Superficial Peroneal Nerve It is (L4, 5, 81) (Figure 388):

It is supplied by superficial peroneal nerve. It is the plantar-flexor and evertor of the foot. One of the two terminal branches of common peroneal nerve given at neck of fibula under cover of peroneus longus muscle. It passes downwards through the peroneus longus lies between the longus and brevis muscles. Next it passes superficial to anterior border of peroneus brevis. It runs downwards medially and finally lies between the extensor digitorum tendon medially and the peroneus brevis laterally under deep fascia. In the lower third of the leg it pierces the deep fascia and then divides into two terminal branches namely medial and lateral. These branches reach the dorsum of foot. Branches: 1. Muscular: a. To peroneus longus and b. To the peroneus brevis. 2. Cutaneous: They are two in number, medial and lateral.

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Figure 388 Superficial peroneal nerve

Medial Branch:

Lateral Branch:

It divides into two, medial and lateral. Medial branch goes to medial side of great toe and lateral branch is distributed to adjoining sides of second and third toes. Many times this lateral branch receives a communication from the deep peroneal nerve. It supplies middle zone of the dorsum of foot. It divides into two branches, of which the medial supplies the adjoining sides of third and fourth toes and the lateral one supplies the adjoining sides of fourth and fifth toes.

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FOOT General structure is based on sound engineering principals as it has to bear weight, move, walk, run and even move on the uneven surfaces heights and the slopes. It is capable of getting flexed, extended, inverted, everted, adducted and abducted. Out of these only movements of flexion and extension (plantar-flexion and dorsi-flexion) are allowed only at the ankle joint being a synovial, uniaxial and hinge variety of joint. The rest of the movements are mentioned above are limited to the foot distal to the ankle. The movements of eversion and inversion do not occur in the ankle joints. It being the synovial, uniaxial and hinge. The movement of eversion and the inversion begin in the midtarsal joints and the space being less the rotatary force generated is transferred to the calcaneus by the long and the short plantar ligaments and it is the calcaneus which rotates under the talus. The movement begins in the midtarsal joint and is completed in the sub-taloid joint. Plantar flexion is accompanied by the movement of adduction and the dorsiflexion is accompanied by the abduction of the fore-foot (Figures 389 and 389A). Figure 389 Bones of foot (dorsal view)

Figure 389A X-ray of foot

Bones of foot are arranged in two rows the proximal and the distal. The proximal row consists of talus and the calcaneus. Talus is placed above the calcaneus which makes the medial longitudinal arch of the foot higher than the lateral. Talus articulates with the navicular with its head and the navicular articulates with the three cuneiforms bones, medial intermediate and the lateral, they articulate with the 1st , 2nd and the 3rd

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metatarsals. Calcaneus articulates with the cuboid which is placed laterally and the cuboid articulate with the bases of the 4th and 5th metatarsals. There are only two phalanges for the great toe while there are three for the rest of the toes. The typical arrangements of bones of the foot presents convexity on the dorsum and the concavity on the planter aspect. The concavity helps in accommodating the important structures of the foot which are prevented from compression. The foot is arranged into four layers, as under: form plantar to dorsal side. 1. 1st Layer: Abductor hallucis, flexor digitorum brevis, and abductor digitiminimi. 2. 2nd Layer: Tendons of flexor digitorum longus, flexor hallucis longus, flexor digitorum accessorius and the lumbrical muscles. 3. 3rd Layer: Flexor hallucis brevis, adductor hallucis and flexor digitiminimi brevis. 4. 4th Layer: Metatarsals, interossei, peroneus longus tendon and tendon of tibialis posterior. Dorsum of Foot (Figures 390 and 390A):

Figure 390 Dorsum of the foot

Skin of the dorsum of foot is lax as it is loosely attached to the underlying structures. This explains the cause of oedema predominately on the dorsum of the foot and around the ankle, in pathological states (infections).

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Figure 390A Dorsum of the foot and dorsalis pedis and arcuate arteries

Cutaneous Nerve on Dorsum of Foot: Dorsalis Pedis Artery (Figure 391):

They are the branches of (1) Saphenous, (2) superficial peroneal (3) deep peroneal and the (4) sural nerves. It is the continuation of anterior tibial artery at the lower part of front of ankle joint. It runs forwards with a slight medial inclination to reach the proximal part of the first inter-metatarsal space. Here, it passes towards the sole of foot by turning downwards between the two heads of the first dorsal interosseous muscle to join the lateral plantar artery. Thus a communication between the branches of anterior tibial and posterior tibial arteries is established.

Figure 391 Dorsalis pedis artery

RELATIONS Posterior:

Superficial:

The artery subsequently lies on lower part of the capsule of ankle Joint, talus, navicular, intermediate cuneiform bones. Lateral terminal branch of the superficial peroneal nerve lies under the artery. Skin, superficial fascia, dorsal venous arch, cutaneous nerves, inferior extensor retinaculum and the tendon of extensor digitorum brevis for the great toe (Extensor hallucis brevis). It crosses the artery from lateral to the medial side.

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Lateral Relation: Tendon of extensor digitorum longus for the second toe. Branches: 1. Tarsal branches given to the bones, 2. Arcuate artery, 3. First dorsal metatarsal artery. Arcuate Artery: It arises at the level of bases of metatarsal bones. It runs laterally under cover of extensor tendons (long and short). Arcuate artery presents a convexity distally and concavity proximally. Three dorsal metatarsal arteries arise from the convexity of arcuate artery. These branches go to 2nd, 3rd and 4th spaces and run further to reach the respective webs. Here, each branch divides into two branches and supplies the adjoining side of respective toes. First Dorsal It arises from dorsalis pedis artery at the point where it disappears. Metatarsal Artery: Between two heads of first dorsal interosseous muscle. This artery runs further to divide into two branches medial and lateral. The lateral branch supplies adjoining sides of the big and second toe, while the medial branch goes to the medial side of great toe. Fascia of Dorsum It is thin and appears to be continuous with the extensor retinaculum of Foot: above. Extensor Digitorum It is the short muscle which tries to give some soft feel to the dorsum of Brevis (Figure 392): foot. It is like to an oasis in the desert of tendons on the dorsum of foot. (Kadasne). An oasis means the pleasant area in the desert. Figure 392 Showing extensor digitorum brevis

Origin:

Insertion:

Nerve Supply: Action:

It arises from the anterior part of upper surface of calcaneus, interosseous ligament between calcaneus and the talus, and the deep part of the stem of inferior extensor retinaculum. The muscle runs medially and forwards and gets divided into four small tendinous slips. Medial most slip crosses dorsalis pedis artery from lateral to medial side and gets inserted into the base of proximal phalanx of great toe (Same slip is known as extensor hallucis brevis). Second, third and forth slips go to second, third and the forth toes where they join the tendons of extensor digitorum longus muscle. Lateral terminal branch of the deep peroneal nerve. It is extensor of proximal phalanx of great toe and of all phalanges of 2nd, 3rd and fourth toes.

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SOLE OF FOOT Superficial Fascia:

Deep Fascia (Figure 393):

It contains more fibrous bands and is tough in character. The character of fascia is appreciated more, on the heel, ball of the foot and at the lateral border. These are weight-bearing areas. In the area of heel the medial calcanean nerves and vessels are present, while in the region of the toes the plantar digital nerves and vessels are seen. Digital vessels and the nerves pass under the cover of thin fibrous bands known as superficial transverse metatarsal ligaments. To be studied as under: 1. In the region of sole of foot and 2. Over plantar aspect of toes.

Figure 393 Showing plantar oponeurosis

In the Region of Sole of Foot:

Surgical:

Deep fascia is present in the form of three well defined longitudinal zones namely: (1) Medial, (2) Intermediate and (3) The lateral. Deep fascia of intermediate zone is remarkably thick and forms the plantar aponeurosis while lateral and medial parts of fascia are thin. Posteriorly plantar aponeurosis is attached to medial tubercle of calcaneus. Anteriorly it becomes broad and at the level of heads of metatarsals it gets divided into five slip for five toes including big toe. (In contrast to this, palmar aponeurosis which gets divided into four slips for four fingers and none for the thumb. Lying in between the slips, digital vessels and nerves are seen. Each slip divides to enclose tendon and further joins the proximal part of fibrous flexor sheath over the toe. These slips also get attached to the skin crease, ligament of metatarsal joints and the deep transverse ligaments of the sole of foot. Lateral and medial margins of plantar aponeurosis is continuous with lateral and medial zones of deep fascia of sole, respectively. Medial septum goes deep from medial margin of plantar aponeurosis and the lateral from the lateral margin. By virtue of these septae three muscles of superficial group (1st layer) are isolated from each other. Fascia of lateral zone covers the abductor digtiminimi muscle and fascia of medial zone covers abductor hallucis brevis muscle. 1. Infection of the Sole: Collection of pus under plantar aponeurosis is well localized. Normally it cannot come out through aponeurosis, because of its tough nature. The condition is very painful and causes more damages to the structures underneath. In flat foot or pes planus the aponeurosis gets stretched and elongated. However, in case of abnormally arched foot, (pes cavus) aponeurosis gets thickened and

Sole of Foot

Deep Fascia Over Toes (Figure 394):

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shortened. The collection of pus can be drained by incising the medial border of aponeurosis in front of medial tubercle of calcaneus. Chronic inflammatory condition of plantar aponeurosis is known as plantar fasciatis. 2. Compartment Syndrome of Foot: Patients having fracture of calcaneous develop compartment syndrome of the foot in 10% of the cases. The presentation is typical having a tense swelling with intensive pain. Urgent fasciotomy is done to prevent ischemia of muscles and subsequent contracture. After the closure of the fasciotomy wound, open reduction and internal fixation of the fracture of calcaneous is done. In the region of the toe, the deep fascia forms thick plates. These plates are thick over phalanges and thin over the interphalangeal joints. Proximally they are continuous with fibrous slips of plantar aponeurosis. Distally, the plates get attached to bases of distal phalanges immediately beyond the insertion of long tendons (flexor tendons). At the sides they are attached to margins of phalanges. Thus the plates and the phalanges forms the osseo-fibrous tunnel or the canal for long flexor tendons of the toes.

