Basics in Hip and Knee Arthroplasty [1 ed.] 9788131240052, 9788131240069

Table of contents :
Cover
Title
Copyright
Dedicated to
FOREWORD
PREFACE
ACKNOWLEDGEMENT
CONTRIBUTORS
CONTENTS
Planning of the Hip and Knee Arthroplasty
Total Joint Arthroplasty: Medical Parameters
WHAT SHOULD I DO ABOUT CARDIOVASCULAR AND PULMONARY COMPLICATIONS?
HOW TO DEAL WITH FEVER AFTER SURGERY?
HOW TO PREVENT DEEP VEIN THROMBOSIS IN MY PATIENT?
DOES MY PATIENT NEED ICU?
WHICH ANTIBIOTICS, WHEN AND FOR HOW LONG?
WHEN SHOULD I TAKE OUT THE URINARY CATHETER?
HOW TO MANAGE POSTOP COGNITIVE CHANGES?
HOW SHOULD I ACHIEVE GLYCEMIC CONTROL PERIOPERATIVELY?
HOW TO PREVENT ADDISONIAN CRISIS IN PATIENTS ON LONGTERM STEROIDS?
DOES THE PERIOPERATIVE PROTOCOL DIFFER FOR BILATERAL SINGLE STAGE?
WHEN TO DISCONTINUE AND RESUME CLOPIDOGREL IN PATIENTS WITH CARDIAC STENTS?
WHEN SHOULD I REMOVE THE EPIDURAL CATHETER IN A PATIENT ON LMWH?
HOW DO OBESITY AND METABOLIC SYNDROME AFFECT MY RESULTS?
TAKE HOME MESSAGE
Blood Transfusion Reduction in Total Joint Arthroplasty
INTRODUCTION
PREOPERATIVE STRATEGIES
INTRAOPERATIVE STRATEGIES
POSTOPERATIVE STRATEGIES
CONCLUSION
Role of Drains in Primary Total Joint Arthroplasty
INTRODUCTION
POSTOPERATIVE DRAINS IN TOTAL KNEE ARTHROPLASTY
USING DRAINS IN TOTAL HIP ARTHROPLASTY
CONCLUSION
Prevention of Periprosthetic Joint Infection
INTRODUCTION
DEFINITION OF PJI
CLASSIFICATION OF PJI
PREVENTION OF PJI
PREOPERATIVE
INTRAOPERATIVE
POSTOPERATIVE
CONCLUSION
Pain Management in Arthroplasty
INTRODUCTION
WHAT IS PAIN?
PAIN PATHWAY
FACTORS AFFECTING TRANSMISSION AND PERCEPTION OF PAIN
MODALITIES OF TREATMENT
PAIN IN ARTHROPLASTY AND ITS MULTIMODAL MANAGEMENT
FUTURE DIRECTIONS
Total Hip Arthroplasty: Techniques and Pearls
Radiological Planning of Total Hip Arthroplasty
INTRODUCTION
RADIOGRAPHIC TECHNIQUE
RADIOGRAPHIC TEMPLATING IN THA
SUMMARY
Choosing Implant for Total Hip Arthroplasty
INTRODUCTION
THE ACETABULAR CUP
THE FEMORAL STEM
BEARING SURFACES
PATIENTRELATED FACTORS
SURGEONRELATED FACTORS
SUMMARY
Tips and Pearls in Total Hip Arthroplasty
INTRODUCTION
AUTHOR’S PREFERRED METHOD
POSITIONING OF THE PATIENT
INCISION AND EXPOSURE
PREPARATION OF THE ACETABULUM AND POSITIONING OF THE ACETABULAR COMPONENT
PREPARATION OF THE FEMUR AND POSITIONING OF THE FEMORAL COMPONENT
REDUCTION AND CLOSURE
ENSURING LIMB LENGTH EQUALIZATION AND STABILITY
SUMMARY
The Cemented Hip: How to Get it Right
INTRODUCTION
TEMPLATING
SURGICAL TECHNIQUE
EXPOSURE OF THE ACETABULUM
IDENTIFICATION OF THE MEDIAL WALL OF PELVIS
REAMING THE ACETABULUM
ANCHORING HOLES
BONE BED PREPARATION
SURGICAL TECHNIQUE
Uncemented Total Hip Arthroplasty
INTRODUCTION
ACETABULAR COMPONENT
DESIGN CONSIDERATIONS
SURFACE AND COATINGS
INDICATIONS AND CONTRAINDICATIONS
TECHNIQUE
FEMORAL COMPONENT
SURFACE AND COATINGS
STEM GEOMETRY
TECHNIQUE
POSTOPERATIVE PROTOCOL
Total Hip Arthroplasty in Peritrochanteric Fractures
FRESH FRACTURES
APPROACH
FAILED FRACTURES WITH IMPLANT IN SITU
Fused Hips in Ankylosing Spondylitis
INTRODUCTION
MEDICAL DISEASE AND MANAGEMENT
ALTERED ANATOMY
CLINICAL EXAMINATION
PREANAESTHETIC ASSESSMENTS
POSITIONING OF THE PATIENT
THE APPROACH
SURGICAL PROCEDURE
NECKCUT
POSTERIOR EXPOSURE
FEMORAL REAMING AND STEM PLACEMENT
ACETABULAR CUP PLACEMENT
CONCLUSIONS
Total Hip Arthroplasty in Protrusio Acetabulae
SURGICAL TECHNIQUE
COMPONENT CHOICE
SUMMARY
Total Knee Arthroplasty: Techniques and Pearls
Radiological Planning in Primary Total Knee Arthroplasty
INTRODUCTION
Radiological Planning in Primary Total Knee Arthroplasty
INTRODUCTION
HOW TO PLAN
EXTRAARTICULAR DEFORMITIES
CT vs. XRAY
EXTRAARTICULAR DEFORMITIES
CT vs. XRAY
ROLE OF MRI
ANALOG vs. DIGITAL TEMPLATING
SPECIAL RADIOGRAPHIC VIEWS BEFORE UNICOMPARTMENTAL KNEE ARTHROPLASTY
ROLE OF MRI
ANALOG vs. DIGITAL TEMPLATING
SPECIAL RADIOGRAPHIC VIEWS BEFORE UNICOMPARTMENTAL KNEE ARTHROPLASTY
PLANNING FOR PATIENTSPECIFIC INSTRUMENTS AND IMPLANTS
Selection of the Implant in Total Knee Arthroplasty
POSTERIOR CRUCIATE RETAINING TOTAL KNEE REPLACEMENT FIG. 15.1
POSTERIOR STABILIZING TOTAL KNEE REPLACEMENT FIG. 15.2
MOBILEBEARING OR FIXEDBEARING FIG. 15.3
ALL POLY OR METAL BACK TIBIAL COMPONENTS FIG. 15.4
CONDYLAR CONSTRAINED KNEE FIG. 15.5
ROTATING HINGED KNEE PROSTHESES FIG. 15.7
SPECIAL SITUATIONS
SUMMARY AND CONCLUSION
Tips and Pearls: Tourniquets and Position in Total Knee Arthroplasty
TOURNIQUETS
POSITION
Tips and Pearls: Exposure and Retractors in Total Knee Arthroplasty
EXPOSURE
Tips and Pearls: Saw Technique in Total Knee Arthroplasty
BLADE SHAPE
Principles: Alignment and Balancing
INTRODUCTION
BASIC PRINCIPLES OF ALIGNMENT
PRINCIPLES OF BALANCING
SUMMARY
Cementation Techniques in Total Knee Arthroplasty
INTRODUCTION
BONE CEMENT COMPOSITION
OPERATIVE TECHNIQUE
SUMMARY
Patellar Resurfacing in Total Knee Arthroplasty
INTRODUCTION
LITERATURE REVIEW
SURGICAL TECHNIQUE
SUMMARY
Unicondylar Knee Arthroplasty
HISTORY
PRINCIPLE
INDICATIONS
POST OP REHABILITATION
RESULTS
CONCLUSIONS
Technique: Fixed Bearing Total Knee Arthroplasty
INTRODUCTION
POSTERIOR STABILIZED FIXED BEARING TOTAL KNEE ARTHROPLASTY
Mobile-Bearing Total Knee Arthroplasty: Technique and Clinical Results*
INTRODUCTION
SURGICAL TECHNIQUE
CLINICAL OUTCOMES
SUMMARY
Management of Tibial Bone Defects
INTRODUCTION
CLASSIFICATION
MANAGEMENT OPTIONS
OPTIONS TO FILL THE DEFECT
RESULTS
ADDITIONAL SUPPORT FOR CEMENT, BONE GRAFT OR AUGMENT
CONCLUSION
Total Knee Arthroplasty in Fixed Flexion Deformity
PREOPERATIVE EVALUATION
SURGICAL STEPS
POSTOPERATIVE MANAGEMENT
SUMMARY
Total Knee Arthroplasty in Stiff Knee
TOTAL KNEE REPLACEMENT IN STIFF KNEES
PREOPERATIVE ASSESSMENT
SURGERY AND IMPLANT SELECTION
REHABILITATION
COMPLICATIONS
REVIEW OF LITERATURE
Total Knee Arthroplasty in Post High Tibial Osteotomy
INTRODUCTION
PREOPERATIVE ASSESSMENT
TECHNIQUE
RESULTS
Recent Advances in the Hip and Knee Arthroplasty
Trabecular Metal
TANTALUM
MANUFACTURING PROCESS
SALIENT FEATURES OF TRABECULAR METAL
CLINICAL APPLICATIONS
RATIONALE OF TM RECONSTRUCTIONS
TIPS AND TRICKS IN THE USE OF TM DEVICES
ACETABULAR DEFECTS AND USE OF TM SHELLS AND AUGMENTS
USE OF TM IN KNEE ARTHROPLASTY
Recent Advances in Short Stem Designs
INTRODUCTION
RATIONALE
CLASSIFICATION
BIOMECHANICAL ADVANTAGES
BONE CONSERVATION
NECK STABILIZING STEMS
PART OF THE NECK STABILIZED FAMILY PLUGS
METAPHYSEAL STABILIZING STEMS
CONCLUSION
CONTROVERSY
Hi-Flex Knee Design
PATIENT FACTORS
SURGICAL TECHNIQUE
HIGHFLEX KNEE DESIGN CHANGES FIG. 31.1
PRESENT CLINICAL STATUS TABLE 31.1
CONCLUSION
How do I Plan My Trolley: Special Instruments
My Trolley for Total Hip Arthroplasty
PRIMARY HIP REPLACEMENT
SPECIAL SITUATIONS
My Trolley for Total Knee Arthroplasty
INDEX

Citation preview

Basics in

HIP AND KNEE ARTHROPLASTY

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Basics in

HIP AND KNEE ARTHROPLASTY Editor

Shrinand V. Vaidya MS, FACS (USA) Professor Of Orthopaedic Surgery King Edward VII Memorial Hospital Mumbai, India Key Contributors

Thomas P. Sculco MD Douglas A. Dennis MD Javad Parvizi MD Foreword By

Thomas P. Sculco MD

Reed Elsevier India Pvt. Ltd. Registered Office: 305, Rohit House, 3 Tolstoy Marg, New Delhi-110 001 Corporate Office: 14th Floor, Building No. 10B, DLF Cyber City, Phase II, Gurgaon-122 002, Haryana, India

Basics in Hip and Knee Arthroplasty, 1e, Shrinand V. Vaidya Copyright © 2015, by Reed Elsevier India Pvt. Ltd. All rights reserved. ISBN: 978-81-312-4005-2 e-Book ISBN: 978-81-312-4006-9 No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein).

Notice Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. With respect to any drug or pharmaceutical products identified, readers are advised to check the most current information provided (i) on procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose or formula, the method and duration of administration, and contraindications. It is the responsibility of practitioners, relying on their own experience and knowledge of their patients, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions. To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of product liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. Although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer. Please consult full prescribing information before issuing prescription for any product mentioned in this publication. Content Strategist: Dr. Renu Rawat Sr Project Manager—Education Solutions: Shabina Nasim Content Development Specialist: Shravan Kumar Cover Designer: Milind Majgaonkar Printed in India by ………

Dedicated to The enlightening lights in my life Shri Sadguru Purna Brahma Bhau Pandurang Swami Maharaj and Sadguru Manumama My teacher CS Ranawat MD Hospital for Special Surgery New York, USA Loving parents Dr. Vishwanath and Kumud My better half Nisha Wonderful children Anand and Dr. Chintan

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FOREWORD Total joint arthroplasty is truly one of the great surgical advances of the twentieth century. It has led to relief of pain and improved mobility in countless sufferers of arthritis throughout the world. The surgical techniques and improvements in implant design have led to outstanding outcomes in the vast majority of patients undergoing these procedures. In many hospital centers throughout the world, joint replacement surgery has become a common procedure, and protocols and clinical pathways continue to evolve in the management of these patients undergoing joint replacement. Dr. Shrinand Vaidya has provided a comprehensive text with an international roster of experts in joint replacement to cover the basic and more complex techniques in proper surgical and perioperative management of patients undergoing joint replacement.The chapters are beautifully illustrated and accompanying videos help to instruct the reader in the latest in surgical techniques. The authors have provided a step wise approach to both total hip and knee arthroplasty, beginning with preoperative planning to the postoperative management. The expert quality of the authors gives the reader the most evidence based and experienced surgeons’ recommendation for the approach to the arthritic patient undergoing joint replacement. The chapters are comprehensive, clearly written and provide both the experienced and beginning arthroplasty surgeon with outstanding advice in preparing for and executing a well done arthroplasty. This text will instruct neophytes but also help refresh those who do joint replacement less commonly in their practice. Ways to prevent infection and manage blood replacement are also addressed in the text. The international expert authors also provide a broad spectrum of experience in such topics as unicompartmental knee replacement, the high flex designs and cemented and cement-less implants, how to select the proper patient for their use and achieve excellent outcomes. The book emphasizes the surgical techniques needed to achieve outstanding results and this is key to our patients that the procedure be well-performed and complications avoided. I congratulate Dr. Vaidya on a superb accomplishment in providing a much needed and comprehensive book. It deals with the basics in implant technique and planning in both the hip and knee (often these are

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fragmented and not available in a single text). This book will become a reference text that is not on the shelf but on the desk of every surgeon that cares for and operates on the arthritic patient treated with joint replacement. It will be reviewed regularly and provide great assistance to all doing joint replacement and will lead to significant improvement in our surgical outcomes. Thomas P. Sculco MD Surgeon-in-Chief, Emeritus Hospital for Special Surgery New York, N.Y., USA

PREFACE The demand for hip and knee replacement surgery is ever increasing, especially in Asia. The challenges are enormous as most of the presentations are delayed because of lack of awareness. Although lot has been done by collaborative efforts of arthroplasty societies, in liaison with companies, there are many finer aspects that brochures and workshops won’t be able to explain. Also, not everyone is fortunate enough to be fellowship trained under the able guidance of a stalwart. This book is intended to be the extension of “scribbled notes” of a fellow, after a robust hip and knee adult reconstruction fellowship programme at the end of the year. It rather concentrates on planning and executional aspects, of choosing a right implant, keeping key instruments on the trolley and tips and pearls to avoid major mishaps for beginners. Our intention is to facilitate beginners to read it the “night before” and get essence of do’s and don’t. We are fortunate to have Thomas Sculco, Director and Chief Surgeon, Hospital for Special Surgery, Cornell University, New York as a contributor who is kind enough to have consented for the Foreword for this book. His contribution on Planning and Selection of Implant will immensely help budding arthroplasty surgeons to plan their surgeries. Javad Parvizi, Vice-Chair at Rothman’s Orthopaedics, Thomas Jefferson University, Philadelphia has a major contribution towards infection prevention protocol, and is kind enough to consent to contribute synopsis of his “consensus” meeting held in 2013. This chapter will go long way in preventing prosthetic joint infection, which otherwise can play havoc with patients and healthcare providers alike. Douglas Dennis, Assistant Clinical Professor, Dept. of Orthopaedics, University of Colorado School of Medicine is kind enough to contribute major chapters pertaining to TKA. Doug’s chapters with vivid photographs, of step-by-step cementing in TKA, patellar resurfacing, have potential to refine every reader to a level of finesse, like the Master himself! Many stalwarts who founded “Indian Society of Hip and Knee Surgeons” have let their life-time secrets out and, but for their contribution, this book was unthinkable. Friends, I hope this book will be handy

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for all the budding and occasional hip and knee replacement surgeons. It is specifically designed for upcoming arthroplasty surgeons, and hence avoids debates, review of literature, etc. It rather concentrates on practical tips, quick decision making flow charts, and plan to execute your operation better. Experts in their respective fields have contributed, and I hope the end product will be on every beginner’s desk. A unique and practical chapter is added at the end, “My Trolley”, which I am sure will be of great help to team members. It contains illustrations of key instruments; when used, can make surgical task look simpler, and minus stress. I hope our younger colleagues would find this book useful in helping them to make the art of hip and knee arthroplasty an enjoyable experience.

ACKNOWLEDGEMENT All the founders of Indian Society of Hip & Knee Surgeons (ISHKS), who have been pillars of strength. All the Faculty Members and Residents of Department of Orthopaedics, King Edward VII Memorial Hospital, Mumbai, India, especially Kaushik Dash and Chintan Patel, who have lion’s share in making this book possible. Everyone at Elsevier, who put up with me so patiently...

Shrinand V. Vaidya MS, FACS (USA) Professor of Orthopaedic Surgery & Chief of the Unit Joint Replacement Surgery King Edward VII Memorial Hospital Mumbai, India Past President, Indian Society of Hip & Knee Surgeons E-mail: [email protected]

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CONTRIBUTORS

Arvind Arora MS Assistant Professor King Edward VII Memorial Hospital Mumbai, India

HP Bhalodiya MS Professor B. J. Medical College, Ahmedabad Gujarat, India

L Bharath MS Consultant in Joint Replacement Shalby Hospitals, Ahmedabad Gujarat, India

Pradeep Bhosale MS Professor King Edward VII Memorial Hospital Mumbai, India

Vijay C. Bose MS Joint Director, Asian Joint Reconstruction Institute SRM Institutes for Medical Science Chennai, India

Vivek Dahiya DNB Consultant, Knee Division Medanta Bone and Joint Institute, Medanta - The Medicity Gurgaon, Haryana, India

Brian K. Daines MD Colorado Joint Replacement Colorado, USA

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Kumar Kaushik Dash MS, FCPS, DNB Assistant Professor Grant Medical College and Sir JJ Group of Hospitals Mumbai, India Ivan De Martino MD Fellow Adult Reconstruction and Joint Replacement Service Department of Orthopaedic Surgery Hospital for Special Surgery, New York, USA Douglas A. Dennis MD Colorado Joint Replacement, Colorado Adjunct Professor, Dept. of Biomedical Engineering, University of Tennessee Assistant Clinical Professor, Dept. of Orthopaedics University of Colorado School of Medicine Adjunct Professor of Bioengineering, University of Denver Colorado, USA Mohan Desai MS Professor of Orthopaedic Surgery King Edward VII Memorial Hospital Mumbai, India

Justin Duke MD Colorado Joint Replacement Colorado, USA Himanshu Gupta MS Consultant, Knee Division Medanta Bone and Joint Institute, Medanta - The Medicity Gurgaon, Haryana, India Amish S. Kshatriya MS Consultant in Joint Replacement Shalby Hospitals, Ahmedabad Gujarat, India Vipan Kumar MS Assistant Professor Maharaja Agrasen Medical College Agroha, Hisar, Haryana, India

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Rajesh Maniar MS, MCh Consultant Arthroplasty Surgeon Co-ordinator, Department of Orthopaedics, Lilavati Hospital & Research Center, Breach Candy Hospital, Mumbai, India SKS Marya MS DNB, MCh (UK), FRCS (England), FICS Chairman & Chief Surgeon Max Super Specialty Hospital New Delhi, India Shubhranshu S. Mohanty MS, FRCS, FICS, FACS (USA) Professor (Additional), Orthopaedic Surgery King Edward VII Memorial Hospital Mumbai, India Javahir A. Pachore MS, MCh Director of Hip Surgery, Consultant in Joint Replacement Shalby Hospitals, Ahmedabad Gujarat, India Atul Panghate MS Associate Professor King Edward VII Memorial Hospital Mumbai, India Javad Parvizi MD, FRCS James Edwards Professor of Orthopaedic Surgery Sidney Kimmel Medical College Vice Chairman of Research, Rothman Institute at Thomas Jefferson University Hospital Philadelphia, USA Prabodhan Pravin Potdar MS Assistant Professor King Edward VII Memorial Hospital Mumbai, India Lazaros A. Poultsides MD, MSc Fellow Adult Reconstruction and Joint Replacement Service Department of Orthopaedic Surgery Hospital for Special Surgery, New York, USA

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Ashok Kumar PS MS Consultant, Asian Joint Reconstruction Institute SRM Institutes for Medical Science Chennai, India Ashok Rajgopal MS, MCh, FRCS Chairman and Head of Department Medanta Bone and Joint Institute, Medanta - The Medicity Gurgaon, Haryana, India Sumeet Rastogi MS Consultant Dept. of Orthopaedics and Joint Replacement Max Super Specialty Hospital New Delhi, India Peter K. Sculco MD Resident Adult Reconstruction and Joint Replacement Service Department of Orthopaedic Surgery Hospital for Special Surgery, New York, USA Thomas P. Sculco MD Professor of Orthopaedic Surgery Weill Cornell Medical College Adult Reconstruction and Joint Replacement Service Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, USA Ashish Seth MS Consultant in Joint Replacement Shalby Hospitals, Ahmedabad Gujarat, India Vikram Shah MS Chairman & Managing Director Shalby Hospitals, Ahmedabad Gujarat, India Kalpesh Shah MS Consultant in Joint Replacement Shalby Hospitals, Ahmedabad Gujarat, India

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Alisina Shahi MD Rothman Institute Thomas Jefferson University Philadelphia, USA Chandeep Singh MS Consultant Max Super Specialty Hospital New Delhi, India Somesh P. Singh MS Associate Professor, Department of Orthopaedics GMERS Medical College & Sola Civil Hospital Ahmedabad, Gujarat, India Pichai Suryanarayan MS Consultant Orthopaedic Surgeon Asian Joint Reconstruction Institute SRM Institutes for Medical Science, Chennai, India

CJ Thakkar MS Lilavati and Breach Candy Hospitals Mumbai, India Georgios K. Triantafyllopoulos MD Fellow Adult Reconstruction and Joint Replacement Service Department of Orthopaedic Surgery Hospital for Special Surgery, New York, USA Shrinand V. Vaidya MS, FACS (USA) Professor of Orthopaedic Surgery & Chief of the Unit Joint Replacement Surgery King Edward VII Memorial Hospital Mumbai, India Attique Vasdev MS Associate Director, Knee Division Medanta Bone and Joint Institute, Medanta - The Medicity Gurgaon, Haryana, India

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Hemant Wakankar MS, MCh, FRCS Head, Department of Joint Reconstruction and Replacement Deenanath Mangeshkar Hospital Pune, India Subramanyam Yadlapalli MS, MCh Fellow, Asian Joint Reconstruction Institute SRM Institutes for Medical Science Chennai, India

Charlie C. Yang MD Colorado Joint Replacement Denver, Colorado, USA

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CONTENTS Foreword Preface Contributors

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ix xi

Part 1 Planning of the Hip and Knee Arthroplasty 1. Total Joint Arthroplasty: Medical Parameters

3

Mohan Desai, MS

2. Blood Transfusion Reduction in Total Joint Arthroplasty

15

Javad Parvizi, MD, FRCS

3. Role of Drains in Primary Total Joint Arthroplasty

29

Javad Parvizi, MD, FRCS

4. Prevention of Periprosthetic Joint Infection

37

Javad Parvizi, MD, FRCS

5. Pain Management in Arthroplasty

59

Shubhranshu Mohanty, MS, FRCS, FICS, FACS

Part 2 Total Hip Arthroplasty: Techniques and Pearls 6. Radiological Planning of Total Hip Arthroplasty Radiological Planning in Total Hip Arthroplasty

75 77

Thomas P. Sculco, MD

7. Choosing Implant for Total Hip Arthroplasty

87

Thomas P. Sculco, MD

8. Tips and Pearls in Total Hip Arthroplasty Tips and Pearls in Total Hip Arthroplasty

100 101

Thomas P. Sculco, MD

9. The Cemented Hip: How to Get it Right

118

Atul Panghate, MS

10. Uncemented Total Hip Arthroplasty

138

Vijay C. Bose, MS

11. Total Hip Arthroplasty in Peritrochanteric Fractures

149

CJ Thakkar, MS

12. Fused Hips in Ankylosing Spondylitis

156

Pradeep Bhosle, MS

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13. Total Hip Arthroplasty in Protrusio Acetabulae

174

Javahir Pachore, MCh Orth

Part 3 Total Knee Arthroplasty: Techniques and Pearls 14. Radiological Planning in Primary Total Knee Arthroplasty

183

Mohan Desai, MS

15. Selection of the Implant in Total Knee Arthroplasty

190

HP Bhalodiya, MS

16. Tips and Pearls: Tourniquets and Position in Total Knee Arthroplasty

204

Shrinand V. Vaidya, MS, FACS

17. Tips and Pearls: Exposure and Retractors in Total Knee Arthroplasty Total Knee Arthroplasty in Stiff Knee

211 217

Shrinand V. Vaidya, MS, FACS

18. Tips and Pearls: Saw Technique in Total Knee Arthroplasty

222

Shrinand V. Vaidya, MS, FACS

19. Principles: Alignment and Balancing

230

Hemant Wakankar, MS, DNB, FRCS, MCh Orth, FRCS Orth

20. Cementation Techniques in Total Knee Arthroplasty Cementing in Total Knee Arthroplasty

240 242

Douglas A. Dennis, MD

21. Patellar Resurfacing in Total Knee Arthroplasty Patellar Resurfacing in Total Knee Arthroplasty

249 251

Douglas A. Dennis, MD

22. Unicondylar Knee Arthroplasty

257

Ashok Rajgopal, MS, MCh, FRCS

23. Technique: Fixed Bearing Total Knee Arthroplasty

269

Hemant Wakankar, MS, DNB, FRCS, MCh Orth, FRCS Orth

24. Mobile-Bearing Total Knee Arthroplasty: Technique and Clinical Results Rotating Platform Total Knee Arthroplasty Douglas A. Dennis, MD

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280 282

25. Management of Tibial Bone Defects

287

Rajesh N. Maniar, MS, M Ch

26. Total Knee Arthroplasty in Fixed Flexion Deformity

302

SKS Marya, MS, DNB, MCh, FRCS, FICS

27. Total Knee Arthroplasty in Stiff Knee

308

Ashok Rajgopal, MS, MCh, FRCS

28. Total Knee Arthroplasty in Post High Tibial Osteotomy

315

Vikram Shah, MS

Part 4

Recent Advances in the Hip and Knee Arthroplasty

29. Trabecular Metal

327

Pichai Suryanarayan, MS

30. Recent Advances in Short Stem Designs

341

SKS Marya, MS, MCh Ortho

31. Hi-Flex Knee Design

350

HP Bhalodiya, MS

Part 5 How do I Plan My Trolley: Special Instruments 32. My Trolley for Total Hip Arthroplasty

367

Javahir Pachore, MCh Ortho

33. My Trolley for Total Knee Arthroplasty

384

Vikram I. Shah, MS

Index

395

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PART 1

Planning of the Hip and Knee Arthroplasty Chapters 1. 2. 3. 4. 5.

Total Joint Arthroplasty: Medical Parameters Blood Transfusion Reduction in Total Joint Arthroplasty Role of Drains in Primary Total Joint Arthroplasty Prevention of Periprosthetic Joint Infection Pain Management in Arthroplasty

3 15 29 37 59

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CHAPTER 1

Total Joint Arthroplasty: Medical Parameters Mohan Desai, Kumar Kaushik Dash Nearly 90% of total deaths occurring within 60 days after total hip arthroplasty (THA) result from medical complications such as ischaemic heart disease and thromboembolism.1 The four major medical complications associated with poor outcomes are cardiopulmonary problems, thromboembolism, infection and delirium. With improved life expectancy and general health care system, more and more elderly patients will undergo total joint arthroplasties. Their age and pre-existing comorbid conditions will pose a difficult challenge during and after surgery. It is crucial, therefore, for the young surgeons to understand the role of a multidisciplinary approach and optimal care in fighting that battle. This chapter aims at introducing a beginner in arthroplasty to the common medical problems and dilemmas faced by a surgeon in the perioperative period. We will try to address common questions, and evoke an interest in the reader to further read clinical evidence on such questions.

WHAT SHOULD I DO ABOUT CARDIOVASCULAR AND PULMONARY COMPLICATIONS? Prevention remains the best way to avoid dire consequences of cardiovascular complications in arthroplasty surgeries. There have been multiple strategies to anticipate the risk based on preoperative clinical predictors and age of the patient. As per the American College of Cardiology/American Heart Association (ACC/AHA) guidelines, the patient is stratified into major, intermediate or minor risk. Surgery is postponed for patient with high-risk clinical predictors. In patients with low risk, surgery can be done without any delay. For patients with intermediate risk clinical predictors, functional status is evaluated. When functional capacity exceeds four metabolic equivalents (>4 METs), the patient is allowed to proceed with the surgery. The functional capacity of the patient is expressed in terms of METs. One MET is the resting energy expenditure, i.e., the amount of oxygen consumed by a person when he is

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Part 1 | Planning of the Hip and Knee Arthroplasty

at rest. It is approximately 3.5 mL of oxygen per kg per minute. Functional capacity is poor when the amount of oxygen consumed is less than 4 METs. As far as detection of perioperative myocardial events is concerned, it is crucial to remember that the patient may develop silent ischaemic events without any symptoms. Hence, in addition to keeping an eye out for clinical symptoms, the surgeon should also monitor the patient by serial ECGs, cardiac-specific biomarkers, comparative echocardiography and/or nuclear studies.1 Perioperative myocardial infarction (MI) can occur either from acute thrombotic occlusion or demand ischaemia (more likely). Early intervention is crucial, and the result of primary angioplasty is better than thrombolysis in postoperative ST elevation MI. In addition to infarction and hypoxaemia, intraoperative fluid overload can result in heart failure. Pulmonary oedema is common around second postoperative day due to fluid redistribution from extravascular to intravascular space. At any rate, the surgeon should be vigilant towards the development of cardiovascular complications such as myocardial ischaemia, arrhythmia and congestive heart failure; and urgent consultation with a cardiologist should be sought. Pneumonia, chronic obstructive pulmonary disease (COPD) exacerbation, bronchospasm, atelectasis and respiratory failure are the described postoperative pulmonary complications that cause significant morbidity and mortality after total joint arthroplasties. Fortunately, these are relatively uncommon because the surgical sites are not in the vicinity of diaphragm (the single most risk factor for development of pulmonary complications). There are certain modifiable risk factors, including surgeries lasting longer than 3 h, general anaesthesia instead of spinal anaesthesia, current tobacco use and use of intraoperative pancuronium.These risk factors should be targeted when attempting to prevent postoperative complications. Age more than 70, COPD and obstructive sleep apnea are amongst the nonmodifiable risk factors, and in such patients, a more detailed preoperative workup and perioperative care are appropriate. Incentive spirometry reduces incidence of complications, and the effect is maximum when it is started before surgery. Using epidural analgesia as a method of postoperative pain control and reducing the use of sedatives and narcotics are also helpful.

HOW TO DEAL WITH FEVER AFTER SURGERY? First of all, you must remember that elevation of temperature after arthroplasty can be a normal process as a part of body’s natural response to surgery. It

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has been shown that patient’s blood contains elevated amount of cytokines (IL-1ơ, IL-6 and TNF Ơ) after total joint arthroplasties. Patients react to these cytokines in a varied manner, and some patients may develop a rise in temperature. However, fever can also occur due to infection at surgical site, venous thromboembolism, pneumonia, atelectasis or urinary tract infection. A recent study recommends against doing blood culture in such patients because it is not helpful in management decisions, and it adds to health care cost and delays discharge.2 In such a scenario, the clinical acumen of the surgeon becomes more important in taking the call regarding when to investigate further. Certain parameters have been proven to predict higher positive fever evaluation, and these should be remembered as red flags – fever developing after third postoperative day, fever lasting for multiple days and a temperature higher than 39°C.3 Following these criteria, and correlating with physical findings, one can decide when and how much to investigate for fever in the postoperative period. C-reactive protein (CRP) has a bimodal fall pattern after surgery, which normalizes by second to third week. The CRP value on Day 4 is 80% reduction from the value on Postoperative Day 1. The falling trend can reassure the surgeon that it is not infective. Occasionally, procalcitonin values in early postoperative period can be helpful to rule out infection. However, these are not routinely performed due to high cost. Fever may not accompany the infection; more often, copious persisting discharge is usually suggestive of infection. Warning Box If your patient has fever after surgery, don’t panic! A blood culture is often not necessary. Remember the red flags – Onset after Postoperative Day 3, Temperature > 39°C, Duration of multiple days. Do serial CRP and check clinical findings at incision site.

HOW TO PREVENT DEEP VEIN THROMBOSIS IN MY PATIENT? The field of deep vein thrombosis (DVT) prophylaxis has been a confusing and controversial one since the past many years. The guidelines by the American College of Chest Physicians (ACCP) and the American Association of Orthopedic Surgeons (AAOS) were in direct conflict with each other till 2012. However, with recent revision of ACCP guidelines (ninth revision, 2012), the major recommendations are largely clear. The focus is now shifted to clinically symptomatic thromboembolic events

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instead of asymptomatic venography detected episodes. The new guidelines recommend that all patients should receive prophylaxis (pharmacologic agent or intermittent pneumatic compression device, IPCD) for at least 10–14 days, which could be extended up to 35 days. The pharmacologic agents include low molecular weight heparins (LMWH), fondaparinux, apixaban dabigatran, rivaroxaban, aspirin and vitamin K antagonist. Irrespective of the use of IPCD, the use of LMWH is recommended over other pharmacologic agents. LMWH should be started either 12 h before or after surgery instead of within 4 h of surgery. Dual prophylaxis (pharmacologic plus IPCD) and extending duration to 35 days are recommended in cases of major orthopaedic surgeries. In patients who are at high risk of bleeding, instead of using a pharmacologic agent, an IPCD or no prophylaxis should be used. When IPCD use is not possible (uncooperative patient/patient declines), apixaban or dabigatran should be used. There is no need to do ultrasound screening in asymptomatic patients before hospital discharge. The reader is directed to study the guidelines in detail4 and commentaries5 on them, if interested. Warning Box Multimodal strategy is the best approach to tackle DVT prophylaxis. It would also save the surgeon medicolegally. Regional anaesthesia, foot pump/TED stockinette, early mobilization with or without chemical prophylaxis can be helpful.

DOES MY PATIENT NEED ICU? Unforeseen admission to ICU after joint arthroplasty can be a financial and logistical problem for the health care provider in addition to being an emotional burden for the family. Although perioperative and postoperative monitoring can sometimes detect the need, it is best to predict future need for ICU from preoperative and intraoperative factors. A study evaluating 22,343 arthroplasties has identified the risk factors as smoking, low haemoglobin level, higher BMI, older age (>65), higher preoperative C reactive protein, general anaesthesia, allogenic transfusion (3.5 times higher risk) and cemented arthroplasty.6 Recently described Penn Arthroplasty Risk Score7 includes five independent predictors, COPD, coronary artery disease, congestive heart failure (1 point each), estimated blood loss >1000 mL and intraoperative vasopressors (2 points each). The total score can vary from 0 to 7, with probability

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of needing critical care increasing gradually as 7.0%, 13.2%, 23.5%, 38.1%, 55.4%, 71.4%, 83.4% and 91.1%.

WHICH ANTIBIOTICS, WHEN AND FOR HOW LONG? This question is addressed in more detail in Chapter 4 on infection. The choice of antibiotics should be undertaken after understanding the common microbiological organism that contaminates surgical site in your particular institution. AAOS recommends first generation cephalosporin (e.g., cefazolin) whereas in some other parts of world, cefuroxime is the prophylactic antibiotic of choice. There are published reports of incidents wherein hospital infection control committees have moved away from these recommendations to address the unique challenges faced by them (e.g., vancomycin as a primary prophylaxis to tackle high incidence of methicillin-resistant Staphylococcus aureus (MRSA) and coagulase negative Staphylococcus).8 The author’s preference is to use antibiotics recommended by the hospital infection control committee, first dose given at least 30 min prior to tourniquet inflation, and not beyond 24–48 h.