Figure 394 Fibrous flexor sheath

Muscles of First Layer of Sole: Abductor Hallucis (Figure 395):

From medial to lateral side, they are three in number, namely, (1) Abductor hallucis, (2) Flexor digitorum brevis and (3) Abductor digiti minimi. It arises from medial tubercle of the calcaneus and also from flexor retinaculum. It is inserted into medial aspect of the base of proximal phalanx of great toe along with medial belly of flexor hallucis brevis.

Figure 395 Abductor hallucis and abductor digiti minimi muscles

Nerve Supply: Action:

Flexor Digitorum Brevis (Figure 396):

It is supplied by medial plantar nerve. It is an abductor of big toe (abduction is the movement away from the second toe and not the third as in the case of hand, where middle finger is the central of the axis). It takes origin from medial tubercle of calcaneus and also from deep fascia of sole and fascial septa. From its origin, muscle belly goes towards middle of the sole, where it gives four tendons for lateral four toes. The tendons of

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Kadasne’s Textbook of Anatomy (Clinically Oriented) flexor digitorum brevis is perforated by the tendons of flexor digitorum longus. The tendons of the flexor digitorum brevis get inserted into base of the middle phalanx. While the tendons flexor digitorum longus are inserted at the base of the distal phalanx.

Figure 396 Flexor digitorum brevis

Nerve Supply: Action:

It is supplied by medial plantar nerve. As it is inserted into the base of middle phalanx, the muscle acts as: the flexor of metatarso-phalangeal and the proximal interphalangeal joints. Abductor Digiti It takes origin from anterior part of lateral tubercle of calcaneus, however, Minimi: its origin extends medially in front of the origin of flexor digitorum brevis from medial tubercle of calcaneus. This explains why medial part of abductor digitiminimi muscle is hidden under cover of flexor digitorum brevis. The tendon is inserted into lateral aspect of the base of proximal phalanx of little toe. Nerve Supply: It is supplied by lateral plantar nerve. Action: It is an abductor of little toe. Second Layer of It consists of two long flexor tendons, flexor digitorum accessorius and Sole: lumbrical muscles. Flexor Digitorum It presents two heads of origin, namely medial and lateral. Medial head Accessorius arises from medial aspect of calcaneus and the lateral from the part of (Figure 397): lateral border of plantar surface of calcaneus. The heads together get inserted into the tendon of flexor digitorum longus muscle. Nerve Supply: By lateral plantar nerve. Action: By virtue of its attachment into flexor digitorum longus tendon, the muscle is able to perform flexion of lateral four toes. Lumbrical Muscles They are four. They take origin from tendons of flexor digitorum longus (Figure 398): for lateral four toes. First lumbrical arises from medial side of the tendons for second toe. It is unipennate. Figure 397 Flexor digitorum accessorius

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Figure 398 Flexor digitorum longus tendons with lumbrical muscles

Second Lumbrical: Third Lumbrical:

Nerve Supply: Action:

Tendon of Flexor Digitorum Longus (Figure 399):

Arises from adjacent sides of tendons of second and third toes. Arises from adjacent sides of tendons for third and fourth toes. While the fourth arises from adjacent side of tendons for fourth and fifth toes. Except for the first, rest of them are bipennate. The lumbrical muscle has a fine tendon which comes to the medial side of the metatarsophalangeal joint and gets inserted into extensor expansion. First lumbrical is supplied by medial plantar nerve while remaining three are supplied by lateral plantar nerve. The action of lumbricals can be expressed in brief as under. “By virtue of the insertion in the extensor expansion, lumbricals are the flexors of the metatarso-phalyngeal joints and the extensors of the inter-phalangeal joints. As it enters the sole it crosses flexor hallucis longus tendon from below and reaches the middle of the sole where it gets flattened and divides into four tendons for lateral four toes. The tendon of the flexor digitorum longus gets a strong contributory tendinous slip from flexor hallucis longus. Flexor digitorum accessorius muscle gets inserted in the tendon of flexor digitorum longus. Four lumbrical muscles arise from tendons of the muscle. The tendon for each toe enters the fibrous flexor sheath under the tendon of flexor digitorum brevis. It passes through the split tendon of the flexor digitorum brevis and gets inserted into the base of terminal phalanx.

Figure 399 Tendon of flexor digitorum longus. Note the slip from flexor hallucis longus to flexor digitorum longus

Tendon of Flexor Hallucis Longus (Figure 400):

At its entry into the sole of foot, the tendon lies on lateral side of the flexor digitorum longus tendon. The flexor digitorum longus tendon crosses it from medial to lateral side from below. It gives the strong contributory slip to flexor digitorum longus. (William Turner’s Slip). Next it passes between heads of flexor hallucis brevis and sesamoid bones situated at the head of

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Kadasne’s Textbook of Anatomy (Clinically Oriented) first metatarsal bone. It enters fibrous flexor sheath and gets inserted into base of the terminal phalanx of great toe. It is provided with a synovial sheath which may extend upto its insertion.

Figure 400 Flexor hallucis brevis

Third Layer of Sole It consists of three short muscles namely flexor hallucis brevis, flexor (Figure 401): digitiminimi brevis, and adductor hallucis. It is important to note that adductor hallucis has two heads, namely oblique and the transverse. The adductor pollicis muscle of the hand also has two heads namely the transverse and the oblique. Figure 401 Adductor hallucis

Flexor Hallucis Brevis:

This muscle covers first metatarsal bone. It arises from plantar aspect of cuboid, tendinous extension of tibialis posterior muscle in the sole and the plantar aspect of lateral cuneiform bone. It divides into two bellies, medial and lateral, which lie on either side of the first metatarsal bone. Medial belly gets inserted into medial aspect of the base of proximal phalanx in company with the abductor hallucis. The conjoint tendon get fused with the plantar ligament of the metatarso phalangeal joint of the great toe. Lateral belly gets inserted into the lateral aspect of the proximal phalanx in association with the tendon of adductor hallusis muscle. This fact explains why oblique head can act as flexor of great toe. Transverse head helps in approximation of heads of metatarsal bones, This action is certainly helpful in maintaining transverse arches of foot. On the other hand, oblique head can help in maintaining the medial longitudinal arch of the foot. Fourth Layer of Sole It consists of tendons of peroneus longus, tibialis posterior and interossei. (Figure 402): The peroneus longus tendon runs from lateral to medial side and the extensions from tibialis posterior tendon run from medial to lateral side through the sole. The tibialis posterior acts as a binding ligament by virtue of its numerous extensions.

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Figure 402 Fourth layer of sole

Interossei (Figure 403):

They are seven in number, four dorsal and three plantar. It must be noted that central axis of foot passes along the second toe. Therefore, movement away from second toe is abduction and towards it is the adduction.

Figure 403 Dorsal and plantar interossei

Dorsal interossei

Plantar interossei

1. Four in number.

1. Three in number.

2. They arise from adjacent sides of 1st, 2nd, 3rd, 4th and 5th metatarsal bones.

2. They arise from medial side of the shaft of 3rd, 4th and 5th metatarsal bones

3. First dorsal in inserted into medial 3. They are inserted into extensor expansions aspect of base of proximal phalanx and medial aspect of proximal phalanges of 2nd toe and 2nd dorsal is inserted of the respective toes. They have one head. into lateral aspect of the base of phalanx of 2nd, and the 3rd and 4th are inserted into lateral side of proximal phalanx of 3rd and 4th toes respectively. In addition to this all are inserted into respective extensor expansions. They have two heads.

Tendon of Tibialis Posterior (Figure 404):

4. Great toe and fifth toe have no dorsal interossei (As both have their own abductors).

4. Great toe has no plantar interosseous muscle.

5. Second toe is provided with dorsal interosseous.

5. Second toe being in the line of central axis has no plantar interosseous muscle.

6. They are abductors of middle three toes, they are the flexors of the metatarso-phalangeal and extensor of the inter-phalangeal joints.

6. They are adductors of the lateral three toes, flexes the metatarso-phalangeal and extend the inter-phalangeal joints.

As it enters the sole it runs on medial aspect of sustentaculum tali and lies in contact with plantar aspect of plantar calcanea-navicular ligament. The tendon gives support to plantar calcaneo navicular ligament (spring ligament) and thus helps in supporting the head of talus. Here the tendon is provided with a synovial sheath. Main part of the tendon gets inserted into the tuberosity of navicular. The rest of the tendon goes through a groove on plantar surface of navicular and sends strong slips to all tarsals except the talus and to all the metatarsal except the first (talus is a bone of ligaments).

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Figure 404 Tendon of tibialis posterior

Peroneus Longus Tendon (Figure 405):

It enters foot on the lateral aspect through the groove on plantar aspect of cuboid. Next it runs obliquely towards the medial side for insertion into base of the first metatarsal and the adjoining part of the medial cuneiform bone. The tendon is provided with a fibrous sheath throughout. Major contribution for the sheath comes from the long plantar ligament. The groove on the cuboid is converted into the osseous fibrous tunnel by the long and the short plantar ligaments. The tendon is provided with a synovial sheath. On the lateral aspect of groove, the tendon presents a small sesamoid bone.

Figure 405 Peroneus longus tendon and long plantar ligament

Plantar Vessels (Figures 406 and 407) Medial plantar artery

Lateral plantar artery

1. It is one of the two terminal branches of posterior tibial artery given under flexor retinaculum mid-way between calcaneus and medial malleolus.