WHEN SHOULD I TAKE OUT THE URINARY CATHETER? Bladder management in perioperative scenario often boils down to choosing the lesser of two evils. On the one hand, both indwelling and intermittent catheterization have risk of bacteremia, while on the other hand, urinary retention leads to bladder atonia and residual urine, predisposing towards infection. In addition, the patient discomfort due to urinary retention remains an additional concern. The other problems associated with prolonged urinary catheter include development of delirium, higher risk of falls and difficult rehabilitation. Older research studies have preferred indwelling catheters over ‘pro re nata’ straight catheterization protocol.9,10 However, a relatively newer randomized prospective trial favored intermittent catheterization.11 The author’s choice is to avoid indwelling catheter in all cases. In short procedures (e.g., primary total knee replacement), any form of catheterization is completely avoided. In other cases, as and when needed, bladder evacuation with simple rubber catheter is done.

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HOW TO MANAGE POSTOP COGNITIVE CHANGES? Two types of cognitive changes are described in a postoperative setting.12 An acute and transient disturbance of mental function (with possibility of affection of awareness) is known as delirium. The longer lasting and subtle cognitive changes are labeled as postoperative cognitive dysfunction (POCD). POCD, although initially described in cardiac surgeries, is now known to occur also after noncardiac surgeries, such as total knee arthroplasty (TKA). Multiple theories have been proposed regarding the cause of cognitive impairment, including general anaesthesia, postoperative pain and analgesia, cerebral hypoperfusion and intraoperative microemboli.13 Microemboli enters into the systemic circulation when tourniquet is released and they reach cerebral circulation through patent right-to-left intracardiac shunts or intrapulmonary passage. Isoflurane and benzodiazepine should be used with caution, as they are associated with increased risk of postoperative delirium.14 The other causes of delirium include hypoxia, hypoglycemia, electrolyte imbalance, volume depletion, infection and drug interaction. Management of postoperative delirium includes general supportive care and specific measures as per the etiology. The components of such care include adequate oxygen delivery, fluid and electrolyte balance, appropriate pain management, early mobilization, review/discontinuation of unnecessary medications and optimization of environmental stimuli (proper sleep wake cycle, family members at bedside, glasses and hearing aids, etc.).15 Haloperidol is the most common drug used for delirium in ICU setting. Gabapentin provides good pain control without any risk of delirium. POCD is an area of active research with controversies on possible link to Alzheimer’s disease. The reader is advised to keep himself appraised with upcoming literature to stay ahead of the curve in this issue.

HOW SHOULD I ACHIEVE GLYCEMIC CONTROL PERIOPERATIVELY? Many patients undergoing total joint arthroplasty (TJA) also have preexisting diabetes mellitus. Attaining a tight glycemic control not only reduces the risk of surgical site infection16 but also decreases mortality, following MI.17 It is equally important to prevent hypoglycemic episodes. Patients who are on insulin preoperatively should continue taking their basal insulin; however, their shorter-acting insulin should only be administered after

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blood glucose measurements before each dose. Oral medications are best started after patient resumes normal oral intake.

HOW TO PREVENT ADDISONIAN CRISIS IN PATIENTS ON LONGTERM STEROIDS? A dose as low as 7.5 mg of prednisone (or equivalent) taken daily for 7 days can suppress hypothalamic-pituitary-adrenal axis till 9 months.18 Patients undergoing TJA may be on steroids for rheumatoid arthritis, collagen vascular diseases or pulmonary conditions. In an ideal situation, adrenocorticotropic hormone (ACTH) stimulation test should be done preoperatively to assess the adrenal reserve. When not possible, it is safe to give stress dose steroids to all such patients who have been on 7.5 mg or more of prednisone (for five or more days) at any point during last year. The stress dose is gradually lowered to the standard dose in patients on chronic steroids.

DOES THE PERIOPERATIVE PROTOCOL DIFFER FOR BILATERAL SINGLE STAGE? Direct head-to-head comparison of complications of staged vs. single stage bilateral TKA is difficult because often the patient groups are quite different. Nonetheless, single stage bilateral TKA are associated with higher incidence of postoperative complications, especially cardiopulmonary. Postoperative atrial fibrillation is one of the commonest complications (4.8% in one series).19 Cardiac monitoring is thus more paramount in such scenarios. The role of systemic inflammatory response in the development of fat emboli syndrome and acute respiratory distress syndrome is being understood increasingly. IL-6 (tissue marker for systemic inflammation) and desmosin (markers of tissue damage in lung) decrease significantly when corticosteroids are administered perioperatively.20 This has been proven to reduce the incidence of fat embolism syndrome in long bone fractures21 and perhaps a similar benefit will be obtained in arthroplasty patients who are at high risk. To summarize, appropriate patient selection, regional anaesthesia, strict perioperative cardiac monitoring, control of systemic inflammatory response, perioperative corticosteroids and early mobilization are some of the special efforts required to guarantee a better outcome with minimal complications in patients undergoing single stage bilateral TKA.

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WHEN TO DISCONTINUE AND RESUME CLOPIDOGREL IN PATIENTS WITH CARDIAC STENTS? Dual antiplatelet therapy is the standard recommendation for the prevention of stent thrombosis by AHA and ACC. This usually includes aspirin and clopidogrel, continued for 30–45 days after bare metal stent placement and for 365 days after placement of a drug eluting stent. While it is clearly known that discontinuation of antiplatelet therapy within this timeframe increases the risk of acute stent thrombosis, there are no clear guidelines for clopidogrel use/discontinuation after these time periods. A recent research study concludes that patients continuing clopidogrel perioperatively are more likely to need blood transfusions without any decrease in the incidence of adverse cardiac events (it was actually higher in clopidogrel continuation group, although not statistically significant). It is possible that patients at higher risk of developing adverse cardiac events were allowed to continue clopidogrel (the study was not randomized), or it is likely that allogenic blood transfusion led to the increase in proinflammatory and prothrombotic mediators. Due to existing contradictory literature,22,23 the author is far from the goal of the providing absolute recommendations. However, should the team feel the need to continue clopidogrel in view of serious cardiac risks, the possibility of increased blood transfusion and risk of adverse cardiac events should be anticipated.

WHEN SHOULD I REMOVE THE EPIDURAL CATHETER IN A PATIENT ON LMWH? One often has to face the challenge of optimally timing neuraxial analgesia (e.g., continuous epidural analgesia) when the patient is on anticoagulants/ antiplatelets. Although the decision to use or not use neuraxial analgesia and the timing of catheter removal is best done by individualization based on patient profile,24 there are certain recommendations available to guide us in that decision making process. Low molecular weight heparin dosing practices differ geographically; twice daily dosing is common in North America, while once daily dosing is prevalent in Europe. There are studies that suggest that higher anticoagulant activity is present during epidural catheter removal in patients receiving twice daily dosing.25 Irrespective of once- or twice-daily schedule, there should always be a gap of 2 h between the catheter removal and the next dose of LMWH. When a twice-daily dosing is planned, the first dose of LMWH should

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be administered 2 h after the catheter removal or 24 h after the catheter placement, whichever is later.24 In this setting (i.e., twice-daily dosing), catheter is best removed before starting LMWH. However, if that is not possible, then one should wait for >24 hours after the last dose to remove the catheter. When using once-daily dosing of LMWH, catheter can be removed anytime, that is, 12 h after the administration of LMWH. A gap of 6–8 h between the catheter placement and first dose of LMWH should be present, with subsequent dosing occurring no sooner than 24 h after the first dose.24

HOW DO OBESITY AND METABOLIC SYNDROME AFFECT MY RESULTS? In addition to leading to early development of osteoarthritis, obesity also causes many complications in patients undergoing arthroplasty. While arthroplasty relieves the pain and functional disability associated with osteoarthritis in obese patients, the risks are also high. Hence an orthopaedic surgeon must understand when to intervene and when to leave arthroplasty out of the options when facing obese patients. Wound healing is affected in obese patients, with a higher rate of infection in both TKA and THA. In TKA performed on obese patients, risk of in-hospital wound problem doubles and the risk of deep infection is increased three times (Fig. 1.1).26

Fig. 1.1 Clinical photograph of delayed wound healing and superficial infection after total knee arthroplasty (TKA) in an obese female patient.

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Many obese patients also suffer from comorbidities like obstructive sleep apnea, hypertension, cardiac diseases and diabetes mellitus. These patients are at high risk to suffer thrombosis, pulmonary embolism and sudden cardiac death after TJA. Obesity also leads to arthroplasty-specific complications such as component malposition, prosthesis loosening, higher incidence of dislocation and earlier need for revision surgery. As far as functional results after TJA is concerned, obese patients tend to have lower quality of life and performance compared to nonobese patients. Nonetheless, arthroplasty does improve the functional status from the preoperative level, and the patient satisfaction level shows no difference between the obese and nonobese, suggesting that TKA may still be the best treatment for most obese patients. In many obese patients, particularly those with BMI >40, the functional improvements occur at a slower pace, which needs to be discussed with the patient before the procedure. In morbidly obese (BMI >40) and super-obese (BMI >50), often the risks of complications are too high. In such patients, the surgeon must consider delaying the surgery and starting a weight-loss program. Many obese individuals have insulin resistance associated with altered adipose deposition and function. These patients often have associated comorbidities that are grouped together as metabolic syndrome. Metabolic syndrome is defined as a BMI >30 kg/m2 in addition to any two of the following: hyperlipidemia, hypertriglyceridemia and hypertension or diabetes. Coronary artery diseases and thromboembolism are common in individuals with metabolic syndrome. Insulin resistance seen in metabolic syndrome is believed to be responsible for causing endothelial dysfunction, leading to complications, which are higher compared to patients who are obese but not suffering from metabolic syndrome. Hence, in addition to obesity, metabolic syndrome appears to be an additional and unique risk factor for both in-hospital and long-term complications after TJA, requiring early identification and appropriate patient optimization.

TAKE HOME MESSAGE The elderly population forms a large chunk of TJA cases operated, and the number is growing every year. Despite being a largely effective and successful group of surgeries, TJAs are associated with certain serious perioperative and postoperative complications. It is prudent for arthroplasty surgeons to familiarize themselves with these potential pitfalls. Considering the fact that most of the complications are preventable or salvageable with preop-

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erative screening, planning and timely intervention, there is no excuse for not achieving the best possible standards. Arthroplasties are often described as a highly effective surgical intervention, and we believe, it is important for us to make them highly safe also.

REFERENCES 1. Foerg FE, Repp AB, Grant SM. Medical complications associated with total hip arthroplasty. Seminars in Arthroplasty 2005;16(2):88–99/. doi: 10.1053/j.sart.2005.06.004. 2. Bindelglass DF, Pellegrino J. The role of blood cultures in the acute evaluation of postoperative fever in arthroplasty patients. J Arthroplasty 2007;22(5):701–2. PubMed PMID: 17689779. 3. Ward DT, Hansen EN, Takemoto SK, Bozic KJ. Cost and effectiveness of postoperative fever diagnostic evaluation in total joint arthroplasty patients. J Arthroplasty 2010;25(6 Suppl):43–8. doi: 10.1016/j.arth.2010.03.016. Epub 2010 May 10. PubMed PMID: 20452174. 4. Falck-Ytter Y, Francis CW, Johanson NA, Curley C, Dahl OE, Schulman S, Ortel TL, Pauker SG, Colwell CW Jr; American College of Chest Physicians. Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest 2012;141(2 Suppl):e278S–325S. doi:10.1378/chest.11-2404. PubMed PMID: 22315265; PubMed Central PMCID: PMC3278063. 5. Barrack RL. Current guidelines for total joint VTE prophylaxis: dawn of a new day. J Bone Joint Surg Br 2012;94(11 Suppl A):3–7. doi:10.1302/0301-620X.94B11.30824. Review. PubMed PMID: 23118370. 6. AbdelSalam H, Restrepo C, Tarity TD, Sangster W, Parvizi J. Predictors of intensive care unit admission after total joint arthroplasty. J Arthroplasty 2012;27(5):720–5. doi: 10.1016/j.arth.2011.09.027. Epub 2011 Nov 15. PubMed PMID: 22088781. 7. Courtney PM, Whitaker CM, Gutsche JT, Hume EL, Lee GC. Predictors of the need for critical care after total joint arthroplasty: an update of our institutional risk stratification model. J Arthroplasty 2014; pii:S0883-5403(14):00142–9. doi: 10.1016/j. arth.2014.02.028. [Epub ahead of print] PubMed PMID: 24703365. 8. Smith EB,Wynne R, Joshi A, Liu H, Good RP. Is it time to include Vancomycin for routine perioperative antibiotic prophylaxis in total joint arthroplasty patients? J Arthroplasty 2012;27(8 Suppl):55–60. doi:10.1016/j.arth.2012.03.040. Epub 2012 May 17. PubMed PMID: 22608685. 9. Oishi CS, Williams VJ, Hanson PB, Schneider JE, Colwell CW Jr, Walker RH. Perioperative bladder management after primary total hip arthroplasty. J Arthroplasty 1995;10(6):732–6. PubMed PMID: 8749753. 10. Knight RM, Pellegrini VD Jr. Bladder management after total joint arthroplasty. J Arthroplasty 1996;11(8):882–8. PubMed PMID: 8986564. 11. Van den Brand IC, Castelein RM.Total joint arthroplasty and incidence of postoperative bacteriuria with an indwelling catheter or intermittent catheterization with one-dose antibiotic prophylaxis: a prospective randomized trial. J Arthroplasty 2001;16(7):850–5. PubMed PMID: 11607900. 12. Hovens IB, Schoemaker RG, van der Zee EA, Heineman E, Izaks GJ, van Leeuwen BL. Thinking through postoperative cognitive dysfunction: How to bridge the gap between clinical and pre-clinical perspectives. Brain Behav Immun 2012;26(7):1169–79. doi: 10.1016/j.bbi.2012.06.004. Epub 2012 Jun 21. Review. PubMed PMID: 22728316. 13. Scott JE, Mathias JL, Kneebone AC. Postoperative cognitive dysfunction after total

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joint arthroplasty in the elderly: a meta-analysis. J Arthroplasty 2014;29(2):261–7.e1. doi: 10.1016/j.arth.2013.06.007. Epub 2013 Jul 23. PubMed PMID: 23890520. 14. Nandi S, Harvey WF, Saillant J, Kazakin A, Talmo C, Bono J. Pharmacologic risk factors for post-operative delirium in total joint arthroplasty patients: a case-control study. J Arthroplasty. 2014;29(2):268–71. doi: 10.1016/j.arth.2013.06.004. Epub 2013 Jul 5. PubMed PMID: 23831083. 15. Flinn DR, Diehl KM, Seyfried LS, Malani PN. Prevention, diagnosis, and management of postoperative delirium in older adults. J Am Coll Surg 2009;209(2):261–8; quiz 294. doi: 10.1016/j.jamcollsurg.2009.03.008. Epub 2009 May 1. Review. PubMed PMID: 19632604. 16. Golden SH, Peart-Viligance C, Kao WH, et al. Perioperative glycemic control and the risk of infectious complications in a cohort of adults with diabetes. Diabetes Care 1999;22:1408. 17. Malmberg K, Ryden L, Efendic S, et al. Randomized trial of insulin- glucose infusion followed by subcutaneous insulin treatment in diabetic patients with acute myocardial infarction (DIGAMI Study): effects on mortality at 1 year. J Am Coll Cardiol 1995;26:57. 18. Graber AL, Ney RI, Nicholson WE, et al. Natural history of pituitary adrenal recovery following long-term suppression with glucocorticoids. J Clin Endocr Metab 1965;25:11. 19. Pavone V, Johnson T, Saulog PS, Sculco TP, Bottner F. Perioperative morbidity in bilateral one-stage total knee replacements. Clin Orthop Relat Res 2004;421:155– 61. 20. Sculco TP, Sculco PK. Simultaneous-bilateral TKA: double trouble - opposes. J Bone Joint Surg Br 2012;94(11 Suppl A):93–4. doi: 10.1302/0301-620X.94B11.30829. PubMed PMID: 23118392. 21. Bederman SS, Bhandari M, McKee MD, Schemitsch EH. Do corticosteroids reduce the risk of fat embolism syndrome in patients with long-bone fractures? A meta-analysis. Can J Surg 2009;52:386–93. 22. Grujic D, Martin D. Perioperative clopidogrel is seven days enough? Am Surg 2009;75:909. 23. Kang W, Theman TE, Reed III JF, et al. The effect of preoperative clopidogrel on bleeding after coronary artery bypass surgery. J Surg Educ 2007;64:88. 24. Horlocker TT. Regional anaesthesia in the patient receiving antithrombotic and antiplatelet therapy. Br J Anaesth 2011;107(Suppl 1):i96–106. doi:10.1093/bja/aer381. Review. PubMed PMID: 22156275. 25. Douketis JD, Kinnon K, Crowther MA. Anticoagulant effect at the time of epidural catheter removal in patients receiving twice-daily or once-daily low-molecular-weight heparin and continuous epidural analgesia after orthopedic surgery. Thromb Haemost 2002;88(1):37-40. PubMed PMID: 12152674. 26. Workgroup of the American Association of Hip and Knee Surgeons Evidence Based Committee. Obesity and total joint arthroplasty: a literature based review. J Arthroplasty 2013;28(5):714–21. doi: 10.1016/j.arth.2013.02.011. Epub 2013 Mar 19. Review. PubMed PMID: 23518425.

Chapter 2

Blood Transfusion Reduction in Total Joint Arthroplasty Alisina Shahi, Javad Parvizi

INTRODUCTION Due to the high levels of blood loss associated with the procedures, orthopaedic surgery commonly requires allogeneic blood transfusions. This is a concern, particularly with older patients who are at higher risk of intraoperative haemorrhage. Although banked blood has become increasingly safe, transfusion has been identified as an independent risk factor for adverse outcomes.1 Additionally, homologous donation may be a limited resource for many health care centers because blood banks regularly undergo shortages.2,3 In response, various predonation and salvage mechanisms and pharmacological methods to mitigate blood shed have been introduced. While the popularity of preoperative autologous donation has declined for logistical reasons, erythropoietin (EPO) and perioperative autologous blood salvage strategies have increased in popularity.4 Still, homologous transfusion remains the gold-standard approach for increasing blood cell count in anaemic patients in the perioperative period. Erythrocyte transfusion is associated with a considerable impact on morbidity. Studies have shown that blood transfusions are linked to significant short- and long-term risks including stroke, renal failure, myocardial infarction and death,1 as well as infection and allergic reactions,5 and the nebulous transfusion-related acute lung injury (TRALI). Reducing these risks by minimizing both intraoperative and postoperative blood loss and consequent transfusion requirement remains an important element of patient care for the orthopaedic surgeon. The number of blood transfusions can be reduced through proper surgical planning, patient management and overall thoughtful care. For instance, it is essential to follow blood conserving techniques, including anaemia and haemostasis management. Preoperative patient ‘optimization’ is important. A range of factors such as lifestyle, many comorbidities, anaemia, sarcopenia and medications are modifiable, and can be optimized to reduce perioperative morbidity.5 Certain perioperative medications can be

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used to reduce blood loss and transfusion requirement. Lastly, intraoperative and postoperative salvage mechanisms and positioning techniques are potentially effective methods of reducing blood loss. Achieving optimal patient outcomes can be made possible through a well-planned, multidisciplinary, patient-centered approach to care.6 The goal of this chapter is to provide information regarding the currently available medications, interventions and techniques that can be utilized in orthopaedic surgical procedures to reduce allogeneic erythrocyte consumption.

PREOPERATIVE STRATEGIES According to the World Health Organization (WHO), 10.5% of orthopaedic surgery patients are diagnosed with marked anaemia.7 Bierbaum et al. found that more than 35% of patients in the United States had haemoglobin (Hb) levels of 13 g/dL or less, and that a baseline Hb below this level was associated with the highest rates of transfusion of allogeneic blood.8 There is mounting literature evidence supporting the notion that preoperative anaemia increases the risk of postoperative morbidity and mortality, in addition to impairing functional recovery and reducing the quality of life.9–12 In order to increase the number of erythrocytes in circulation, preoperative medications such as erythropoietin-stimulating agents (ESAs) and synthetic EPO can be administered. However, these medications must be used with caution and only patients with sufficiently low Hb levels should be prescribed ESAs or EPO. When given to patients with higher Hb levels (typically above 13 g/dL),13 the risk of polycythaemia increases. Polycythaemia can lead to complications such as haemorrhage, thrombosis and cardiac failure. Although the increased risk of such complications as related to medications is somewhat controversial, the risk of thrombosis in orthopaedic operations is significantly high regardless of the treatment regimen.14,15 For this reason, it is recommended to minimize ESA and EPO utilization in association with orthopaedic procedures.

Erythropoietin EPO is an innate cytokine hormone produced by interstitial fibroblasts in the kidneys. Renocortical interstitial cells release endogenous EPO into the bloodstream when the circulating oxygen tension is low. EPO plays a role in recruiting and differentiating erythroid progenitor cells and assisting with their survival, and also stimulates Hb synthesis.16 The most commonly

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used synthetic form of EPO is epoetin alpha, which is made up of the same amino acid sequence, and therefore, exerts identical biological activity as endogenous EPO. In conjunction with endogenous EPO, epoetin alpha is capable of safely stimulating the synthesis of Hb.13,17 To effectively boost erythrocyte production, EPO should be combined with either oral or intravenous iron supplementation.18 Three injections of EPO are typically administered over a 3-week period prior to the surgery, and the fourth one is given in the operating room immediately following the operation. The dosage of EPO is either 300 IU/kg/day over 15 days, or 600 IU/kg over 4 weeks, starting 3 weeks before the procedure (Fig. 2.1). It is best to give these injections subcutaneously rather than intravenously because the subcutaneous method slows release, yielding a more consistent sustained plasma level.16 Pretreatment Hb

>10 to ) 13 g/dL

If the preoperative period is 13 g/dL

Not a candidate for epoetin alpha therapy

If the preoperative period is *3 wk, treat with epoetin alpha 40,000 U* (600 U/kg) on days -21, -14, and -7, and the day of surgery Fig. 2.1 Treatment algorithm for use of epoetin alpha in anaemic patients scheduled for elective, non-cardiac, non-vascular surgery at high risk for transfusion because of anticipated blood loss. *Based on patient weight of 70 kg.¹⁹

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Although EPO is costly, the effectiveness of this medication in elevating Hb levels is compelling. Preoperative treatment with EPO has been shown to increase blood cell mass, Hb and haematocrit levels and to decrease transfusion rate significantly.15,20,21 A recent study followed a cohort of patients undergoing total hip replacement with low Hb who received 600 IU/kg epoetin beta over a 4 week period. Only 3.6% of patients in the treatment group required a transfusion, compared to a group of patients not administered EPO, 45.2% of which required transfusions. In a control group with normal levels of Hb, the transfusion rate was 11.9%. The authors concluded that a 92% reduction in transfusions was evident with the administration of EPO.2 However, the cost–benefit analysis is less encouraging. In 1998, Coyle et al. published an economic analysis of EPO use for orthopaedic surgery in Ottawa, Canada. Among other results, they found that EPO used led to only modest benefits when compared to both no intervention and as an augmentation to preoperative autologous donation. From a cost-effectiveness perspective, the authors concluded that EPO administration to reduce perioperative allogeneic transfusions for orthopaedic patients ‘did not meet criteria conventionally considered acceptable.’21 A similar recent randomized control trial evaluated EPO and blood salvage as transfusion alternatives in adult elective hip- and knee-arthroplasty patients in Leiden, the Netherlands. The authors found a reduction in mean erythrocyte usage, and a significant decrease in the proportion of patients transfused, when a restrictive transfusion threshold of 8 g/dL was used. In this report, the optimal benefit for EPO to decrease transfusions was observed in patients with preoperative Hb levels of 10 to 13 g/dL. The authors similarly found that EPO increased costs substantially, in this case by €785 per patient, or €7300 per transfusion avoided, concluding that EPO avoids transfusion significantly but at ‘unacceptably high costs.’4

Iron, Vitamin B₁₂ and Folic Acid Iron deficiency accounts for approximately one-half of anaemia cases and is the most common nutritional disorder worldwide.23 An estimated 25% of the total world population is affected by iron-deficiency anemia (IDA). Excluding parasitosis, most cases are due to inadequate intake, increased ferric requirement, or related to blood loss or disease states. Iron is necessary for oxygen transport in the bloodstream. The human body contains approximately 4–5 g of iron, 65% of which is bound by Hb and unavailable for use in erythropoiesis. Around 15–30% of the iron can be found in the hepatic parenchyma and the reticuloendothelial system,

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stored as ferritin. The remainder of total body iron is circulating in the blood plasma, largely bound to transferrin. Appropriate levels of iron, vitamin B12 and folic acid are required for erythropoiesis to take place. If a patient is deficient in any of those elements, cellular differentiation and proliferation are negatively affected, leading to central aregenerative anaemia. Another form of anaemia, termed functional iron deficiency, is when the body possesses adequate iron levels, yet there is insufficient iron available to the bone marrow to adequately support the needs of erythroid precursors. When chronic inflammation blocking the transfer of stored iron, this form is referred to as anaemia of chronic disease, and may be caused by a proinflammatory cytokine-mediated effect on erythropoiesis. In functional iron deficiency, serum ferritin levels may be normal or elevated, yet the red blood cell count continues to be diminished. Iron consumption is an essential adjuvant to EPO treatment, and may also be administered prior to autologous predonation to optimize the haemogenesis processes. The iron dosage can be determined based on the initial Hb levels and the presence or absence of total iron deficiency. Oral administration of iron has been reported to have a beneficial effect on reducing the number of necessary allogeneic blood transfusions.24 However the availability of orally administered iron is affected by various factors that reduce iron absorptive capacity and by gastric disorders that interfere with iron uptake, such as inflammatory bowel disease.25 In these cases, it may be necessary to deliver iron treatment intravenously. Due to some associated risks and side effects, once the intravenous administration is no longer necessary, it is recommended to switch to oral. Because PO iron supplementation is more convenient than intravenous, it is generally preferred for orthopaedic surgery patients without iron deficiency when EPO treatment is considered.13

Autologous Blood Predonation It is common for surgical patients to have lower Hb count on the day of the surgery than a previous reading, prompting the need for a transfusion. In the days or weeks leading to surgery, a phlebotomy may be performed and the extracted blood collected can be used during or after the procedure. Although autologous predonation can increase the chance of a transfusion requirement, it is considerably safer than homologous transfusion because there is much lower risk of rejection, blood incompatibility and infection. These donations may be carried out multiple times prior to surgery, in recommended intervals of not shorter than 3 days (350–400 mL each time). In this manner, there is ample time for protein synthesis and haematogen-

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esis to occur between donations; again appropriate iron supplementation should be administered. The storage of donated blood is the same as for allogeneic transfusions, requiring meticulous record-keeping and an extensive collection system, and the use is generally limited to hospitals with established blood bank capabilities. However, because the predonation is not typically tested, typed or screened, the harvested blood may not be kept and used for other patients. Certain criteria must be met to be eligible for predonation. First, Hb level greater than 11 mg/dL is required because the donation introduces an acute iron deficiency anaemia with all related signs and symptoms including fatigue, headache, syncope, shortness of breath, angina, intermittent claudication and palpitations. Second, a well-planned surgery is recommended as the extracted blood unit(s) carry an ‘expiration date.’ Storage time is known to be the most important factor related to cell quality, and therefore, predonation should be done no more than 35 days before surgery. Because autologous predonation is exposed to the same potential errors in processing, storage and identification, the following are contraindications for the procedure: history of serious cardiac disease, history of hepatitis B or C or positive markers for hepatitis C virus (HCV), human T-cell lymphotropic virus (HTLV) or human immunodeficiency virus (HIV) and active bacterial infection.

INTRAOPERATIVE STRATEGIES To improve the effectiveness of intraoperative strategies, the following recommendations should also be associated with preoperative optimization whenever possible. Performing the operation using minimally invasive techniques has been shown to reduce overall blood loss and should be employed whenever possible.

Individualized Transfusion Threshold Most physicians would recognize the importance of following a strict transfusion protocol, with a threshold for transfusion at Hb levels of 7 g/dL. Additional complexities such as anaemia from disease states should be taken into consideration on a case-by-case basis. In some instances, the transfusion threshold may be lowered, delaying the initiation of the transfusion until the surgery’s completion. However, it is imperative that patients with Hb levels at or below 6 g/dL undergo transfusion.

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Normovolemic Dilution Similar to autonomic predonation, this strategy involves drawing the patient’s own blood. In this method, the phlebotomy is performed either shortly before or during the operation; typically 0.5–1.5 L of blood is extracted, and an equal volume of colloid or crystalloid solution is infused to replace it. In this way, the haemorrhage contains fewer erythrocytes, and therefore, the total blood loss is less significant. If necessary, the extracted blood may be returned to the patient as an autologous transfusion. A study performed by Davies et al. concluded that acute normovolemic dilution is a cost-effective technique for reducing allogeneic blood transfusions.25 Goodnough et al. similarly compared acute normovolemic haemodilution to preoperative autologous donation in total hip arthroplasty patients and concluded that normovolemic haemodilution is considered safe. Although there were no differences between the two groups regarding the requirement for allogeneic blood transfusion, acute normovolemic haemodilution was dramatically more cost-effective than preoperative autologous blood donation.10

Autotransfusion The use of autotransfusion systems are gaining in popularity. These systems are available in several categories and are known by a variety of terms including ‘cell saver,’ ‘cell washers,’ ‘RBC-savers,’ direct transfusion and ultrafiltration of whole blood. In some systems, the aspirate undergoes centrifugation and is ‘washed’ with 9% sodium chloride. In others, the content is unwashed and simply returned to the patient after passing through a filter. Cell savers are routinely used during orthopaedic procedures in the United States and have become increasingly popular worldwide. The use of a cell saver may recover up to 70% of the intraoperative blood shed in an orthopaedic procedure.27 This has the potential to significantly reduce transfusion requirements. However, the results from a recent randomized control trial revealed that autologous blood reinfusion failed to decrease mean erythrocyte use, and did not result in a smaller proportion of transfused patients. The authors reasoned this may be due to the relatively low visible blood loss, and hence, low volume of recovered blood. Reinfusion was also associated with an increased length of hospital stay, albeit in non-intensive care. Hence, autotransfusion can potentially reduce overall blood loss but may not be cost-effective.4,28

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Anaesthetic Measures Anaesthetic approaches are mainly related to pain management and blood volume maintenance, as well as controlling heart rate and high blood pressure. Hyperoxic ventilation can be used to improve oxygen transport in patients with low Hb levels. Optimal patient positioning during surgery can reduce venous congestion. It is also recommended that regional anaesthesia be used whenever possible, as several studies have demonstrated decreased perioperative bleeding compared to general anaesthesia.29,30 This effect is believed to be related to the lower blood pressure. Other anaesthesiological methods such as normothermia management, normovolemic dilution and controlled hypotension can also play a role in reducing blood loss. Although still controversial, it has been shown that lowering the blood pressure can be relatively effective in reducing the amount of blood shed throughout the course of surgery. Related contraindications consist of untreated high blood pressure, serious lung disease, coronary disease, significant polycythemia, severe anaemia, cerebrovascular disease, serious liver or kidney dysfunction and pregnancy. Various drugs are used to control hypertension, the most common of which are inhalers (isoflurane, sevoflurane), beta blockers (esmolol, labetalol), direct acting vasodilators (sodium nitroprusside, nitroglycerin) and others such as urapidil and captopril.

Antifibrinolytic Agents Antifibrinolytic agents (AFAs) may be used preoperatively, intraoperatively or postoperatively, and have been shown to have a dramatic effect on blood loss and transfusion requirement. Agents such as aprotinin, lysine analogs such as tranexamic acid (TXA) and Ƥ-aminocaproic acid (EACA) are widely used, particularly for cardiac surgery. AFAs have been shown to enhance haemostasis by interfering with fibrinolysis and thus are believed to reduce blood loss.3,31 Previous reviews have found that these medications were effective in reducing blood loss, transfusion requirement and reoperations due to bleeding.32 However, many studies performed to-date were either underpowered or performed for other specialties such as cardiac surgery.3 Hence, the effect of AFAs on reducing blood loss specifically for arthroplasty remains relatively less explored. A recent review article investigated the use of antifibrinolytics in orthopaedics by examining 43 randomized control trials in various operations including spinal fusion, hip and knee arthroplasty, tumour and musculoskeletal sepsis. The authors found a significant reduction in the proportion

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of patients requiring allogeneic transfusion associated with aprotinin and TXA, whereas EACA was not effective.3 A 2011 Cochrane review article on the subject concluded that ‘anti-fibrinolytic drugs provide worthwhile reductions in blood loss and the receipt of allogeneic red cell transfusion.’ Aprotinin, previously the most popular agent, was withdrawn from the market in 2008 due to concerns about cardiovascular complications. While aprotinin was slightly more effective, the lysine analogues appear to be safe and effective in reducing blood loss during and after surgery.32 Tranexamic Acid TXA, a synthetic derivative of the amino acid lysine, is perhaps the most popular AFA currently used for orthopaedic surgery. A recent review article on patients undergoing total knee arthroplasty examined 15 randomized control trials, finding that TXA reduced total blood loss by 487 mL, intraoperative loss by 127 mL and postoperative blood loss by 245 mL, with a significant reduction (56%) in patients requiring transfusion. In addition, there were no apparent differences in risk of thrombotic or embolic complications.31

Haemostasis It is necessary for surgical haemostasis to be thoroughly performed during each operation. With regards to orthopaedic surgery, the most commonly used method is electrocautery. Another potential method of haemostasis, intra-articular epinephrine injection, can also reduce bleeding but might be associated with skin necrosis.5,33 Fibrin Spray A newer method of haemostasis is topical fibrin spray (FS), a mixture of thrombin and fibrinogen that is believed to control bleeding, improve tissue healing and increase postoperative recovery rate.34 Fibrin sealer was shown to reduce perioperative and postoperative blood loss after primary total hip replacement compared to controls and treatment with bipolar sealer.35 This reduction was significant at every time interval measured, and the volume saved was comparable to one unit of blood at each 24 and 48 h with a total savings of 1735 mL.35 McConnell et al. found that both TXA at induction and intraoperative topical FS reduced blood loss relative to a control group, and that neither active treatment was superior. In a similar study of computer-navigated cemented primary knee arthroplasty patients, 10 mL of FS effectively reduced blood loss compared to a control group, but the effect of a 10 mg/kg bolus of TXA did not reach significance.35 A

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recent meta-analysis on its use in TKA before wound closure concluded that fibrin sealant was safe and effective, reduced postoperative drainage and drop in Hb levels, reduced haematoma formation and transfusion requirement and did not increase adverse events.34 However, it was acknowledged that limited literature was available and additional randomized control trials on the subject were recommended.34 Furthermore, the use of FS may reduce overall blood loss and length of hospital stay and increase postoperative range of motion, although not statistically significantly.34 Tourniquets Additional viable methods for surgical haemostasis include tourniquets and exsanguination, but they must be used with caution. Tourniquets are often used in total knee arthroplasty in order to decrease intraoperative blood loss.37-39 A study performed recently by Zhang et al. demonstrated a reduction in intraoperative bleeding; however, there was a dramatic increase in blood shed during the postoperative period.38 Similarly, a systematic review by Smith and Hing concluded that tourniquets were associated with a significant decline in intraoperative blood loss compared to procedures in which tourniquets were not used. However there was no difference in total blood loss between the two groups, and there was a somewhat higher frequency of complications in the tourniquet group.37 Hence, tourniquets should be used judiciously. While there is a clear positive impact in controlling operative blood loss, the levels of postoperative bleeding tend to increase with tourniquets, as well as the risk of other complications.

POSTOPERATIVE STRATEGIES In addition to the aforementioned, several postoperative strategies can be employed to reduce blood loss. These methods may be particularly beneficial to TKR patients due to the quantity of blood loss in the postoperative period.

Drainage Reinfusion Similar to autotransfusion systems, postoperative drainage and reinfusion devices involve reinfusion after the content has passed through a filter mechanism, and typically employ continuous or intermittent vacuum pressure. These systems are gaining popularity worldwide due to their efficacy, feasibility and relatively low cost. However, a randomized control trial performed in the Netherlands explored the use of a drain system and found results similar to those with cell saver systems, namely,

Blood Transfusion Reduction in Total Joint Arthroplasty

25

a statistically significant decrease in transfusion requirement but also increased length of hospital stay by nearly one whole day. The authors concluded that ‘autologous blood salvage devices were not effective’ overall and that use of these devices increased costs and did not reduce erythrocyte use. This was a two-part report, and these results were observed for patients with preoperative Hb levels 10–13 g/dL as well as patients with Hb greater than 13 g/dL.4,28

CONCLUSION Many strategies can be employed to reduce blood loss in the orthopaedic patient. Comorbidity management and patient optimization should be employed whenever possible for patients undergoing elective procedures. Preoperative iron deficiency anaemia should be controlled with appropriate supplements. EPO may be used when oral or intravenous supplementation fails and has been shown to reduce transfusions; the optimal benefit for EPO is seen in patients with 10–13 g/dL Hb. However, EPO is excessively costly and its use may be unfeasible for many patients or treatment centers. Autologous predonation is potentially safer than homologous transfusion and may be performed whenever a transfusion requirement is anticipated. This strategy requires proper planning and storage and its use has been declined due to cost and logistic reasons. Tourniquets and exsanguination may be used judiciously; while a tourniquet can lessen intraoperative blood loss, bleeding tends to increase postoperatively and complications may be higher. Procedures should be performed with minimally invasive techniques whenever possible and using blood-conserving techniques including meticulous haemostasis. The use of TXA appears to be safe and effective in reducing perioperative blood loss without increasing adverse outcomes. FS has been shown to reduce bleeding following both hip and knee arthroplasty and may reduce overall blood loss and number of transfusions. Both TXA and FS seem to reduce haematoma formation. Anaesthetic measures such as hyperoxic supplementation and patient positioning may be of some value. Lowering the blood pressure intraoperatively is controversial but has potential to reduce blood shed in select patients. Postoperative knee flexion or leg elevation appears to be beneficial. Autotransfusion and drainage reinfusion devices have the potential to ‘recycle’ shed blood and reduce transfusion requirements but may not be cost-effective overall.

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REFERENCES 1. Rawn J. The silent risks of blood transfusion. Curr Opin Anaesthesiol 2008;21(5):664–8. 2. Laffosse J-M, Minville V, Chiron P, Colombani A, Gris C, Pourrut J-C, et al. Preoperative use of epoietin beta in total hip replacement: a prospective study. Arch Orthop Trauma Surg 2010;130(1):41–5. 3. Zufferey P, Merquiol F, Laporte S, Decousus H, Mismetti P, Auboyer C, et al. Do antifibrinolytics reduce allogeneic blood transfusion in orthopedic surgery? Anesthesiology. 2006;105(5):1034–46. 4. So-Osman C, Nelissen RGHH, Koopman-van Gemert AWMM, Kluyver E, Pöll RG, Onstenk R, et al. Patient blood management in elective total hip- and knee-replacement surgery (Part 1): A randomized controlled trial on erythropoietin and blood salvage as transfusion alternatives using a restrictive transfusion policy in erythropoietin-eligible patients. Anesthesiology 2014;22. 5. Napier RJ, Bennett D, McConway J, Wilson R, Sykes AM, Doran E, et al. The influence of immediate knee flexion on blood loss and other parameters following total knee replacement. Bone Jt J 2014;96-B(2):201–9. 6. Seeber P, Shander A. History and Organization of Blood Management. Basics of Blood Management. 2nd edition. Oxford, UK: Wiley-Blackwell; 2012. pp. 1–8. 7. Bisbe E, Castillo J, SAEz M, Santiveri X, RuIZ A, MuNOz M. Prevalence of preoperative anemia and hematinic deficiencies in patients scheduled for elective major orthopedic surgery. Transfus Altern Transfus Med 2008;10(4):166–73. 8. Bierbaum BE, Callaghan JJ, Galante JO, Rubash HE, Tooms RE, Welch RB. An analysis of blood management in patients having a total hip or knee arthroplasty. J Bone Joint Surg Am 1999;81(1):2–10. 9. Beattie WS, Karkouti K, Wijeysundera DN, Tait G. Risk associated with preoperative anemia in noncardiac surgery: a single-center cohort study. Anesthesiology 2009;110(3):574–81. 10. Goodnough LT, Despotis GJ, Merkel K, Monk TG. A randomized trial comparing acute normovolemic hemodilution and preoperative autologous blood donation in total hip arthroplasty. Transfusion (Paris) 2000;40(9):1054–7. 11. Conlon NP, Bale EP, Herbison GP, McCarroll M. Postoperative anemia and quality of life after primary hip arthroplasty in patients over 65 years old. Anesth Analg 2008;106(4):1056–1061, table of contents. 12. Gruson KI, Aharonoff GB, Egol KA, Zuckerman JD, Koval KJ. The relationship between admission hemoglobin level and outcome after hip fracture. J Orthop Trauma 2002;16(1):39–44. 13. Earnshaw P. Blood conservation in orthopaedic surgery: the role of epoetin alfa. Int Orthop 2001;25(5):273–8. 14. De Andrade JR, Jove M, Landon G, Frei D, Guilfoyle M,Young DC. Baseline hemoglobin as a predictor of risk of transfusion and response to Epoetin alfa in orthopedic surgery patients. Am J Orthop 1996;25(8):533–42. 15. Faris PM, Ritter MA, Abels RI. The effects of recombinant human erythropoietin on perioperative transfusion requirements in patients having a major orthopaedic operation. The American Erythropoietin Study Group. J Bone Joint Surg Am 1996;78(1):62–72. 16. Erslev AJ. Erythropoietin. N Engl J Med 1991;324(19):1339–44. 17. Storring PL, Gaines Das RE. The International Standard for Recombinant DNAderived Erythropoietin: collaborative study of four recombinant DNA-derived erythropoietins and two highly purified human urinary erythropoietins. J Endocrinol. 1992;134(3):459–84. 18. García-Erce JA, Cuenca J, Haman-Alcober S, Martínez AA, Herrera A, Muñoz M. Efficacy of preoperative recombinant human erythropoietin administration for reduc-

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ing transfusion requirements in patients undergoing surgery for hip fracture repair. An observational cohort study. Vox Sang 2009;97(3):260–7. 19. Deutsch A, Spaulding J, Marcus RE. Preoperative epoetin alfa vs autologous blood donation in primary total knee arthroplasty. J Arthroplasty. 2006;21(5):628–35. 20. Faris PM, Ritter MA. Epoetin alfa. A bloodless approach for the treatment of perioperative anemia. Clin Orthop 1998;(357):60–7. 21. Coyle D, Lee KM, Fergusson DA, Laupacis A. Economic analysis of erythropoietin use in orthopaedic surgery. Transfus Med 1999;9(1):21–30. 22. Short MW, Domagalski JE. Iron deficiency anemia: evaluation and management. Am Fam Physician 2013;87(2):98–104. 23. Okuyama M, Ikeda K, Shibata T, Tsukahara Y, Kitada M, Shimano T. Preoperative iron supplementation and intraoperative transfusion during colorectal cancer surgery. Surg Today 2005;35(1):36–40. 24. Cuenca J, García-Erce JA, Muñoz M, Izuel M, Martínez AA, Herrera A. Patients with pertrochanteric hip fracture may benefit from preoperative intravenous iron therapy: a pilot study. Transfusion (Paris). 2004;44(10):1447–52. 25. Davies L, Brown TJ, Haynes S, Payne K, Elliott RA, McCollum C. Cost-effectiveness of cell salvage and alternative methods of minimising perioperative allogeneic blood transfusion: a systematic review and economic model. Health Technol Assess 2006;10(44):iii–iv, ix–x, 1–210. 26. Warner C. The use of the orthopaedic perioperative autotransfusion (OrthoPAT) system in total joint replacement surgery. Orthop Nurs Natl Assoc Orthop Nurses 2001;20(6):29–32. 27. So-Osman C, Nelissen RGHH, Koopman-van Gemert AWMM, Kluyver E, Pöll RG, Onstenk R, et al. Patient blood management in elective total hip- and knee-replacement surgery (Part 2): A randomized controlled trial on blood salvage as transfusion alternative using a restrictive transfusion policy in patients with a preoperative hemoglobin above 13 g/dl. Anesthesiology 2014;23. 28. Park JH, Rasouli MR, Mortazavi SMJ, Tokarski AT, Maltenfort MG, Parvizi J. Predictors of perioperative blood loss in total joint arthroplasty. J Bone Joint Surg Am 20132;95(19):1777–83. 29. Covert CR, Fox GS. Anaesthesia for hip surgery in the elderly. Can J Anaesth J Can Anesth 1989;36(3 Pt 1):311–9. 30. Zhang H, Chen J, Chen F, Que W. The effect of tranexamic acid on blood loss and use of blood products in total knee arthroplasty: a meta-analysis. Knee Surg Sports Traumatol Arthrosc. 2012;20(9):1742–52. 31. Henry DA, Carless PA, Moxey AJ, O’Connell D, Stokes BJ, Fergusson DA, et al. Antifibrinolytic use for minimising perioperative allogeneic blood transfusion. Cochrane Database Syst Rev 2011;(3):CD001886. 32. Ryu J, Sakamoto A, Honda T, Saito S. The postoperative drain-clamping method for hemostasis in total knee arthroplasty. Reducing postoperative bleeding in total knee arthroplasty. Bull Hosp Jt Dis N Y N 1997;56(4):251–4. 33. Li Z-J, Fu X, Tian P, Liu W-X, Li Y-M, Zheng Y-F, et al. Fibrin sealant before wound closure in total knee arthroplasty reduced blood loss: a meta-analysis. Knee Surg Sports Traumatol Arthrosc 2014. 34. Falez F, Meo A, Panegrossi G, Favetti F, La Cava F, Casella F. Blood loss reduction in cementless total hip replacement with fibrin spray or bipolar sealer: a randomised controlled trial on ninety five patients. Int Orthop 2013;37(7):1213–7. 35. McConnell JS, Shewale S, Munro NA, Shah K, Deakin AH, Kinninmonth AWG. Reducing blood loss in primary knee arthroplasty: a prospective randomised controlled trial of tranexamic acid and fibrin spray. The Knee 2012;19(4):295–8. 36. Matziolis D, Perka C, Hube R, Matziolis G. [Influence of tourniquet ischemia on peri-

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operative blood loss after total knee arthroplasty]. Orthop 2011;40(2):178–82. 37. Smith TO, Hing CB. Is a tourniquet beneficial in total knee replacement surgery? A meta-analysis and systematic review. The Knee. 2010;17(2):141–7. 38. Zhang F-J, Xiao Y, Liu Y-B, Tian X, Gao Z-G. Clinical effects of applying a tourniquet in total knee arthroplasty on blood loss. Chin Med J (Engl) 2010;123(21):3030–3. 39. Keating EM, Meding JB. Perioperative blood management practices in elective orthopaedic surgery. J Am Acad Orthop Surg 2002;10(6):393–400.

Chapter 3

Role of Drains in Primary Total Joint Arthroplasty Alisina Shahi, Javad Parvizi

INTRODUCTION The use of drainage systems has a very long history. Hippocrates recommended using a wooden tube to drain the wound after operation.1 The canon book of Avicenna is probably one of the first written evidence that mentions the use of drains in the field of orthopaedic surgery.2 It was believed that drains decreased the volume of the haematoma, and therefore, reduced postoperative swelling, pain and even the rate of surgical site infection (SSI).3 Waugh and Stinchfield performed a study in 1961 on the advantages of draining. This study popularized the use of drainage in the field of orthopaedic surgery. Their study consisted of two groups of matched patients and the only variable was the usage of drain. They showed that the duration of postoperative rehabilitation was significantly shorter in patients with drainage, and the rate of infection was higher in patients without drainage (this difference was not statistically significant).4 On the other hand, there is mounting evidence to support that closed suction draining systems can increase the risk of bleeding due to elimination of the tamponade effect that is created in a closed wound.5–9 The tamponade effect implies that bleeding continues until the pressure in the wound increases to a certain level that eliminates further bleeding. In order to achieve this pressure, enough bleeding is required to fill the wound space. However, the space of a drainage device is also added to this dead space. Therefore, more blood is required to achieve this pressure. Surgeons who support the use of drains tend to use autologous blood transfusions, fibrin tissue adhesives, local ice packing and compression bandaging in order to prevent severe blood loss.10–12 However, there is still controversy concerning drainage use. The aim of this chapter is to review the current evidence in order to evaluate the role of drainage systems post total joint arthroplasty (TJA).

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POSTOPERATIVE DRAINS IN TOTAL KNEE ARTHROPLASTY Use of wound drainage after TJA is a controversial issue. Drain usage has fluctuated throughout time. Several studies stated that the use of drains could decrease haematoma formation after surgery.13–15 Some studies present that drains can improve wound outcomes in orthopaedic surgery and can theoretically decrease pain and swelling postoperatively.3,16,17 The size of the haematoma can be evaluated using different techniques. The easiest way is to compare the pre- and postoperative haematocrit measures to estimate the hidden blood loss, which would be the haematoma. A more accurate way to measure the amount of haematoma is by using ultrasonography to evaluate the thickness of the blood mass around the implant. Murphy et al. measured the hidden blood loss in two groups of patients; one group with drains and the other without them. They found that the size of the haematoma in the drained group was not smaller. The findings were justified by the tamponade effect mechanism.18 The most accepted benefit of drains is postoperative wound management. Many studies support this statement. Some studies report less accumulation of blood in the wound dressing.3,14,17 Other studies compared the weight of the discarded dressings of patients with and without drains to prove this matter.7,19 In support of drainage usage, some studies reported that the area of ecchymosis is notably less in the drainage group.3,14 Furthermore, formations of haematoma and effusion were evaluated in a study by Omonbude et al. using ultrasound 4 days after the procedure, and the results indicated that the drainage group had less haematoma when compared to the nondrainage group.20 A survey by Canty et al. presented that the majority of surgeons believed closed suction drainage can prevent infection.21 However, various articles have failed to prove the effectiveness of the drains and their role in infection prevention.3,7,14,17,19,22,23 A meta-analysis by Zhang et al. showed that infection occurred in 1.2% of the nondrainage group and in 0.5% of the drainage group; nevertheless, there was no significant difference in the pooled data.24 One of the most important complications after performing total knee arthroplasty (TKA) is thromboembolism. It is associated with increased mortality and morbidity. Currently, there is no consensus among orthopaedic surgeons for venous thromboembolic prophylaxis. The protocols

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31

for prophylaxis vary in different centers. Some surgeons claim performing TKA using a drain decreases postoperative knee swelling and can also play a role in thromboembolism risk reduction. However, the literature does not seem to support this claim. No significant difference was observed when the incidence of deep vein thrombosis was compared in case-control studies using drainage systems.5,14,25 The role of drains in the outcomes of TKA has been debated. Several studies have demonstrated that there is no statistical significance in range of motion in the absence or presence of a drainage system.5,17,19 We believe that using a drain cannot improve the range of motion long-term. As of now, there have been various articles that do not support the use of a drainage system in TKA.5–9,26–28 These studies juxtaposed the outcomes of using and not using drainage systems, concluding that not only is the drainage system not significantly beneficial, but that it can also be harmful. It has been shown that the risk for blood transfusion is higher when drainage systems are used.7,17,22 It was also shown that a postoperative drop in the level of haemoglobin is more severe when drains are used, along with a longer length of hospital stay.23 Although length of hospital stay depends on various factors, one reason why patients with drainage have a longer stay is due to the fact that they refuse to engage in any physical activities while having a drain placed in their knees, thus delaying their rehabilitation. In a meta-analysis comparing closed suction drainage and nondrainage in TKA, Zhang et al. found no significant difference in the incidence of infection, deep venous thrombosis and postoperative range of motion between the two groups.24

USING DRAINS IN TOTAL HIP ARTHROPLASTY Several studies have evaluated the impact of drains on total hip arthroplasty (THA). SSIs are considered the most important complication related to using drainage systems. Other studies focused on haematoma size, transfusion rate and hospital stay.

Drains and SSIs It was believed that drains could decrease the rate of SSI by draining the haematoma. Willett et al. investigated the relationship between the duration of drains and wound infection. They recommended that drains

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should be removed 24 h after the surgery, as they do not reduce the size of the haematoma after this period and can even increase the risk of infection.29 Since then, other studies have supported that the duration of drains is linked with wound infection. Many agree that the optimal time to remove the drains after THA is 24 h postoperatively.13,30–32

Size of the Haematoma In 2002, Widman et al. used an objective method to estimate the haematoma size. They compared two groups of patients; one with twodrain drainage and the other one without drainage. Using single photon emission computed tomography, the haematoma size was measured quantitatively by scintigraphy with labeled erythrocytes. Their study showed that the haematoma size was not statistically different between the two groups. Furthermore, patients in the drainage group lost more blood and had a higher rate of blood transfusion postoperatively. Authors explained these findings with the tamponade effect.33 Another study by Parrini et al. evaluated the haematoma size in 82 patients after THA using ultrasonography. They compared two groups of patients with different number of drains; one with two and the other with only one drain. They found that haematoma was always present in both groups. Nevertheless, the size of haematoma was significantly larger in the group where only one drain was applied.34

Postoperative Requirement for Blood Transfusion The need for blood transfusion is one of the most important evidences of the theory of the tamponade effect. It is still a controversial issue in the literature that using drains can increase or decrease the need for transfusion after surgery. Walmsley et al. investigated the rate of blood transfusion in a prospective, randomized, controlled trial among 552 patients; their results showed that patients with a drain have a significantly higher rate of blood transfusion.35 In another trial by Cheung et al., it was found that the rate of postoperative blood transfusion is not significantly different in patients with or without drains.36 Zeng et al. supported the results of Cheung et al. and concluded that no-drainage may decrease postoperative blood loss but has no advantage in reducing the rate of blood transfusion or even deep infection. They also believed postoperative complications may be higher with no drainage, as early

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33

postoperative exercise can be restricted by pain and swelling.37 On the other hand, a meta-analysis by Parker et al. presented that closed suction drainage can increase the need for blood transfusion after TJA and has no significant advantages.8

Length of Hospital Stay Some surgeons believe that usage of drainage does not directly affect the length of stay after primary THA.35,38 However, Cheung et al. presented that the wound in patients with no drains dries significantly sooner (mean 3 days) compared to autologous blood transfusion drains (mean 4 days) and patients with suction drains (mean 4 days). They have concluded that patients with no drains have significantly shorter duration of stay in hospital.36 González Della Valle et al. also showed that length of hospital stay is longer in patients who underwent elective THA when a drain is inserted (5.1 days vs. 4.7; p = 0.01). They recommended not using close-suction drainage in elective THA.39 Borghi and Casati found that there is a link between allogeneic blood transfusion and the length of hospital stay.40 There is also a relationship between allogeneic transfusion and disturbances in wound healing that can also affect the length of hospitalization.41 It can be concluded that prevention of allogeneic blood transfusion can reduce the duration of stay, and any matter that increases the risk of allogeneic blood transfusion can also lead to longer hospitalization.

CONCLUSION Routine use of drains in the field of orthopaedic surgery has been questioned recently. Several randomized trials have been carried out to address this issue. A recent meta-analysis by Zhou et al. indicated that closed suction drainage increases the rate of homologous blood transfusion. They observed no statistically significant difference in the incidence of blood loss, changes in haemoglobin level, infection, functional assessment, or other major complications. Their results demonstrated that using closed suction drainage in elective THA could be even of more harm.42 In conclusion, randomized studies have presented that usage of drainage is not mandatory in THA and TKA and in some cases could be deleterious.27

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In the end, it is surgeon’s judgment, which can identify the patients that may benefit from insertion of a drainage device.

REFERENCES 1. Levy M. Intraperitoneal drainage. Am J Surg 1984;147(3):309–14. 2. Afshar A. Concepts of orthopedic disorders in Avicenna’s Canon of Medicine. Arch Iran Med 2011;14(2):157–9. 3. Kim YH, Cho SH, Kim RS. Drainage versus nondrainage in simultaneous bilateral total hip arthroplasties. J Arthroplasty 1998;13(2):156–61. 4. Waugh TR, Stinchfield FE. Suction drainage of orthopaedic wounds. J Bone Joint Surg Am 1961;43-A:939–46. 5. Adalberth G, Byström S, Kolstad K, Mallmin H, Milbrink J. Postoperative drainage of knee arthroplasty is not necessary: a randomized study of 90 patients. Acta Orthop Scand 1998;69(5):475–8. 6. Niskanen RO, Korkala OL, Haapala J, Kuokkanen HO, Kaukonen JP, Salo SA. Drainage is of no use in primary uncomplicated cemented hip and knee arthroplasty for osteoarthritis: a prospective randomized study. J Arthroplasty 2000;15(5):567–9. 7. Esler CNA, Blakeway C, Fiddian NJ. The use of a closed-suction drain in total knee arthroplasty. A prospective, randomised study. J Bone Joint Surg Br 2003;85(2):215–7. 8. Parker MJ, Roberts CP, Hay D. Closed suction drainage for hip and knee arthroplasty. A meta-analysis. J Bone Joint Surg Am 2004;86-A(6):1146–52. 9. Jones AP, Harrison M, Hui A. Comparison of autologous transfusion drains versus no drain in total knee arthroplasty. Acta Orthop Belg 2007;73(3):377–85. 10. Gibbons CE, Solan MC, Ricketts DM, Patterson M. Cryotherapy compared with Robert Jones bandage after total knee replacement: a prospective randomized trial. Int Orthop 2001;25(4):250–2. 11. Kullenberg B,Ylipää S, Söderlund K, Resch S. Postoperative cryotherapy after total knee arthroplasty: a prospective study of 86 patients. J Arthroplasty. 2006;21(8):1175–9. 12. Radkowski CA, Pietrobon R,Vail TP, Nunley JA 2nd, Jain NB, Easley ME. Cryotherapy temperature differences after total knee arthroplasty: a prospective randomized trial. J Surg Orthop Adv 2007;16(2):67–72. 13. Drinkwater CJ, Neil MJ. Optimal timing of wound drain removal following total joint arthroplasty. J Arthroplasty 1995;10(2):185–9. 14. Holt BT, Parks NL, Engh GA, Lawrence JM. Comparison of closed-suction drainage and no drainage after primary total knee arthroplasty. Orthopedics 1997;20(12):1121– 1124; discussion 1124–1125. 15. Martin A, Prenn M, Spiegel T, Sukopp C, von Strempel A. Relevance of wound drainage in total knee arthroplasty--a prospective comparative study. Z Für Orthop Ihre Grenzgeb 2004;142(1):46–50. 16. Berman AT, Fabiano D, Bosacco SJ, Weiss AA. Comparison between intermittent (spring-loaded) and continuous closed suction drainage of orthopedic wounds: a controlled clinical trial. Orthopedics 1990;13(3):309–14. 17. Ovadia D, Luger E, Bickels J, Menachem A, Dekel S. Efficacy of closed wound drainage after total joint arthroplasty. A prospective randomized study. J Arthroplasty 1997;12(3):317–21. 18. Murphy JP, Scott JE. The effectiveness of suction drainage in total hip arthroplasty. J R Soc Med 1993;86(7):388–9. 19. Tao K, Wu H, Li X, Qian Q, Wu Y, Zhu Y, et al. The use of a closed-suction drain in total knee arthroplasty: a prospective, randomized study. Zhonghua Wai Ke Za Zhi 2006;44(16):1111–4.

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20. Omonbude D, El Masry MA, O’Connor PJ, Grainger AJ, Allgar VL, Calder SJ. Measurement of joint effusion and haematoma formation by ultrasound in assessing the effectiveness of drains after total knee replacement: a prospective randomised study. J Bone Joint Surg Br 2010;92(1):51–5. 21. Canty SJ, Shepard GJ, Ryan WG, Banks AJ. Do we practice evidence based medicine with regard to drain usage in knee arthroplasty? Results of a questionnaire of BASK members. The Knee 2003;10(4):385–7. 22. Cao L, Ablimit N, Mamtimin A, Zhang K, Li G, Li G, et al. Comparison of no drain or with a drain after unilateral total knee arthroplasty: a prospective randomized controlled trial. Zhonghua Wai Ke Za Zhi. 2009;47(18):1390–3. 23. Tai T-W, Jou I-M, Chang C-W, Lai K-A, Lin C-J,Yang C-Y. Non-drainage is better than 4-hour clamping drainage in total knee arthroplasty. Orthopedics. 2010;33(3). 24. Zhang Q, Guo W, Zhang Q, Liu Z, Cheng L, Li Z. Comparison between closed suction drainage and nondrainage in total knee arthroplasty: a meta-analysis. J Arthroplasty. 2011;26(8):1265–72. 25. Mengal B, Aebi J, Rodriguez A, Lemaire R. A prospective randomized study of wound drainage versus non-drainage in primary total hip or knee arthroplasty. Rev Chir Orthopédique Réparatrice Appar Mot 2001;87(1):29–39. 26. Crevoisier XM, Reber P, Noesberger B. Is suction drainage necessary after total joint arthroplasty? A prospective study. Arch Orthop Trauma Surg 1998;117(3):121–4. 27. Kosins AM, Scholz T, Cetinkaya M, Evans GRD. Evidence-based value of subcutaneous surgical wound drainage: the largest systematic review and meta-analysis. Plast Reconstr Surg 2013;132(2):443–50. 28. Zhang X, Wu G, Xu R, Bai X. Closed suction drainage or non-drainage for total knee arthroplasty: a meta-analysis. Zhonghua Wai Ke Za Zhi. 2012;50(12):1119–25. 29. Willett KM, Simmons CD, Bentley G. The effect of suction drains after total hip replacement. J Bone Joint Surg Br 1988;70(4):607–10. 30. Sørensen AI, Sørensen TS. Bacterial growth on suction drain tips. Prospective study of 489 clean orthopedic operations. Acta Orthop Scand. 1991;62(5):451–4. 31. Erceg M, Beciþ K. Postoperative closed suction drainage following hip and knee aloarthroplasty: drain removal after 24 or after 48 hours?. LijeĀniĀki Vjesn 2008;130 (5-6):133–5. 32. Rowe SM, Yoon TR, Kim YS, Lee GH. Hemovac drainage after hip arthroplasty. Int Orthop 1993;17(4):238–40. 33. Widman J, Jacobsson H, Larsson SA, Isacson J. No effect of drains on the postoperative hematoma volume in hip replacement surgery: a randomized study using scintigraphy. Acta Orthop Scand 2002;73(6):625–9. 34. Parrini L, Baratelli M, Parrini M. Ultrasound examination of haematomas after total hip replacement. Int Orthop 1988;12(1):79–82. 35. Walmsley PJ, Kelly MB, Hill RMF, Brenkel I. A prospective, randomised, controlled trial of the use of drains in total hip arthroplasty. J Bone Joint Surg Br 2005;87(10):1397–401. 36. Cheung G, Carmont MR, Bing AJF, Kuiper J-H, Alcock RJ, Graham NM. No drain, autologous transfusion drain or suction drain? A randomised prospective study in total hip replacement surgery of 168 patients. Acta Orthop Belg 2010;76(5):619–27. 37. Zeng W-N, Zhou K, Zhou Z-K, Shen B, Yang J, Kang P, et al. Comparison between drainage and non-drainage after total hip arthroplasty in chinese subjects. Orthop Surg 2014;6(1):28–32. 38. Strahovnik A, Fokter SK, Kotnik M. Comparison of drainage techniques on prolonged serous drainage after total hip arthroplasty. J Arthroplasty 2010;25(2):244–8. 39. González Della Valle A, Slullitel G,Vestri R, Comba F, Buttaro M, Piccaluga F. No need for routine closed suction drainage in elective arthroplasty of the hip: a prospective randomized trial in 104 operations. Acta Orthop Scand 2004;75(1):30–3.

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40. Borghi B, Casati A. Incidence and risk factors for allogenic blood transfusion during major joint replacement using an integrated autotransfusion regimen. The Rizzoli Study Group on Orthopaedic Anaesthesia. Eur J Anaesthesiol 2000;17(7):411–7. 41. Weber EWG, Slappendel R, Prins MH, van der Schaaf DB, Durieux ME, Strümper D. Perioperative blood transfusions and delayed wound healing after hip replacement surgery: effects on duration of hospitalization. Anesth Analg 2005;100(5):1416–1421, table of contents. 42. Zhou X, Li J, Xiong Y, Jiang L, Li W, Wu L. Do we really need closed-suction drainage in total hip arthroplasty? A meta-analysis. Int Orthop 2013;37(11):2109–18.

Chapter 4

Prevention of Periprosthetic Joint Infection Alisina Shahi, Javad Parvizi

INTRODUCTION Total joint arthroplasty (TJA) is one of the most effective medical interventions and improves the quality of life and function level in most of the patients suffering from degenerative joint disease. It is predicted that by the year 2030, the number of primary total knee arthroplasty (TKA) procedures will reach 3.48 million annually, that is, a 673% increase in comparison to 2005. The demand for primary total hip arthroplasty (THA) is projected to grow by 174% to 5,72,000, which means that more than 4 million primary TJAs will be performed in a year just in the United States.1 The number of revision knee and hip procedures will increase correspondingly. The average incidence of periprosthetic joint infection (PJI) is between 0.25% and 2.0% within 2 years after primary THA or TKA.2–4 PJI is a serious complication of TJA; it is the primary indication for revision TKA and the third indication for revision THA.5–7 Diagnosis of PJI is very challenging because it can present at any time postoperatively.8,9 Once it is diagnosed, managing PJI is also very difficult. It requires prolonged rehabilitation, antibiotic therapy and often multiple procedures to treat.10 It also has a very high and growing impact on the health care system, with an approximate cost of $320 million for infected revisions in the United States in 2001 and $566 million in 2009. It is estimated that the cost will exceed $1.62 billion by the year 2020.11 Therefore, strong efforts to effectively treat PJI are mandatory. Treatment of the infection requires appropriate evaluation of the chronicity and the causing germ. The wound status and the overall condition of the patient should also be considered. In this chapter, we will survey PJI and associated risk factors. Finally, an overview of the current evidence available for the prevention of PJI will be provided.

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DEFINITION OF PJI The Musculoskeletal Infection Society has provided a list of criteria based on the recent available evidence to define PJI. Based on the described criteria, definite PJI exists when12: A. there is a sinus tract communicating with the prosthesis; or B. a pathogen is isolated by culture from two or more separate tissues or fluid samples obtained from the affected prosthetic joint; or C. when four of the following six criteria exist; i. elevated serum erythrocyte sedimentation rate and serum C-reactive protein (CRP) concentration, ii. elevated synovial white blood cell count, iii. elevated synovial polymorphonuclear percentage (PMN%), iv. presence of purulence in the affected joint, v. isolation of a microorganism in one culture of periprosthetic tissue or fluid, or vi. greater than five neutrophils per high-power field in five highpower fields observed from histologic analysis of periprosthetic tissue at ×400 magnification. PJI may still be present if fewer than four of these criteria are met. Furthermore, in cases infected by low-virulence organisms such as Propionibacetium acnes, despite the presence of PJI, some of these criteria may not be usually present.

CLASSIFICATION OF PJI Depending on the type of pathogenesis or time of clinical diagnosis, there are different types of classifications of PJI. When pathogenesis is concerned, two different routes are possible, exogenous or haematogenous. Exogenous infections often occur during the surgery or shortly after it, usually when there is a large haematoma. On the other hand, haematogenous infections can occur at any time postoperatively.13 There are some reports that infected prostheses can impair the immune system; these reports have also shown that the minimal dose of abscess forming for Staphylococcus aureus has decreased significantly to at least 10,000-fold in both animal and human models.14,15 Implants could also increase the chance of haematogenous infections; reports have shown a risk of 30–40% for device-related haematogenous infection during S. aureus sepsis.16,17

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One PJI classification is according to the duration of its clinical manifestation postoperatively. This time period is divided into four stages13,18,19: 1. Early postoperative infection occurs within the first 4 to 8 weeks after the implantation. 2. Delayed-onset PJI presents between the third month up to 24 months postoperatively. 3. Late-onset PJI usually happens after 2 years from the surgery and often has a sudden onset in an otherwise well-functioning joint. 4. Silent PJI occurs with the presence of a positive culture at the time of revision with no previous evidence of infection. Early, delayed and silent infections usually have exogenous sources. Early PJIs are often caused by virulent organisms such as S. aureus and Escherichia coli. On the other hand, delayed and silent are usually caused by low-virulence microorganisms such as coagulase-negative staphylococci and Propionibacterium acnes.19,20 As mentioned earlier, late PJI has an acute presentation and is usually caused by haematogenous spread. The most common source of infection is known to be skin and soft tissue, but there are some reports of seeding from respiratory, urinary, gastrointestinal tract and dental infections.21 Sendi et al. reported that the source of infection in 57.5% of haematogenous cases of PJI could not be identified, as there was no sign of primary bacteremia/infection by the time of PJI presentation.16

PREVENTION OF PJI Development of PJI depends on both host and environmental factors, and the best way to prevent it is to improve these two factors during the pre-, intra-, and postoperative phases. A number of preoperative host factors that can increase the chance of PJI have recently been identified. These include, but are not limited to, diabetes, rheumatoid arthritis, congestive heart failure, renal disease, hypercholesterolaemia, chronic pulmonary disease, venous thromboembolism (VTE), preoperative anaemia, peripheral vascular disease, alcohol abuse, depression, psychoses, metastatic tumour and valvular disease.4,22,23 Patients who present for elective orthopaedic procedures are typically in suboptimal health. Furthermore, the impact of various risk factors appears to be accumulative, such that each factor has an individual affect to increase the risk of infection and a synergistic potential on the risk conferred by other factors.24,25 Thus, identifying risk factors and

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addressing them in the preoperative setting is critical to reduce PJI and other postoperative complications.

PREOPERATIVE Optimization of General Health Optimizing adjustable health factors such as blood sugar is crucial to ensure a safe TJA. Reports have shown that the general condition of the patient’s health has a direct link with the rate of postoperative complications; and conditions such as ASA >2, uncontrolled diabetes and rheumatoid arthritis can significantly increase the risk of PJI.4,22,26–28 As mentioned earlier, some studies presented that medical conditions have an accumulative effect on the risk of PJI. Lai et al. and Malinzak et al. have shown that any other medical comorbidity accompanied by diabetes leads to a higher risk of infection.24,29 Therefore, it is mandatory to assess all patients in a multidisciplinary clinic prior to TJA and manage comorbidities if required. These assessments have shown to reduce the postoperative mortality rate and per-admission costs significantly in complex orthopaedic surgeries, including TJA.30 Marchant et al. also presented that glycemic control has a high impact on PJI.31 They found that patients with a higher level of haemoglobin A1c had significantly higher incidence of PJI, at an odds ratio of 2.31. Furthermore, Mraovic et al.32 presented that not only is the preoperative blood glucose level important but the postoperative level also plays an important role. Patients with sugar levels greater than 200 mg/dL on postoperative Day 1 are at a higher risk of developing PJI by twofold. Therefore, there is a general consensus in the literature supporting the importance of preoperative health optimization, focusing on the control of blood glucose level. Pre-assessment clinics mostly focus on optimizing the host factors in the preoperative phase (adjustable risk factors) such as nutrition status, blood sugar level, cardiac and respiratory evaluation, and assessment for possible sources of infection and Methicillin-resistant S. aureus (MRSA) decolonization.

Bacterial Decolonization Prevention guidelines regarding surgical site infections (SSIs) published by the Centers for Disease Control (CDC) have recommended taking a bath

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with an antiseptic agent at least once on the night before the operation to reduce the load of bacteria.33 Many reports have shown that a whole-body bath with an antiseptic agent reduces the bacterial load in the skin and lowers the risk of SSIs.34–37 The CDC has also mentioned that SSIs are the second most common cause of nosocomial infections and are responsible for more than 25% of hospital-related infections in the United States.38,39 There is still a debate on how to achieve entire body coverage and to maintain adequate concentrations of the solution for effective results.68 Another issue is the patient’s compliance with these protocols.40 There is some evidence that applying the aforementioned protocol using chlorhexidine gluconate (CHG) twice daily by patients at home prior to TJA could significantly reduce the risk of SSIs.41,42 In conclusion, although home skin preparation before TJA seems to be a simple and costeffective technique, patient compliance is still an issue. Future randomized controlled trials are required to study the effectiveness of these protocols in the prevention of PJI. In our institution, patients are required to start using a shower scrub 2 days before the surgery using 4% CHG with 4% isopropyl alcohol (Hibiclens) once daily. We do not suggest routine decolonization for nasal MRSA.