1. It is one of the two terminal branches of posterior tibial artery given under flexor retinaculum mid-way between calcaneus and medial malleolus.

2. It is a smaller branch.

2. It is a larger branch.

3. It runs forwards along medial side of medial plantar nerve. It joins the digital branch of first metatarsal artery and gets exhausted.

3. It runs forwards and laterally towards base of fifth metatarsal with lateral side of lateral plantar nerve which lies on its lateral side. This course of the artery runs between the first and second layers of the sole. At the base of fifth metatarsal bone, the artery changes its direction and runs medially towards proximal part of first interosseous space, where it joins dorsalis pedis artery. This medially directed artery lies between the third and fourth layers of sole. This part of artery is known as plantar arch and the deep branch of lateral plantar nerve lies proximal to arch.

4. Branches: (i) Muscular (ii) Digital: Not 4. Branches: (i) Muscular - To muscles always present (iii) Cutaneous:To nearby and (ii)Cutaneous - To skin of skin of medial part of the sole of foot. posterior and lateral aspects of sole of foot.

Sole of Foot Plantar Arch (Figure 406):

Branches:

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It is formed by lateral plantar artery (2nd part) and is completed by the dorsalis pedis artery. It extends from base of fifth metatarsal to first interosseous space. The arch lies between third and fourth layers of sole. It presents a concavity proximally and convexity distally. In its concavity lies deep branch of lateral plantar nerve. The arch is accompanied by two vanae-comitantes. 1. Articular: They arise from concavity of arch. They are distributed to traso-metatarsal joints. 2. Posterior Perforating Branches: They are three in number. They pass through 2nd, 3rd and 4th spaces between the metatarsals. They join dorsal metatarsal arteries. The perforating branches are accompanied by the veins.

Figure 406 Plantar vessels

Figure 407 Cross section of foot showing layers

First Plantar Metatarsal Artery:

Lateral Plantar Nerve (Figures 408 and 409):

3. Plantar Metatarsal Arteries: They arise from convex side of the arch and reach the 2nd, 3rd and 4th inter-metatarsal spaces. Each of them gives an anterior perforating branch and next divides into plantar digital arteries, which supply adjoining sides of respective toes. Plantar digital artery for lateral side of little toe arises directly from the lateral end of the arch. It is the branch of dorsalis pedis. It arises from it just before dorsalis pedis joins the lateral plantar artery. It supplies adjoining sides of great and second toes. It gives a branch to medial aspect of big toe, which is joined by the medial plantar artery. Note: Arteries are accompanied by two venae comitantes. It is one of two terminal branches of tibial nerve given under cover of flexor retinaculum. It runs obliquely forwards towards base of fifth metatarsal bone. Here it divides into a superficial and the deep branches and lies between flexor digitorum brevis and abductor digiti minimi brevis.

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Kadasne’s Textbook of Anatomy (Clinically Oriented) The deep branch follows deep part of the lateral plantar artery (plantar arch), where is runs in between the third and fourth layers of sole. From origin to base of fifth metatarsal it runs between the first and second layers of sole. (Its laterally directed course is between the first and the second layers of the sole of the foot while its medially directed course is placed between the 3rd and 4th layers of the sole of the foot. The deep branch virtually represents the continuation of the lateral plantar nerve. During the laterally directed course of the nerve, lateral plantar artery lies laterally, and during the medially directed course of the nerve, the artery (plantar arch) lies in front of the nerve.

Figure 408 Lateral plantar nerve (Highly schematic)

Figure 409 Course of lateral plantar nerve

Branches:

1. From the Trunk: Muscular and cutaneous muscular branches are given to flexor digitorum accessorius muscle. Cutaneous branches pierce the deep fascia between flexor digitorum brevis and the abductor digitiminimi muscles. Branches to intertarsal and traso-metatarsal joints come from the trunk of the nerve. 2. Superficial Branch: It divides into two branches, namely medial and lateral. Lateral branch gives muscular branches to flexor digitiminimi brevis and fourth dorsal and third plantar interossei muscles. The cutaneous branch of the lateral supplies the lateral half of the fifth toe. Medial branch of superficial division supplies adjoining sides of fourth and fifth toes. It is important to note that the medial branch of superficial division of lateral plantar is connected with fourth digital branch of medial plantar nerve by means of small medial communicating nerve. This communicating nerve lies under plantar aspect of fourth metatarso-phalangeal joint. Abnormal pressure on the nerve leads to the painful condition known as metatarsalgia. (Mortan’s metatarsalgia). 3. Deep Branch: It supplies following muscles and does not have a cutaneous branch. i. First three dorsal interossei. ii. First two plantar interossei.

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iii. Lateral three lumbrical muscle. iv. Adductor hallucis: deep branch ends in the adductor hallucis. Note: Deep branch reminds us of the deep branch of the ulnar nerve in hand which ends into the adductor pollicis muscle. The adductor pollicis muscle is described as the graveyard of the deep branch of ulnar. Similarly, the deep branch of the lateral plantar as it ends in the adductor hallucis muscle. The adductor hallucis muscle can be described as the graveyard of the lateral plantar nerve. Summary of Lateral Plantar Nerve:

1. 2. 3. 4.

It is the branch of tibial nerve. It runs laterally upto base of the fifth metatarsal. Above course of the nerve is in between first and second layers of sole. At the base of fifth, the nerve divides into a superficial and a deep branches. 5. Superficial branch supplies three muscles (flexor digitiminimi brevis, and two interossei, third plantar and fourth dorsal) and the skin of plantar aspect of lateral one and half toes. 6. Deep branch runs medially between third and fourth layers of the sole of foot. It supplies the remaining interossei (i.e. 1st, 2nd and 3rd dorsal and 1st and 2nd plantar), lateral three lumbrical muscles and adductor hallucis muscle, where it meets its graveyard. Comparison of Ulnar Nerve of Hand with the Lateral Plantar Nerve of Sole Lateral plantar nerve

Ulnar nerve of the hand

Branch of the tibial.

Continuation of ulnar nerve.

Enters sole on medial side. Before entry, lies under flexor retinaculum

Before entry, lies on flexor retinaculum.

It is close to calcaneus.

It is close to the pisiform.

Divides into superficial and deep branches.

Divides into superficial and deep branches.

This division occurs at the base of fifth metatarsal, far away from flexor retinaculum.

This division occurs immediately occurs under the flexor retinaculum.

Superficial branch divides into two, the medial and the lateral. The lateral branch supplies lateral one and half toes and the medial branch supplies adjacent side of fourth and fifth toes.

Superficial branch divides into two branches the medial branch supplies the medial one and half fingers while the lateral branch supplies adjacent sides of fourth and fifth fingers.

Superficial and deep branches supply The deep branch alone supplies four dorsal three plantar and four dorsal interossei. and four palmar interossei. Deep branch supplies lateral three lumbrical muscles.

Medial Plantar Nerve (Figure 410):

Deep branch supplies the medial two lumbrical muscles.

It is one of the two terminal branches of tibial nerve given under flexor retinaculum mid-way between the medial malleolus and the calcaneus. It passes in the sole by traveling under abductor hallucis brevis towards the toes. In the middle of the sole it emerges between the flexor digitorum brevis and the abductor hallucis. Medial plantar artery lies medial to nerve.

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Figure 410 Medial plantar nerve

Branches

1. Muscular: It supplies abductor hallucis brevis, flexor digitorum brevis, flexor hallucis brevis and first lumbrical. First two branches to the muscles arise from the trunk while flexor hallucis brevis gets its nerve supply from the first digital and the first lumbrical from second digital nerve. 2. Cutaneous: They arise from the trunk and innervate the skin of medial side of sole. 3. Digital Nerve: They supply the skin of plantar aspect of the medial three and half toes like the median nerve in the hand which supplies lateral three and half fingers. The digital branches supply the skin on dorsum of terminal phalanx of respective toes, and also give branches to the ligaments and the joints.

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ANKLE JOINT Classification: Bones Taking Part (Figure 411):

It is situated between the foot and leg in the region of ankle. It is synovial, uniaxial and the hinge variety of the joint. Lower end of tibia, lower end of fibula and the talus.

Figrue 411 Bones taking part in ankle joint

Lower End of Tibia: Broad articular area covers lower end of tibia and the lateral surface of medial malleolus. The areas on the lower end and medial malleolus of tibia are continuous. The articular area at the lower end of the tibia articulates with upper surface of talus. The medial malleolus articulates with comma shaped articular area on medial aspect of the talus. On the lateral aspect of lower end of the tibia lies a rough area for attachment of interosseous ligament of the inferior tibio-fibular joint. (Inferior tibio-fibular joint is an example of fibrous variety of joint and is known as syndesmosis). Lower End of Fibula: It presents the triangular articular area on the medial aspect of lateral malleolus. The base of the area is directed above and apex is pointing below. Immediately behind articular area lies the depression known as malleolar fossa. The articular area articulates with similar area on the lateral aspect of talus. At the apex of lateral malleolus lies the small notch which gives attachment to calcaneo-fibular ligament. Immediately above articular area is the attachment of interosseous ligament of the inferior tibia-fibular joint. Talus: Upper, lateral and medial aspects of talus present articular areas which are continuous with each other. Articular area on medial side is comma shaped, and the area on lateral side is triangular. The area on the superior surface of the bone is wider in front and narrow behind. By virtue of the fact that the superior surface is wider in front and narrow behind, stability of ankle joint is increased during dorsiflexion. During progressive dorsiflexion wider anterior area of superior surface of talus gets successively engaged or locked in the socket formed by the tibia and fibula (Tibio-fibular mortise). This prevents the further dorsiflexion. Posterior part of the lateral border of superior articular area presents the flattened impression for the inferior transverse tibio-fibular ligament.