Prophylactic Antibiotics There is mounting evidence in the literature supporting the benefits of prophylactic antibiotics in the prevention of PJI.43–46 One of the pioneer studies in the field of orthopaedic surgery is without a doubt that performed by Fogelberg et al. in 1970, where they compared two groups of patients; one group was given a prophylactic penicillin preoperatively, intraoperatively and up to 5 days postoperatively; and the other group was the control with no antibiotics. The incidence of infection was 1.7% in the treated group versus 8.9% in the control group. The other point mentioned in this study was the increase in the prevalence of MRSA infections, demonstrating the fine line between the proper use and overuse of antibiotics.43 The aim of prophylactic antibiotics is to cover the spectrum of the most common organisms of PJI, Staphylococci and Streptococci. Therefore, cefazolin and cefuroxime are the antibiotics of choice. There are many debates about the duration of antibiotic coverage in the literature. Engesaeter et al. have shown that in THA the effectiveness of four doses of intravenous antibiotics on the operation day is significantly higher than that for fewer doses. On the other hand, Kasteren et al. have shown that there

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is no statistical difference between the single-dose and four-dose regimen. Furthermore, they found that the rate of aseptic loosening was higher in patients who received a single-dose regimen.47,48 According to the guideline of the American Academy of Orthopaedic Surgeons (AAOS), recommendations for the use of intravenous prophylaxis antibiotics are as follow49: First, special care is required for selecting the prophylaxis antibiotic, consistent with the current recommendation of the literature. Patient allergies and resistance issues also need to be taken into account. Currently, the preferred antibiotics for orthopaedic procedures are cefazolin and cefuroxime. In patients allergic to ơ-lactam, clindamycin and vancomycin are good substitutions. Vancomycin is also recommended for patients with known MRSA colonization or in centers with recent MRSA outbreaks. There is always a risk of colonization and infection development of VRE due to exposure to vancomycin. An excessive use of vancomycin is strongly discouraged. It should be reserved for serious ơ-lactam-resistant infections or in patients with allergy to ơ-lactam antimicrobial agents. Second, the efficiency of the therapy depends on the timing and dose adjustment of antibiotics. The best time for administration of prophylactic antibiotics is within 1 h before skin incision. For antibiotics with longer infusion time such as vancomycin, this time period should be extended to 2 h. In case of tourniquet use, the antibiotic must be fully infused prior to tourniquet inflation. Dose adjustment of the antibiotics is also a very important issue and there are some circumstances in which the dose should be increased: 1. Antibiotic dosage should correspond with the patient’s weight; for example, in patients heavier than 80 kg, the dose of cefazolin should be doubled. 2. If the surgical duration lasts one to two times longer than the half-life of the administered antibiotic. 3. In cases of significant blood loss. The guideline for intraoperative administration of antibiotics is: every 2–5 h for cefazolin, every 3–4 h for cefuroxime, every 3–6 h for clindamycin and every 6–12 hours for vancomycin. Third, postoperatively, the administration duration of the prophylactic antibiotics should not be more than 24 h. There is no evidence in the literature to support the benefit of continuing prophylactic antibiotics after drains or catheters are removed after 24 h postoperatively.

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Indications for Vancomycin For the majority of patients who undergo elective arthroplasty, firstgeneration cephalosporins are sufficient. However, vancomycin might be needed for some patients. In our opinion, patients with the following criteria are required to have vancomycin in addition to a first-generation cephalosporin: 1. Known carriers of MRSA. 2. Patients from dialysis units, nursing homes, or centers with confirmed outbreak of MRSA. 3. Health care workers. 4. Patients with a history of penicillin allergy. While clindamycin is a wellknown alternative for these patients, because of the high association of Clostridium difficile enteritis and clindamycin consumption, it is highly recommended to use vancomycin.50 There are two important points that should be considered when vancomycin is prescribed: first, vancomycin must be administered with slow infusion (at least 1 h) to prevent adverse effects such as hypotension, chest pain and red man syndrome.51 Second, vancomycin does not have full coverage on methicillin-sensitive S. aureus. Therefore, it should always be administered in combination with a cephalosporin.52 The current practice at the Rothman Institute for administration of prophylactic antibiotics is as follows: 1. Approximately 30 min before the surgery, cefazoline is given to all patients. 2. In patients with a positive history of MRSA or allergy to penicillin, vancomycin is infused 60 min previous to the skin incision. 3. All prophylactic antibiotics are discontinued 24 h postoperatively.

INTRAOPERATIVE Preoperative Hair Removal Although hair removal at the incision site is part of the routine preparation for surgery, there is no evidence to support that this practice can decrease the risk of SSIs. Furthermore, there are some reports showing that hair removal could even be harmful and increase the risk of infection. A review article pub-

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lished by the Cochrane group concluded that there was no statistical difference in the rate of SSIs between operations where patients had hair removal and those in which hair was not removed. The study also mentioned that there was a significantly higher rate of SSIs among patients having hair removal with a razor than those whose hair was removed with clippers.53

Preoperative Skin Preparation Patients Native microorganisms of the skin have always played an important role in SSIs. Von Eiff et al. have presented that the cause of more than 80% of hospital-acquired S. aureus infections is endogenous bacteria, which colonize in the patient’s epidermis, according to genotyping studies.54 According to the estimation of the CDC, the SSIs are the second major cause for nosocomial infections, which are responsible for more than onefourth of the health care related infections in the United States.38,39 Orthopaedic surgery is not exceptional and many SSIs in this field are acquired during the surgery, with the main source being skin flora.55,56 Regardless of the recent advances in prophylactic antibiotics, the importance of skin decolonization agents is more prominent than ever before.57 There are many kinds of antiseptic agents available for skin preparation before surgery. The three agents most commonly used are CHG, alcohol-based solutions, and povidone-iodine. Each of them has some advantages and some disadvantages. Chlorohexidine, for instance, is very popular due to long-lasting, accumulative effect against gram-positive and gram-negative bacteria commonly found in human skin flora. On the other hand, povidone-iodine is very effective on skin flora but becomes relatively ineffective upon contact with blood and has shorter duration of activity than CHG. Alcohol is a very good antimicrobial agent but the flammability and discontinued effects after drying are the downsides of this agent. A metaanalysis published by Cochrane group in 2004 presented that there is no significant difference in the rate of SSIs in clean surgeries carried out with different antiseptic agents for the skin preparation.57 More recent studies have mentioned that the combination of alcohol and CHG is more successful than alcohol and povidone-iodine in reducing the bacterial load of the skin; however, the rate of SSIs is not significantly different.58–60

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Surgeon There are two main types of hand antiseptic agents for hand preparation: hand scrub solutions and hand rub agents. Usually hand scrubs are solutions of CHG or povidone-iodine and hand rubs are mostly alcoholbased solutions. Most of the studies in the literature claim that the efficacy of povidoneiodine and CGH are the same in decreasing bacterial colony units, and the rate of SSIs was not different in using either hand scrub solutions or hand rubs.61,62 In addition to being cost-effective, some reports mentioned that hand rubs reduce water consumption and increase surgeon compliance.61 Draping There are numerous articles supporting the use of plastic surgical adhesive tapes or non-permeable paper drapes for draping the surgical site.63–66 Traditional cloth drapes tend to get wet during the surgery and could increase bacterial penetration; nonpermeable paper drapes were introduced to overcome this issue.63 Ritter et al. have presented that Ioban iodophorimpregnated drapes (3M Health Care) can reduce wound contamination but do not decrease the wound infection rate after TJA.67 In a microbial evaluation study of adhesive plastic surgical drapes, deep wound contamination was compared between plastic adhesive drapes and cloth drapes. The cultures were collected right before the closing and the result showed 60% of contamination when cloth drapes were used vs. 6% contamination with plastic adhesive drapes.63 In another study performed by Fairclough et al., it was reported that the rate of wound contamination during hip surgery decreased from 15% to 1.6% after using plastic adhesive drapes.68 The efficacy of plastic adhesive drapes is optimum when the skin preparation is performed using alcohol-based solutions. DuraPrep is considered to improve the adhesion properties of the drapes, and it is hypothesized to decrease wound contamination.69 Plastic adhesive drapes can provide a sterile operative field at the beginning of the surgery and by immobilization of the bacteria underneath the drape; the risk of surgical site contamination is also reduced. Furthermore, iodophor-impregnated drapes also apply antimicrobial protection to the skin and can reduce the risk of contamination. However, there are controversies about the effectiveness of plastic adhesive drapes in the prevention of bacterial contamination. In 2007, the Cochrane Wound Group reviewed 4000 patients in seven different studies

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and concluded that there is no positive evidence for the reduction of the rate of SSI by using adhesive drapes (plain or infused with antimicrobials).70

Gloving Sterile surgical gloves are dual protection barriers; on one hand, they protect the patients from residual bacteria on the surgeon’s hands, and on the other hand, they protect the surgeon from the patient’s body fluids. Because double-gloving reduces the risk of perforation, it is highly recommended for orthopaedic procedures, where sharp edges are commonly encountered during the surgery.71–73 In a study, Beldame et al. presented that changing the exterior glove after the incision and prior to the implantation can reduce the risk of perforation by 80%.74 Furthermore, some studies have shown that even double-gloving is not enough and inner gloves could have perforations and contamination. Accordingly, triple-gloving has been recommended during TJA to prevent the risk of contamination and PJI.75,76 The triple-gloving protocol was introduced by Sutton et al. in 1998. The protocol was to use two latex gloves with a cut-resistant layer between them. Results showed a meaningful decrease in the incidence of perforation in comparison with the double-gloving protocol. Triple-gloving is also very popular in maxillofacial surgeries.77 In a study by Pieper et al., different protocols of triple-gloving were compared with double gloving in maxillofacial surgeries. The study showed that all different techniques of triple-gloving are superior to double-gloving in terms of inner glove perforation. However, triple-gloving has some disadvantages, such as a decrease in tactile sensation and surgical dexterity.78

Operating Room Environment Laminar Flow The main goal in designing the operating room (OR) is to reduce patient’s exposure to bacteria during surgery. Laminar airflow (LAF) was first introduced in the United States in 1964. Positive air pressure is created in the surgical field via the directional airflow passing through higher-efficiency particulate air by vertical LAF and can help to reduce the incidence of PJI.79–82 However, Brandt et al. state that LAF provides no benefits and even increases the risk of SSI after THA. Eight studies conducted over a span of 10 years were pooled in a recent systematic review, which concluded that LAF does not reduce the rates of PJI; therefore, the authors did not recommend its installation in ORs.83

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The LAF is often disrupted by the opening of the OR door, therefore giving pathogens an opportunity to enter the area around the operation site and increasing the risk of PJI.67,79,84 The average rate of door openings for primary and revision TJA has been reported by Panahi et al. to be 0.69 openings per min and 0.84 openings per min, respectively. Despite frequent traffic entering and exiting the OR, it is recorded that only 8% corresponds with scrubbing in and out, showing a high amount of unjustified traffic during the operation. Therefore, it is recommended to try and decrease traffic in the OR in order to reduce the risk of PJI.85 On the other hand, there is mounting evidence supporting that LAF can decrease the incidence of SSIs and the bacterial count in the surgical site and on instruments.79,86–91 In 1982, Lidwell et al. presented that there was a direct relationship between the number of airborne organisms and the rate of deep postoperative infections. The authors showed that the incidence of SSIs had decreased from 3.4% to 1.6% by adding LAF systems to the ORs. Nevertheless, there is still controversy about the pros and cons of LAF.92 The CDC has no comment supporting whether LAF may reduce the rate of SSI. There is no specific suggestion for performing arthroplasty procedures under LAF. Nonetheless, the CDC has published the following guidelines: CDC Guidelines:93 1. Maintain positive-pressure ventilation with respect to corridors and adjacent areas. 2. Maintain *15 ACH, of which *3 ACH should be fresh air. 3. Filter all recirculated and fresh air through the appropriate filters, providing 90% efficiency (dust-spot testing) at a minimum. 4. In rooms not engineered for horizontal LAF, introduce air at the ceiling and exhaust air near the floor. 5. Do not use ultraviolet lights to prevent SSIs. 6. Keep OR doors closed except for the passage of equipment, personnel and patients, and limit entry to essential personnel. Personal Protection Systems In the 1960s, Sir John Charnley was the first to introduce the idea of the personal protection system (PPS), also known as the human exhaust system, in order to decrease the number of airborne bacteria and contamination in TJA.94 There is no uniform opinion regarding the use of PPS in relation to the incidence of PJI.95–98 Major issues to consider regarding PPSs are

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their bulkiness and susceptibility to contamination. Kearns et al. reported in a current study that out of 102 PPSs that were tested, 53 were contaminated with Staphylococcus and one was contaminated with MRSA. They concluded that in more than half of the cases, the PPS does not stay sterile externally. It was advised that the PPSs not be touched during procedures, and if contact does occur, the gloves should be replaced.99 OR Traffic Contamination rates have a direct association with OR traffic. Some studies have shown that the major cause of OR contamination is OR staff. Furthermore, more staff leads to more door openings, which can interfere with LAF and cause turbulence, which itself can increase the rate of infection.87,100,101 In a study performed by Panahi et al., it was shown that the average door openings is 0.65 per min during the course of a primary arthroplasty and this rate is 0.84 per min for revision cases. Among these door openings, 35% occurred before the incision. Most of the door openings were created by circulating nurses and equipment company representatives. In 47% of cases, the people who entered the OR had no identified reason for entering the room. The study concluded that the majority of OR traffic could easily be eliminated.85 Another disadvantage of increased OR traffic is the distraction it causes for the surgeon.101 The CDC recommendation for OR traffic is to ‘keep OR doors closed except for the passage of equipment, personnel and patients, and limit entry to essential personnel.’93

Operative Time The risk of PJI after TJA has been stated to increase after extensive operative times.102–104 After observing 9245 patients undergoing TJA, it was concluded by Pulido et al.4 that longer operation hours are mainly responsible for PJI. Kurtz et al. and Peersman et al. support this conclusion.105,106 The rate of PJI tends to be inversely proportional to the surgeon’s volume, meaning that the lower the surgeon volume, the higher the risk of infection. This seems to be especially statistically significant after TKA.107

Addition of Antibiotics to Cement As of now, the use of antibiotic-impregnated cement is the standard for use when performing cemented primary arthroplasty. When both intravenous antibiotic prophylaxis along with antibiotic-impregnated cement is used in procedures, the risk of PJI tends to be lower.27,47

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Antibiotic-impregnated cement is particularly used in revision settings.108–110 When juxtaposing the effects of solely using prophylactic antibiotics against its combination with cement-impregnated antibiotics, it is evident that the combination of the two is much more efficient for patients possessing other PJI risk factors.111,112 Polymethyl methacrylate (PMMA), more routinely called bone cement, is an effective method for topical delivery of antibiotics in the bone and joint.113 However, not all antibiotics are compatible for use with PMMA. In order to be suitable, the antibiotic should meet the following criteria114: 1. Tolerance to high temperature caused by exothermic reaction in the cement. 2. Diffusible in water. 3. Ability to be combined with other antibiotics. 4. Have low allergic potential. 5. Preferably have a long half-life.

Wound Closure and Surgical Dressing Numerous techniques such as skin staples, absorbable sutures and knotless barbed sutures are used for skin closure in arthroplasty procedures. It has been concluded in a recent study by Smith et al. that compared to traditional suturing, skin staples increase the risk of infection when closing the wound. However, only one among six reviewed studies possessed acceptable methodology.115 In a study performed by Newman et al. observing 181 patients after TKA, it was reported that there were far fewer complications when using skin staples for wound closure when paralleled with the absorbable subcuticular sutures method.116 A randomized control study was conducted by Eggers et al. in order to record the superficial infection rates of subcuticular sutures and tissue adhesives and skin staples after TKA. The results indicated that subcuticular sutures had the highest rate of infection (26%) and skin staples had the lowest (5%); yet neither technique needed any antibiotic treatment. Additionally, the skin staple method was not only quicker but also the most cost-efficient. However, it required the patient to have a longer hospital stay compared to other techniques.117 Knotless barbed sutures have recently been a topic of high interest in wound closure techniques after TJA. The majority of studies done on this method have reported that barbed sutures have a quicker closure time when juxtaposed with traditional techniques.118–120

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In another study done by Patel et al., it was reported that using barbed sutures could cause a higher chance of wound complications particularly after TKA (4.3%) as opposed to staples (1.1%) and standard absorbable method risks (4.2%).118 Nevertheless, there are still disputes regarding the ideal closure technique. Cautious tissue handling and the kind of dressing applied after the procedure are essential factors in the wound healing process and influence the surgical method performed.121,122 The role of the wound dressing is to act as a barrier between the tissue and the external bacteria, preventing the wound from possible injuries. It also assists with homeostasis and reduces dead space and discomfort. Furthermore, re-epithelization and collagen synthesis rates are increased in wounds that have the wound dressing applied to them when compared to wounds that are allowed to be exposed to air.123,124 Dumville et al. conducted a recent Cochrane review comparing different dressings and found that there is no evidence to support that one dressing is more ideal than the other for preventing SSIs. The review suggests the decision of choosing a dressing should be based on the cost and necessity of the product.125 Using the jubilee technique, a hydrofiber/hydrocolloid dressing has been observed to reduce blister formation rates after TJA, but has no particular effect on the rate of SSIs.121 A prospective randomized study performed by Burke et al. paralleling standard adhesive dressing and the jubilee method after TJA recorded a noteworthy decrease in leakage and blister formation with the jubilee dressing technique; however, no significant decrease in the SSI rate was observed. Therefore, the authors suggest using the hydrofiber/hydrocolloid dressing technique in order to reduce possible complications after TJA.126

POSTOPERATIVE Postarthroplasty Antibiotic Prophylaxis As mentioned earlier, PJI can occur any time after the surgery. Episodic bacteremia could be a potential risk for PJI and certain medical procedures are more likely to cause bacteremia. Therefore, in 2012, the AAOS released a new guideline on ‘The Prevention of Orthopaedic Implant Infections in Patients Undergoing Dental Procedures.’ The guideline is a production of teamwork between the AAOS and the American Dental Association (ADA). It has three main recommendations127:

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1. The practitioner might consider discontinuing the practice of routinely prescribing prophylactic antibiotics for patients with hip and knee prosthetic joint implants undergoing dental procedures. 2. We are unable to recommend for or against the use of topical oral antimicrobials in patients with prosthetic joint implants or other orthopaedic implants undergoing dental procedures. 3. In the absence of reliable evidence linking poor oral health to prosthetic joint infection, it is the opinion of the work group that patients with prosthetic joint implants or other orthopaedic implants maintain appropriate oral hygiene. Although the first recommendation is supported by limited documentation, it has the highest level of evidence. The second is an inclusive recommendation; according to the current literature, the benefits of topical oral antimicrobials are not quite clear. The third recommendation is a consensus. In August 2013, 400 delegates from 52 countries and 130 professional societies gathered together, forming 15 different workgroups to discuss recommendations and convening again to form a consensus on the practices of treating PJI. The meeting resulted in a book, which discusses almost all of the critical and debateable points of PJI. The workgroup concluded that the use of prophylactic antibiotics prior to dental procedures in patients who underwent TJA should be based on individual patient risk factors and the complexity of the dental procedure. Furthermore, in cases of viral infection, it is recommended that there is no role for oral antibiotics, even for patients at higher risk. The workgroup also concluded that for other minor surgical procedures such as endoscopy and colonoscopy, transient bacteremia could be minimized by administration of prophylactic antibiotics, especially in highrisk patients.128

CONCLUSION PJI infection is a serious complication with significant morbidity and mortality. Several factors in the pre-, intra- and postoperative phases are involved that can predispose a patient to PJI. It is always better to focus on prevention rather than treatment. One of the most important preoperative factors to reduce the risk of PJI is optimization of the patient’s health. It is recommended to have all patients evaluated in pre-assessment clinics prior to elective TJA. Administration of preoperative prophylactic antibiotics

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should always be considered. It is crucial to follow the recommendations of the CDC and AAOS to minimize the risk of infection intraoperatively. Finally, patients who undergo TJA are always at risk of infection; therefore, it is very important to prescribe prophylactic antibiotics prior to certain medical procedures.

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clothing. A randomised, prospective trial using air and wound bacterial counts. J Bone Joint Surg Br 2003;85(4):490–4. Howard JL, Hanssen AD. Principles of a clean operating room environment. J Arthroplasty 2007;22(7 Suppl 3):6–11. Pasquarella C, Pitzurra O, Herren T, Poletti L, Savino A. Lack of influence of body exhaust gowns on aerobic bacterial surface counts in a mixed-ventilation operating theatre. A study of 62 hip arthroplasties. J Hosp Infect 2003;54(1):2–9. Sanzén L, Carlsson AS, Walder M. Air contamination during total hip arthroplasty in an ultraclean air enclosure using different types of staff clothing. J Arthroplasty 1990;5(2):127–30. Kearns KA,Witmer D, Makda J, Parvizi J, Jungkind D. Sterility of the personal protection system in total joint arthroplasty. Clin Orthop Relat Res 2011;469(11):3065–9. Andersson AE, Bergh I, Karlsson J, Eriksson BI, Nilsson K. Traffic flow in the operating room: an explorative and descriptive study on air quality during orthopedic trauma implant surgery. Am J Infect Control 2012;40(8):750–5. Young RS, O’Regan DJ. Cardiac surgical theatre traffic: time for traffic calming measures? Interact Cardiovasc Thorac Surg 2010;10(4):526–9. Ong KL, Lau E, Manley M, Kurtz SM. Effect of procedure duration on total hip arthroplasty and total knee arthroplasty survivorship in the United States Medicare population. J Arthroplasty 2008;23(6 Suppl 1):127–32. Urquhart DM, Hanna FS, Brennan SL, Wluka AE, Leder K, Cameron PA, et al. Incidence and risk factors for deep surgical site infection after primary total hip arthroplasty: a systematic review. J Arthroplasty 2010;25(8):1216–1222.e1–3. Ong KL, Kurtz SM, Lau E, Bozic KJ, Berry DJ, Parvizi J. Prosthetic joint infection risk after total hip arthroplasty in the Medicare population. J Arthroplasty 2009;24(6 Suppl):105–9. Peersman G, Laskin R, Davis J, Peterson M. Infection in total knee replacement: a retrospective review of 6489 total knee replacements. Clin Orthop Relat Res 2001;(392):15–23. Kurtz SM, Ong KL, Lau E, Bozic KJ, Berry D, Parvizi J. Prosthetic joint infection risk after TKA in the Medicare population. Clin Orthop Relat Res 2010;468(1):52–6. Muilwijk J, van den Hof S, Wille JC. Associations between surgical site infection risk and hospital operation volume and surgeon operation volume among hospitals in the Dutch nosocomial infection surveillance network. Infect Control Hosp Epidemiol 2007;28(5):557–63. Cassar Gheiti AJ, Baker JF, Brown TE, Mulhall KJ. Management of total femoral bone loss using a hybrid cement spacer surgical technique. J Arthroplasty 2013;28(2):347–51. Dairaku K, Takagi M, Kawaji H, Sasaki K, Ishii M, Ogino T. Antibiotics-impregnated cement spacers in the first step of two-stage revision for infected totally replaced hip joints: report of ten trial cases. J Orthop Sci 2009;14(6):704–10. Romanò CL, Romanò D, Logoluso N, Meani E. Long-stem versus short-stem preformed antibiotic-loaded cement spacers for two-stage revision of infected total hip arthroplasty. Hip Int J 2010;20(1):26–33. Hanssen AD, Spangehl MJ. Practical applications of antibiotic-loaded bone cement for treatment of infected joint replacements. Clin Orthop Relat Res 2004;(427):79–85. Chiu FY, Lin CF, Chen CM, Lo WH, Chaung TY. Cefuroxime-impregnated cement at primary total knee arthroplasty in diabetes mellitus. A prospective, randomised study. J Bone Joint Surg Br 2001;83(5):691–5. Wenke JC, Owens BD, Svoboda SJ, Brooks DE. Effectiveness of commerciallyavailable antibiotic-impregnated implants. J Bone Joint Surg Br 2006;88(8):1102–4. Jaeblon T. Polymethylmethacrylate: properties and contemporary uses in orthopaedics. J Am Acad Orthop Surg 2010;18(5):297–305.

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115. Smith TO, Sexton D, Mann C, Donell S. Sutures versus staples for skin closure in orthopaedic surgery: meta-analysis. BMJ 2010;340:c1199. 116. Newman JT, Morgan SJ, Resende GV, Williams AE, Hammerberg EM, Dayton MR. Modality of wound closure after total knee replacement: are staples as safe as sutures? A retrospective study of 181 patients. Patient Saf Surg 2011;5(1):26. 117. Eggers MD, Fang L, Lionberger DR. A comparison of wound closure techniques for total knee arthroplasty. J Arthroplasty 2011;26(8):1251–1258.e1–4. 118. Patel RM, Cayo M, Patel A, Albarillo M, Puri L. Wound complications in joint arthroplasty: comparing traditional and modern methods of skin closure. Orthopedics. 2012;35(5):e641–646. 119. Stephens S, Politi J, Taylor BC. Evaluation of Primary Total Knee Arthroplasty Incision Closure with the Use of Continuous Bidirectional Barbed Suture. Surg Technol Int 2011;XXI:199–203. 120. Eickmann T, Quane E.Total knee arthroplasty closure with barbed sutures. J Knee Surg 2010;23(3):163–7. 121. Clarke JV, Deakin AH, Dillon JM, Emmerson S, Kinninmonth AWG. A prospective clinical audit of a new dressing design for lower limb arthroplasty wounds. J Wound Care. 2009;18(1):5–8, 10–1. 122. Cosker T, Elsayed S, Gupta S, Mendonca AD, Tayton KJJ. Choice of dressing has a major impact on blistering and healing outcomes in orthopaedic patients. J Wound Care 2005;14(1):27–9. 123. Cho CY, Lo JS. Dressing the part. Dermatol Clin 1998;16(1):25–47. 124. Mertz PM, Marshall DA, Eaglstein WH. Occlusive wound dressings to prevent bacterial invasion and wound infection. J Am Acad Dermatol 1985;12(4):662–8. 125. Dumville JC, Walter CJ, Sharp CA, Page T. Dressings for the prevention of surgical site infection. Cochrane Database Syst Rev 2011;(7):CD003091. 126. Burke NG, Green C, McHugh G, McGolderick N, Kilcoyne C, Kenny P. A prospective randomised study comparing the jubilee dressing method to a standard adhesive dressing for total hip and knee replacements. J Tissue Viability 2012;21(3):84–7. 127. Gross L. AAOS, ADA Release CPG for Prophylactic Antibiotics. AAOS website. Available at: http://www.aaos.org/news/aaosnow/jan13/cover1.asp. Last updated December 7, 2012. Last accessed April 9, 2014. 128. Chen A, Haddad F, Lachiewicz P, Bolognesi M, Cortes LE, Franceschini M, et al. Prevention of late PJI. J Arthroplasty 2014;29(2 Suppl):119–28.

Chapter 5

Pain Management in Arthroplasty Shubhranshu S. Mohanty, Kumar Kaushik Dash

INTRODUCTION While pain after arthroplasty involves both acute perioperative pain, and chronic/late-onset pain, the latter is beyond the scope of this chapter (and perhaps best studied along with complications of arthroplasty). The following section will describe pain in general, along with the pain pathway, followed by different modalities available for pain relief in general, and ultimately, the chapter will end with algorithm of multimodal pain management specific to the arthroplasty scenario.

WHAT IS PAIN? Pain is designed as a protective mechanism in a living organism to detect potential or actual tissue-damaging processes and to maintain homeostasis.1 In addition to the sensation of stabbing/burning/tearing, etc., pain usually also has associated emotional and behavioral responses in the form of fear, nausea, increased pulse and blood pressure.1 Often, local muscle contraction (e.g., limb flexion) is also present.1

PAIN PATHWAY Pain pathway involves a peripheral and a central component, starting from pain receptors at periphery, going up till thalamus and cerebral cortex centrally (see Fig. 5.1). Peripheral nerves contain motor, sensory and autonomic (e.g., sympathetic) fibers.The cell bodies of primary afferent neurons reside in dorsal root ganglion. Their axon divides into two branches, with one projecting peripherally and the other centrally into the spinal cord (Fig. 5.2). These sensory primary afferents are classified according to their diameter, myelination and conduction velocity. Small-diameter myelinated A-ƣ and unmyelinated C axons conduct pain sensation, and their nerve endings respond maximally only to painful/ noxious stimuli.These are known as the primary afferent nociceptors. The noxious

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Pain receptor

Pain receptor

Pain receptor

Pain receptor

Primary afferent axon (Type A Delta)

Primary afferent axon (Type C)

Primary afferent axon (Type A Delta)

Primary afferent axon (Type C)

Spinal neurons in dorsal horn grey matter

Spinal neurons in dorsal horn grey matter

Spinal neurons in dorsal horn grey matter

Spinothalamic tract (contralateral)

Thalamus

T pro halam jec t ic cor ion t tex o

ic alam Th ection j pro cortex to

Somatosensory

Insular & cingulate

Cortex

Cortex

Fig. 5.1 The pain pathway.

Spinal neurons in dorsal horn grey matter

Here, each axon terminal activates multiple spinal neurons and each spinal neuron is activated by multiple axon terminals.

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Synapse at dorsal grey horn

Dorsal root ganglion

Ventral grey horn

Lateral spinothalamic tract Fig. 5.2 Arrangement in spinal cord.

stimuli include heat, intense cold, intense mechanical stimuli, acidic environment and certain chemicals (ATP, serotonin, bradykinin, histamine). Terminals of primary afferent axons end at dorsal horn of spinal grey matter by synapsing with spinal neurons of central pain pathway. Each axon terminal activates multiple spinal neurons, and each spinal neuron is activated by multiple axon terminals. Axons from most of the spinal neurons cross to opposite side and ascend to thalamus as the contralateral spinothalamic tract. Pain signal travels from thalamus to different areas of cortex through thalamo-cortical projections. Thalamic projection to the somatosensory cortex provides the perception of sensory aspect of pain. The emotional perception and response to pain involves the thalamic projection to cingulate gyrus and insular cortex in the frontal lobe.

FACTORS AFFECTING TRANSMISSION AND PERCEPTION OF PAIN Sensitization Sensitization refers to the phenomenon where the threshold for activation of pain receptors is lower and the frequency of firing is higher for all stimulus intensities.1 This can occur both at the level of peripheral nerve endings

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(peripheral sensitization) and at dorsal horn of spinal cord (central sensitization). Deep tissues, e.g., joints, which are usually relatively insensitive to noxious stimuli, become extremely sensitive after sensitization during inflammation and postsurgical period. Central sensitization has been proven to play an important role in painful knee osteoarthritis.2

Nociceptor-induced Inflammation Primary afferent nociceptors do not function as simple passive pathways for pain conduction. When activated, they release polypeptide mediators (e.g., substance P), and cause local inflammation. Targeting pain control before anticipated event (e.g., surgery) may minimize this.

Referred Pain (Convergence-Projection Hypotheses) Visceral primary afferent fibers carrying the pain sensation converge on same pain-projection neurons as the fibers from somatic structures. This leads to mistaken projection of pain to the somatic structure by the brain.

Pain Modulation Patients who have more pain catastrophizing preoperatively have more pain after surgery.3 Furthermore, patients with low preoperative mental health have more pain and worse functioning lasting longer after total knee arthroplasty (TKA). Similar intensity and type of stimuli can produce variable perception of pain in different scenarios. Expectation of pain can induce pain even without any noxious stimulus.1 While the ascending pathway carries pain sensation from the site of stimulus to the brain, neurogenic circuits from hypothalamus, midbrain and medulla control and modulate the spinal transmission neurons through a descending pathway. This forms the basis of how pain perception is affected by expectation, behavioral changes and psychological variables. Endogenous opioids (e.g., enkephalins, ơ-endorphin) provide pain relief through this pain modulating circuit. Both pain-inhibiting and pain-facilitating neurons form the parts of this circuit. Hence, the role of suggestion, attention, expectation and other psychological factors is important in pain perception.

MODALITIES OF TREATMENT Cyclooxygenase Inhibitors Aspirin, acetaminophen (paracetamol) and other nonsteroidal anti-

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inflammatory drugs inhibit cyclooxygenase (COX), producing analgesic and anti-inflammatory effects. The most common side effect is gastric irritation. Aspirin additionally increases the risk of gastro-intestinal bleeding by irreversibly acetylating platelet COX. Nephrotoxicity, although rare, must be kept in mind in old dehydrated patients; patients with heart failure, liver cirrhosis, and longterm diuretic use; or during acute volume depletion (e.g., blood loss during surgery).4 Parenteral ketorolac is potent and rapid acting enough to replace opioids for many patients. COX-2 selective inhibitors (e.g., celecoxib) are beneficial in post-surgical environment because they do not affect blood coagulation and produce less gastric irritation. However, they do not lower the risk of nephrotoxicity. Due to increased cardiovascular risk, they should be used with caution in patients with cardiac disease or cardiac risk factors. Celecoxib is currently the only COX-2 inhibitor available in the United States.4 It is possible that increased cardiovascular risk is a class effect of all nonsteroidal anti-inflammatory drugs (NSAIDs) except aspirin.1 Etoricoxib, although being used in many countries, is yet to gain FDA (US) approval.

Opioid Analgesics Opioid analgesics are the most potent, reliable and effective methods for rapid pain relief. The common but reversible side effects are nausea, vomiting, constipation and pruritus. Recently, peripherally acting opioid antagonists (e.g., alvimopan, methylnaltrexone) have become available for treating opioidinduced side effects. The most serious side effect is respiratory depression; hence, patients with respiratory illnesses must be kept under close observation during opioid administration. Opioids produce pain relied by acting on pain-inhibitory neurons and pain-transmission neurons, probably through the opioid receptor (μ-receptor). The effects are dose-related, and the dose for pain relief and side effects varies greatly among patients. The most common error made by physicians in managing severe pain with opioids is to prescribe an inadequate dose. This can be attributed to the exaggerated fear of addiction and possibly other side effects such as respiratory depression. An interesting way to achieve adequate pain relief in such a scenario is the use of patient controlled analgesia (PCA). In this method, a microprocessor-controlled infusion device administers a pre-programmed dose of an opioid drug, which is titrated to the optimum level by the patient. To prevent overdosing and its side effects, there is a provision for lockout period after each demand dose and a limit on total dose of opioid delivered in an hour.

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Another way to maximize pain relief without increasing side effects involves administering opioids directly to the spinal or epidural space. This is particularly beneficial in postoperative scenarios. The dose of morphine required when used intrathecally is less than a tenth of dose required when administered intravenously.

Combination of Opioid and COX Inhibitors The analgesic effect of opioids and COX inhibitors is additive when used simultaneously, while the side effects are non-additive. This allows effective pain relief without any significant side effects. However, fixed ratio combinations of opioid and acetaminophen (paracetamol) may lead to hepatotoxicity during dose escalation (due to acetaminophen).

Other Analgesics (Antidepressants and Antiepileptics) Tricyclic antidepressants (TCA) produce analgesic effects at a lower dose and shorter time than their antidepressant effect. They potentiate opioid analgesia and are most effective in neuropathic pain. The significant side effects include orthostatic hypotension, cardiac conduction delay, memory impairment and drowsiness. Selective serotonin reuptake inhibitors (SSRI) have less serious side effects but their analgesic efficacy is also lower. Venlafaxine and duloxetine (serotonin norepinephrine reuptake inhibitors, SNRI) provide pain relief similar to that of TCAs with fewer side effects. Newer anticonvulsants such as gabapentin and pregabalin have good analgesic efficacy and a favorable side effect profile. Randomized trials of their use in total joint arthroplasties have shown decreased narcotic use and less chance of future neuropathic pain, although increased sedation and confusion particularly with pregabalin.5,6

Neuraxial Anaesthesia Spinal and epidural anaesthesias usually involve injection of a local anaesthetic in to the intrathecal or epidural space for pain control during surgical procedures. Addition of morphine improves the pain relief and decreases the usage of intravenous opioids required post-op. Addition of epinephrine increases local concentration of local anaesthetic by causing vasoconstriction. Epidural anaesthesia is further helpful by providing effective pain control during the post-operative period. Also, the side effects of opioid (nausea, vomiting, pruritus) are comparatively fewer in this when compared with parenteral route.

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Peripheral Nerve Block Urinary retention and hypotension are two unpleasant problems seen with continuous epidural anaesthesia. Peripheral nerve blocks provide similar level of pain relief without these problems. Under the guidance of ultrasound or nerve stimulator, local anaesthetic is injected around peripheral nerves. Femoral and sciatic nerves are targeted in TKA; with lumbar plexus being the target in total hip arthroplasty (THA). Block can be administered as a one-time injection or as continuous release catheter. Long acting local anaesthetics (e.g., bupivacaine) and adjuvants (e.g., epinephrine, steroids) prolong the pain control. Catheter method provides better pain control, but has 0–3% risk of infection and 0.2% risk of nerve injury. Peripheral nerve blocks should ideally be done in a separate designated block room to increase efficiency and allow adequate time for onset of analgesia.4 The procedure usually takes less than 15 min to perform.

Periarticular Injections There have been multiple well-designed studies on injection of local anaesthetic alone or local anaesthetic (bupivacaine/ropivacaine) plus epinephrine/ morphine/ketorolac (multidrug injections) within and around the joint intraoperatively, with conflicting results. The protocols vary according to dose, composition, location and presence/absence of catheter. ROC cocktail is one of the commonly described combinations; consisting of 0.5% bupivacaine (200–400 mg), morphine sulphate (4–10 mg), 1:1000 epinephrine (300 mcg), methylprednisolone acetate (40 mg) and cefuroxime (750 mg) in normal saline.7 Vancomycin is to be used instead if patient is allergic to penicillin. Steroids are avoided in diabetics and immunocompromised patients. The benefits include better pain relief, decreased narcotic consumption, and in some trials, better patient satisfaction. Because of heterogeneity of results, critical appraisal of individual protocol by the surgeon is important before incorporating this modality as a part of the pain management strategy.

PAIN IN ARTHROPLASTY AND ITS MULTIMODAL MANAGEMENT Historically, pain after joint replacement has often been inadequately managed.8 The problems of uncontrolled pain include patient discomfort, slow/ delayed rehabilitation, prolonged hospital stay, unplanned readmissions, higher health care cost, perioperative medical complications and eventually, com-

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promised ultimate function and patient dissatisfaction.4,9 Traditionally, high dose intravenous opioids have been used in the form of PCA. However, this has led to the problems of delayed recovery, and has increased length of stay. Also, in patients who are desensitized and tolerant to opioids, pain control becomes difficult. Multimodal pain management was devised by Kehlet and Dahl10 and Wall11 to address these problems. It uses the principle of targeting different sites of pain pathway with multiple agents acting synergistically, requiring lower dose of each drug. It achieves more efficient pain control while decreasing the incidence of side effects at the same time. Pain is addressed pre-emptively to prevent the beginning of a cycle of pain4 and to limit sensitization of the nervous system.12 The comprehensive multimodal management algorithm involves the following components. 1. Pre-emptive analgesia with preoperative medications. 2. Neuraxial anaesthesia. 3. Regional nerve blocks or periarticular injection. 4. Postoperative oral and intravenous medications. There have been multiple comparative studies to assess the benefits of multimodal pain management. Few important ones are mentioned in Table 5.1. Choosing a protocol for multimodal pain management should take into the consideration the above-mentioned principles and components. Institutes should be able to develop their own protocol that gradually evolves over time with inputs from past experience and available inventory. Few important points to remember are listed below.4,9 1. Tolerance to opioids: A thorough pre-op assessment is essential in patients who are on opioid analgesics for chronic pain. Such patients may not get adequate pain control with the standard protocol. Consideration should be given to weaning these patients off the opioids before surgery and/or involving a dedicated pain management specialist in the team. 2. Patient expectations: Unrealistic expectation of the patient may lead to decreased satisfaction and more perception of pain. Patient assessment, counseling and education are essential before surgery. 3. Pre-op cocktail: Pre-emptive does not mean only before incision, but also implies adequate magnitude and time.12 Oral analgesic cocktail should be given to the patient with one sip of water 1 h prior to surgery. This ensures therapeutic plasma levels of analgesics at the time of the end of the surgery. (see Table 5.2 for details) 4. Neuraxial anaesthesia: Unless contraindicated, spinal anaesthesia

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Table 5.1 Evidence for multimodal strategy Study

Design

Details of multimodal regimen

Advantage of multimodal strategy

Peter et al.13

Two retrospective cohorts of 50 TJA patients, before and after introduction of multimodal protocol

Oral narcotics, COX-2 inhibitors, femoral nerve catheters and periarticular injections

Less narcotic consumption, better pain control and walking distance. No change in complications.

Fu et al.14

RCT, 100 TKA patients, multimodal vs. placebo

Oral celecoxib and tramadol before and after surgery; intraarticular injection of morphine, ropivacaine, epinephrine and betamethasone

Less narcotic consumption, lower VAS scores, earlier achievement of physiotherapy milestones. Apart from decreased nausea and vomiting, other complications were similar

Lee et al.15

RCT, 60 THA patients, multimodal vs. conventional analgesia

Pre- and postoperative sustained release oxycodone and acetaminophen; intra-operative injection of morphine, methylprednisolone and ropivacaine

Lower VAS scores, earlier ambulation with crutches. No difference in rate of complication, length of stay or narcotic consumption

Lavernia Cohort of 1136 et al.16 TKA patients, retrospective comparison of rate of arthrofibrosis

Patient education, preand post-operative oxycodone, celecoxib and acetaminophen, femoral nerve block, posterior capsular injection of pain cocktail

Significantly less chance of requiring manipulation under anaesthesia for arthrofibrosis

Duncan Evaluation of ecoet al.17 nomic impact; 100 patients of multimodal therapy with historically matched controls

Oxycodone extended release and rofecoxib preoperatively, lumbar plexus regional block with infusion catheter, postoperative intravenous ketorolac with oral acetaminophen and oxycodone

Significantly decreased mean direct hospital cost (approximately $2000)

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with bupivacaine should be used. In addition to pain relief, spinal–epidural anaesthesia also provides the additional benefits like decreased risk of deep vein thrombosis. In patients without respiratory and cardiovascular compromise, intrathecal morphine should be added. 5. Regional blocks and injections: As far as regional blocks and periarticular injections are considered, THA and TKA patients present different scenarios. Usually THA patients do not have pain that is severe enough to demand periarticular injection or regional block. If deemed appropriate, a psoas compartment block of lumbar plexus using an indwelling catheter is the block of choice.4 If fascia iliaca block is chosen instead, the block should be administered postoperatively because of the proximity of the insertion site to the surgical field.4 For TKA patients, either periarticular injection or regional block (sciatic, femoral) should be used. Some surgeons are apprehensive of regional block due to the fear of weakness of muscle groups that lead to delayed rehabilitation and risk of falls. For periarticular/intraarticular injections, continuous infusion devices provide better postoperative pain control. However, these devices are best avoided when some amount of native cartilage is preserved (e.g., partial knee arthroplasty) because of risk of chondrolysis. 6. Postoperative pain management: THA patients experience comparatively less pain and can be continued on the same medications used in pre-op cocktail (acetaminophen, celecoxib, pregabalin) can be continued postoperatively, with addition of an opioid patient controlled analgesia (Fentanyl PCA) for any breakthrough pain. In TKA patients, intravenous ketorolac (30 mg, 6 hourly) should be used in Table 5.2 Pre-operative cocktail Preoperative cocktail medications

Cautions

1.

Acetaminophen 1 g oral (can also be given intravenously)

2.

Celecoxib 400 mg oral (200 mg if patient is on celecoxib preoperatively) Pregabalin 75 mg oral

Avoided if patient has history of liver disease or elevated liver enzymes. Contraindicated in sulfa allergy. Substituted with naproxen 500 mg orally. Avoided in elderly patients with preexisting affection of cognition because of the risk of postoperative delirium.

3.

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place of celecoxib, starting from the evening of surgery till postoperative Day 2. 7. Medical comorbidities: NSAIDs are avoided in patients with renal insufficiency. In elderly patients, ketorolac dose is reduced to 15 mg from the usual 30 mg. Antacids in form of proton pump inhibitors should be added when using NSAIDs. 8. Role of opioids: Because of the risk of postoperative delirium and respiratory depression, these are best avoided in patients older than 80 years. Opioids can be used as second line drugs for breakthrough pain or residual pain. Tramadol (50–100 mg 6 hourly) is effective in mild to moderate pain and Oxycodone (5–10 mg 4 hourly) is useful for moderate to severe pain. In some institutions, oral OxyContin (sustained release form of Oxycodone) 20 mg every 12 hourly is used along with acetaminophen for postoperative pain control for initial 48 h.4 9. Timing of medication: Planning to ensure that patient receives oral pain medications one hour before the physical therapy sessions ensures less discomfort and fewer disruptions. 10. Patient education: Among all psychological factors, pain catastrophizing is the strongest factor associated with pain experience.18 It is defined as an exaggerated negative mental set brought to fore during an actual or anticipated painful experience.19 Low preoperative mental health and pain catastrophizing lead to more pain, worse function and poorer quality of life after surgery.3,19 Addressing the mental health of patient preoperatively, with particular attention to anxiety, depression, expectations and catastrophizing should be done. Author's Preferred Treatment The authors believe in multimodal approach to pain control in dealing with arthroplasty patients. It starts right from the first clinic visit when the surgeon gets a first-hand information about the patient's perception to postoperative pain, which differs in each individual. Hence, the approach to each patient is different according to his or her perception and clinician's day-to-day management. It starts right from preemptive analgesia in the form of (a) patient education for expectation management and (b) oral NSAIDs before surgery. Authors prefer a combined spinal–epidural anaesthesia for the analgesia during surgery, which continues as postoperative epidural analgesia. Patient is simultaneously started on oral NSAIDs and Fentanyl patch depending upon degree of threshold, these being continued even after removal of epidural catheter. Early, pain-free mobilization

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remains the primary aim. Optimal oral analgesia is provided throughout the early rehab period. Injectable Tramadol/NSAIDs are introduced for any breakthrough pain during rehabilitation. Exact duration of analgesic medications varies from patient to patient based on functional needs. Almost all patients stop demanding analgesics after a period of 2–3 weeks from surgery. However, the authors do not prefer use femoral blocks or periarticular injections in their patients.

FUTURE DIRECTIONS New research is throwing more light on how pain is processed in our brain. In addition to the ascending pain pathway involving spinothalamic tract, somatosensory and insular cortex, midline emotional systems in the supraspinal lower brainstem and diencephalon now appear to play a significant role.20 These regions and the limbic system are involved in the autonomic, affective, motivational, discriminative and cognitive aspects associated with the pain sensation.20 Biopsychosocial models have suggested that physical, psychological and social factors must be considered to fully understand pain-related outcomes.21 Further analyses of these avenues will allow development of newer pharmacologic and non-pharmacologic (e.g., music therapy, cognitive behavioral therapy) agents to act at various target sites to manage pain in a better way, with perhaps less side effects. The future looks interesting.

REFERENCES 1. Rathmell JP, Fields HL. Pain: pathophysiology and managemtn. In: Longo DL, Fauci AS, Kasper DL, Hauser SL, Jameson JL, Loscalzo J, eds. Harrison's Principles of Internal Medicine. 18th ed. New York, NY: McGraw-Hill, 2012: 93–101. 2. Arendt-Nielsen L, Nie H, Laursen MB, Laursen BS, Madeleine P, Simonsen OH, Graven-Nielsen T. Sensitization in patients with painful knee osteoarthritis. Pain 2010;149(3):573–81. doi: 10.1016/j.pain.2010.04.003. Epub 2010 Apr 24. PubMed PMID: 20418016. 3. Vissers MM, Bussmann JB, Verhaar JA, Busschbach JJ, Bierma-Zeinstra SM, Reijman M. Psychological factors affecting the outcome of total hip and knee arthroplasty: a systematic review. Semin Arthritis Rheum 2012;41(4):576–88. doi: 10.1016/j.semarthrit.2011.07.003. Epub 2011 Oct 28. Review. PubMed PMID: 22035624. 4. Ali M, Pagnano MW, Horlocker T, Lennon RL. How I manage pain after total hip arthroplasty. Seminars in Arthroplasty 2008;19:231–6. 5. Clarke H, Pereira S, Kennedy D, et al. Gabapentin decreases morphine consumption and improves functional recovery following total knee arthroplasty. Pain Res Manag 2009;14(3):217–22. 6. Buvanendran A, Kroin JS, Della Valle CJ, Kari M, Moric M, Tuman KJ. Perioperative oral pregabalin reduces chronic pain after total knee arthroplasty: a prospective, randomized, controlled trial. Anesth Analg 2010; 110(1):199–207.

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7. Ranawat AS, Ranawat CS. Pain management and accelerated rehabilitation for total hip and total knee arthroplasty. J Arthroplasty 2007;22(7 Suppl 3):12–15. Review. PubMed PMID: 17919586. 8. Apfelbaum JL, Chen C, Mehta SS, Gan TJ. Postoperative pain experience: results from a national survey suggest postoperative pain continues to be undermanaged. Anesth Analg 2003;97(2):534–40. 9. Parvizi J, Bloomfield MR. Multimodal pain management in orthopedics: implications for joint arthroplasty surgery. Orthopedics. 2013;36(2 Suppl):7–14. doi: 10.3928/0147744720130122-51. Review. PubMed PMID: 23379570. 10. Kehlet H, Dahl JB.The value of “multi- modal” or “balanced analgesia” in postoperative pain treatment. Anesth Analg 1993;77(5):1048–56. 11. Wall PD. The prevention of postoperative pain. Pain 1988;33(3):289–90. 12. Horlocker TT, Kopp SL, Pagnano MW, Hebl JR. Analgesia for total hip and knee arthroplasty: a multimodal pathway featuring peripheral nerve block. J Am Acad Orthop Surg 2006;14(3):126–35. PubMed PMID: 16520363. 13. Peters CL, Shirley B, Erickson J. The effect of a new multimodal perioperative anesthetic regimen on postoperative pain, side effects, rehabilitation, and length of hospital stay after total joint arthroplasty. J Arthroplasty 2006; 21(6 Suppl 2):132–38. 14. Fu PL, Xiao J, Zhu YL, et al. Efficacy of a multimodal analgesia protocol in total knee arthroplasty: a randomized, controlled trial. J Int Med Res 2010; 38(4):1404–12. 15. Lee KJ, Min BW, Bae KC, Cho CH, Kwon DH. Efficacy of multimodal pain control protocol in the setting of total hip arthroplasty. Clin Orthop Surg 2009; 1(3):155–60. 16. Lavernia C, Cardona D, Rossi MD, Lee D. Multimodal pain management and arthrofibrosis. J Arthroplasty 2008;23(6 Suppl 1):74–9. 17. Duncan CM, Hall Long K, Warner DO, Hebl JR. The economic implications of a multimodal analgesic regimen for patients undergoing major orthopedic surgery: a comparative study of direct costs. Reg Anesth Pain Med 2009;34(4):301–07. 18. Sullivan M, Tanzer M, Stanish W, Fallaha M, Keefe FJ, Simmonds M, Dunbar M. Psychological determinants of problematic outcomes following Total Knee Arthroplasty. Pain 2009;143(1–2):123–9. doi: 10.1016/j.pain.2009.02.011. Epub 2009 Mar 21. PubMed PMID: 19304392. 19. Khan RS, Ahmed K, Blakeway E, Skapinakis P, Nihoyannopoulos L, Macleod K, Sevdalis N, Ashrafian H, Platt M, Darzi A, Athanasiou T. Catastrophizing: a predictive factor for postoperative pain. Am J Surg 2011;201(1):122–31. doi: 10.1016/j.amjsurg.2010.02.007. Epub 2010 Sep 15. Review. PubMed PMID: 20832052. 20. Bernatzky G, Presch M, Anderson M, Panksepp J. Emotional foundations of music as a non-pharmacological pain management tool in modern medicine. Neurosci Biobehav Rev 2011;35(9):1989–99. doi: 10.1016/j.neubiorev.2011.06.005. Epub 2011 Jun 16. Review. PubMed PMID: 21704068. 21. Sullivan M, Bishop S, Pivik J.The pain catastrophising scale: development and validation. Psychol Assess 1995;7:524–32.

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PART 2

Total Hip Arthroplasty: Techniques and Pearls Chapters 6. 7. 8. 9. 10. 11. 12. 13.

Radiological Planning of Total Hip Arthroplasty Choosing Implant for Total Hip Arthroplasty Tips and Pearls in Total Hip Arthroplasty The Cemented Hip: How to Get it Right Uncemented Total Hip Arthroplasty Total Hip Arthroplasty in Peritrochanteric Fractures Fused Hips in Ankylosing Spondylitis Total Hip Arthroplasty in Protrusio Acetabulae

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Chapter 6

Radiological Planning of Total Hip Arthroplasty Ivan De Martino, Peter K. Sculco, Georgios K. Triantafyllopoulos, Lazaros A. Poultsides, Thomas P. Sculco

INTRODUCTION Total hip arthroplasty (THA) is one of the most successful orthopaedic procedures providing pain relief and improved function to patients with end-stage degenerative joint disease. A thoughtful preoperative plan and radiographic templating have an important role and increase the likelihood of achieving a successful outcome. Preoperative templating gives the treating surgeon information on several important surgical variables and forces him to think in the three dimensions demanded during the surgical procedure. How the prosthesis fits within the femoral canal and provides insight on the correct type of implant and estimated size. Correct acetabular component position can be assessed, and expected acetabular coverage or undercoverage can be noted. Restoration of hip biomechanics is necessary in a well-functioning THA, and templating provides data on the degree of offset required for the proximal femur in addition to projected leg lengthening. Radiographic templating allows the treating surgeon to anticipate potential difficulties in the operating room and make adjustments in advance leading to a reduction in intraoperative time and complications.1–9 Templating contributes to more accurate leg length restoration and may reduce the risk of overlengthening, which is associated with several postoperative complications including sciatic and femoral nerve palsies,10 abnormal gait,11 low back pain,12 instability13 and aseptic loosening.14 Leg-length discrepancy (LLD) leads to patient dissatisfaction15 and is one of the most common reasons for litigation against orthopaedic surgeons.16 An accurate preoperative plan, including an appropriate history and physical examination, radiographic evaluation and surgical templating, is mandatory to improve intraoperative accuracy of leg length, offset, center of rotation (COR) and component position. Müller17 in 1975 introduced a method for preoperative planning in THA and since then it has been considered an integral part of the surgical procedure and has remained

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remarkably unchanged. Templating in THA has traditionally been performed using implant-specific acetate templates on hard copy X-rays. The advance of digital radiography has led to digital templating and the use of dedicated software. This is now becoming the standard technique in most hip arthroplasty centers. In this chapter, we will describe the components of a comprehensive and reliable preoperative radiological evaluation. This will then be followed by presenting an established protocol for accurate hip templating that can be applied to both hard copy and digital platforms.

PREOPERATIVE PLANNING Radiological planning is a part of the preoperative planning when evaluating a patient for a THA. An accurate diagnosis and indication for surgery is based on patient symptoms in addition to radiographic findings. For this reason, each surgeon should take an accurate medical history and perform a complete physical examination in order to confirm the diagnosis and indications, and educate the patient as to the details of the procedure. Surgical decisions such as implant selection, bearing type and mode of implant fixation (cemented versus uncemented) are influenced by age, sex, preoperative diagnosis, activity level and mental status. A systematic assessment of the lumbosacral spine and knee is performed to identify any extra-articular sources for hip pain. Flexion contractures, previous scars and a neurovascular exam are then performed. True and functional LLDs should be carefully evaluated and recorded. The true LLD is determined clinically with the patient in the supine position measuring the distance between the anterior superior iliac spine (ASIS) and the medial malleolus. True LLD is usually secondary to bony hip pathology,18 especially with femoral head collapse or severe hip dysplasia. A functional LLD is usually noted by the patient in the standing position. Rigid blocks are placed under the foot of the shorter leg until the leg lengths become subjectively even. Soft tissue contractures (flexion and/or abduction) and scoliosis with pelvic obliquity are the most common causes for functional LLD.18 Pelvic obliquity can be evaluated by comparing the level of both hemipelvises with the patient sitting and standing, and if present, the surgeon should assess whether its origin is suprapelvic, intrapelvic or infrapelvic. In the seated position, suprapelvic obliquity persists usually secondary to a fixed lumbosacral scoliosis. In contrast, intrapelvic and infrapelvic obliquity resolve in the seated position. Any clinical findings of a significant LLD should also be confirmed radiographically.

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RADIOGRAPHIC TECHNIQUE The standard preoperative radiographic evaluation for THA includes three radiographs: an anteroposterior (AP) view of the pelvis and an AP and lateral of the affected hip. The AP pelvis view is centered over the pubic symphysis and includes the proximal third of the femur to allow for templating (Fig. 6.1 ). The AP views are obtained with the patient positioned supine

Fig. 6.1 The AP pelvis view. The beam is centered over the pubic symphysis and includes the proximal third of the femur to allow for templating.

on the radiographic table with the lower limbs in approximately 15°±5° of internal rotation to allow a true AP view of the femoral neck, which has a normal anteversion of 15°±5°. A well done AP pelvis view should have neutral pelvic rotation and tilt. To determine the proper pelvic rotation, the pubic symphysis should project on a line through the center of the sacrum and coccyx, and the two obturator foramina should appear symmetrical.19 The pelvic tilt is estimated by the distance between the upper border of the symphysis and the center of the sacrococcygeal joint. This distance should be 2–3 cm above the superior end of the symphysis in males and between 2–6 cm in females.20 This distance is increased when the pelvis is tilted forward, and the AP view is close to an inlet view. Conversely,

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this distance is decreased when the pelvis is tilted backwards, and the AP view is close to an outlet view.20 In patients with a fixed external rotation contracture who cannot internally rotate their hips, a posteroanterior (PA) view of the femur should be obtained. This PA view is obtained with the patient positioned prone on the radiographic table with the contralateral hip elevated to an angle equivalent to the contracture. The most frequently used lateral view of the hip is a modification of the frog-leg (Lowenstein) lateral view (Fig. 6.2) and is obtained with the patient positioned supine on the radiographic table with the affected hip externally rotated and the knee and ankle flat on the table. This view is used for locating proximal femoral entry point in the piriformis fossa.

Fig. 6.2 The lateral view of the femur. This is a modification of the frog-leg (Lowenstein) lateral view.

Additional views may be necessary and dependent on the history and physical examination. Cross-sectional imaging should be obtained in the case of a pelvic fracture or dislocation, in addition to standard Judet views (obturator oblique and iliac oblique). Bone quality and the geometry of the proximal femur can be assessed using the indexes of Singh21 and Dorr.22 The Singh index is commonly used to assess osteoporosis and is based on the density of trabecular bone of the proximal femur21 and the Dorr classification classifies the geometry of the proximal femoral canal. Both indexes contribute to decision making on implant type and mode of implant fixation.22

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RADIOGRAPHIC TEMPLATING IN THA Step 1: Determination of Magnification Surgeons must be aware of the amount of magnification of the hip radiographs before templating. Usually with the X-ray tube at 100 cm from the top of the table and the X-ray tray placed 5 cm below the table, magnification is 20% (± 6%, 2 SDs) as soft tissues are interposed between the hip and the X-ray plate.23 To match the radiographic magnification, acetate templates are usually 10–20% oversized. Attention should be paid to the patient’s body habitus because magnification is directly proportional to the distance between the pelvis and the film. Therefore, increased magnification should be anticipated in extremely obese patients and, conversely, less magnification would be expected in extremely thin patients.24 If the radiographies are digitized, they must be calibrated before templating.25,26 A radio-opaque marker, such as sphere which is 25 mm in size27 or a coin with a known size,25 is usually used as a calibration tool in order to scale the dimensions shown on the radiograph and the digital templates. These markers should be at the same level of the hip joint in the AP plane. Usually they are positioned near the greater trochanter or between the patient’s legs, close to the pubis, on the greater trochanter’s plane.28 Alternatively, when a contralateral hip prosthesis of known dimension is present, it can be used as a calibration tool.

Step 2: Radiographic Landmarks Identification There are several radiographic landmarks that should always be identified and are useful for preoperative templating: the ilioischial line (Kohler’s line), the base of the teardrop, and the superolateral margin of the acetabulum (Fig. 6.3) at the acetabular side; the lesser and the greater trochanter and the medullary canal at the femoral side. The radiographic teardrop (also known as the U-figure) is located in the inferomedial portion of the acetabulum, just above the obturator foramen. The teardrop is a consistent radiographic landmark and is in close proximity to the center of hip rotation and the acetabular floor.29 The ilioischial line, or Kohler's line, is drawn from the medial border of the ilium to the medial border of the ischium, and is a useful landmark when assessing the degree of protrusio acetabuli. The superolateral margin of the acetabulum provides a reference for the degree of osseous coverage around the implanted acetabular component. During the surgical procedure, these landmarks should be identified to convert the two-dimensional planning, made on the X-rays, into the in vivo three-dimensional intraoperative situation.

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Fig. 6.3 Radiographic landmarks identification. The radiographic teardrop (in green), the ilioischial line (in red) and the superolateral margin of the acetabulum (in blue).

Step 3: Determination of Leg-Length Discrepancy To assess preoperative LLD, a pelvic horizontal reference line is made using the lower margin of the two teardrops and drawing an interteardrop line (Fig. 6.4). If the teardrops are not identifiable, a horizontal reference line can be drawn through the distal aspect of the ischial tuberosities or the distal aspect of the sacroiliac joints. The LLD at the hip can be calculated as the difference in the vertical distance between the horizontal reference line and a fixed point on the femur (Fig. 6.5). Fixed points on the femur could be the lesser trochanter, the greater trochanter or the center of the femoral head. LLD may be present at a level distal to the hip joint, such as in case of bony abnormalities (osteotomies or malunions) or functional limitations (hip or knee contractures). In this case, LLD should be assessed on a standing AP view radiograph, with the distance measured between the interteardrop line and the floor.

Step 4: Acetabular Templating Acetabular templating is always performed first because it establishes the

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Fig. 6.4 Identification of the pelvic reference line. In this case, the inter-teardrop line is drawn through the lower margin of the two teardrops.

new COR after component implantation. Using the previously described pelvic radiographic landmarks, the template should be oriented to achieve an abduction angle of 40°–45° in relation to the interteardrop line, with the inferomedial border of the cup seated near the ilioischial line, or the lateral edge of the teardrop (Fig. 6.6). The superolateral margin of the acetabulum is used as a reference for the coverage of the cup, and final component size should maximize cup coverage while avoiding excessive subchondral

Fig. 6.5 Digital templating. The leg-length discrepancy (LLD) is calculated as the difference in the vertical distance between the horizontal reference line and the most medial aspect of the lesser trochanter. The calibration ball is positioned between the patient’s leg (arrow).

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Fig. 6.6 Digital acetabular templating. The template should be oriented to achieve an abduction angle of 40°–45° in relation to the interteardrop line, with the inferomedial border of the cup seated near the lateral edge of the teardrop. The center of rotation of the cup is marked.

bone resection. The COR should be medialized in order to decrease the moment arm generated by the patients body weight during the gait cycle, theoretically reducing wear30,31 and improving clinical outcomes.32 In cemented cups, a uniform 2–3 mm space should be left for cement mantle. Once final acetabular implant size and position have been determined, the new COR of the hip should be marked and compared to the contralateral side for vertical and horizontal symmetry. Protrusio Acetabuli The cup should be lateralized to increase femoral offset and decrease cup-neck impingement. The cup template should be positioned in the anatomic position, adjacent to the lateral edge of the teardrop and lateral to the ilioischial line. Lateralized Acetabulum The cup should be medialized as much as possible in order to gain the proposed benefits of improved postoperative hip biomechanics. The cup template should be positioned in the anatomic position, adjacent to the lateral edge of the teardrop and lateral to the ilioischial line. Dysplastic Acetabulum Dysplastic hips present challenging acetabular and femoral anatomy and

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require careful preoperative planning. Basic radiographs will show the superolateral migration of the femoral head and insufficient acetabular coverage. To replace the socket in these cases, the surgeon must decide between two options a ‘high hip center’ or an ‘anatomic hip center’ and template accordingly.33,34 If a well-established pseudoacetabulum is present, the cup may be placed at a high hip center. However, placing the cup in this position results in a lateralized hip COR that increases failure rate.33,35 If the cup is placed in the anatomic position, near the lateral edge of the teardrop, the result is usually an inadequate superolateral bony coverage. A 10–20% of bony uncoverage can be accepted, and if additional coverage is needed, a femoral head bone autograft can be used.

Step 5: Femoral Templating Once the COR of the reconstruction is marked, the femur can be templated from this point. The goal of the femoral templating is to choose an implant that permits adequate fixation and restores offset and leg length. To achieve this result, it is important to consider both the intraosseous parameters (stem fixation and alignment) and the extraosseous parameters (offset and leg length). Stem size is best determined on the AP view radiograph, and depends on stem type choice (straight or anatomic), fixation choice (cemented or cementless) and coating choice (proximally coated or fully coated). For a proximally coated cementless stem, emphasis should be given to the proximal fit and fill. For an extensively coated stem, fixation must be achieved distally, and a diaphyseal isthmic fill should be achieved. For a cemented stem, a uniform 2–3 mm cement mantle should be considered. The entry point (piriformis fossa) and the fit of the stem should be assessed on both AP and lateral views. Once the stem size is decided, the template should be positioned inside the femoral canal, along the longitudinal femoral axis, and the COR of the femoral head should be marked (Fig. 6.7A). Attention should be paid in cases of coxa vara or coxa valga. Now, the positions of both centers of rotation (femoral and acetabular) should be checked. The vertical and horizontal distances between those points represent the change in limb length and offset that will be obtained. If the two centers of rotation are overlapped, leg length and offset will remain unchanged. If the COR of the femoral stem lies medially to the COR of the acetabular cup, femoral offset will be increased. Conversely, if the COR of the femoral stem lies laterally to the COR of the acetabular cup, femoral offset will be decreased. If the

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Fig. 6.7 Digital femoral templating on the anteroposterior (AP) view radiograph. The template is positioned inside the femoral canal, along the longitudinal femoral axis, and the center of rotation of the femoral head is marked (A). The distances between the proximal corner of the lesser trochanter and the center of rotation of the femoral head as well as the proposed neck cut level are also determined (B).

COR of the femoral component lies more proximally than the COR of the acetabular cup, lengthening of the limb will occur. Conversely, shortening of the limb will be the result if the COR of the femoral component lies more distally than the COR of the acetabular cup. Leg length should be restored based on the patient’s history and clinical examination as previously mentioned. Once the offset and the femoral head COR are determined, the level of the femoral neck cut can be marked. The distances between the proximal corner of the lesser trochanter and the COR of the femoral head as well as the proposed neck cut level are also determined at this point (Fig. 6.7B). The width of the calcar, medial to the stem at the level of the neck cut is determined, so as to help the surgeon during intraoperative stem alignment assessment at the frontal plane (varus or valgus). At this point, if templating for a cemented stem, plug size and insertion depth should be calculated based on the stem size.

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SUMMARY Preoperative planning and templating play an important role in modern hip joint reconstruction and likely improve the probability of achieving a successful outcome in THA. Preoperative planning helps the surgeon decide the type, size and position of the femoral and acetabular components in addition to giving information on offset and leg length parameters that must be restored, while allowing this to be performed in an expeditious and accurate manner. As a final note, while preoperative radiographic templating gives the surgeon an operative road map to follow, final surgical decisions will be based on intraoperative factors that continue to rely on surgical experience.

REFERENCES 1. The B, Verdonschot N, van Horn JR, van Ooijen PM, Diercks RL. Digital versus analogue preoperative planning of total hip arthroplasties: a randomized clinical trial of 210 total hip arthroplasties. J Arthroplasty 2007;22:866–70. 2. Suh KT, Cheon SJ, Kim DW. Comparison of preoperative templating with postoperative assessment in cementless total hip arthroplasty. Acta Orthop Scand 2004;75:40–4. 3. Wedemeyer C, Quitmann H, Xu J, Heep H, von Knoch M, Saxler G. Digital templating in total hip arthroplasty with the Mayo stem. Arch Orthop Trauma Surg 2008;128:1023– 29. 4. Muller ME. Lessons of 30 years of total hip arthroplasty. Clin Orthop Relat Res 1992;274:12–21. 5. Dore DD, Rubash HE. Primary total hip arthroplasty in the older patient: optimizing the results. Instr Course Lect 1994;43:347–57. 6. Blackley HR, Howell GE, Rorabeck CH. Planning and management of the difficult primary hip replacement: preoperative planning and technical considerations. Instr Course Lect 2000;49:3–11. 7. Eggli S, Pisan M, Muller ME. The value of preoperative planning for total hip arthroplasty. J Bone Joint Surg Br 1998;80:382–90. 8. Haddad FS, Masri BA, Garbuz DS, Duncan CP. The prevention of periprosthetic fractures in total hip and knee arthroplasty. Orthop Clin North Am 1999;30:191–207. 9. Goldstein WM, Gordon A, Branson JJ. Leg length inequality in total hip arthroplasty. Orthopedics 2005;28(Suppl 9):s1037–s1040. 10. Nercessian OA, Piccoluga F, Eftekhar NS. Postoperative sciatic and femoral nerve palsy with reference to leg lengthening and medialization/lateralization of the hip joint following total hip arthroplasty. Clin Orthop Relat Res 1994;304:165–71. 11. Gurney B, Mermier C, Robergs R, et al. Effects of limb-length discrepancy on gait economy and lower extremity muscle activity in the older adults. J Bone Joint Surg Am 2001;83:907–15. 12. Friberg O. Clinical symptoms and biomechanics of lumbar spine and hip joint in leg length inequality. Spine 1983;8:643–51. 13. McCollum DE, Gray WJ. Dislocations after total hip arthroplasty. Causes and prevention. Clin Orthop Relat Res 1990;261:159–70. 14. Ramaniraka NA, Rakotomanana LR, Rubin PJ, Leyvraz P. Non-cemented total hip arthroplasty: influence of extramedullary parameters on initial implant stability and on bone-implant interface stresses. Rev Chir Orthop 2000;86:590–97.

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15. Ranawat CS. The pants too short, the leg too long! Orthopedics 1999;22:845–46. 16. Hofmann AA1, Skrzynski MC. Leg-length inequality and nerve palsy in total hip arthroplasty: a lawyer awaits! Orthopedics 2000;23:943–44. 17. Müller ME. Total hip replacement: planning, technique and complications. In: Cruess RL, Mitchell NS, eds. Surgical Management of Degenerative Arthritis of the Lower Limb. Philadelphia, PA: Lea and Faber;1975:90–113. 18. Ranawat CS, Rodriguez JA: Functional leg-length inequality following total hip arthroplasty. J Arthroplasty 1997;12:359–64. 19. Massin P, Schmidt L, Engh CA. Evaluation of cementless acetabular component migration. An experimental study. J Arthroplasty 1989;4:245–51. 20. Siebenrock KA, Kalbermatten DF, Ganz R. Effect of pelvic tilt on acetabular retroversion: a study of pelves from cadavers. Clin Orthop Relat Res 2003; 407:241–48. 21. Singh M, Nagrath AR, Maini PS. Changes in trabecular pattern of the upper end of the femur as an index of osteoporosis. J Bone Joint Surg Am 1970;52:457–67. 22. Dorr LD, Faugere MC, Mackel AM, Gruen TA, Bognar B, Malluche HH. Structural and cellular assessment of bone quality of proximal femur. Bone 1993;14:231–42. 23. Clarke IC, Gruen T, Matos M, Amstutz HC. Improved methods for quantitative radiographic evaluation with particular reference to total-hip arthroplasty. Clin Orthop 1976;121:83–91. 24. Carter LW, Stovall DO,Young TR. Determination of accuracy of preoperative templating of noncemented femoral prostheses. J Arthroplasty 1995;10:507–13. 25. Conn KS, Clarke MT, Hallet JP. A simple guide to determine the magnification of radiographs and to improve the accuracy of preoperative templating. J Bone Joint Surg Br 2002; 84:269–72. 26. Oddy MJ, Jones MJ, Pendegrass CJ, Pilling JR, Wimhurst JA. Assessment of reproducibility and accuracy in templating hybrid total hip arthroplasty using digital radiograph. J Bone Joint Surg Br 2006;88:581–85. 27. White SP, Shardlow DL. Effect of introduction of digital radiographic techniques on preoperative templating in orthopaedic practice. Ann R Coll Surg Engl 2005;87:53–4. 28. Wimsey S, Pickard R, Shaw G. Accurate scaling of digital radiographs of the pelvis. A prospective trial of two methods. J Bone Joint Surg 2006;88:1508–12. 29. Goodman SB, Adler SJ, Fyhrie DP, Schurman DJ. The acetabular teardrop and its relevance to acetabular migration. Clin Orthop Relat Res 1988;236:199–204. 30. Sakalkale DP, Sharkey PF, Eng K, Hozack WJ, Rothman RH. Effect of femoral component offset on polyethylene wear in total hip arthroplasty. Clin Orthop 2001;388:125–34. 31. Schmalzried TP, Shepherd EF, Dorey FJ, et al. Wear is a function of use, not time. Clin Orthop 2000;381:36–46. 32. Charnley J. Low Friction Arthroplasty of the Hip: Theory and Practice. Berlin, Germany: Springer-Verlag;1979:246. 33. Russotti GM, Harris WH. Proximal placement of the acetabular component in total hip arthroplasty. A long-term follow-up study. J Bone Joint Surg Am 1991;73:587–92. 34. Callaghan JJ, Salvati EA, Pellicci PM, Wilson PD Jr, Ranawat CS. Results of revision for mechanical failure after cemented total hip replacement, 1979 to 1982. A two to fiveyear follow-up. J Bone Joint Surg Am 1985; 67:1074–85. 35. Pagnano MW, Hanssen AD, Lewallen DG, Shaughnessy WJ.The effect of superior placement of the acetabular component on the rate of loosening after total hip arthroplasty. J Bone Joint Surg Am 1996;78:1004–14.