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Tibio-fibular Mortise:

Attachment of Capsule:

Capsule:

Ligaments (Figures 412 and 413):

Lower end of tibia and the fibula along with inferior transverse tibio fibular ligament form the socket for the talus. It is known as tibio-fibular mortise. The stability and integrity of mortise mainly depend on the interosseous ligament of the inferior tibio-fibular joint. 1. To lower end of tibia and lower end of fibula: The capsule is attached to these bones a little beyond articular areas. 2. To Talus: The capsule is attached to the bone a little beyond the articular area except on superior aspect of the neck of the talus where the capsule is attached to the neck well away from articular area. Thus a small part of the neck of talus is intra-capsular. Anterior and the posterior parts of the capsule are thin and the medial and the lateral are thick. Anterior part of capsule is thinnest, therefore, a small and relatively superficial incision in the front of ankle can open the joint. 1. Capsular 2. Anterior ligament 3. Posterior ligament 4. Lateral ligament 5. Medial ligament and 6. Inferior transverse tibio-fibular ligament. Capsular ligament is already described. Anterior and posterior ligaments are thin. However, in spite of the thinness the anterior part of the capsule plays an important role in preventing excessive plantar flexion of the foot.

Figure 412 Ligaments of ankle joint

Figure 413 Ligaments of ankle joint

Lateral Ligament:

Anterior Talo Fibular Ligament:

It is thick and presents three parts: 1. Anterior talo-fibular 2. Posterior talo-fibular and 3. The Calcaneo-fibular. It is attached to anterior border of lateral malleolus and the lateral aspect of the neck of the talus. It plays a very important role in the stability of the ankle joint. During plantar flexion anterior talo-fibular ligaments gets taut and prevents further plantar flexion. At the same time posterior end of the talus gets fixed against posterior part of tibia-fibular mortise.

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Posterior Talo Fibular Ligament: Calcaneo Fibular Ligament:

It is attached to posterior border of lateral malleolus and the posterior tubercle of the talus. It plays role in preventing excessive dorsiflexion of foot. It is a cord-like ligament attached to the notch on the apex of lateral malleolus and the tubercle on the lateral aspect of calcaneus. The ligament is placed well away from lateral aspect of capsule. Medial Ligament: It is one of the strongest ligaments in the body. It is triangular in shape, hence is known as deltoid ligament. Superiorly it is attached to the tip of medial malleolus and inferiorly it is attached to plantar calcanea-navicular ligament, neck of the talus, sustentaculum tali and the medial aspect of the body of talus. The deep part of ligament is attached to the medial aspect of the talus over a well marked tubercle or tuberosity known as deltoid tubercle or tuberosity. By virtue of its attachment, deltoid ligament pulls spring ligament upwards and thus adds to the strength of it. Tendons of the tibialis posterior and the flexor digitorum longus are related to the deltoid ligament. Inferior Transverse It helps to form the socket for talus, along with lower end of tibia and fibula. Tibio-Fibular It is attached to the medial malleolus of the tibia and the malleolar fossa of Ligament: the fibula. Synovial Membrane It covers the capsule from inside and bones excepting their articular areas. (Figure 414): A small extension of synovial membrane lies between lower ends of tibia and fibula, immediately below interosseous ligament of inferior tibiafibular joint. Figure 414 Synovial membrane

Nerve Supply:

Blood Supply: Movements:

Plantar Flexion:

Ankle joint is supplied by: 1. Deep peroneal nerve 2. Tibial nerve and 3. Superficial peroneal nerve. Malleolar branches of the anterior tibial and the peroneal arteries supply the joint. Being of hinge variety, only the dorsiflexion and plantar-flexion are allowed. However, during plantar flexion a slight amount of side to side movement do occur. During dorsiflexion broad anterior part of trochlear surface of talus gradually occupies the tibio-fibular mortise and prevents further dorsiflexion. (Please note that the movements of inversion and eversion do not occur at the ankle joint.) It is done by the following muscles: 1. Gastrocnemius 2. Soleus 3. Plantaris 4. Tibialis posterior 5. Flexor hallucis longus and 6. Flexor digitorum longus.

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Dorsi-Flexors:

Relation:

It is done by the following muscles: 1. Tibialis anterior 2. Extensor hallucis longus 3. Extensor digitorum longus and 4. Peroneus tertius. Anterior Relations from Medial to Lateral Side (Figure 415): 1. Tibialis anterior 2. Extensor hallucis longus 3. Anterior tibial artery 4. Deep peroneal nerve 5. Extensor digitorum longus 6. Peroneus tertius and 7. Perforating branch of peroneal artery.

Figure 415 Relations of ankle joint (schematic)

Posterior Relations from Medial to Lateral Side: 1. Tibialis posterior 2. Flexor digitorum longus 3. Posterior tibial artery 4. Tibial nerve 5. Flexor hallucis longus. Clinical: Injury of the ankle is common in inversion than in eversion as the foot is more stable in eversion. Dislocation of the joint without rupture of the ligament is uncommon. Damage to the anterior ligament along with the rupture of the anterior talo-fibular ligaments are the factors responsible for failure of surgery for foot drop. Pott’s fracture: It is an external rotation injury when the foot is supinated. There is rupture of the anterior talo-fibular ligament and the fracture of distal end of the fibula. During further eversion deltoid ligament gets ruptured and possibly with the fracture of the medial malleolus. Tibia goes anteriorly and the posterior margin of the distal end of the tibia gets detached due to the talus. As the distal end of the tibia is recognized as the third malleolus the fracture is known as tri-malleolar fracture. Ankle sprain: Anterior talofibular and the calcano-fibular ligament are torned when the foot is twisted in the lateral direction. Ankle calf pump: Due to the movements of the ankle joint, calf muscles work and help in propagation of blood towards the heart against the gravity. Sever’s disease: It is a traction apophysitis of the tendo-calcaneou’s attachment to the calcaneous. Position of function 0° flexon , 0-5 Valgus, 5-10 External rotation. of ankle joint:

Ankle Joint Superior TibioFibular Joint (Figure 416):

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It is a synovial plane variety of joint. Head of fibula articulates with articular facet on postero-Iateral aspect of lateral condyle of tibia. Capsule is relatively thick and is attached to the bones beyond the articular areas. Capsule is thicker in front than behind. At times synovial tube associated with popliteus muscle communicates with joint cavity through an opening and establish communication between the cavities of the knee and the superior tibio-fibular joint.

Figure 416 Superior tibio-fibular joint

Nerve Supply:

1. Nerve to popliteus 2. Recurrent genicular nerve.

Movements:

The slight degree of gliding type of movement occurs at the joint. Movements at the ankle are projected in the superior tibio-fibular joint in the form of gliding.

Relation:

1. Lateral ligament of knee joint. 2. Tendon of biceps femoris. 3. Tendon of popliteus. 4. Synovial tube associated with the tendon of popliteus.

Inferior TibioFibular Joint (Figure 417):

It is a classical example of syndesmosis (bones are connected together by means of ligament alone). Lower ends of tibia and fibula are connected by the interosseous ligament. Interosseous ligament is formed by tough and strong transverse fibres. In addition to this, there are anterior and posterior ligaments. By virtue of being a syndesmosis, strength and stability of the ankle is more. When the person lands on the ground from the height there is slight separation of lower ends of tibia and fibula. It leads to gliding movement in the superior tibio-fibular joint.

Figure 417 Inferior tibio-fibular joint

Nerve Supply: Interosseous Membrane of Leg (Figure 418):

Inferior tibio-fibular joint is supplied by nerve to popliteus. It is attached to interosseous borders of the tibia and the fibula. Fibres are directed downwards and laterally from interosseous border of tibia. There is an opening in the upper part of the interosseous membrane meant for the anterior tibial artery. The perforating branch of peroneal artery passes through the opening in the lower part of the interosseous membrane.

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Figure 418 Interosseous membrane of the leg viewed from front

Relations of the 1. Anterior: Anterior tibial artery, deep peroneal nerve, tibialis anterior interosseous and the peroneus tertius muscles. membrane of the leg: 2. Posterior: Tibial nerve, tibialis posterior, soleus, gastrocnemius and the plantaris muscles. Function of 1. Connects two bones, Interosseous 2. Provides extra area for origin muscles. Membrane: 3. Divides the leg into the flexor and the extensor compartments along with the tibia and the fibula. Nerve Supply: It is supplied by the nerve to popliteus. You may recollect that the nerve to the popliteus the branch of the tibial supplies the popliteus, interosseous membrane, superior tibio-fibular and the inferior tibio-fibular joints. Joints of Foot: Tarsals, metatarsals, and phalanges of toes articulate through the interosseous ligaments, forming the joints of foot. Following facts - Talus tops the calcaneus making the medial longitudinal arch of the should always be foot higher than the lateral. remembered: - Head of talus is directed medially and it articulates with the navicular. - Navicular articulates with three cuneiforms. - Three cuneiforms articulate with medial three metatarsals. - Calcaneus articulates with cuboid. - Cuboid articulates with the fourth and the fifth metatarsals. Following Joints 1. Joint between calcaneus, and talus (Talocalcanean joint). Need to be Studied: 2. Talo-calcaneo-navicular joint. 3. Calcaneo ‘cuboid joint. 4. Cuneonavicular joint. 5. Cuboideo-navicular joint. 6. Indirect articulation between calcaneus and navicular. 7. Intercuneiform joints. 8. Cuneocuboid joint. 9. Tarsometatarsal joints and intermetatarsal joints. 10. Metatarso-phalangeal joints. 11. Interphalangeal joints. Talocalcanean Joint It is synovial joint. It is also known as sub-talar or sub-taloid articulation. (Figure 419): The large posterior calcanean articular facet on the under surface of the body of talus articulates with the similar posterior talar articular facet on the superior aspect of calcaneus. Immediately in front of the respective articular facet lies the sulcus. The sulcus on talus is known as sulcus tali and sulcus on calcaneus is known as sulcus calcani. Articular facet of the calcaneus is convex, while that on talus is concave. The joint is provided with a separate capsule and hence the cavity is independent.