Chapter 7

Choosing Implant for Total Hip Arthroplasty Georgios K. Triantafyllopoulos, Ivan De Martino, Peter K. Sculco, Lazaros A. Poultsides, Thomas P. Sculco

INTRODUCTION The success of total hip arthroplasty (THA) in relieving pain and improving function in patients with advanced hip arthritis is undisputed. Certainly, besides surgical technique, the implants that are used also play a considerable role to the procedure’s success. Since Sir John Charnley introduced the concept of low friction arthroplasty in the 1960s, advances in materials, implant design and surgical techniques, as well as conclusions from long-term studies of patients with THA have contributed to the development of contemporary implants. A wide range of implant options is offered today. However, different designs abide by some principles which can help categorize them. Even though absolute indications for each type of prosthesis remain debatable, orthopaedic surgeons should be familiar with the basic concepts behind various acetabular cup and femoral stem options, so that they can make the right selection for any given patient. Moreover, implant selection can be influenced by factors related not only to the patient but to the surgeon as well. All these aspects will be discussed in the subsequent section.

THE ACETABULAR CUP Acetabular options include cemented and cementless cups. Cemented cups are monoblock and provide immediate mechanical stability. They can be utilized in cases with a compromised biologic environment, such as metabolic bone disease, postirradiation and renal carcinoma. On the other hand, the demanding technique along with initial concerns for higher rates of aseptic loosening led to a gradual decline in their use, especially in North America. However, recent evidences do not confirm inferior survivorship of cemented cups as compared to cementless options.1 Currently available cementless acetabular cups rely on an initial press-

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fit fixation, followed by subsequent bone ingrowth over an appropriately textured surface. Their shape can be hemispherical or elliptical. Press-fit fixation is achieved through under-reaming of the native acetabulum either 1 or 2 mm. Sequential reaming of the acetabulum should be done until optimal contact with the acetabular rim and dome is achieved. Insertion of a component with a diameter greater by 1–2 mm than the last reamer will provide maximum interference fit at the acetabular rim, while allowing contact of the dome of the cup with the medial acetabular wall, ensuring component medialization. When initial press-fit fixation is not considered optimal (e.g., when repositioning of the cup is required), supplemental fixation can be obtained with the use of screws; spikes, fins or pegs are other alternatives. Porous surface texture provides an osteoconductive milieu for bone ingrowth. There are several different porous coatings, including gritblasted or plasma sprayed titanium, titanium fiber-metal and, more recently, ‘trabecular’ metal. Crystalline hydroxyapatite (HA), known for its osteophilic properties, has also been used as coating. All these options have been proven clinically successful.2–5 Modular cementless cups are widely used, as they offer flexibility in terms of liner selection, and simplify future revision procedures due to liner wear. Modularity brings potential issues including locking mechanism failure and polyethylene backside surface wear. The effective joint space is expanded through the screw holes and accumulated debris can access the ilium and lead to acetabular osteolysis. Monoblock cups with compression molded polyethylene (Fig. 7.1) were introduced to address these concerns, but nonetheless offer less intraoperative versatility. In terms of level of constraint, liners that enclose the femoral head have been used in cases of anticipated postoperative instability or in revision cases. A major disadvantage of constrained liners is the increased risk of early aseptic loosening, due to the excessive shear stresses applied to the cup–bone interface. Dual mobility or tripolar cups, which feature a dual articulation of the polyethylene liner with the femoral head and with the acetabular cup, can be used in selected patients with concurrent or anticipated instability. Concerns of increased linear wear have not been substantiated; however, dual mobility cups are related with the unique complication of ‘intraprosthetic dislocation’ of the polyethylene liner.6–9

THE FEMORAL STEM Cemented fixation of the femoral stem was the technique originally used after the introduction of THA in clinical practice. Whereas not that

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Fig. 7.1 Acetabular monoblock cup with 10° liner directly compression molded into the metal shell.

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popular in North America, cemented stems are still quite frequently used in Europe.10 Long-term studies of patients with Charnley hip arthroplasty have demonstrated an excellent survivorship when revision for aseptic loosening of the femoral component was used as the end-point.11,12 Since the initial Charnley stem, many changes in implant design as well as advances in the bone cement preparation technique were introduced. There are two philosophies behind contemporary cemented stem designs. Both facilitate transmission of axial and torsional loads to the bone, while maintaining mechanical stability. The composite beam concept (Fig. 7.2A) is based on establishing a strong bond between the stem and the acrylic cement. Axial loads are transmitted through the stiffer stem to its distal part and then to the adjacent bone, increasing the risk of stress shielding. The addition of a collar intends to distribute part of the loads to the proximal bone earlier, as well as to unload the proximal cement mantle, which is susceptible to crack formation. Shear stresses at the stem–cement interface are substantial, and the disruption of the bond can result in micromotion, production of cement and metallic debris and loosening of the implant. Composite beam stems are straight or anatomically shaped. The latter offer the potential of better centralization within the femoral canal and of a more evenly distributed cement mantle. The loaded taper philosophy (Fig. 7.2B) incorporates a collarless stem with a shape tapered in one or more planes and a highly polished surface. The stem is embedded into the cement mantle but rather than bonding with it, it initially further subsides until sufficient hoop stresses are created and transferred to the bone.12 The polished surface facilitates subsidence and diminishes wear debris from micromovement in the cement–stem interface. Moreover, the absence of a strong stem–cement mantle bond reduces tensile stress in the interface. However, compressive forces do not depend on such a bond. Overall, with the loaded taper design, axial loads are transmitted to the metaphyseal bone relatively early, thus theoretically reducing the risk of proximal stress-shielding. Despite the fact that good mid- and long-term results have been reported with both a polished13 and a rough surface cemented stem,14,15 there are comparative studies that discourage the use of a textured or matte-surface stem.16,17 Differences in the cross-sectional shape also exist, with oval and square stems available, but their effect on implant performance and survivorship is not clear.18 Regardless the philosophy of the stem though, meticulous cement technique, including avoidance of excessive reaming, preparation of the cement

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B

Fig. 7.2 Cemented stems. (A) Composite beam type. (B) Loaded taper type.

in vacuum and proper pressurization, is of paramount importance for ensuring the longevity of the implant. Cementless femoral stem fixation was initially introduced as an alternative for younger and more active patients, even though today its use is frequently expanded in older age groups. As is the case with the acetabular cup, good bone biology is a prerequisite as it provides the potential for bone ingrowth. Of course, bony ingrowth also depends on adequate initial mechanical stability of the prosthesis. Ingrowth is promoted by the appropriate surface porosity, which can be acquired with sintered cobalt–chrome beads or plasma-sprayed titanium. HA coating has also been used to promote bone ongrowth. Based on the extent of the porous coated surface, cementless femoral stems can be divided into two large categories: extensively and proximally porous coated. Extensively porous coated stems attain broad fixation. However, from a biomechanical point of view, when a stem of this type is used and is securely fixed to its most distal part at the isthmus, axial loads bypass proximal bone, leading to bone remodeling and resorption (stress shielding).19 Proponents of

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extensively porous coated stems point out that stress shielding does not compromise fixation.20 However, in case of a future revision for a reason other than loosening, extensive ingrowth complicates implant removal, necessitating a more extensile approach and compromising an already deteriorated bone stock. On the other hand, extensively porous coated stems can be used in cases of revision surgery, where proximal bone loss warrants distal fixation. In proximally coated stems, only the proximal third of the stem is porous or hydroxyapatite coated and fixation involves only its metaphyseal part. When the hip is axially loaded, loads are transferred to metaphyseal bone, therefore reducing the risk of stress shielding. Despite their different philosophy, in a comparative prospective study, the clinical outcome of the two types was similar and the only difference was a greater reduction in bone mineral density in Gruen zone 7 with the extensively coated stem.19 Based on their shape, cementless femoral stems can be divided into tapered, anatomical and straight cylindrical. Tapered stems have a rectangular cross-section, which allows them to achieve initially both axial and rotational stability (Fig. 7.3A–D). Their shape may be tapered in frontal or both frontal and sagittal planes (single-tapered and double-tapered, respectively), and options may include variations such as flattened, round, conical and rectangular shapes.21 This shape facilitates initial fixation. Some of these types (e.g., flattened and rectangular) do not require any reaming but only broaching. The absence of a shoulder may also accommodate for a more medial entry point. Fixation is achieved proximally, therefore allowing for a more eccentric seating of the stem tip and minimizing the risk of fracture and thigh pain. Recently, shorter variations of the tapered design have been introduced. These facilitate bone stock preservation and are compatible with minimally invasive surgical techniques.22 Anatomic stems are tailored to the anatomy of the femur (Fig. 7.3E–F). As secure diaphyseal fit is very important for this type of implant, reaming of the femoral canal is necessary (fit and fill concept). The diverse femoral anatomy observed among patients and the risk of femoral fractures are concerns with this type of implant. Nevertheless, reported clinical results of their use have been excellent.23,24 Cylindrical stems (Fig. 7.3G) are extensively coated or proximally coated and also require reaming of the femoral canal, as distal fixation is crucial. In fact, distal fixation is important not only for axial but also for rotational stability. Fitting a cylindrical stem in an under-reamed femoral canal by 1–2 mm provides better rotational fixation initially than lineto-line reaming. However, when femoral canal under-reaming is applied,

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E

B

C

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D

G

Fig. 7.3 Cementless stems. (A and B) Single wedged tapered stem. (C and D) Rectangular tapered stem. (E and F) Anatomic stem. (G) Straight cylindrical, extensively coated stem.

insertion of the stem should be done with caution, as fracture of the femur is not an uncommon complication. As already stated, extensively porous coated cylindrical stems are associated with proximal stress shielding. In spite of these concerns, long-term survival of this type of prostheses has been reported to be excellent.25

BEARING SURFACES Several options of bearing surface combinations have been offered throughout the years of THA clinical application. Bearing surfaces can be roughly divided into two large categories: hard-on-soft and hard-on-hard. Hard-on-soft bearings refer to the use of a polyethylene acetabular liner and either a metallic or a ceramic femoral head. On the other hand, hardon-hard bearings include ceramic-on-ceramic and metal-on-metal combinations. Metal-on-polyethylene bearings incorporate an articulation of a

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cobalt–chrome alloy femoral head against a highly cross-linked, ultra-high molecular weight polyethylene liner. In ceramic-on-polyethylene bearings, a similar liner is used, but the femoral head is composed of a ceramic material. Polyethylene wear with the production of large particle debris and consequent osteolysis remains a significant problem with these configurations. Ceramic-on-polyethylene bearings have been shown to exhibit a better wear profile and thus are considered appropriate for younger and more active patients.26 Improvements in ceramic materials have been related with a decreased risk for head fracture, although that risk cannot be completely overlooked, especially in the younger patient. A considerable research effort has focused in improving polyethylene properties and minimizing linear wear. Sterilization in the absence of air, increase of crosslinking through remelting or annealing27 and vitamin E impregnation28 are methods of improving polyethylene wear resistance. Highly cross-linked polyethylene exhibits a better linear wear profile compared to traditional polyethylene, but its mechanical properties in terms of fatigue resistance, ductility, tensile strength and toughness are inferior. Ceramic-on-ceramic bearings are not related with polyethylene wear-related problems, but require accurate cup positioning, as deviations can result in impingement or edge loading, and consequent squeaking or fracture of the ceramic components.29 Despite initial enthusiasm about metal-on-metal bearings, their use has been disfavored because of issues regarding metal ion release and adverse local tissue reactions.30,31 Therefore, as newer polyethylene liners exhibited a better wear behavior, hard-on-soft bearings were gradually widely endorsed. Polyethylene liners can be combined with a wide range head sizes, including those with larger diameters. Potential future wear and osteolysis can be treated with liner exchange and bone grafting.32

PATIENTRELATED FACTORS Implant selection should always be individualized to the needs and characteristics of each patient. Factors that should be considered include patient age, bone quality and anatomy, and co-morbidities that may affect the procedure’s success. In the very young patient, as modern mean life expectancy can exceed 80 years, bone and soft tissue preservation is of paramount importance. Therefore, implants in this group of patients should accommodate to these goals. Cementless press-fit fixation is the method of choice in

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younger patients. The presence of indwelling instrumentation, short-stature with small acetabular and proximal femoral size, as well as concomitant bone metabolic disease are factors that may affect the ultimate decision. Nonetheless, as discussed below, surgeon preference also plays an integral role in the process of implant selection, even under these circumstances. As a future revision seems inevitable, another important variable that might affect implant selection in the younger patient population is the ease of revision. Unfortunately, certain approaches to achieve this, such as increased femoral stem modularity, have not been proven successful.33 On the other end of the spectrum are patients older than 75 years. Often, these patients have compromised bone quality and osteoporosis or lower level of activity, and may benefit from cemented fixation. Cemented fixation has shown satisfactory and reproducible results in this group of patients.34,35 However, cement-related morbidity, and most importantly, respiratory complications in a patient with a possibly already compromised respiratory and cardiovascular function, along with excellent reported results of cementless fixation,36 have led to a gradual increase in the use of press-fit options, even in patients of greater age. In cases of hip dysplasia, atypical anatomy warrants the use of smaller or even custom-made femoral stems and cemented cups. The role of preoperative planning in these patients is even more critical. Modular stems with proximal cementless fixation are commonly used. In certain cases where proximal bone stock is inadequate, diaphyseal fixation through an extensively coated, cylindrical stem is warranted. Finally, concomitant conditions including rheumatoid arthritis or previous irradiation of the pelvic region could necessitate cemented fixation options. The senior author’s suggestions regarding the use of an uncemented vs. a cemented stem are summarized in Fig. 7.4.

SURGEONRELATED FACTORS In a recent survey among orthopaedic surgeons,37 100% stated that they use uncemented acetabular components, with 48% adding no augmentation, 44% using additional screw fixation and 7% using implants with spikes or fins. As per femoral options, more than 95% of the responders reported the use of uncemented stems in more than 50% of their cases, with 47% using this option in all of their patients. Tapered stems seem to be widely preferred, as use of double-tapered stems was reported by 53% of surgeons, whereas single-tapered stems were routinely used by 38% of

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Yes

Poor bone biology (e.g. previous irradiation) No No

No

Other anatomic considerations (e.g. fracture malunion, dysplasia)

Age > 75 years

No

Yes

Dorr Type C Proximal Femur Yes

Yes Uncemented fixation

Cemented fixation

Fig. 7.4 General recommendations for the use of uncemented vs. cemented stems.

responders. For cemented stems, composite beam designs were the preferred option among survey participants (65%). When polyethylene bearings were chosen, invariable use of either a metallic or a ceramic head was reported by 65% of surgeons, with 80% preferring the use of a head *36 mm in diameter. Undoubtedly, surgeon preference and familiarity with a certain implant or technique are very important parameters. Even in the hands of a skilled surgeon, a new technique is associated with a respective learning curve. Other procedures, such as cementing a cup, can be very demanding. It should also be noted that clinical experience plays a key role in selecting an implant, as surgeons can be reluctant in choosing a prosthesis that they are not familiar with. On the other hand, as recent experience has shown, a considerable number of clinicians can be prompted to use a novel implant that seems advantageous, but has not been supported with solid evidence, leading to detrimental consequences. Often there is a grey zone between evidence-based support and marketing of an implant, and the industry puts pressure on using novel and costly implants. However, hospital payments for joint replacements have not been increasing with the same rate as implant costs. Some hospital organizations could therefore advocate the use of less expensive implants, leading to a conflict with surgeons.38 It is the surgeons’ responsibility to use an implant that will provide favorable and reproducible long-term outcomes, using current best evidence and sound clinical reasoning.

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SUMMARY Contemporary implant options offer great versatility and can address the needs of almost every patient with end-stage hip arthritis undergoing THA. While all of these options exhibit roughly equivalent short-term results, it is their performance in the long-term that can affect selection. Surgeons should have knowledge of the basic concepts behind different designs and their advantages and disadvantages, as well as should take into consideration distinct patient characteristics. Finally, they should keep in mind that even the appropriate selection of the best available implant cannot ensure a successful outcome without a sound surgical technique.

REFERENCES 1. Toossi N, Adeli B, Timperl ey AJ, Haddad FS, Maltenfort M, Parvizi J. Acetabular components in total hip arthroplasty: is there evidence that cementless fixation is better? J Bone Joint Surg Am 2013;95:168–74. 2. Engh CA, Hopper RH, Jr, Engh CA, Jr. Long-term porous-coated cup survivorship using spikes, screws, and press-fitting for initial fixation. J Arthroplasty 2004;19(Suppl 2):54–60. 3. Reina RJ, Rodriguez JA, Rasquinha VJ, Ranawat CS. Fixation and osteolysis in plasma-sprayed hemispherical cups with hybrid total hip arthroplasty. J Arthroplasty 2007;22:531–34. 4. Urban RM, Hall DJ, Della Valle C, Wimmer MA, Jacobs JJ, Galante JO. Successful longterm fixation and progression of osteolysis associated with first-generation cementless acetabular components retrieved post mortem. J Bone Joint Surg Am 2012;94:1877–85. 5. Poultsides LA, Sioros V, Anderson JA, Bruni D, Beksac B, Sculco TP. Ten- to 15-year clinical and radiographic results for a compression molded monoblock elliptical acetabular component. J Arthroplasty 2012;27:1850–56. 6. Adam P, Farizon F, Fessy MH. Dual articulation retentive acetabular liners and wear: surface analysis of 40 retrieved polyethylene implants. Rev Chir Orthop Reparatrice Appar Mot 2005;91:627–36. 7. Philippot R, Boyer B, Farizon F. Intraprosthetic dislocation: a specific complication of the dual-mobility system. Clin Orthop Relat Res 2013;471:965–70. 8. Boyer B, Philippot R, Geringer J, Farizon F. Primary total hip arthroplasty with dual mobility socket to prevent dislocation: a 22-year follow-up of 240 hips. Int Orthop 2012;36:511–18. 9. Philippot R, Farizon F, Camilleri JP, et al. Survival of cementless dual mobility socket with a mean 17 years follow-up. Rev Chir Orthop Reparatrice Appar Mot 2008;94:e23–e27. 10. Murray DW. Cemented femoral fixation: the north Atlantic divide. Bone Joint J 2013;95B(11 Suppl A):51–2. 11. Callaghan JJ, Albright JC, Goetz DD, Olejniczak JP, Johnston RC. Charnley total hip arthroplasty with cement. minimum twenty-five-year follow-up. J Bone Joint Surg Am 2000;82:487–97. 12. Shen G. Femoral stem fixation. an engineering interpretation of the long-term outcome of charnley and exeter stems. J Bone Joint Surg Br 1998;80:754–56. 13. Ling RS, Charity J, Lee AJ, Whitehouse SL, Timperley AJ, Gie GA. The long-term results of the original exeter polished cemented femoral component: a follow-up report.

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J Arthroplasty 2009;24:511–17. 14. Callaghan JJ, Liu SS, Firestone DE, et al. Total hip arthroplasty with cement and use of a collared matte-finish femoral component: nineteen to twenty-year follow-up. J Bone Joint Surg Am 2008;90:299–306. 15. Vail TP, Goetz D, Tanzer M, Fisher DA, Mohler CG, Callaghan JJ. A prospective randomized trial of cemented femoral components with polished versus grit-blasted surface finish and identical stem geometry. J Arthroplasty 2003;18(7 Suppl 1):95–102. 16. Datir SP, Kurta IC, Wynn-Jones CH. Ten-year survivorship of rough-surfaced femoral stem with geometry similar to charnley femoral stem. J Arthroplasty 2006;21:392–97. 17. Della Valle AG, Zoppi A, Peterson MG, Salvati EA. A rough surface finish adversely affects the survivorship of a cemented femoral stem. Clin Orthop Relat Res 2005;436:158–63. 18. Scheerlinck T, Casteleyn PP.The design features of cemented femoral hip implants. J Bone Joint Surg Br 2006;88:1409–18. 19. MacDonald SJ, Rosenzweig S, Guerin JS, et al. Proximally versus fully porous-coated femoral stems: a multicenter randomized trial. Clin Orthop Relat Res 2010;468:424–32. 20. Engh CA, Jr, Young AM, Engh CA S, Hopper RH, Jr. Clinical consequences of stress shielding after porous-coated total hip arthroplasty. Clin Orthop Relat Res 2003;417:157–63. 21. Khanuja HS,Vakil JJ, Goddard MS, Mont MA. Cementless femoral fixation in total hip arthroplasty. J Bone Joint Surg Am 2011;93:500–09. 22. Patel RM, Stulberg SD. The rationale for short uncemented stems in total hip arthroplasty. Orthop Clin North Am 2014;45:19–31. 23. Archibeck MJ, Berger RA, Jacobs JJ, et al. Second-generation cementless total hip arthroplasty: eight to eleven-year results. J Bone Joint Surg Am 2001;83-A:1666–73. 24. Kawamura H, Dunbar MJ, Murray P, Bourne RB, Rorabeck CH. The porous coated anatomic total hip replacement. A ten to fourteen-year follow-up study of a cementless total hip arthroplasty. J Bone Joint Surg Am 2001;83-A:1333–38. 25. Engh CA, Hopper RH, Jr. The odyssey of porous-coated fixation. J Arthroplasty 2002;17(4 Suppl 1):102–07. 26. Kim YH. Comparison of polyethylene wear associated with cobalt-chromium and zirconia heads after total hip replacement. A prospective, randomized study. J Bone Joint Surg Am 2005;87:1769–76. 27. Callary SA, Field JR, Campbell DG. Low wear of a second-generation highly crosslinked polyethylene liner: a 5-year radiostereometric analysis study. Clin Orthop Relat Res 2013;471:3596–600. 28. Oral E, Christensen SD, Malhi AS, Wannomae KK, Muratoglu OK. Wear resistance and mechanical properties of highly cross-linked, ultrahigh-molecular weight polyethylene doped with vitamin E. J Arthroplasty 2006;21:580–91. 29. D’Antonio JA, Sutton K. Ceramic materials as bearing surfaces for total hip arthroplasty. J Am Acad Orthop Surg 2009;17:63–8. 30. Bosker BH, Ettema HB, Boomsma MF, Kollen BJ, Maas M, Verheyen CC. High incidence of pseudotumour formation after large-diameter metal-on-metal total hip replacement: a prospective cohort study. J Bone Joint Surg Br 2012;94:755–61. 31. Smith AJ, Dieppe P,Vernon K, Porter M, Blom AW, National Joint Registry of England and Wales. Failure rates of stemmed metal-on-metal hip replacements: analysis of data from the National Joint Registry of England and Wales. Lancet 2012;379:1199–1204. 32. Haidukewych GJ, Petrie J. Bearing surface considerations for total hip arthroplasty in young patients. Orthop Clin North Am 2012;43:395–402. 33. Cooper HJ, Urban RM, Wixson RL, Meneghini RM, Jacobs JJ. Adverse local tissue reaction arising from corrosion at the femoral neck-body junction in a dual-taper stem with a cobalt-chromium modular neck. J Bone Joint Surg Am 2013;95:865–72. 34. Ekelund A, Rydell N, Nilsson OS. Total hip arthroplasty in patients 80 years of age and older. Clin Orthop Relat Res 1992; 281:101–06.

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35. Levy BA, Berry DJ, Pagnano MW. Long-term survivorship of cemented all-polyethylene acetabular components in patients > 75 years of age. J Arthroplasty 2000; 15:461–67. 36. Healy WL. Hip implant selection for total hip arthroplasty in elderly patients. Clin Orthop Relat Res 2002; 405:54–64. 37. Berry DJ, Bozic KJ. Current practice patterns in primary hip and knee arthroplasty among members of the American Association of Hip and Knee Surgeons. J Arthroplasty 2010;25(6 Suppl):2–4. 38. Healy WL, Iorio R. Implant selection and cost for total joint arthroplasty: conflict between surgeons and hospitals. Clin Orthop Relat Res 2007;457:57–63.

Chapter 8

Tips and Pearls in Total Hip Arthroplasty Ivan De Martino, Georgios K. Triantafyllopoulos, Peter K. Sculco, Lazaros A. Poultsides, Thomas P. Sculco

INTRODUCTION Total hip arthroplasty (THA) is one of the most common and successful surgical procedures over the past 50 years,1 and has been proven to decrease a patient's pain and improve function and quality of life.2 Despite variations in surgical technique and implant selection, several studies have demonstrated over 90% implant survival at minimum 10 years.3 In order to relieve pain and improve function and quality of life in patients undergoing a THA, it is mandatory for a surgeon to restore or maintain the center of rotation and offset, ensure equal limb length and achieve durable implant fixation and stability. There are several different exposures to perform a THA today: the anterior (Smith-Peterson4), anterolateral (Watson-Jones5), direct lateral (Hardinge6), posterolateral (Moore7) and direct posterior (Gibson8). The direct anterior approach (DAA) allows the surgeon to approach the hip through an internervous and intermuscular plane, thus demonstrating potential advantages over other surgical approaches to the hip. Specifically, it does not violate the integrity of the iliotibial band, greater trochanter and hip abductor muscles, thereby potentially reducing the risk for painful THA.9 Studies have shown that recovery of gait and hip function was more rapid after DAA compared with the miniposterior approach10 and that postoperative hip dislocation precautions are not required following DAA.11 Supine position may offer an advantage to the intraoperative cardiovascular and pulmonary monitoring, facilitate potential urgent need for airway and cardiopulmonary access and intervention, and furthermore, provide a direct way to equalize leg-length discrepancy (LLD) during surgery.12 By far, the most common surgical technique is the posterolateral approach. This is utilized in approximately 70% of cases performed in the United States. The current trend is to use less invasive approaches to perform a THA. Even though absolute indications for each approach remain debatable, orthopaedic surgeons should learn the basic strategy and concepts

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required for successful execution of a primary THA. In the following section, we discuss the mini-incision posterolateral surgical technique as described by the senior surgeon13 (TPS), with particular emphasis on patient positioning, surgical exposure, implant positioning and LLD assessment.

AUTHOR’S PREFERRED METHOD Complete history and physical examination are performed for all patients. After a complete radiographic evaluation (anterior–posterior pelvis and lateral view of the hip), a meticulous preoperative planning and templating are performed. We use multimodal hypotensive epidural anaesthesia (HEA) for the vast majority of our patients and reserve general anaesthesia for rare instances in which spinal or epidural anesthesia cannot be performed for technical or medical reasons (e.g., severe degenerative disease of the lumbar spine). HEA has been shown to decrease perioperative morbidity, including thromboembolic disease.14 A second surgical benefit of this type of anaesthesia is a reduction of intraoperative blood loss, which facilitates visualization during hip implantation.14 Prophylactic antibiotics are administered intravenously at least 30 min before skin incision (e.g., a second generation cephalosporin or vancomycine due to patient allergy). We use a multimodal postoperative deep vein thrombosis/pulmonary embolism (DVT/ PE) prophylaxis, both pharmacologic and mechanical; 325 mg of aspirin twice daily in addition to pneumatic compression and early mobilization. Coumadin is preferred over aspirin in high risk patients.

POSITIONING OF THE PATIENT Proper patient positioning is a prerequisite for accurate exposure and intraoperative assessment of the pelvic position during acetabular component implantation. After induction of epidural anaesthesia, the patient is positioned in the lateral decubitus position on a wellFig. 8.1 Patient is placed in the lateral padded hip table (Fig. 8.1 ). In decubitus position on a well-padded order to secure the patient so the standard hip surgical table with the surgi- ASIS is perpendicular to the plane cal side up.

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of the floor and not rotated, the pelvis is secured with padded anterior (pubic) and posterior (sacral) post supports (Fig. 8.2). We also cover the anterior pubic post with an inflatable pad, to improve stabilization and protect the skin from B excessive pressure. An inflatable shoulder float is placed below the axilla to avoid injury to the axillary nerve and reduce postoperative shoulder discomfort (Fig. 8.3). The back is also stabilized with a posteFig. 8.2 The pubic region is secured rior thoracic support to prevent any with padded pubic post support (A) forward or backward rolling of the (arrow). The sacral region and the back are secured with padded sacral and tho- body. All of the bony prominences are padded. The nonsurgical leg is racic post supports (B) (arrows). secured with a belt in a position of slight hip flexion and 90° of knee flexion. A foam rubber pad is also positioned between the knees in order to retain a neutral position of both extremities (Fig. 8.4). Shaving of the surgical site is done with an electric shaver in the pre-op holding area and before the draping procedure. The skin from the calf to the pelvis is prepared with an antiseptic solution A

Fig. 8.3 An inflatable shoulder float is placed below the axilla to avoid injury to the axillary nerve and reduce postoperative shoulder discomfort (arrow).

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(povidone-iodine or chlorexidine). The operative limb is covered with sterile Iobane® drapes to allow full mobility of the limb during the operative procedure, which is essential during the exposure of the proximal femur and during the implantation of the femoral prosthesis.

Fig. 8.4 A foam rubber pad positioned between the knees to retain a neutral position of both extremities.

INCISION AND EXPOSURE The anatomic landmarks for the surgical incision are marked with a skin marker including the proximal, anterior and posterior borders of the greater trochanter and the vastus ridge. In cases of overweight patients, wherein the greater trochanter can be difficult to palpate, rotation of the limb can help in identifying it. A straight skin incision begins in the middle of the femur at the level of vastus ridge and extends 1–2 cm proximally over the posterior corner of the greater trochanter for a total incision length of 8–10 cm (Fig. 8.5). Approximately, one-third of the incision extends proximal to the tip of the greater trochanter. Distally, the incision follows the axis of the distal femur, whereas proximally follows the direction of the underlying gluteus maximus fibers and is slightly curved in the posterior direction. In obese patients, a longer incision may be required in order to avoid excessive pressure on the skin edges. An incision shorter than 6 cm should be avoided, as it increases the risk of skin bruising and blistering. After the skin incision is made, subcutaneous tissue is incised and retracted in line with the skin incision. The fascia lata is also incised in the line of the skin incision, between the middle and posterior third of the greater trochanter along the axis of the femur. The gluteus maximus is gently split along its fibers cranially using blunt finger dissection to

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Fig. 8.5 The anatomic landmarks for placement of skin incision include the proximal tip of the greater trochanter, the anterior and posterior borders of the greater trochanter and the vastus ridge. For the mini posterolateral approach, the length of skin incision ranges from 6 to 10 cm.

expose the proximal part of the great trochanter. Two cotton laps soaked in saline are applied to the skin edges and a Charnley self-retaining retractor is placed deep to the fascial layer while carefully protecting the sciatic nerve. The leg is positioned in neutral extension, and the hip is gently internally rotated with a padded Mayo stand under the foot for support. The trochanteric bursa is then incised and the fat pad behind the great trochanter reflected posteriorly with a surgical lap sponge. The short external rotators are exposed with a Cobb elevator (Fig. 8.6). Haemostasis of the deep medial femoral circumflex vessels is achieved with electrocautery. The piriformis is palpated and separated from the inferior border of the gluteus medius with a blunt dissection to create an anatomic interval. Angled at 90°, Hohmann retractor is placed underneath the gluteus medius in this interval and an Aufranc retractor is placed immediately adjacent to the proximal margin of the quadratus femoris below the inferior capsule and the femoral neck. At the junction of Fig. 8.6 Intraoperative picture showing the exposure of the external rotators of the piriformis and gluteus minimus, the piriformis, conjoined tendon the hip (arrow).

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and underlying capsule are released as a single layer from the posterior border of the femoral neck, extending distally to the level of the lesser trochanter. A portion of quadrates femurs muscle may be released in the distal portion of this incision. This creates a single soft tissue sleeve that is then tagged with two nonabsorbable sutures for later posterior soft tissue repair. The first suture is through the piriformis tendon and capsule and the second suture through the conjoined tendon and capsule (Fig. 8.7). With further flexion, adduction and internal rotation, the femoral head is then dislocated posteriorly. In difficult cases, placing a bone hook around the femoral neck may help. The limb is then internally rotated 90°. The center of the femoral head is marked with Fig. 8.7 The tendons and capsule are electrocautery and the lesser trotagged using two No. 2 non-absorbable chanter is identified. The distance tagging sutures (arrow). from the lesser trochanter to the center of the femoral head is measured intraoperatively (Fig. 8.8) and compared with the preoperative plan. The level of the neck cut level is based on the preoperative plan. The femoral neck osteotomy is performed with a thin oscillating reciprocating saw, starting from the medial calcar towards the great trochanter (Fig. 8.9). Attention must be paid to prevent notching of the greater trochanter or injuring the sciatic nerve. Care should be taken to make sure the saw blade is perpendicular to the

Fig. 8.8 The distance from the less trochanter to the center of the head is measured and the neck osteotomy level is marked.

Fig. 8.9 The reciprocating saw allows for optimal control and gradual change of direction, decreasing chance of notching greater trochanter.

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long axis of the femur so as to prevent an oblique femoral neck cut. The femoral head is removed using a tinaculum pointed clamp and a twisting motion to disrupt remnant of the ligamentum teres (Fig. 8.10).

Fig. 8.10. The femoral head is removed using a tinaculum pointed clamp.

PREPARATION OF THE ACETABULUM AND POSITIONING OF THE ACETABULAR COMPONENT After the femoral neck cut is completed the leg is returned to a neutral position. The femur is retracted with an angled C-shaped Hohmann retractor (Fig. 8.11) over the anterior wall of the acetabulum. A Steinman pin is placed into the supra-acetabular region (ilium) to retract the gluteus medius and minimus superiorly. The inferior capsule is incised to relieve the tension and a wide angled Hohmann retractor (Fig. 8.11) is inserted into the posterior wall of the acetabulum between the labrum and the posterior capsule using a mallet to gain bone fixation. An Aufranc retractor (Fig. 8.11) is placed initially Fig. 8.11. Retractors used for mini-inci- inferior to the transverse acetabular sion posterior lateral approach used to ligament and moved above the ligafacilitate acetabular exposure. From left to right: (1) C-retractor, (2) Aufranc, (3) road ment after further inferior capsular release. The acetabular labrum and bent Hohmann and (4) Bent Hohmann.

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overhanging peripheral soft tissues are then excised with a long-handled scalpel. The full circumference of the acetabular socket should be exposed (Fig. 8.12). The pulvinar is excised with a long electrocautery tip to prevent bleeding from the ligamentum teres vessels. Peripheral osteophytes are generally removed Fig. 8.12 Bend retractors allow excellent after the cup is impacted in its final visualization of the acetabulum. position using a broad osteotome and a rongeur. The acetabulum is initially sequentially reamed in a progressive and concentric manner with an offset handled reamer. The initial reamer is roughly 6 mm smaller than template’s acetabular cup size and is inserted directly into the wound in order to remove the medial osteophyte and expose the true acetabular floor (medial wall) (Fig. 8.13). Then, the surgeon brings the reamer to the desired lateral abduction and anteversion and the periphery of the acetabulum is incrementally (2 mm increments) reamed to the desired size (Fig. 8.14), until sufficiently bleeding subchondral bone is exposed throughout the acetabular wall, and good rim contact with the reamer is achieved. The correct arrangement of the retractors, and especially the inferior Aufranc retractor, allows for adequate inferior

A

B

Fig. 8.13 The acetabulum is initially sequentially reamed with an offset handled reamer (A). The initial reamer is inserted directly into the wound in order to remove the medial osteophyte and expose the true acetabular floor (medial wall) (B).