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Figure 419 Talocalcanean joint and ligament

Following are Ligaments of Joint:

1. 2. 3. 1.

Medial talocalcanean ligament, Lateral talocalcanean ligament and Interosseous talocalcanean ligament. Medial Talocalcanean Ligament: It is attached to medial tubercle of talus and the posterior end of sustentaculum tali. (New Name: sustentaculum talar) and adjoining part of medial surface of calcaneus. Anteriorly the ligament fuses with deltoid ligament. 2. Lateral Talocalcanean Ligament: It is attached to lateral tubercle of talus and the lateral surface of calcaneus. This ligament is partially hidden under cover of the calcaneo-fibular ligament. 3. Interosseous Talocalcanean Ligament (Figure 420): It is attached to the groove on talus and the calcaneus in front of articular facets forming the joint. The ligament is arranged into two distinct parts, the medial and lateral.

Figure 420 Medial part of interosseous talocalcanean ligament

Medial Part:

Lateral Part:

Talocalcaneonavicular Joint (Figures 421 and 422):

(True interosseous talocalcanean ligament). It lies in medial part of sinus tarsi and is represented by two lamellae, anterior and posterior. Immediately lateral to medial part of the ligament lies the attachment of the stem of the inferior extensor-retinaculum. It lies lateral to medial part and is placed in the wider part of the tunnel between talus and calcaneus (Sinus tarsi). It runs between the floor of the groove of calcaneus and the neck of talus. It is directed supero-medially. This ligament is also known as cervical ligament. It is claimed that it gets taut during the movement inversion of foot and thus checks the excessive inversion. Movements of inversion and eversion occur at subtaloid joint. It is synovial and ball and socket type of joint. Proximal component of this joint is formed by rounded head of talus, while distal component is formed by the articular facet of the navicular bone, calcaneus and spring ligament. It is provided with a fibrous capsule.

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Figure 421 Talocalcaneonavicular joints and calcaneonavicular portion of bifurcated ligament

Figure 422 Calcaneo-cuboid joint

Ligaments:

1. Talonavicular Ligament: It runs from dorsal surface of the neck of talus to dorsal surface of navicular bone. 2. Calcaneo-navicular portion of bifurcated ligament: It lies on the lateral aspect of the joint. Bifurcated ligament is Y shaped having medial limb, lateral limb and the stem. Stem is attached to the upper surface of calcaneus to the part not covered by talus. Medial limb runs to dorsilateral part of navicular and lateral limb goes to dorsal aspect of cuboid. Movements: Movements of inversion occur at this joint. Calcaneo-cuboid Anterior surface of calcaneus articulates with posterior surface of cuboid. Joint: The joint surfaces are concave-convex (Saddle shaped). Joint is provided with a separate fibrous capsule and synovial membrane. Ligaments: Apart from other ligaments, the long and short plantar ligaments are important. Short Plantar It lies above the long plantar ligament and runs between the anterior Ligament: tubercle of the calcaneum and ridge on the under surface of the cuboid. As already mentioned lateral limb of bifurcated ligament (Calcaneo-cuboid ligament) connects calcaneus and cuboid. Long Plantar It is attached to plantar surface of calcaneus between medial, lateral anterior Ligament: tubercles. Anteriorly it is attached to the ridge on the plantar surface of cuboid. By virtue of the ligament the groove on the plantar aspect of cuboid is converted into a tunnel for the peroneus longus tendon. Anterior extension of the ligament can be seen attached to the bases of second, third and fourth metatarsals. Movements: Rotation and gliding type of movements occur in this joint. Cuneo-navicular Three cuneiform bones articulate with anterior surface of navicular. Joint: Cuneiforms are interconnected by means of interosseous ligaments. It is a synovial joint and is provided with a fibrous capsule. Joint cavity is continuous with the inter-cuneoform, cuneo-cuboid, the third cuneometatarsal joints and the inter-metatarsal joints between second, third and fourth metatarsals. Ligaments: Dorsal and plantar ligaments connect the cuneiform and the navicular bones. Movement: Gliding type. Cuboideo-navicular Here the medial aspect of cuboid articulates with lateral aspect of the Joint: navicular. This articulation is direct in some and indirect in many. When indirect articulation exists these two bones are connected by means of

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interosseous ligament, dorsal and the plantar ligaments. In case of direct articulation, a small synovial joint of a plane variety exists. It is continuous with cavity of cuneo-navicular joint. Movement: Gliding type. Indirect Articulation As already mentioned calcaneus is connected with dorsi-lateral aspect of Between Calcaneus navicular bone by means of medial limb (calcaneo-navicular) of the and Navicular: bifurcate ligament. On the plantar aspect of navicular it is connected to the calcaneous through the spring ligament (plantar calcaneo-navicular ligament.) Spring Ligament Anteriorly is attached to the under surface of the navicular and posteriorly (Figure 423): to the anterior part of sustentaculum talare (Tali.). Ligament support inferomedial part of the head of talus. Dorsal part of the ligament has a fibrocartilaginous facet for the head of the talus. Lower border of deltoid ligament is attached to the spring ligament. The tendon of tibialis posterior supports the spring ligament from below. These two factors add to the weight bearing and strain bearing capacity of the spring ligament. (Deltoid pulls the spring from above and the tibialis posterior supports the spring from below). Description of the spring ligament is incomplete and half without the mention of the deltoid ligament and the tendon of tibialis posterior. The deltoid and spring ligament are equally thick. In the event of rupture of spring ligament, medial longitudinal arch of foot collapses. It is considered as an indispensable ligament for the maintenance of the medial longitudinal arch of foot. Figure 423 Spring ligament

Intercuneoform Joint (Figure 424):

Cuneiform 1, 2 and 3 are interconnected by means of interosseous and plantar ligaments. Joints between cuneiforms are of plane synovial variety.

Figure 424 Intercuneiform of the metatarsal cuneo-cuboid and intermetatarsal joint

Cuneo-cuboid Joint: It is an articulation between medial surface of cuboid and lateral surface of lateral cuneiform bone. Tarsometatarsal These are of plane synovial variety. Base of first metatarsal articulates with Joint: the kidney shaped facet of medial cuneiform bone. It is provided with a separate joint cavity. Second metatarsal base gets wedged between the medial and the lateral cuneiform bones and articulates with intermediate cuneiform bone. Base of the third articulates with lateral cuneiform. The cavities of second and third tarso metatarsal joints communicate with the inter-cuneiform and calcaneo-navicular joints. They do not communicate with the cavities of the fourth and fifth tarso-metatarsal joints. Bases of fourth and fifth metatarsals articulates with the cuboid. These joints are

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Movements:

Intermetatarsal Joints:

Metatarsophalangeal Joints (Figure 425):

provided with plantar tarso-metatarsal, dorsal tarso-metatarsal and interosseous cuneo-metatarsal ligaments. Gliding movement occurs in other joints, except the first tarso-metatarsal, i.e. joint between medial cuneiform and the base of first metatarsal. Here upward and downward displacement of the base of first metatarsal with some amount of rotation take place. It is important for the movements of inversion end eversion. First metatarsal base enjoys relatively free mobility as it does not articulate with the base of the second metatarsal. A bursa exists between the bases of the first and the second metatarsals. Great toe is isolated from other toes like the thumb. Isolation is partial and incomplete. Its head is connected to head of the second by means of deep transverse ligament as in other metatarsals. The rest of the metatarsal are connected, by ligaments at the bases and heads. The joints at the bases are provided with dorsal, plantar and interosseous ligaments. Interosseous ligaments are the transverse bands connecting the non-articular parts of the metatarsal bases. Movements: Gliding type. Heads of metatarsals articulate with concave articular facets on the bases of proximal phalanges. These joints are provided with fibrous capsule and following ligaments: (1) Plantar ligament (2) Deep transverse metatarsal ligament and (3) Collateral ligament which runs from tubercle on the side of the head of metatarsal downwards and forwards to the base of proximal phalanx. Deep transverse ligament connects adjoining metatarsophalangeal joints through plantar metatarso-phalangeal `ligaments.

Figure 425 Metatarsophalangeal joint

Inter-phalangeal Joints:

Movements of Inversion and Eversion (Figures 426 and 427): Figure 426 Axis of inversion and eversion

Movements: Flexion, extension, adduction, gliding and rotation. They are synovial hinge type of joints. Each is provided with an articular capsule, plantar and the collateral ligaments. Movements: Main - Flexion and extension. Accessory - Adduction, abduction and rotation. When the sole of foot tries to face medially and its medial border is raised, it is known as movement of inversion. When sole of the foot tries to face laterally and its lateral border is raised, is known as movement of eversion.

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Figure 427 Joints in which movements occur

Axis: Joints Involved in Movements of Inversion and Eversion:

Movements associated with inversion and eversion: 1. During inversion, there is adduction of forefoot associated with plantar flexion of foot. 2. During eversion, there is abduction of the forefoot associated with the dorsiflexion. The axis runs upwards, medially and forwards, passing through the body of calcaneus and the neck of talus. Movements of inversion and eversion do not occur at the ankle joint, as it is synovial, uni-axial and hinge. The movements solely occur at the mid -tarsal and the sub-taloid joints. As there is hardly any scope for movements at mid-tarsal joints, the rotatary force generated is transmitted to the calcaneus, and it is the calcaneus which rotates under the talus (Figure 428).