Fig. 8.14 After the exposure of the medial wall, the reamer is brought to the desired lateral abduction and anteversion and the periphery of the acetabulum is incrementally reamed to the desired size.

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mobilization of the skin (mobile window) and helps placing the reamers horizontally enough to achieve the desired cup position. After acetabular reaming is concluded, a trial shell is inserted and fully seated to verify size, orientation and stability of the cup. The surgeon, especially beginner, should note the position of the trial shell so that the acetabular cup can be inserted in the same position. Screws can be added to increase fixation if is needed. The senior surgeon’s preference for primary cases is the use of a monoblock cup. This is an elliptical monoblock cup with a direct compression molded polyethylene into a trabecular metal shell. Due to the elliptical shape, the cup is 2 mm wider in the periphery comparing to a hemispherical cup and reaming is performed to 1 mm below the external rim circumference, thus providing a stable rim fit. With a vertically placed medializing impactor, the cup is initially brought medially (Fig. 8.15). It is then impacted axially to the desired orientation. Before press-fitting the cup, its position is checked with an angle guide which rests on the acetabular rim (Fig. 8.16), and fine adjustments can be made with the impaction of a shovel placed on the appropriate positions of the rim (Fig. 8.17). Once optimal orientaA B tion is achieved, the cup is press-fitFig. 8.15 The cup is attached to an insertted with a ball impactor to its final er (A) and a few taps are applied initially to a vertically placed impactor in order position. In our practice, for a primedialize the cup (B). mary total hip arthroplasty, we opt

Fig. 8.16 An angle guide is used to assess the cup orientation. Optimal cup position is considered a coronal inclination angle of 45° and an anteversion of 20°.

Fig. 8.17 Cup insertion tools. From left to right: (1) medial cup impactor, (2) cup rim impactor and (3) angle guide.

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for a medial and inferior placement of the acetabular cup (in line with the plane connecting the two teardrop signs in the AP pelvis X-ray), in order to restore the normal hip joint center of rotation and biomechanics. The optimal lateral abduction angle of the cup is considered to be 40°–45°, whereas desired cup anteversion is 15°–25°. Nevertheless, cup anteversion should be always considered in combination with femoral anteversion and the goal should be obtaining a combined anteversion of 25° to 35° for men and 30° to 45° for women. This further stresses the importance of scrutinizing preoperative radiographs and templating.

PREPARATION OF THE FEMUR AND POSITIONING OF THE FEMORAL COMPONENT After the actabular cup implantation is completed, the Charnley retractor is removed and the femur is 90° internally rotated, flexed and adducted. Two clean laps are used to protect the skin and a third lap sponge is inserted into acetabular shell to protect the polyethylene and shell. The proximal femur is delivered into the mobile window, and exposure is aided with a narrow femoral neck retractor (modified toothed Aufranc retractor) placed on the anterior neck. An Aufranc retractor is placed along the inferior/medial neck below the lesser trochanter and preferably in contact with the modified Aufranc retractor used to lift the femur. A C-retractor is placed anterior to the greater trochanter into the trochanteric fossa superiorly to separate the gluteus minimus and medius muscles which provides exposure to the femoral neck and protects the abductors during subsequent reaming and broaching of the femoral canal (Fig. 8.18). It is the senior author’s preference to use a splined femoral stem to enhance rotational stability of the final implant. Once the retractors have been placed around the proximal femur, the remaining lateral cortex of the neck is removed with a curved gouge placed at the junction of the femoral neck and the greater trochanter. The femoral canal is subsequently opened with a rasped cylindrical reamer. Care is taken to lateralize the femoral Fig. 8.18 The proximal femur is delivered canal during reaming, in order to into the incision with the aid of retractors. avoid varus insertion of the stem.

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Sequential reaming of the distal portion of the canal is performed with a straight reamer, until adequate cortical contact is reached (Figs 8.19– 8.20). Broaching of the proximal femur is then carried out, with the broaches inserted with approximately 10°–15° of anteversion and follows the patients native version (Figs 8.20–8.21). The posterior neck cortex in relation to the epicondyles of the knee with the leg perpendicular to the floor can be used as a reference for determining anteversion. The broach size is then incrementally increased until adequate fit and rotational stability are achieved. A calcar planer is used to remove any excess bone around the neck of the final trial broach once the handle has been detached (Fig. 8.22). A rongeur may also be used at this time to remove

Fig. 8.19 Femoral canal preparation using cylindrical reamers.

Fig. 8.20 Femoral component preparation tools.

Fig. 8.21 Broaching of the femoral canal using the appropriate femoral rasps.

Fig. 8.22 A calcar planer is used to remove any excess bone around the neck of the final trial broach once the handle has been detached.

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any osteophytes located usually at the anterior aspect of the femoral neck. After insertion of the trial neck and a standard head (+0 mm) of the appropriate diameter, the hip is reduced, and cup coverage and combined anteversion of the components are evaluated (Fig. 8.23). In addition, the hip is brought to range of motion to check for impingement and instability (for more details, see the section on leg length and soft tissue balancing). After confirming appropriate positioning, the broach is removed and the chosen implant is inserted. Irrigation is not performed before the insertion of the prosthesis as a press-fit stem is used, and autogenous bone should not be removed from the canal. Again, care is taken to maintain the desired anteversion during impaction of the stem to its final position (Fig. 8.24). A final femoral head is impacted onto a clean and dry femoral stem taper. A

Fig. 8.23 Trial reduction is always performed in order to assess offset, leg length, range of motion and hip stability.

B

Fig. 8.24 Intraoperative image showing the impaction of the final femoral component, taking care to ensure correct rotational alignment (A). The femoral stem used by the senior surgeon relies on proximal fixation for initial stability and is enhanced by the distal splines for added rotational stability (B).

REDUCTION AND CLOSURE Once the implants have been placed and reduced, the wound is irrigated via pulsed lavage and haemostasis achieved. The short external rotators, including the conjoined tendon and the piriformis tendon, as well as the posterior joint capsule are repaired through two transosseus holes in the greater trochanter and ideally in the site of the native insertions (Fig. 8.25). The sutures are pas-

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Fig. 8.25 Using a 3.2 mm drill bit, two transosseus tunnels are created in the posterolateral aspect of the greater trochanter.

sed through the drill holes with a suture passer and tied in slight abduction and external rotation to allow the posterior tissues to come in close proximity to the femur. Two 12 mm drain tubes are placed under the fascia, and the wound is copiously irrigated with normal saline using pulsatile lavage. The fascia lata is closed with interrupted 0 Vicryl sutures. The wound is closed in layers. A sterile dressing is then placed over the wound, which is wrapped in a hip spica fashion using an Ace bandage. The final position of the leg is secured using an abducting pillow. The patient is then transferred to the recovery room. In order to prevent a perioperative dislocation, standard hip precautions for a posterolateral approach are followed.

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It should be highlighted that although this technique applies to the majority of patients undergoing primary total hip arthroplasty via a posterolateral approach, each patient should be carefully evaluated before surgery to identify factors that would warrant a modification of this approach. For example, patients with ankylosing spondylitis frequently compensate vertebral deformity with hip hyperextension. This can lead to a propensity of placing the cup in a more vertical and anteverted position, which in combination with the increased femoral anteversion, frequently seen in these patients, increases the risk of anterior dislocation. Hence, in such patients, cup orientation and femoral anteversion should be adjusted accordingly. Another example is the patient with hip dysplasia and high congenital dislocation, where placement of the cup in the anatomic position is not feasible. In these patients, a high-hip center can be a viable option, provided that adequate medialization is achieved, as lateral placement of a high-center cup is associated with poor hip biomechanics. In summary, preoperative planning together with sound surgical technique can ensure the appropriate positioning of both implants, so as to obtain the optimal functional outcome and abate the risk of mechanical complications.

ENSURING LIMB LENGTH EQUALIZATION AND STABILITY The process of preserving limb length or restoring LLD during total hip arthroplasty begins with preoperative templating. The perpendicular distance between the proximal corner of the lesser trochanter and the interteardrop line is measured for both sides and any difference noted represents the LLD that needs to be restored. The results should always be compared to the clinical limb length measurements performed during patient evaluation. After templating for the acetabular and femoral components (Fig. 8.26), the vertical distance between the centers of rotation of the acetabular cup and the femoral stem represents the change in limb length that will be obtained. This could be either lengthening (if the femoral component’s center of rotation is more proximal than that of the acetabular cup) or shortening of the limb (if the femoral component’s center of rotation is more distal than that of the acetabular cup). Similarly, if the center of rotation of the femoral stem lies medially to the center of rotation of the acetabular cup, femoral offset will be increased and vice versa. The distances between the proximal corner of the lesser trochanter

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and the center of rotation of the femoral head (lesser trochanter center [LTC] ), as well as the level of the femoral neck osteotomy are also determined (Fig. 8.26). For more details regarding preoperative templating, the reader is referred to the relevant section. Intraoperatively, the findings of preoperative templating need to be confirmed. After dislocating the hip, the proximal corner of the lesser trochanter is released and exposed, the center of the femoral head is determined and the distance between these two points is measured and compared to the LTC distance measured during preoperative templating, to evaluate for accuracy of preoperative measurements. The level of the neck osteotomy is also marked. Once the surgeon has proceeded with neck osteotomy, after reaming and broaching of the femoral canal and with the final broach in place, a trial femoral neck and a femoral head of the appropriate diameter are inserted. The selection of a neck with a standard or an extended offset depends on the findings of preoperative templating with a general goal of using the midrange of available neck lengths. Moreover, a femoral head with the largest possible diameter accommodated by the acetabular cup is prefer-

Fig. 8.26 Preoperative digital templating.

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able (up to 36 mm), as it is well established that a greater head/neck ratio increases range of motion and stability of the implant. After inserting the selected femoral neck and a +0 head, the LTC distance is determined again (Fig. 8.27). If there is a difference with the LTC measured before the neck osteotomy, then a femoral head of longer or shorter length is inserted. The hip joint is reduced and the surgeon assesses soft tissue tension, range of motion and stability. Soft tissue tension can be evaluated with the drop kick test and the shuck test. In the drop kick test, when

Fig. 8.27 Measurement of the distance from the lesser trochanter to the center of the head ensures adequate leg length.

the hip is brought to extension, the knee should remain in flexion. If the knee is extended with this maneuver, then soft tissue tension is too tight. The shuck test involves telescopic distraction of the femoral head from the acetabulum, which should only allow for a few millimeters of translation. Range of motion is then evaluated and any restriction, particularly in internal or external rotation, is indicative of tight soft tissue tension. The presence of gross instability is also assessed. Finally, the impingement test is performed, by adducting and internally rotating the hip and assessing for hip stability and range of motion before impingement occurs. As noted earlier, if any modifications are deemed necessary after these tests, fine adjustments can be made by using different neck and head offsets and lengths. An effort should be made to avoid the use of femoral heads with

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excessive lengths, as they exhibit reduced head/neck ratio and therefore limit range of motion before impingement ensues. This further underlines the importance of careful preoperative planning. Once optimal hip biomechanics is achieved, the chosen femoral stem and head are inserted, the hip is reduced and the surgeon proceeds with closure. Careful repair of the posterior capsule with the technique described earlier is critical for enhancing hip stability after total hip arthroplasty. It must be noted that it is not within the senior surgeon’s practice to intraoperatively assess LLD by palpating the patient’s knees and/or feet. Careful preoperative templating, accurate intraoperative measurements, reproducing and confirming preoperative measurements, and restoration of the periarticular soft tissue tension, as evaluated with the maneuvers described earlier, are considered adequate for preserving equal limb lengths or addressing any LLDs.

SUMMARY The most common surgical technique to perform a primary THA is the posterolateral approach. Most surgeons around the world are familiar to this approach. The current trend is to use minimal invasive approaches to perform a THA. However, this approach should not be utilized in patients with severe dysplasia, in revision surgery or in patients with a body mass index greater than 35 kg/m2. Ensure an accurate patient positioning is mandatory for an accurate cup positioning. A meticulous planning and templating are essential for an adequate femoral neck cut osteotomy level and restoration of limb length and offset. Special instrument should be used to facilitate minimal invasive surgery. If in doubt, the incision should be more extensive. Finally, surgeons should keep in mind that a well-performed operation is much more important than a short incision.

REFERENCES 1. Learmonth ID, Young C, Rorabeck C. The operation of the century: total hip replacement. Lancet 2007;370:1508–19. 2. Ethgen O, Bruyere O, Richy F, et al. Health-related quality of life in total hip and total knee arthroplasty. A qualitative and systematic review of the literature. J Bone Joint Surg Am 2004;86-A:963–74. 3. Soderman P, Malchau H, Herberts P. Outcome after total hip arthroplasty: part I: general health evaluation in relation to definition of failure in the Swedish national total hip arthroplasty register. Acta Orthop Scand 2000;71:354–59. 4. Smith-Peterson MN. Approach to and exposure of the hip joint for mold arthroplasty. J Bone Joint Surg Am 1949;31:40–6.

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5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

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Watson-Jones R. Fractures of time neck of time femur. Br J Surg 1930;23:787–808. Hardinge K. The direct lateral approach to the hip. J Bone Joint Surg Br 1982;64:17–19. Moore A. The self-locking metal hip prosthesis. J Bone Joint Surg Am 1957;39:811–27. Gibson A. Vitallium-cup arthroplasty of the hip joint: review of approximately 100 cases. J Bone Joint Surg Am 1949;31:861–68. Goebel S, Steinert AF, Schillinger J, Eulert J, Broscheit J, RudertM, Nöth U. Reduced postoperative pain in total hip arthroplasty after minimal-invasive anterior approach. Int Orthop 2012;36:491–98. Nakata K, Nishikawa M,Yamamoto K, Hirota S,Yoshikawa H. A clinical comparative study of the direct anterior with miniposterior approach: two consecutive series. J Arthroplasty 2009;24:698–704. Matta JM, Shahrdar C, Ferguson T. Single-incision anterior approach for total hip arthroplasty on an orthopaedic table. Clin Orthop Relat Res 2005; 441:115–24. Unger AS, Stronach BM, Bergin PF, Nogler M. Direct anterior total hip arthroplasty. Instr Course Lect 2014;63:227–38. Sculco TP. Minimally invasive total hip arthroplasty: in the affirmative. J Arthroplasty 2004;19(4 Suppl 1):78–80. Sharrock NE, Salvati EA. Hypotensive epidural anesthesia for total hip arthroplasty: a review. Acta Orthop Scand 1996; 67:91–107.

Chapter 9

The Cemented Hip: How to Get it Right Atul Panghate

INTRODUCTION Our journey into the world of hip arthroplasty started when Sir John Charnley performed the first cemented hip replacement in 1954 in England. Even today, hip replacement remains one of the most successful surgeries. With more than half a century of experience, we have learnt a lot and modified our surgeries and prostheses to achieve outstanding results. Important lessons that we have learnt from multiple studies and registry data:1–5 1. Quality and adequacy of cement mantle are the most important factors in deciding the longevity of the cemented hip. 2. Poor quality of polyethylene, leading to early wear, osteolysis and loosening, is an important cause of failure. 3. Some designs have done exceedingly well over the long term, and should be preferred over others. Small changes in designs or coatings can lead to disastrous results. So beware of ‘look-alikes’ or ‘copies’ of successful designs. Hence, for good long-term results, choose a prosthesis based on registry data and clinical studies. The bearing surface with the least wear rate should be chosen,6 for example, highly cross-linked polyethylene cup on metal/ceramic head. The surgeon must meticulously perform his bone preparation and cementing technique to achieve good depth of cement penetration and mechanical interlock at bone and cement interface.7,8 It is very critical to understand that thorough bony preparation, washing and cleaning with pulsatile lavage, good pressurized cementing and perfect positioning of implant will ensure good long-term survival of the cemented hip. The aim should be to place the cup at the perfect position and centre of rotation, with a good cement penetration in bone and a strong mantle. After evaluating results from multiple studies, the author prefers a flanged, highly cross-linked polyethylene cup with polymethyl meth-

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acrylate (PMMA) spacers, without extended posterior lip.9–11 Extended posterior lips are known to lead to neck–lip impingement with a risk of poly-wear and late dislocations.

TEMPLATING A line is drawn, joining the bottom of the bilateral teardrops on anteroposterior (AP) pelvis radiograph. The limb length discrepancy due to the acetabulum and the femur is measured with respect to this line. The offsets are measured as distances between the lesser trochanter and the center of head, and between the piriformis fossa and the center of head and noted down for intra-op correlation. Then a point is taken, 1 cm lateral to the most inferior point of teardrop (this corresponds to the transverse acetabular ligament (TAL) during surgery), which is the planned lower extent of cup. A line is drawn at 45° from this point, and the point at which it crosses the superior rim of the acetabulum is marked, corresponding to the intraop superior end-point of the cup. Using the sizing templates provided by the implant manufacturer, the size of the component is noted to avoid over reaming intraoperatively.

SURGICAL TECHNIQUE Hypotensive anaesthesia with systolic BP < 90 mm of Hg is preferred, which is usually achieved by spinal and/or epidural anaesthesia, to achieve good cement preparation and avoid bleeding in the interface.

EXPOSURE OF THE ACETABULUM The surgeon must use the exposure that he is most familiar with and one that gives him the best results. But a complete (360°) exposure of the acetabulum is the most critical step in cementing the cup. Correct placement of retractors after release of tight structures, (reflected head of rectus femoris, capsule,gluteusmaximus, etc.) whenever needed, should be done. A pin is placed at 12 O’clock position, which helps to retract the gluteus medius and also acts as a fixed landmark on ilium for accurate limb length correction. Sharp, narrow retractors are then placed around the anterior and posterior rims of acetabulum. The inferior capsule is then released to

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expose the TAL and a blunt Hohmann’s retractor is placed under the TAL in the acetabular notch to achieve a complete exposure (Fig. 9.1).

B

A

C

Fig. 9.1 (A) Good exposure. (B) Newer retractors. (C) Pre-op limb length measured from a fixed pelvic landmark.

The anatomic landmarks are then marked to get the center of rotation (COR) of hip correctly restored. The anterior, posterior, superior rims of the acetabulum and the TAL are marked. Erosions and deficient parts of the acetabulum are then marked. The anterior superior iliac spine, ischial tuberosity and lumbar spine are palpated to appreciate pelvic tilts and rotations. Acetabular osteophytes are then marked and should be preserved until the cup has been cemented, as the osteopyhtes may enhance cement containment and aid cement pressurization. However, in some cases, with very large osteophytes, these have to be partially removed early to facilitate access to the acetabulum.

IDENTIFICATION OF THE MEDIAL WALL OF PELVIS It is important to identify the true medial wall of the acetabulum. If the ligamentumteres is not ossified, it can be excised to reveal the fossa acetabuli. However, the ligamentous fibers are invariably overgrown by central osteophyte formation. Resecting the central overhanging osteophyte, prior to reaming, using an osteotome or a sharp curette, exposes the true floor of the acetabulum. This will ensure adequate roof coverage and medialization of the component.

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REAMING THE ACETABULUM After the inner floor has been identified, a small reamer is placed horizontally in the unroofed acetabular fossa, and directed medially, until the medial wall is reached. Once the medial wall is reached, the cancellous bone of the fossa becomes flush with the cortical surface of the floor, which corresponds radiographically to the lateral border of the teardrop. After medial wall reaming, the following reamers are directed superiorly to enlarge the cavity, but no attempt is made to remove the eburnated roof sclerosis. The last reamer should be the AP diameter of the acetabulum on lateral projection (Fig. 9.2). If one goes by inferior to superior size of the acetabulum, one can err towards over-reaming of

Fig. 9.2 Initial reaming should be horizontal to avoid lateralization of hip centrer.

the acetabulum. As a rule of thumb, the largest and final reamer size should only exceed the AP diameter by 2–4 mm. Finally, a smaller sized reamer, which can easily be maneuvered in all directions like a burr, is used, to roughen the sclerosed roof till it shows bleeding bone. Finally, osteophytes are trimmed so that the cup can be placed in the desired position. The new acetabulum rim cutter is a handy instrument to trim the overhanging osteophytes and expose the cancellous bone for accurate placement of the cup and for better cementing (Fig. 9.3).

ANCHORING HOLES Anchor holes are drilled in reamed acetabulum, so that there is better penetration of the cement into cancellous bone and strong cement bone interface

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Fig. 9.3 Rim Cutter: The Rim Cutter (an instrument which cuts a rim into the acetabulum and is not intended to cut the rim of the implant) marked with the same size as the cup OD to be inserted is attached to the power reamer. The Rim Cutter is designed to cut a groove in the periphery of the acetabulum of the appropriate diameter for the flange. Do not use Rim Cutter if there is inadequate bone stock. The hemisphere on the Rim Cutter centralizes the cutter in the reamed socket and sets the depth of the rim and thus the position of the cup. Each Rim Cutter has to be used with its correct hemispherical guide. If the acetabulum is reamed to 56mm, use Rim Cutter size 54 with 54 green hemispherical guide. (Source: Exeter X3 RimFit Acetabular Cup Surgical Technique).

(Fig. 9.4). Multiple anchoring holes of approximately 6–8 mm depth are made in all the zones using a flexible drill. Care has to be taken not to perforate the thin anterior, posterior or medial walls. Smaller anchor holes in ischium and pubis are made, as large holes in these areas were known to be loaded in tension and lead

Fig. 9.4 Packing of morselized bone in obturator foramen (blue) to avoid pelvic spillage of cement (red).

Fig. 9.5“Retractor Aspirator”/“Iliac Sucker”Fluid is sucked out of the wing of the ilium by the sucker aspirator to get blood/ fluid less field for cementing. (Source: Exeter X3 RimFit Acetabular Cup Surgical Technique).

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to de-bonding of cement mantle and unnecessary bone loss. A newly designed (Stryker inc. USA) ‘Iliac Sucker’ can now be inserted at 12 O’clock position, about 1 cm away from the acetabular rim (Fig. 9.5).

BONE BED PREPARATION Pulsatile Lavage Pulsatile lavage is a very important step towards good cementing. It helps in removing the soft tissue, blood, bone and marrow particles from cancellous bone, thus helping in good pressurized cementing. Before the last wash, the acetabular cavity is packed with hydrogen peroxide or norepinephrine soaked pack to reduce bleeding and better penetration of cement. Some surgeons use a brush to remove the remnants of blood, marrow and fibrous tissue, but there is a danger of the bristles remaining behind, hence it is not routinely used.

Cement Application and Pressurization A medium or high viscosity cement is preferred to reduce the risk of blood laminations at the interface. The surgeon must go through the registry studies and choose the cement with good long-term results. Commercially made antibiotic cement is preferred as the uniform distribution and ‘leeching’ of antibiotic is essential.12 Timing is critical and the bone bed should be as clean and dry as possible. Cement setting times and viscosity are

Fig. 9.6 Newer acetabular cement pressurizers for good cementing of acetabulum.

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dependent on the operating room (OR) temperature and a surgeon must be aware of the cement behavior in his OR and must decide on application and pressurization time accordingly. In the acetabulum, the cement is applied en bloc, so immediate pressurization can be implemented. Usually till socket size of 54 mm, a 40 g pack of cement is sufficient; 60–80 g packs are needed for larger sizes (Fig. 9.6). The cement is pressurized using the newly designed acetabulum pressurizer, usually a size 4 mm larger than the last reamer is selected, to act as an effective seal and avoid cement escape. Sustained pressurization is maintained till good cement penetration and high viscosity are reached (Fig. 9.7).

A

B

Fig. 9.7 (A) Cement pressurized till doughy stage. (B) Excess cement over transverse acetabular ligament (TAL) removed and cup inserted.

Cup Insertion Usually a flanged, highly cross-linked polyethylene cup, of size 4 mm smaller than the last reamer, is selected to ensure a 2 mm thick cement mantle in all zones. Polymethyl methacrylate (PMMA) spacers in newer designs help maintain uniformity of mantle and avoid bottoming out of cup. The cup is then inserted using the cup holder. Initially the cup is inserted horizontally and pushed fully medially, and then gradually inclined to the desired 45° with about 15° to 20° of anteversion. Depending on the native femoral anteversion, the anteversion of the cup and the femoral stem is adjusted. Cup holder is then removed and a simple ball pressurizer is inserted to visually confirm the final position of the cup and remove excess cement (Fig. 9.8). Finally, all the loose cement and cementophytes are removed carefully to avoid the risk of third body wear. Overhanging residual osteophytes are also removed to avoid impingements and dislocations.

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A

B

C

Fig. 9.8 (A–C) Flanged highly cross-linked poly-ethylene cup with polymethyl methacrylate (PMMA) pegs for uniform cement mantle.

Points to Remember 1. Good pre-op planning to achieve perfect positioning of cup. 2. Meticulous bone preparation to achieve perfect cementing. 3. Selection of prosthesis and cement with good long-term track record of longevity. 4. Use of proven and wear-resistant bearing to avoid early loosening and revision. 5. All osteophytes and cementophytes have to be carefully removed to avoid impingement and dislocation. 6. The long-term success of cemented acetabulum is decided by the technique of pressurization employed during the cup insertion.

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Long-term results of cemented femoral components are very good, with almost 100% survival rates at 10 year follow-up. Components have undergone various changes over time, and today, many implant designs have achieved near perfection with long survival records. Cementing has progressed from early hand packing of canal to cement restrictors and retrograde pressurized cementing using a gun. Cement itself has undergone many changes to today’s antibiotic cement, vacuum-mixing and optimum handling time.13–16 Newer cementing techniques help us to achieve good bony penetration of cement, and thus achieving good mechanical interlock between bone and cement.

SURGICAL TECHNIQUE Hypotensive anaesthesia with systolic BP < 90 mm of Hg is preferred, which is usually achieved by spinal and/or epidural anaesthesia, to achieve good cement preparation and avoid bleeding in the interface.

Femoral Preperation25 The hip is dislocated and the piriformis fossa identified. Femoral exposure is usually hassle-free and can be easily done through a minimal invasive manner. Newer and better designedretractors are very useful in good, allround exposure (Fig. 9.9).

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Fig. 9.9 (A–C) Newer femoral retractors (Courtesy: Stryker International Inc.).

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The entry point should be made posterolaterally in order to facilitate the correct direction of reaming and will ensure a well-centralized stem and a good cement mantle all around (Fig. 9.10).

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C Fig. 9.10 (A–C) Postero-lateral entry to avoid varus and centralize the stem in canal.

Femoral Neck Cut and Head Resection The exact osteotomy level is not critical if a collarless tapered stem design is favored. If a collared femoral stem design is used, the neck resection should be made according to the preoperative planning, utilizing the special instrumentation provided by the manufacturer. Resection of the femoral head is carried out in the routine manner, approximately 1.5–2 cm above the lesser trochanter. A relatively high neck-cut at the level of the piriformis fossa, going down at an angle of 35° to the shaft, is considered useful as it preserves a part of the distal neck and provides good rotational stability to the stem.

Proximal Femoral Preparation The cortical overhang of bone from the greater trochanter is removed with a box chisel or a curved gouge to avoid varus positioning of the

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stem. Canal entry should be as posterolateral as possible. Posterolateral canal entry ensures a central placement of stem in lateral profile to avoid the tip of the stem from touching the anterior cortex, which may lead to thigh pain post-op. If a stem with lateral flare is used, an osteotome can be useful in removing the cortical bone from the medial wall of the greater trochanter (Fig. 9.11).

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D

Fig. 9.11 (A–D) Remove the medial wall of greater trochanter with box chisel or rasp it with broach to avoid varus.

The canal is then opened with the smallest sized canal-finder. The position should be radiologically confirmed if there is any resistance during the progress of the reamer, or if the surgeon has any doubt about its position in the canal. At this stage, a copious lavage is given and the medullary cavity is meticulously aspirated, to remove as much medullary marrow as possible, to prevent embolism during preparation and cementing.

Broaching Broaching is then done in a serial manner with pressure application in the posterior and lateral directions using the broach handle. Broaching is proceeded till the template size.

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In some systems, it is required to broach to a size more than the templated size, and the surgeon should be aware of this to ensure a good cement mantle (Fig. 9.12).

B

A

C

D

Fig. 9.12 (A–D) Broach till template size and check for restoration of offsets.

At the end of broaching, about 3–4 mm of cancellous bone should be left in the anterior and medial side of the neck cut to reassure the surgeon about correct direction and alignment of stem. Trial neck and head length is selected to facilitate the assessment of leg length and stability.

Canal Preparation The medullary canal is cleansed with copious pulsatile lavage. A cementrestrictor is then inserted to about 1.5–2 cm distal to the tip of the prosthesis. However, now-a-days, the cement restrictors are placed at about 4–5 mm distal to the stem, as a thick cement mantle in Zone 4 may prevent subsidence, which is deemed important for long-term survival and for prevention of stress shielding (Fig. 9.13). Usually a restrictor size of 2 mm larger than the largest olive tip that can be passed to the isthmus is used. Modern cement restrictors are made of

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A

B

C Fig. 9.13 (A–C) Cement restrictors made of polymethyl methacrylate (PMMA).

PMMA and bind readily with cement mantle. While the cement is being prepared, the canal is now paced with hydrogen peroxide or norepinephrine packs (Fig. 9.14). (An air vent is important at this stage, as the oxygen released from hydrogen peroxide can cause air embolism.)

Cement Mixing The surgeon should use the cement with good long-term results in the registry data. The surgeon should be familiar with the handling and the setting time of the cement in his OR (for cement characteristics, refer to Ch. 20: Cementation Techniques in Total Knee Arthroplasty – Tables 20.1 and 20.2). Both the timing and the technique of the entire cementing procedure are essential contributing factors for a successful cemented THA and long-term outcome. Author prefers to use a low-viscosity antibiotic cement mixed under vacuum.17 For the femur, usually 80 g of cement is used, but a stove-pipe type canal may require up to 120 g. After having reached the preferred

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A

B Fig. 9.14 (A) Canal packed with a hydrogen peroxide pack. (B) Vacuum mixing of cement.

viscosity, the cement is then rapidly applied in a retrograde fashion using a cement-gun under pressure. The venting tube will remove air trapped between the cement and the restrictor. As the canal fills up, the cement shall ‘drive’ the gun out. The nozzle is then cut short and final pressurization is done using a proximal femoral seal (Fig. 9.15). Usually the cement remains deficient in Zone 1, and it may be a good habit to digitally pack the cement in this zone (Fig. 9.16).18 If pressurization is good, some bone marrow will be seen escaping the proximal femoral cortex, and this is considered as a tell-tale sign of good technique. The final femoral stem19–25 is inserted slowly in line with the longitudinal axis of the femur using sustained pressure (Fig. 9.17).26,27 A centralizer helps to maintain central position of the stem in the canal. If a centralizer is used, the stem should not be inserted late as the centralizer can cause lamination of cement mantle. The stem should never be hammered as it may ‘break’ the cement mantle. Ideally, a good composite cement–bone mantle of 5 mm should be seen medially at the neck cut (Fig. 9.18).

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A

B

C

D

Fig. 9.15 (A–D) Cement guns and proximal seal.

A

C

B

Fig. 9.16 (A, B) Cement pressurization. (C) Digital pressurization of cement in Zone 1.

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A

B

C

D

Fig. 9.17 (A–D) Stem inserted till templated level with surgeon’s thumb as medial cement seal.

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A

B

C Fig. 9.18 (A) Excess cement removed. (B) Trial reduction to done to check leg length correction. (C) Trial reduction to done to check leg length correction.

A Barack type 1 cementing ‘White Out’ should be the aim of the surgeon every time he cements a hip (Fig. 9.19). Points to Remember 1. Pre-op planning is critical; select the stem that gives correct offsets and allows a good cement mantle. 2. Careful canal entry and canal preparation are important for good alignment. 3. Pulsatile lavage and cleaning of the canal are important in avoiding embolism and for good cementing. 4. Use well-documented antibiotic-impregnated cement and pressurize with cement-gun and seals.Vacuum-mix the cement, whenever possible. 5. Long-term survival of a cemented femoral stem is ensured by technique of canal preparation and cementing employed by the surgeon.28,29

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Fig. 9.19 Final goal — “White-Out”: A well-cemented hip.

Editorial Comment: The tribology (the bearing surface couple) and the head diameter of the femur have been kept out of the purview of this book, as it is intended for basic techniques on hip and knee arthroplasty. This has been done for all the following chapters: s Chapter 9: The Cemented Hip: How to Get it Right s Chapter 10: Uncemented Total Hip Arthroplasty s Chapter 30: Recent Advances in Short Stem Designs The reader can refer to the references for further details.

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REFERENCES 1. Aamodt A, Nordsletten L, Havelin LI, Indrekvam K, Utvag SE, Hviding K. Documentation of hip prostheses used in Norway: a critical review of the literature from 1996–2000. Acta Orthop Scand 2004;75(6): 663–76. 2. Havelin LI, Engesater LB, Espehaug B, Furnes O, Lie SA, Vollset SE. The Norwegian Arthroplasty Register: 11 years and 73,000 arthroplasties. Acta Orthop Scand 2000;71(4):337–53. 3. National Health Care. Quality Registries in Sweden 1999. Stockholm: Information Department, The Federation of Swedish County Councils, 2000. 4. Swedish National Hip Arthroplasty Register. Annual Report, 2002. Available at: http://www.jru.orthop.gu.se/. 5. Williams HDW, Browne G, Gie GA, Ling RSM,Timerley AJ,Wendover NA. The Exeter cemented femoral component at 8–12 years. J Bone Joint Surg B 2002; 84B:324–34. 6. Joshi AB, Porter ML, Trail IA. Long-term results of Charnley low friction arthroplasty in young patients. J Bone Joint Surg 1993;75-B:616–23. 7. Barrack RL, Mulroy RD, Harris WH: Improved cementing technique and femoral component loosening in young patients with hip arthroplasty. A 12-year radiographic follow up. J Bone Joint Surg 1992;4-B:385–89. 8. Breusch, M. The Well Cemented Hip, Theory and Practice. Springer, 2005. 9. Charnley J. The long term results of low-friction arthroplastyof the hip performed as primary interventions. J Bone Joint Surg (Br.);1972:54-B:61–76. 10. Hodgkinson JP, Maskell AP, Paul A, Wroblewski BM. Flangedacetabular components in cemented Charnley hip arthroplasty. Ten-year follow-up of 350 patients. J Bone Joint Surg 1993;75-B:464–67. 11. Timperley J, Howell JR, Gie GA. Implant choice: rationale for a flanged socket, Chapter 7.6. In: The Well Cemented Total Hip Arthroplasty. Springer; 2005: 208–13. 12. Adams K, Couch l, Cierny G, Calhoun J, Mader JT. In vitro and in vivo evaluation of antibiotic diffusion from antibiotic-impregnated polymethymethacrylate beads. Clin Orthop 1992;278:244–52. 13. Kuhn KD. Bone Cements. Berlin, Heidelberg, New York, Tokyo: Springer, 2000. 14. Kuhn KD, Ege W, Gopp U. Acrylic bone cements: composition and properties. Orthop Clin N Am 2005;36:17–28. 15. Kuhn KD. Handling properties of polymethacrylate bone cements. In: Walenkamp GHIM, Murray DW, eds. Bone Cements and Cementing Technique. Berlin, Heidelberg, New York, Tokyo: Springer, 2001. 16. Kuhn KD. Handling properties of polymethacrylate bone cements. In: Walenkamp GHIM, Murray DW, eds. Bone Cements and Cementing Technique. Berlin, Heidelberg, New York, Tokyo: Springer, 2001. 17. Wilkinson JM, Eveleigh R, Hamer AJ, Milne A, Miles AW, Stockely I. Effect of mixing technique on the properties of acrylic bone cement. J Arthroplasty 2000;15:663–7. 18. Iwaki H, Scott G, Freeman MAR. The natural history and significance of radiolucent lines at a cemented femoral interface. J Bone Joint Surg 2002;84-B:550–55. 19. Collis DK, Mohler CG. Comparison of clinical outcomes in total hip arthroplasty using rough and polished cemented stems with essentially the same geometry. J Bone Joint Surg Am 2002;84-A(4):586–92. 20. Crawford RW, Gie GA, Ling RSM. An 8–10 year clinical review comparing matt and polished Exeter stems. Orthop Trans 1998;22(1):40. 21. Crawford RW, Evans M, Ling RS, Murray DW. Fluid flow around model femoral components of differing surface finishes – In vitro investigations. Acta Orthop Scand 1999;70(6):589–95. 22. Crawford RW, et al. Fluid migration around model cemented femoral components. J

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Bone Joint Surg Br 1999;81(Supp I):82. 23. Ling RSM, Hon F. The use of a collar and precoating on cemented femoral stems is unnecessary and detrimental. Clin Orthop 1992;285:73–83. 24. Race A, Miller MA, Ayers DC, Cleary RJ, Mann KA. The influence of surface roughness on stem-cement gaps. J Bone Joint Surg Br 2002; 4(8):1199–204. 25. Savilahti S, Myllyneva I, Pajamaki KJ, Lindholm TS. Survival of Lubinus straight (IP) and curved (SP) total hip prostheses in 543 patients after 4–13 years. Arch Orthop Trauma Surg 1997;116(1–2): 10–13. 26. Breusch SJ. Cementing technique in total hip replacement: factors influencing survival of femoral components. In: Walenkamp GHIM, Murray DW, eds. Bone and Cementing Technique. Berlin, Heidelberg, New York, Tokyo: Springer, 2001. 27. Charity JAF, Gie GA, Hoe F, Timperley AJ, Ling RSM. The Exeter polished stem in the long-term: a survivorship study to the 33rd year of follow-up and a study of stem subsidence. Hip Int 2004;14:83. 28. Malchau H, Herberts P, Soderman P, Oden A. Prognosis of total hip replacement: Update and validation of results from the Swedish National Hip Arthroplasty Registry. 67th Annual Meeting of the American Academy of Orthopaedic Surgeons, Orlando, USA, March 15–19, 2000. 29. Malchau H, et al. Prognosis of total hip replacement – update of results and risk-ratio analysis for revision and re-revision from the Swedish National Hip Arthroplasty Register 1979–2000. 69th Annual Meeting of the AAOS, Dallas, USA, February 13–17, 2002.