Figure 428 Role of muscles in inversion and eversion

Mid-tarsal Joints are: Calcaneo-cuboid, talo-calcaneo-navicular. Muscles producing inversion and eversion Invertors

Evertors

Tibialis anterior and tibialis posterior.

Peroneus longus,

Extensor hallucis longus, Flexor hallucis longus.

Peroneus brevis and the peroneus tertius.

Note: Tibialis anterior and posterior are main invertors. However, extensor hallucis longus and flexor hallucis longus do help in the movement of inversion.

Note: Extensor digitorum longus acts as an evertor when the foot is in dorsiflexed position, but in plantar flexed position, peroneal muscles are the main evertors.

If the main movers are considered it becomes obvious that tibialis anterior is dorsiflexor, and the tibialis posterior is plantar flexor. When both the muscles act at the same time the action of the plantar flexion and dorsiflexion get cancelled and the third action emerges in the form of inversion. Peroneus longus and the peroneal brevis are the plantar flexor while the peroneus tertius is the dorsiflexor. When all three muscles act at the same time the action of the dorsiflexion and the plantar flexion gets cancelled and the third action emerges in the form of eversion. When the foot is off the ground, movements of inversion and eversion are relatively free. We walk on the uneven surfaces because of the movements of inversion and eversion. Foot is more secure and stable in eversion. This explains why the injuries of the foot are common in the state of inversion and not the eversion.

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ARCHES OF FOOT (F igures 429A to C) (Figures Figure 429A Normal print of foot (arched)

Figure 429B Showing bones forming the medial longitudinal arch viewed from medial side

Figure 429C Showing bones forming the lateral longitudinal arch viewed from lateral side

It becomes evident from the study of the print of normal foot that the foot has arches. Arches are the springs of the human body. They provide resilience, elasticity and efficiency which is useful for running, walking and jumping from the height. Arches help in distribution of weight. They act as shock absorber and protect the plantar nerves and the vessels, due to the concavity of the foot (Figure 429A). Note: Flat footed person is rejected in the army and police, but you will be surprised to know that some of the best athletes in the world are flatfooted. Bones, interosseous ligaments, special ligaments, intrinsic muscles, extrinsic muscles and even the deep fascia contribute to the maintenance of the arches of foot.

Arches of Foot 337 Classification of arches: 1. longitudinal 2. transverse. Longitudinal arches: 1. medial and the 2. lateral. Transverse arches of the foot (Figures 430A to 430D): 1. Anterior 2. Posterior. Figure 430A Arches

Figure 430B Showing transverse arch of the foot note the shape of the bones and the interosseous ligaments

Figure 430C Showing a stony bridge

Figure 430D Showing transverse arches of the foot. Note transverse arches coplete in front and incomplete behind like a half dome

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Medial Longitudinal Arch:

It is higher than the lateral and is more pliable and resilient. The arch is formed by the following components. The bones: shape and method of articulation. 1. Calcaneus 2. Talus 3. Navicular 4. Three cuneiforms 5. Medial three metatarsals (Figure 429B). Calcaneus forms the posterior pillar while the heads of the three metatarsals form the anterior. Talus is a bone which acts as a “key stone”. The apex of the medial longitudinal arch is the trochlear surface of the talus. It is difficult to define the apex of the lateral longitudinal arch although body weight is transmitted via the talus and yet the talus is not part of the arch. (Talar Paradox). It articulates with the navicular anteriorly through its head and the navicular articulates with the three cuneiforms in front. The cuneiforms articulate anteriorly with the three metatarsal. 1. Interosseous ligaments: Interosseous ligaments act as cement or the mortar bridging the gap between the bones, like the bricks or stones. According to Basu the interosseous ligaments are important in maintaining the arches of the foot. 2. Intrinsic muscles: The muscles of the first and the third layers of the sole of the foot play an important part. 3. Extrinsic muscles: Muscles of the leg i.e. tibialis anterior, tibialis posterior, peroneus longus and the flexor hallucis longus act as slings and pull up the arches preventing their collapse. 4. Plantar aponeurosis: It extends from the posterior pillar of the arch to the anterior i.e. from calcaneus to the heads of the metatarsals. The function of the plantar aponeurosis is like a tie-beam which prevents the separation of the anterior and the posterior pillars under weight on the top. 5. Sling action of muscles: Ideally the tibialis anterior and the peroneus longus, which are attached to the first metatarsal and the adjoining part of the medial cuneiform bone form the real sling. It pulls the arch up from above. 6. Tibialis posterior: It acts as a sling mainly for the medial longitudinal arch of the foot, however, the mode of attachment of the tibialis posterior to the tuberosity of the navicular, all tarsals except the talus and all the metatarsals except the first confirms its role as the bond of the bones. (bond means thing used to fasten). Plantar calcaneoThe arch is maintained by the plantar calcaneo-navicular ligament which navicular ligament: is also known as spring ligament. It is attached to the sustentaculum talii posteriorly and the edge on the plantar surface of the navicular bone anteriorly. Head of the talus lies on the substanteculum talli and the plantar calcaneo-navicular ligament. Plantar calcaneo-navicular ligament is pulled up by the deltoid ligament and is supported from below by the tibialis posterior tendon.

FACTORS RESPONSIBLE FOR MAINTENANCE OF ARCHES OF FOOT A. Arrangement of Bones:

Talus rides the calcaneus making the medial arch higher than the lateral.

Arches of Foot 339 B. Interosseous Ligament: C. Special Ligaments: Short Muscles of the Foot.

They connect the adjoining bones and act as cementing material. They play an important part in maintaining the arches of the foot. (Basu) 1. Spring ligament 2. Deltoid ligament. Muscles of the first and the third layers of the sole of the foot also act as tiebeams. They are powerful as the smaller segments of the muscle contract more powerfully than the longer. Following muscles assist in maintaining the medial longitudinal arch of the foot. 1. Flexor digitorum brevis 2. Abductor hallucis brevis 3. Flexor hallucis brevis. D. Long Tendons: The tibialis anterior and the peroneus longus are inserted in to the base of the first metatarsal and the adjoining the part of the medial cuneiform bone, forming an ideal sling. It maintains medial as well as longitudinal arches of the foot. Peroneus longus tendon crosses sole of the foot from lateral to medial side for attachment into the lateral aspect of base of the first metatarsal and the medial cuneiform bone. It helps in maintaining the transverse arches of the foot. F. Plantar Plantar aponeurosis acts as tie beam for the arch. It extends from the Aponeurosis: calcaneus to the heads of the metatarsals. It prevents spreading of the lower ends of the beams of the arch under heavy weight. Lateral Longitudinal A. Bones Taking Part Arch (Figure 429C): 1. Calcaneus 2. Cuboid 3. Two lateral metatarsals. (fourth and the fifth). B. Interosseous Ligaments: They act as the cementing material connecting the bones. C. Special Ligaments: Long and short plantar ligaments. Long plantar It is attached to the undersurface of the calcaneus between the medial, Ligament: lateral and the anterior tubercles posteriorly. Anteriorly it is attached to the ridge on the undersurface of the cuboid. The Short Plantar It is covered by the long plantar ligament. It runs from the anterior tubercle Ligament: of the calcaneus to the posterior margin of the groove for the peroneus longus tendon. Long tendons: Peroneus longus and the peroneus tertius helps in maintaining the lateral arch of the foot. Short Muscles: Abductor digitiminimi, lateral half of the flexor digitorum brevis and the flexor digitiminimi brevis helps in maintaining the arch . Role of the interossei do help as they are attached to the bones and bring them together. Plantar Aponeurosis As discussed above. It acts as a tie-beam. (Figure 431): Transverse Arches They are the series of arches placed transversely from before backwards. (see Figures 430A to D): They are complete in front as the heads of the first and the fifth metatarsals touch the ground. However they are incomplete posteriorly as half domes. Person standing on the ground feet together converts the half arches into the full posteriorly. Weight Transmission 50% of the weight is transferred to the posterior pillar and the 50% to the in Arches of foot: anterior. Out of the 50% weight transferred to the anteriorly pillar, 33% is shared by the medial longitudinal arch and the 17% by the lateral. Bones: Arrangement of all the tarsals and the metatarsals are responsible for the formation. The three cuneiform are arranged in an arched fashion. The key stone lies at the top and the rest of the stones are arranged accordingly.

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Long Tendons (Figure 432):

Dorsal surfaces of the intermediate and the lateral cuneiform bones are larger than the plantar. Medial cuneiform bone has a larger dorsal surface, however its articular facet on its proximal aspect appears triangular, the apex of which is directed medially. Ligaments: Interosseous ligaments play an important part. Special ligaments: Long and the short plantars. Direction of tendon of peroneus longus helps in maintaining the arches as it crosses the sole from lateral to the medial side.

Figure 431 Role of plantar aponeurosis

Figure 432 Sling action

Figure 432A Summary of factors for maintenance of arches of foot

Short Muscles: Biomechanics of the Arches: Clinical:

Transverse head of the adductor hallucis helps in maintaining the transverse arches. It can be explained by Newton’s third law “Every action has an equal and opposite reaction”. Weight of the body is supported by two ends of the arches. Action load has an equal and opposite ground reaction force. Abnormality of the arches are as under a. Flat foot (Pes planus) and b. Arched foot (Pes Cavus) it is also known as Club foot.

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Pes cavus:

Claw Foot:

Surgical:

Flat foot is due to stretching of the ligaments and the weakness of the muscles in those who are required to stand for long time. Flat foot may be congenital. A flat footed person looses the spring action of the foot and has a clumsy walk. Due to the non-functioning of the shock absorbing mechanism foot is prone to trauma and osteoarthritis. As there is loss of concavity on the under surface of the foot, compression of nerve between the medial and lateral plantar nerves causes pain. It is known as metatarsalgia. (Morton’s). Note: Flat foot is classified in two the mobile and the rigid. No treatment is required for the mobile flat foot. In children the foot appears flat due to the fat on the inner side of the foot. Contracture of the plantar flexors results in high arched foot. There is dorsiflexion of the metatarso-phalangial joints and the flexion of the interphalangial joints. It is due to the atrophy of small muscles of the foot. i.e. interossei and the lumbrical. It is known as claw foot. It is seen in spina bifida and also in cases of poliomyelitis. Talipes equino varus is common in which the foot is plantar flexed, adducted, inverted and medially rotated. Note: The treatment for the telepes equino varus should be started at the earliest (How early?). As soon as the baby’s foot comes out of the mother’s womb!. It can result due to peroneal muscle atrophy, in a neurological disease. (Charcot-Marie-Tooth disease) or even due to poliomyelitis there is an imbalance between the muscles of the peroneal and the muscles of the extensor compartment with paralysis of the interossei of the foot, similar to ulnar nerve palsy. 1. Hallux Valgus: Big toe is displaced laterally. Once it goes laterally the flexor hallucis longus tendon pulls it further as the line of pull changes and the deformity progress (Figure 433).

Figure 433 Showing hallux valgus

2. Hallux rigidus: The metatarso phalangeal joint becomes fixed and painful. 3. Hammer toe: It affects the second, third and the fourth toes. There is hyper-extension of the metatarso-phalangeal joints and the distal interphalangeal joints. However there is flexion of the proximal interphalangeal joint. 4. Claw Toe: The toe pads do not touch the ground when the person stands. It is due to loss of contact in which the distal inter-phalangeal joint is flexed. 5. Bunion: It is an inflammation of the adventitious bursa on the prominent head of the first metatarsal as a result of pressure and friction. 6. Morton’s metatarsalgia: It affects the third and the fourth toes which causes pain. Tenderness is confirmed by pressing between the

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Treatment:

metatarsal heads. It is due to the entrapment of inter-metatarsal nerve of the affected cleft. The nerve gets degenerated and later regenerates. Condition is similar to the ulnar neuritis. The affected nerve is excised. 7. Plantar fasciatis: There is localized tenderness under the heal. The pain is severe when a person takes weight which interferes with walking. It is due to a tear or injury of the plantar fascia. At times a bony spur appears in the plantar aponeurosis near the calcaneus, it is known as calcaneun spur. Surprisingly the spur is not the cause of the pain, therefore should be left alone. 8. Ingrowing toe-nail (embedded toe-nail): It is seen in those who wear tight shoes and have tendency to sweat. It affects the big toe. It is treated by wedge resection of the part of the nail. 9. Infections: They are common in children due to the injuries which mostly affect the heel and the region near the heads of the metatarsals, being the weight bearing areas. It can lead to cellulitis, abscess and osteomyelitis. Abscess should be incised without hesitation as the wound of the sole heals without leaving a painful scar. Incision is given along the medial border of the plantar aponeurosis. Wound is probed and explored thoroughly. Osteomyelitis of the foot can be treated by midline incision and the calcaneus is cut into two pieces and the infected material is removed. 10. Diabetic Foot: There are three evils responsible for diabetic gangrene of the foot. (Gangrene means death of the tissue with putrefication superadded). They are: 1. Sugar 2. Ischaemia 3. Neuritis. Note: above three SIN’s are the challenges before the treating the surgeon. The treatment is the amputation of the foot through the ankle. Care should be taken to preserve the blood supply of the calcaneal flap. Summary of the factors for maintenance of arches of foot (Figure 431B): 1. Shape 2. Segment 3. Strings and 4. Slings. Shape of the bone, Segmental ties which include ligaments and muscles. Strings, beams that connect the ends of the arches. Slings keep the top of the arch pulled up.

Clinical Pictures

CLINICAL PICTURES Figure 434

Figures 434 and 435 Showing X-ray of knee

Figure 436 Showing X-ray of elbow

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Figure 437

Figure 437 and 438 Showing X-ray of knee

Figure 439 Showing X-ray of foot

Clinical Pictures Figure 440 Showing X-ray of hip

Figure 441 Showing of X-ray of hand

Figure 442 Showing X-ray of shoulder

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Figure 443 Popliteal angiogram showing trifurcation

Figure 444 Right lower limb angiogram showing anterior tibial artery and posterior tibial artery

Figure 445 Angiogram of brachial artery showing normal bifurcation

Figure 446 Angiogram showing 1st part of left sublavian artery with branches

Clinical Pictures Figure 447 Showing pectoral region of right side

Figure 448 Showing flexor aspect of the right forearm and hand

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Figure 449 Showing extensor aspect of the left forearm and hand

Figure 450 Palmar aspect of the right hand

Clinical Pictures Figure 451 Showing synovial sheaths of the right hand

Figure 452 Showing attachments of linea aspera

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Index

i

INDEX A Acetabulum 180, 253 Achilles tendonitis 300 Acromioclavicular joint 76 Adductor brevis 237 Adductor compartment 236 Adductor longus 236 Adductor magnus 237 Adductor pollicis muscle 156 Adductor space 166 Allen’s test 117 Amastia 43 Anconeous 136 Angle of Louis 32 Ankle calf pump 328 Ankle joint 325 bones taking part end of fibula 325 end of tibia 325 talus 325 tibia-fibular mortise 326 capsule 326 joints of foot 330 calcaneo-cuboid 332 cuneo-navicular 332 intercuneoform 333 intermetatarsal 334 inter-phalangeal 334 metatarsophalangeal 334 talocalcanean 330 talocalcaneonavicular 331 ligaments 326 movements 327 muscles producing inversion and eversion 335 relation 328 synovial membrane 327 Ankle sprain 328 Annular ligament 19 Anterior tibial artery 292 Antibrachial vein 147 Appendicular skeleton 1 Arches of foot 336 factors responsible for maintenance 338 biomechanics 340 Arterialisation of the vein 146 Arteriovenous fistula 118 Articular disc 132 Articularis genu 222 Athelia 43 Axial skeleton 1 Axilla 27, 49 anterior wall 49 axillary artery 54 axillary nerve 62

axillary vein 59 brachial plexus 60 branches from the cords 61 coracobrachialis 53 latissimus dorsi 51 medial wall 52 posterior wall 49 serratus anterior 52 short head of biceps 53 subscapularis 49 teres major 51 Axonotmesis 63

B Back 66 Baker’s cyst 278 Bassi’s perforator 211 Bennett’s fracture-dislocation 24 Biceps femoris muscle 219 Bicipital aponeurosis 87, 88 Bones of upper limb 6 clavicle 10 ossification 11 sternal end 11 humerus 11 angle of humeral torsion 15 capsular attachment 13 contents of groove 14 greater tubercle 13 ossification 15 radius 16 ossification 18 scapula 6 important features 9 neck of scapula 7 ossification 9 ulna 19 capsular attachment 20 lower end 19 upper end 19 Boyd’s perforator 211 Brachial artery 88 Brachioradialis 136 Braynt’s triangle 179, 180 Brodie’s bursa 279, 299 Bucket handle tear 275 Bunion 341

C Calcaneo-cuboid joint 201 Calcaneum 194 Calcaneus 197 Capitate 23 Carcinoma of the breast 47

Carpal bones 20 Carpal tunnel 125 causes 154 Carrying angle 104 Cave of Retzius 179 Cephalic vein 145 Cervico-axillary canal 28 Charcot-Marie-Tooth disease 341 Charley horse’s syndrome 220 Chauffor’s fracture 18 Chiene’s test 259 Classification of bones 1 Clavipectoral fascia 36 Claw foot 341 Claw hand 128 Claw toe 341 Clergyman’s knee 279 Cockett’s perforators 210 Colles’ fracture 17-19 children’s 19 Compartment syndrome 286, 315 abductor digiti minimi 316 abductor hallucis 315 digitorum longus 317 flexor digitorum accessorius 316 flexor digitorum brevis 315 flexor hallucis brevis 318 hallucis longus 317 interossei 319 layer of sole 315 lumbrical muscles 316 peroneus longus tendon 320 plantar arch 321 plantar metatarsal artery 321 plantar nerve 323 tendon of flexor 317 tendon of tibialis posterior 319 third layer of sole 318 Compression 5 Coracoid process 6 Costocoracoid membrane 31 Cruciate anastomosis 235 Crutch palsy 98 Cubital fossa 130 Cubital tunnel syndrome 128 Cutaneous innervation of gluteal region 243

D Dead leg syndrome 220 Deep branch of radial nerve 118 Deep fascia 244, 285

ii Kadasne’s Textbook of Anatomy (Clinically Oriented) Deep group of muscles of forearm 112 flexor digitorum profundus 113 flexor pollicis longus 112 pronator quadratus 113 Deep palmar arch 159 Deep peroneal muscles 290 Deep vein thrombosis 211 Deltoid muscle 73 Deltopectoral groove 35 Dermatome axial line 176 Diabetic foot 342 Diaphysis 5 Dinner fork deformity 17 Dislocation 257 Dorsum of foot 311 Drawer sign 278 Ductography 47 Dupuytren’s contracture 151, 152

E Elbow joint 101 lower end of humerus 101 bony points 105 exposure of the elbow joint 106 head of radius 102 ligaments of the elbow joint 103 synovial membrane 104 upper end of ulna 102 Ellipsoid joints 172 Epiphysis 5 Erb’s paralysis 64 Exposure of hip 259 Extensor hallucis 287

F Femoral artery 227 Femoral hernia 217 Femoral nerve 234 Femoral triangle 226, 228, 234 Femoral vein 233 Femur 182 calcar femorale 185 greater trochanter 183 intercondylar notch 185 intertrochanteric crest 184 intertrochanteric line 184 neck of femur 183 ossification 185 Fibroadenoma 47 Fibrous flexor sheath 163 Fibula 192 anterior surface 192 ossification 193 upper end 192 Flexor digiti minimi 157 Flexor retinaculum 152

Flexor tendons of fingers 166 Fong’s syndrome 188 Foot 310 relations 312 Forearm 107 muscles of the flexor compartment 108 flexor carpi ulnaris 111 flexor digitorum sublimis 110 palmaris longus 110 pronator teres 109 Formation of bone 2 Fracture neck of femur 257 Fracture of patella 220 Freiberg disease 201 Froment sign 128 Funny bone 128

G Galeazzi fracture 132 dislocation 19 Gastrocnemius 299 Genu valgum 278 Gland of Cloquet 216 Glenoid cavity 6, 8, 9, 77 Glenoid tubercles 9 Gluteal muscles 244 Gluteus medius 245 Golfer’s elbow 139, 140 Gracilis 239 Guyon’s canal 126

H Hallus valgus 341 Hamate 23 Hammer toe 341 Haversian canals 6 Head of femur 253 Head of the humerus 78 Henry’s method 144 Hip bone 177 House maid’s knee 279 Hunter’s canal 210, 211, 228 Hypothenar eminence 157

I Iliac crest 177, 179, 180 Iliacus 226 Ilio-femoral ligament 254 Iliopubic eminence 177 Individual metacarpal bones 24 Infection of the sole 314 Inferior limb 177 Infraglenoid 6 Ingrowing toe-nail 342 Interior limb 30 Intermuscular spaces 73 Interosseous membrane 133 Irritable hip 259

Ischial spine 180 Ischial tuberosity 179 Ischio-femoral ligament 255 Ischium 179

J Joints cartilaginous 3 fibrous 3 sutural 3 synovial 4 Joint replacement surgery 259

K Klumpke’s paralysis 64 Knee joint bones taking part 269 capsular attachment 271 capsular ligament 272 lower end of femur 269 muscles producing different movements 280 relations of knee joint 281 upper end of tibia 270 Krukenburg’s tumour 46

L Labourer’s nerve 124 Langer’s lines 34 Leg 282 compartment 286 general consideration 283 nerve supply 284 superficial fascia 283 superficial veins 283 surface landmarks 282 surgical anatomy 286 Leonardo da Vinci’s vein 210 Ligaments of Sir Astley Cooper 45 Linea aspera 182, 184, 224, 349 Lumbar plexus 212 Lumbar triangle of Petit 72 Lumbrical spaces or canals 166 Lunate (moon) 21 Lymphangitis 175 Lymphatic drainage of the breast 46

M Mammary abscesses 47 Mammary gland 43 Mammography 47 March fracture 203 Marjolean’s ulcer 211 Medial semilunar cartilage 275 Membrane bones 2 Metacarpals 23 Metaphysis 5

Index Metastasis 259 Metatarsalgia 341 Metatarsals 201 Morrant Baker’s cyst 278 Morton’s metatarsalgia 341 Movement of the thumb 156 Muscle of the deep group 140 Muscles 67 infraspinatus muscle 70 latissimus dorsi 68 rhomboideus major 69 rhomboideus minor 69 rotator cuff 67, 70 serratus posterior 71 supraspinatus muscle 69 teres major 71 teres minor 70 trapezius muscle 67 Muscles of the flexor compartment 294 flexor digitorum longus 295 flexor hallucis longus 297 flexor retinaculum 307 gastrocnemius 299 peroneus brevis 308 peroneus longus 307 plantaris 300 popliteus 294 soleus muscle 301 synovial sheath of tibialis posterior 307 tibial nerve 302 tibialis posterior 297 Musician’s nerve 162

Osgood shlatter’s disease 278 Ossification 3 centers of phalanges 26 bone of foot 203 Osteoarthritis 259

P

Nailpatella syndrome 188 Navicular bone 199 Neleton’s line 180 Nerve of Bell 61 Nerves and vessels of the forearm 115 interosseous artery 121 median nerve 122 radial artery 115 radial nerve 118 ulnar artery 119 Neuropraxia 63 Neurotmesis 63 Nutrient artery 90

Painful arc syndrome 84 Palmar aponeurosis 150, 151 Palmar interossei 160 Palmar spaces 165, 166 Paranasal air sinuses 1 Patella 187 dislocation 188 ossification 188 Patelo-femoral pain syndrome 277 Peau d’ orange 45, 46 Pectineal surface 177 Pectoral fascia 35 Peroneus tertius 288 Perthes’ disease 259 Perthes test 211 Pes anserius 279 Pes cavus 341 Phalanges 203 hand 25 PIN syndrome 139 Pisiform 22 Plantar fascitis 342 Pointing index 123, 125 Poland syndrome 39, 43 Policeman’s tip 64 Polymastia 43 Polythelia 43 Popliteal angiogram 346 Popliteal lymph nodes 268 Popliteal vein 265 Pott’s fracture 328 Pre-patellar bursitis 279 Profunda brachii artery 90 Profunda femoris 230 Profunda femoris artery 231 Pronation and supination 134 Pseudo-ganglion 143 Psoas major 225 Pubis 177 Pudendal nerve 251 Pulled elbow 132 Putti-Platt’s procedure 50

O

Q

N

Oblique cord 133 Obturator artery 242 Obturator externus 239 Obturator foramen 177 Obturator nerve 240, 241 Obturator vein 242 Omovertebral bar 10 Osborne’s canal 95, 126

Quadrate ligament 132 Quadrate tubercle 243 Quadratus femoris 248 Quadriceps angle 220 Quervain’s disease 142

R Radial club hand 18

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Radical mastectomy 39, 48 Radioulnar loop 118 Rectus femoris 219 Regimental badge anaesthesia test 63 Retro-pubic space 179 Rider’s bone 224 Runner’s knee 277

S Sacro-spinous ligaments 249 Saphena varix 211 Saphenous vein 284 Sartorius 219 Saturday night paralysis 98 Scaphoid 21 Scarpa’s triangle 226 Sciatic foramina 249 Sciatic nerve 249 Semi-lunar cartilages 277 Sesamoid bone 157 Sever’s disease 328 Shenton’s line 259 Sherman’s perforator 211 Shoe-maker’s line 180 Shoulder joint 77 abduction at the shoulder 82 bursae around the joint 80 dislocation on examination 83 ligaments 79 surgical treatment 84 synovial membrane 80 Skeleton of the foot 193 Smith’s fracture 18 Sole of foot deep fascia 314 superficial fascia 314 Spring ligament 338 Springle shoulder 10 Stenosing tenovaginitis 142 Sternoclavicular joint 75 Sternocostal head 38 Sulcus calcanei 197 Superfcial palmar arch 158 Superficial veins 146 Superior extensor retinaculum 289 Superior limb 1, 27, 31 embryological background 28 pectoral region 31 cutaneous nerves 34 flexuer line 34 muscles of the anterior wall of the axilla 37 nerve supply 42 pectoralis minimus 40 pectoralis minor 40 relations 41 skin and cutaneous vessels and nerves 33

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Kadasne’s Textbook of Anatomy (Clinically Oriented)

sub-clavius muscle 42 superficial fascia 34 surface landmarks 31 Superior limb 30 Superior radioulnar joint 132 Supinator crest 19 Supracondylar fracture 15 Supraglenoid 6 Suspensory ligaments of Cooper 44 Sustetaculum tali 197 Symphysis pubis 177 Synovial membrane 255, 278 Synovial sheath 163, 288, 349 for tendon 287

T Tail of Spence 43, 48 Tailor muscle 219 Talar paradox 338 Talus 195 Tardy ulnar palsy 128 Tarsal bones 193 Tendon of biceps 87 Tennis elbow 139, 140 Tensor fascia latae 223 The arm 85 anastomosis around the elbow 91 compartments 86 extensor compartment 96 general description 85 musculocutaneous nerve 94 triceps muscle 96 Thenar eminence 148, 155 Thenar space 165 Thigh bones back 261

biceps femoris 262 cutaneous nerves 261 muscles of flexor compartment 261 nerve of thigh 261 popliteal artery 264 popliteal fossa 263 semi-membranosus 262 semitendinosus 262 front 204, 218 compartments 205 cutaneous nerves 209 cutaneous nerves and vessels 206 general account 205 long saphenous vein 207 lymph nodes 207 perforating veins 210 surface land-marks 204 tributaries 210 gluteal region 243 medial side 236 valves 211 deep fascia of thigh 214 femoral canal 216 femoral sheath 216 inguinal ligament 215 pectineal part of inguinal ligament 216 Thrombosis (clotting of blood) 58 Tibia 189 capsular attachment 191 ossification 191 shaft 191 upper end 190 Tibialis anterior 287 Traction 5 Trapezium 22 Trapezoid 23

Trendelenburg test 211 Triangle of auscultation 72 Triangular space 74 Tubercle 6 of Montgomery 43 Tuberculosis of the hip 259 Tumour of fatty tissue 66

U Ulnar bursa 163 Ulnar nerve 95, 126, 161 Ulnar paradox 129, 162 Unhappy triad’s of knee 277

V Varicose veins 211, 212 Vastus intermedius 222 Vastus lateralis 220 Vastus medialis 221 Venae comitantes 293, 306 Volkman’s canals 6

W Wasting and quadriceps drill 220 William Turner’s slip 317 Wrist and the hand 148 skin of the hand 150 surface landmarks 148 Wrist drop 99 Wrist joint 168 articular disc 169 attachment of capsule 168 blood supply 169 ligaments 168 surgical approaches 170