Chapter 10

Uncemented Total Hip Arthroplasty Vijay C. Bose, Subramanyam Yadlapalli, Ashok Kumar

INTRODUCTION Uncemented total hip arthroplasty was introduced in early 1980s in an attempt to address the issues of aseptic loosening and late failures associated with cemented hip arthroplasty. Cementless fixation by means of bone ingrowth has been successful in achieving good long-term results, especially in patients with good bone stock. It is often the choice in young and active patients; however, older age is not an absolute contraindication. Initial implant stability and long-term osteointegration have been proven to be the key factors in achieving good outcome in uncemented hip arthroplasty.

ACETABULAR COMPONENT Cemented acetabular components have demonstrated early mechanical failure, especially in the younger age group.1,2 It is often the mechanical failure of the bone–cement interface, which leads to these poor results. Cementless acetabular components were designed to address the issues of bone implant interface. The implants establish and maintain a rigid bone implant interface that has remodelling potential such that bony intercalation into the implant is re-established. Clinically, achieving immediate implant stability at the time of surgery is the single most important factor in the subsequent development of bone ingrowth and long-term fixation. The immediate implant stability can be achieved either through press-fit or polar fixation. Press-fit fixation involves implantation of oversized acetabular component, making use of the viscoelastic properties of the bone to allow deformation and recoil of the bone in order to grip the implant firmly. Additional screws are used to achieve immediate stability in polar fixation. Both these techniques rely on bone ingrowth to achieve long-term stability. Though the initial results of the uncemented components were poor,

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better understanding of the component shape and coating surfaces significantly improved the survival rates of the newer generation cementless sockets. Callaghan et al. in their series have reported no loosening at 8.5 and 14 years follow up.3, 4

DESIGN CONSIDERATIONS Initial designs of uncemented acetabular components were cone shaped with fixation rod into the posterior column of the pelvis.5 Mittelmeier in 1974 introduced the threaded ring designs.6 These components relied only on mechanical interlock between the acetabular bone and the implant threads for both initial and long-term fixation and hence had high revision rates in long term studies.7–9 Second generation threaded cups had addition of porous coating or grid blasting to provide bone ingrowth or ongrowth. These cups achieved initial mechanical stability through mechanical interlock and relied on biological fixation for long-term stability. Current designs are hemispherical or modified hemispherical cups made of commercially pure titanium or titanium-based alloy.

SURFACE AND COATINGS Ingrowth of the component occurs when bone grows inside a porous surface. The pore size required is between 50 and 400 mcm (micrometers), and the percentage of voids within the coating should be between 30% and 40% to maintain mechanical strength.10 Chromium or titanium alloy beads, metal fiber mesh and porous material are the commonly used ingrowth surfaces. These surfaces differ in the preparation technique. Beads are added on to the surface at very high temperatures. Diffusion bonding technique is used in components using fiber mesh. As the name implies, porous metal is high porous (75% to 85%).11 Ongrowth occurs when bone grows onto a roughened surface. These roughened surfaces are often prepared by grit blasting or plasma spraying. In grit blasting, aluminum oxide particles are bombarded onto the surface of the stem to create a rough surface of 3–5 mm. Plasma spray technique involves pressurized molten material mixture of metal and inert gas sprayed onto the component. Ongrowth surfaces maintain 90% of the fatigue strength. Calcium phosphate compound, hydroxyapatite is also often used as

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a surface coating to improve osteoconductivity into implant surface. Concerns of interface degradation, leading to implant loosening, have been raised with these coatings.

INDICATIONS AND CONTRAINDICATIONS Cementless fixation is usually reserved for, though not limited to, young active individuals with good bone quality. Paget’s disease, tumour involvement and postirradiation might not have good bone ingrowth potential and are not ideal candidates for cementless fixation.

TECHNIQUE Exposure It is essential to ensure an unimpeded view of the entire socket all along the circumference. Appropriate placement of the retractors is essential so that the line of sight, in the plane of socket orientation is free of any obstruction. Superior pin is placed in the ilium at 12 O’clock position, and posterior pin is placed in the ischium. A blunt cobra retractor is placed over the anterior column to displace the femur anteriorly. Two retractors are positioned on either side of the transverse acetabular Fig. 10.1 (A) Anterior retractor. (B) ligament inferior to it (Fig. 10.1). Posterosuperior pin. (C) Posterior ischial

Cup Orientation

pin. (D, E) Inferior retractors on either side of transverse acetabular ligament (TAL).

The safe zone for acetabular component placement is 10°–25° of anteversion and 35°–45° inclination. Transverse acetabular ligament (TAL) and the anterior wall of the acetabulum are the common indices used for cup orientation. After adequate exposure of the acetabulum, TAL is identified. Any inferior osteophytes covering the TAL are removed. The anteversion of the cup is determined by aligning it collinear to the TAL (Fig. 10.2), and it should be in line with the anterior wall. It should be remembered that increased anterior wall uncoverage increases the anteversion. Inclination is

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determined by aligning the inferior margin of the cup to the inner margin of the TAL (Fig. 10.3).

Socket Preparation

Fig. 10.2 Acetabular component aligned parallel to transverse acetabular ligament (TAL).

Fig. 10.3 Acetabular component aligned along the inferior margin of transverse acetabular ligament (TAL).

This step is crucial in obtaining the initial stability of the acetabular component. Fovea is cleared off the soft tissue to define the true medial wall. Most of the newly available uncemented acetabular components are hemispherical and the native acetabulum is oblong. Acetabulum should be reamed to accommodate these hemispherical components. Initially a small reamer is used to deepen the acetabulum to the true floor. Once the true floor is identified, reaming proceeds in the direction of the native anteversion and inclination with 2 mm increment in reamer size. Once the acetabular reamer makes excellent contact with the anterior, posterior, dome and lateral rim acetabular, reaming has to proceed cautiously with 1 mm increment. Under-reaming of the acetabulum depends on bone quality and the sharpness of the reamers. A 1 mm under-ream is usually sufficient in most sockets and 2 mm of underreaming is preferred in less dense bones. However, it might even be required to ream the socket to the same size as the original cup. This often happens in sclerotic bone, and it should be done with caution. Initially only the rim is reamed and is gradually deepened depending on the fit obtained.

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Special Tips for Monoblock Cups Monoblock cups are large profile cups and most often require line-to-line reaming. However, the reaming should be done in an extremely cautious manner. As a first step, trailing should be done with socket under-reamed by 2 mm. In most cases, it is not enough and it will require further reaming. In the next step, trailing is done with cup under-reamed by 1 mm. If adequate seating is not achieved, then line-to-line reaming is done, and the trail component is inserted to check the adequacy of press fit. At times, even over-reaming by 1 mm might be required to achieve adequate seating of the component. This is usually encountered in sclerotic sockets and should be done cautiously.

Sizing and Positioning of the Component Trail component acetabular 1 mm larger diameter than the final reamer size is placed in determined anteversion and inclination. It should always be kept in mind that up to 20% of posterosuperior uncoverage of the cup is common and must be ignored. The size of the component is confirmed if the whole pelvis can be rocked with the trail component in situ. Once the size is confirmed, original component is impacted into position in the same anteversion and inclination. In hemispherical acetabular component, rim contact occurs before dome seating of the cup, and it requires additional impaction to ensure adequate seating. Seating is confirmed by sighting through the apical hole or screw holes. Acetabular screws can be placed for additional stability. Once the acetabular component is inserted, liner is placed and femur approached.

Supplemental Fixation Various supplemental fixation options like screws, dome spikes, peripheral pegs and fins are available. However, screws are the most commonly used mode of adjunctive fixation. Screws effectively convert torsional forces to compressive forces. This preloads the bone prosthesis interface, increasing the contact area and promoting bone growth. Lacheiwicz et al.12 showed that greater torque was required for screw failure as compared to spikes and pegs. Stiehl et al.13 revealed less micromotion with the use of screws compared to fins. Indications of screw fixation: 1. Osteoporotic bones and soft bones of inflammatory arthritis with inadequate press fit. 2. Protrusio acetabuli requiring bone grafting. 3. Dysplastic hips. Acetabular screws usually should lie within the safe quadrant, which

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lies from the anteroinferior iliac spine to the centre of the acetabulum and posteriorly by a line from sciatic notch to the center of the acetabulum. Posterosuperior quadrant is often the safe zone.

FEMORAL COMPONENT Excellent long-term clinical and radiological outcomes of uncemented femoral component have been reported by many authors.14–16 Good osseous integration without fibrous tissue intervention is required for these good results. Micromotion of 150 mm leads to fibrous tissue formation, between 40 and 150 mm leads to a combination of bone and fibrous tissue formation.17,18 Initially designed uncemented femoral components had poor results in terms of longevity. Austin Moore was the first to demonstrate the possibility of biologic fixation in the femoral component.19 Intensive experimental research on surface coatings and tissue ingrowth in 1970s revealed basic criteria and paved the way for uncemented implants. They emphasized the importance of pore size (50–500 mcm) and stable implant with minimal microinterface motion. Initially, fully porous coated femoral component was designed and later it underwent modifications with regard to size, surface coating, etc. Stem with porous coating on >80% of surface is often considered extensively porous coated. Forty per cent porosity has been considered optimal for balancing strength of the porous coating substrate interface and that of porous coating bone interface. The first designs of uncemented femoral components were cylindrical, with extensive porous coating. These stems had good fixation but had issues with cortical atrophy, proximal stress shielding and bone loss. These stems were improvised and philosophy of metaphyseal fixation was developed to naturally load the femur. Press fit stems were initially developed by Judet. Later calcar supporting and wedge fit stems were developed. Main concern with these stems was sizing and ability to achieve press-fit due to varied proximal femoral anatomy. Increasing the number of sizing options addressed this issue. These implants can be either metaphyseal or diaphyseal fit. Principally, a femoral prosthesis should be fixed as proximal as possible to prevent stress shielding. However, significant proximal femur deficiency necessitates distal fixation. Irrespective of these, uncemented femoral components rely on firm mechanical initial fixation of the implant to the bone.

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Proximal Femoral Geometry Assessment of the proximal femoral geometry is essential in planning an uncemented total hip arthroplasty. Dossick et al. classified proximal femur based on calcar to canal ratio (Fig. 10.4).20 The outer diameter of the femur at the mid portion of lesser trochanter is divided by the diameter at a point 10 cm distal.

Fig. 10.4 Dossick calcar to canal ratio - a/b.

s 4YPE!Ratio < 0.5 s 4YPE"Ratio 0.5–0.75 s 4YPE#Ratio >0.75 Type A femur has good cortices in both views. Type B femur has thinning of posterior cortex on lateral view. Type C is a typical stovepipe type femur with thinning of cortices on both views. Type A is generally believed to be appropriate for uncemented femoral component. Type B bone is intermediate, and cemented component use is generally preferable in Type C femurs.

Factors That Influence the Primary Fixation of Femoral Component 1. 2. 3. 4.

Roughness and coating of the stem Stem geometry Technique of preparation Bone quality

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SURFACE AND COATINGS Surface and coatings of femoral components are similar to uncemented acetabular components. Common issues with uncemented femoral components like thigh pain and proximal stress shielding are better addressed with materials that have elastic properties closer to that of normal bone. This makes stems made of titanium alloys a better choice than that of cobalt–chromium alloys.21,22 Thigh pain, however, is believed to result also from the stem geometry.

STEM GEOMETRY 1. 7EDGE DESIGNS In these designs, fixation is in the proximal femoral metaphyseal bone. They have integrating surface limited to the proximal part of the stem and they taper distally. There are two types of wedge designs based on their fit in the proximal femur. Single wedge type of stems engage primarily the mediolateral plane. Double wedge stems engage both the mediolateral and the anteroposterior surfaces 2. 4APEREDDESIGNSThese designs have long, consistent taper in both the mediolateral and the anterior–posterior plane. Unlike wedge designs, there is no abrupt change in geometry or coating, and fixation is obtained more at the metaphyseal–diaphyseal junction than in the metaphysis. 3 &ULLY COATED CYLINDRICAL DESIGNS These stems have integration surface all along the prosthesis. Their fixation is primarily diaphyseal. Some of these stems have a collar, which is designed to load the calcar of the proximal femur. 4 -ODULARDESIGNSThese stems are often used in patients with abnormal proximal femoral geometry. They are primarily proximal metaphyseal integrating stems. Additional stability can be achieved through diaphyseal fixation. It requires appropriate preparation of both the proximal and distal femur.

TECHNIQUE Femoral Neck Resection After dislocation of the head, initial neck cut is made at the level of base of the head for easy retraction during exposure of the acetabulum. Once the acetabular component placement is completed, the leg is internally rotated

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and the neck is exposed with a spike under the femoral neck. The remnant of pyriform is removed to expose the pyriform fossa. Initial cut is made along the medial border of the greater trochanter in line with the intertrochanteric crest.This facilitates desired appropriate lateral entry.The neck is then osteotomized at predetermined level, with the thigh parallel to the ground to avoid uneven anteroposterior cut.

Femoral Preparation and Component Placement Adequate preparation of the canal is the key for component stability. Initially, a box chisel is used to remove the lateral bone and facilitate appropriate entry. Medial entry point in the neck results in a varus positioning of the component (Fig. 10.5).

Fig. 10.5 Varus positioning of the component following medial entry point.

The main concern with varus positioning would be undersizing of the femur component, resulting in early subsidence. The chiselled bone is compacted into the proximal metaphysis with a bone tamp to preserve the cancellous bone (Fig. 10.6). Then a canal identifier is passed and femoral canal is identified. Femoral broaching is started with the smallest broach and gradually increased till adequate rotational stability is achieved. Anteversion of the femoral component is determined by placing the broach parallel to the posterior cortex of the femoral neck (Fig. 10.7).

Uncemented Total Hip Arthroplasty

Fig. 10.6 Cancellous bone compaction with bone tamp.

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Fig. 10.7 Femoral component aligned parallel to posterior cortex of the femoral neck.

This often gives the desired anteversion in most cases. Trail reduction is done with an undersized trail. Three key factors contributing to balancing of the hip are assessed. 1. Combined anteversion 2. Impingement 3. Limb length If additional neck cut, offset or anteversion adjustment is required to achieve appropriate limb length, hip balance and combined anteversion, it is done at this point. It should be remembered that the anteversion with a nonmodular metaphyseal filling stems can only be adjusted by 5°–10°. Once the above three factors are adequately restored, the stem is checked for rotational stability. This is done with the leg held in internal rotation and the assistant holding the stockinet of the leg. The trail is moved clockwise and anticlockwise, checking for implant bone interface mobility. If the stem is rotationally stable, the whole leg should move as a single unit when held and moved with the implant. Once the size is determined, original component is placed and the head is reduced.

Closure The leg is repositioned in abduction and neutral or slight external rotation and capsule-to-capsule closure is done with ethibond. This is followed by suturing of the external rotators and the rest of the posterior soft issues.

POSTOPERATIVE PROTOCOL Patients start weight bearing and physical therapy the same day. They are followed up at 2 weeks, 6 months, and then 2 yearly thereafter.

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REFERENCES 1. Dorr LD, Luckett M, Conaty JP. Total hip arthroplasties in patients younger than 45 years: a nine to ten year follow up study. Clin Orthop 1990;(260):215–19. 2. Cornell CN, Ranawat CS. Survivorship analysis of total hip replacements: results in a series of active patients who were less than fifty-five years old. J Bone Joint Surg AM. 1986;68(9):1430–34. 3. Callaghan JJ, Tooma GS, Olejniczak JP, et al. Primary hybrid total hip arthroplasty: an interim follow up. Clin Orthop 1996;333:118–25. 4. Callaghan JJ, Gaffey JL, Goetz DD, et al. Cementless acetabular fixation at 15 years with HG 1 cup: comparison to the gold standard Charnley. Paper presented at American Association of Hip and Knee surgeons 12th Annual meeting, Dallas, TX, 2002. 5. Ring PA, Ring UPM. total hip arthroplasty. Clin Orthop 1983;176:115–23. 6. Mittelmeier H. Report on the first decennium of clinical experience with a cementless ceramic total hip arthroplasty. Acta Orthop Belg 1985;51:367–76. 7. Bruijn JD, Seelen JL, Feenstra R, et al. Failure of the mercring screw-ring acetabular component in total hip arthroplasty. J Bone Joint Surgery. 1995;7A:760–66. 8. Fox GM, Mc Beath AA, Heiner JP. Hip replacement with a threaded acetabular cup: a follow up study. J Bone Joint Surgery 1994;76A:195–201. 9. Pupparo F, Engh CA. Comparison of porous-threaded and smooth-threaded acetabular components of identical designs: two to four year results. Clin Orthop 1991; 271:201–06. 10. Bobyn JD, Pilliar RM, Cameroon HM, et al. The optimum pore size for fixation of porous-surface metal implants by the ingrowth of bone. Clin Orthop 1980; 298:27. 11. Engh CA, Bobyn JD, Glassman AH. Porous coated hip replacement. J Bone Joint Surgery 1987;69B:44–55. 12. Lachiewicz PF, Suh PB, Gilbert JA. In vitro initial fixation of porous-coated acetabular total hip components. A biomechanical comparative study. J Arthroplasty 1989;4(3):201–5. 13. Stiehl JB, MacMillan E, Skrade DA. Mechanical stability of porous-coated acetabular components in total hip arthroplasty. J Arthroplasty 1991;6(4):295–300. 14. Archibeck MJ, Berger RA, Jacobs JJ, et al. Second generation cementless total hip arthroplasty: eight to eleven year results. J Bone Joint Surg 2001;83A:1666–73. 15. Capello WN, D’Antonio JA, Feinberg JR, et al. Ten year results with hydroxyapatite components in patients less than fifty years old. J Bone Joint Surg 2003;85A:885–89. 16. Sinha Rk, Dungy DS, Yeon HB. Primary total hip arthroplasty with proximally coated stem. J Bone Joint Surg 2004;86-A(6):1254–61. 17. Jasty M, Bragdon C, Bruke D, et al. In vivo skeletal responses to porous –surfaced implants subjected to small induced motions. J Bone Joint Surg 1997;79A:707–14. 18. Pilliar RM, Lee JM, Maniatopoulos C. Observations on the effect of movement on bone growth into porous-surfaced implants. Clin Orthop 1986:208:108–13. 19. Moore AT. A metal hip joint: a new self-locking Vitallium prosthesis South. Med J 1952;45:1015–19. 20. Dossick PH, Dorr LD, Gruen T, et al. Technique of pre operative planning and post operative evaluation of non cemented hip arthroplasty. Techniques Orthop 1991;6:1–6. 21. Marshall AD, Mokris JG, Reitmanr D, Dandar A, Mauerhan DR. Cementless titanium tapered-wedge femoral stem: 10–15 year follow up. J Arthroplasty 2004;19(5):546–52. 22. Bourne RB, Rorabeck CH, Patterson JJ, Guerin J. Tapered titanium cementless total hip replacements: a 10- to 13 year follow up study. Clin Orthop 2001;393:112–20.

Chapter 11

Total Hip Arthroplasty in Peritrochanteric Fractures C. J. Thakkar

Fractures of trochanteric region of femur are common in elderly. Internal fixation of these fractures is a standard practice. Replacement with either bipolar or total hip is considered mainly for failed fixation. In fresh comminuted fracture through porotic bone in elderly with medical comorbidities, replacement may be preferred to allow early full weight bearing mobilization.1 Technical challenges on the operating room (OR) table include selection of prosthesis, equalization of limb length, management of trochanter and prevention of dislocation. According to our experiences, patients of intertrochanteric fractures with good bone stock and stable fracture configuration with no associated comorbidities are candidates for internal fixation. On the other hand, patients with poor bone stock (osteoporosis) and/or unstable fracture configuration and/or significant comorbid conditions, which require early mobilization and are associated with high risk for revision surgery, are candidates for replacement surgery.2,3 The choice of femoral implant is based on the life expectancy of the patient and the quality of the remaining bone.4,5 Usually these patients are more fit than the patients in whom primary hip replacement is done. Noncemented calcar replacement, diaphyseal fit revision prosthesis may be the first choice, since one needs to build up the supratrochanteric length and also needs to have an implant that goes the distance of two canal width, distal to the last screw hole in order to prevent stress fracture in the postoperative period. When one considers replacement for trochanteric fractures that had previous fixation device in place, one needs to consider the mode of failure of fixation. In majority of cases, the fracture collapses in varus, resulting in cutting out of the implant in the head in superior and anterior direction. The tip of the head implant may or may not damage the acetabulum. If the acetabular articular surface is not damaged, one may consider bipolar replacement, else total hip would become an obvious choice.

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There may be instances when the failure involves breakage of fixation device itself, like broken screw through the shaft or broken intramedullary device. In these situations, one is faced with the challenge of removal of broken implant that may need special instruments.

FRESH FRACTURES Replacement is considered mainly for multifragmentary fractures, especially when there is posterior comminution either posteromedial due to the separation of lesser trochanter or posterolateral due to comminution of greater trochanter. In either situation, there is lack of bony support to the proximal part of the prosthesis. This may require either calcar replacement prosthesis or building up of the proximal femur either by cement or bone graft. Distortion of proximal anatomy causes difficulty in assessment of version and limb length equalization. Fixation of abductor mechanism to the prosthesis is another challenge, as the trochanteric piece is either porotic or comminuted posing difficulty in fixation.

APPROACH The greater trochanteric split is used for direct approach to the proximal femur, preserving the soft tissue attachment and vascularity of its pieces. The anterior fragment with its attached glutei and vastus lateralis is retracted anteriorly. Due to its digastric attachment, proximal migration of trochanteric piece is prevented. The posterior fragment with its attached short external rotators is retracted posteriorly. This exposes the neck of the proximal fragment end on. Excision of the proximal fragment consisting of head and neck of femur is not as easy as in the case of subcapital fracture, because of the capsular attachment to the proximal fragment, which requires radial capsulotomy. Corkscrew femoral head extractor is introduced through the exposed neck, into the femoral head, helping maneuvers to remove the proximal fragment. Unless the hip is arthritic, bipolar replacement is preferred. Since most of these patients are elderly with wide medullary canal and limited life expectancy, we prefer cemented femoral implant. If the lesser trochanter piece is large, it may be prudent to attach it to the shaft fragment using cerclage wire to build proximal bone stock.

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At this stage, one faces the challenge of absence of calcar, which in neck fracture helps in supporting proximal portion of femoral prosthesis and in maintaining correct version. To overcome this problem, we harvest graft from the femoral head and wedge it between the medial femoral cortex and the prosthesis (Figs 11.1–11.6). This technique helps in building the

Fig. 11.1 Bone graft harvested from medial neck and head.

Fig. 11.2 Graft wedged between the rasp and medial femoral cortex, supporting proximal portion of the rasp.

Fig. 11.3 Bone model depicting intertrochanteric fracture.

Fig. 11.4 Area of head and neck from where the graft is harvested.

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Fig. 11.5 Graft wedged in the medial void.

A

B

Fig. 11.6 Graft–prosthesis composite.

missing proximal bone, and prevents varus and retroversion by supporting the prosthesis medially. In the absence of calcar, the prosthesis would be inserted deeper than when the calcar is present, resulting in shortening of the limb. This graft replaces the missing calcar and when the prosthesis

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is then inserted and its proximal edge rests on the proximal edge of the graft, the limb length equalization is achieved (Fig. 11.7).

Fig. 11.7 Graft wedged between medial femoral cortex and medial edge of prosthesis, supporting upper end of the prosthesis.

Since majority of the patients are old with wide osteoporotic canals, the prosthesis is cemented, hence the load is shared by the femoral diaphysis, and the graft then does not fail. Trochanteric pieces are then wired to each other and to the shaft in standard fashion. Though trochanteric nonunion is known to occur, but since the trochanteric pieces have digastric attachment, they do not migrate proximally and the abductor lurch is minimal.

FAILED FRACTURES WITH IMPLANT IN SITU One may encounter either intra-medullary or extra-medullary implants. The common mode of failure is varus of the proximal fragment, leading to anterosuperior cut out of the implant through the femoral head. Rarely there may be instance of breakage of screws or the nail or the plate (Fig. 11.8).

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B

C

Fig. 11.8 Total hip replacement (THR) for failed IT fracture.

Our preferred approach is posterior, detaching the short external rotators from the trochanter and dislocating the hip by internal rotation and adduction. It is prudent to dislocate the hip before removing the implants, because if the implants are removed first, then the screw holes may act as stress riser, and there is a possibility of creating a fracture through weak osteoporotic bone. It is also advisable to put minimum two cerclage wires around the diaphysis, one distal to the last screw hole and one proximal, to prevent splitting of the shaft while rasping the medullary canal. In majority of cases, there is fibrous union between the head neck fragment and trochanteric and shaft fragments. A large void is left at the base of the trochanter on removal of head fixing screw. This site is another weak point, which may result in the separation of trochanter from the shaft while inserting the implant. It is better to wire the trochanter to the shaft, else if it separates in the postoperative period, it may lead to proximal migration of the trochanter and hip dislocation due to unopposed force of adductors or residual abductor lurch. Postoperative rehabilitation is aimed at rapid upright position to prevent complications of recumbency in this elderly group of patients. Support walking with tolerated weight bearing is started as early as pos-

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sible. Routine hip mobilization protocols are followed unless there is some contraindication to the same.

REFERENCES 1. Kayali C, Agus H, Sanli C- J. Treatment for unstable intertrochantric fractures in elderly : Internal fixation v/s cone hemiarthroplasty. Orthop Surg (Hong Kong) 2006;14(3);240–4. 2. Harwin SF, Kulick RG. Primary bateman–leinbach bipolar prosthetic replacement of hip in treatment of unstable intertrochantric fractures in elderly. Orthopaedics 2009;13(10):1131–36. 3. Pho RW, Nather A, Tong GO, Korku. Endoprosthetic replacement of unstable, comminuted intertrochantric fracture of femur in the elderly, osteoporotic patient. J Trauma 1981; 21(9): 792–97. 4. Broos PL, Rommens PM, Deleyn PR, Geens VR, Stappaerts KH. Pertrochanteric fractures in the elderly: are there indications for primary prosthetic replacement? J Orthop Trauma 1991;5(4):446–51. 5. Haentjens P, Casteleyn P P, De Boeck H, Handelberg F, Opdecam P. Treatment of unstable intertrochanteric and subtrochanteric fractures in elderly patients. Primary bipolar arthroplasty compared with internal fixation. J Bone Joint Surg Am 1989;71(8):1214–25.

Chapter 12

Fused Hips in Ankylosing Spondylitis Pradeep B. Bhosale, Prabodhan P. Potdar

INTRODUCTION Ankylosing spondylitis (AS) is a medical disease of young adults with bony complications relating to spontaneous joint fusion over a period of time. India has a prevalence of 0.06%, the disease being of juvenile onset with peripheral symptoms of enthesitis and peripheral arthritis developing earlier than axial symptoms.1 Most commonly affected joints are sacroiliac joints, facet joints, hips, knees and ankles. AS has been traditionally linked with spondyloarthritides associated with HLA B27 allele. About 90% of AS patients have positive reaction on HLA B27 testing. However, the HLA association is not correlated to severity of the disease. Males have a 3:1 predominance over females and are affected in the second or third decade of life. Median age of presentation in western countries is approximately 23 years. Hereditary factors play a role with a concordance rate in identical twins of 65%. Immunological factors have also been implicated in the pathogenesis of AS. AS can be clinically diagnosed by the modified New York criteria set in 1992 with documented sacroilitis being the major criteria.2 Of all the cases of AS, about 24–36% have hip involvement. The role of total hip arthroplasty (THA) in AS is in the arthritis stage. The joint may have a jog of movement or may present with variable grades of ankylosis. Though hip replacement follows similar protocol as other etiologies with unfused hips, the surgical procedure for fused hips needs to be modulated according to the deformity. The management of ankylosed hips in AS has improvised over period of time with the use of better implants, newer surgical techniques and imaging tools.3–5

MEDICAL DISEASE AND MANAGEMENT Though an ankylosed joint is the sequelae of AS process, the medical abnormality is still ongoing and a thorough control is necessary to prevent

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further joint deterioration in rest of the body. A multidisciplinary approach, coordinated by rheumatologist, adjusted to individual patient profile, which includes nonpharmacological and pharmacological treatment modalities is recommended for the optimal management.3,6 AS has been traditionally treated with anti-inflammatory drugs and disease modifying anti-rheumatic drugs (DMARDs). The introduction of newer anti-rheumatic drugs like TNF-Ơ inhibitors is effective in retarding the progression to the stage of spontaneous fusion.7 Tips and Pearls s 0 ATIENT MAY BE ON ANTI INFLAMMATORY DRUGS STEROIDS $-!2$S SUCH AS methotrexate or TNF-Ơ antagonists. The appropriate use of perioperative dosages is imperative for surgical recovery and prevention of complications. s ) NFLAMMATORY PARAMETERS MAY BE ELEVATED IN PATIENTS WITH!3 DUE TO inflammatory process and may not conclude preoperative infection.

ALTERED ANATOMY AS affects all synovial joints of the body with predominance of axial skeleton. The lumbosacral spine is affected very early on. In the spine, zygapophyseal joints get involved, primarily leading to progressive fusion from caudal to cranial direction. The flattening of lumbar spine due to lumbar spine fusion and fusion of the sacroiliac joints leads to loss of compensatory mechanisms. Of the major joints, hip involvement is early. The hip may be mobile at first with synovitis. If untreated, there is a rapid progression to frank ankylosis in more than 90% of cases, within a period of 2–5 years. Sometimes the hips may be ankylosed in flexion resulting in ‘pseudo-kyphotic’ deformity (Fig. 12.1). Involvement of cervicothoracic spine leads to true kyphotic deformities in the cervico-thoracic region. In majority of cases, there is a positive sagittal vertical axis (SVA) and anterior shift of the center of gravity. Subsequently, flexion of the knees and dorsiflexion of the ankles develop. Most of the cases with Fig. 12.1 Frontal and side profile of patient bilateral hip ankylosis may be able with ankylosing spondylitis.

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to ambulate using their knees and ankles. However, these joints become fixed over a period of time, resulting in complete immobility and patient is bedridden. Restoration of the abnormal sagittal and coronal balance of the body takes precedence in surgical treatment of AS.

CLINICAL EXAMINATION 3TIFFNESSISTHEMAJORCOMPLAINTIN!30AUCITYOFMOVEMENTINTHEHIPCANBE DUETOINFLAMMATORYSPASMORCOMPLETETRABECULARBONYCONTINUITY0ATIENTS may present with varied deformities of abduction, adduction, flexion or a combination of these. The need to evaluate true and apparent shortening cannot be overemphasized. Also evaluation of the spine may demonstrate a fixed pelvic obliquity, which would eventually require the tweaking of inclination of the acetabular cup. Shifting of the center of gravity due to lumbosacral fusion may need special attention to cup placement as regards anteversion. Knee range of motion (ROM) and flexion deformity need to be determined preoperatively for placing the stem in adequate anteversion. The findings of clinical examinations need to be confirmed with radiological findings. Tips and Pearls s +NOWTHETRUEANDAPPARENTSHORTENING s +NOWTHESTATUSOFOTHERLOWERLIMBJOINTS ESPECIALLYREGARDINGFLEXION deformity and ROM. s +NOWTHESTATUSOFTHESPINEREGARDINGCORONALANDSAGITTALPLANEDEFORMITY s $EFORMITIESAREBETTEREVALUATEDCLINICALLYRATHERTHANRADIOLOGICALLY

Radiological Investigations An anteroposterior and lateral radiograph of the hip would be the basic investigation (Fig. 12.2). The following features need to be specifically looked out for. 1. Magnitude of deformity and quality of bony fusion. 2. Abduction and adduction angles of the limbs.  0ROTRUSIOACETABULInINVARIABLEPRESENTINOFTHECASESOFCOMPLETE fusion. 4. Femoral canal diameters in anteroposterior and lateral views. 5. Sacroiliac (SI) joint fusion and pelvis rotation in coronal and sagittal planes. 6. Osteopenia

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Fig. 12.2 Anteroposterior and lateral radiographs of pelvis with both hips.

Sometimes lateral radiographs may be difficult to obtain due to bony fusion and inability to abduct the limbs. A computer tomography (CT) scan may be helpful in these cases. Radiographs of the lumbosacral spine would confirm fixed pelvic obliquity and status of the sacral slope. A neck to foot scannogram may be done, to evaluate the true extent of the pelvic obliquity and pelvic inclination. C7 plumb lines drawn on coronal and sagittal views can help us evaluate the true extent of deformity of the spine in coronal and sagittal views. The placement of the cup depends entirely on maintaining the inclination and anteversion with respect to the plumb line and is independent of the position of the hip deformity.

Computer Tomography A CT scan is needed for further evaluation and standardization of the radiological investigation. It also helps to determine the existing bone stock in the acetabular floor and medullary canal diameters for stem placement. Use of CT can be invaluable in studying the anteversion of the femoral neck and preoperatively decide on the choice of modular implants if required. The trabecular continuity is well seen on a CT scan. In cases of protrusio acetabuli, coronal CT cuts gives an idea about medial acetabular bone stock. We would recommend the use of a CT scan in difficult deformities of the hip and acetabulum.

Preoperative Radiological Templating Radiological templating is important in difficult primary hip arthroplasty. The center of head and acetabular cup may be accurately templated in a few cases. However, radiological templating may not be helpful in choice of a stem, and the type of canal may not dictate the choice of implant. A

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radiological Dorr C canal may just allow the smallest uncemented stem. The decision to implant a cemented or cementless implant is pending on intraoperative assessment of bone quality. Templating may be useful in a few cases where proximal femoral morphology may change implant selection and positioning, requiring the use of specialized modular implants. Tips and Pearls s 2 ADIOLOGICAL FEMORAL CANAL DIAMETERS ARE DECEPTIVE AND INTRAOPERATIVE assessment is recommended. s 2OTATIONINTHEPELVISMAYNOTALLOWACCURATERADIOLOGICALTEMPLATING In most cases, radiological templating may be erroneous.

PREANAESTHETIC ASSESSMENTS8 Spine fusion is invariably present in patients with an ankylosed hip. The cervical spine fusion can make neck extension difficult, and the arthritis of the crico-aryetenoid joint can further compromise the passage of the endotracheal tube. Awake fiber-optic intubation is used world over for the passage of endotracheal tube in AS. Tracheostomy is not required even in difficult cases. General anaesthesia is the anaesthesia of choice. At our center, we have been successful in using regional (spinal with epidural) anaesthesia with fiber optic intubation kept as standby. Regional anaesthesia is possible since the ligamentum flavum is unaffected by the disease process. It is essential to be prepared for general anaesthesia in case regional anaesthesia is not possible. Decrease in tidal volume due to decreased chest expansion is a negative prognostic factor for general anaesthesia and intubaTION0ULMONARYFUNCTIONTESTSSHOULDBEDONEBEFORETHEPROCEDURE5PTO 30% of these patients may develop an A–V block or right bundle branch block (RBBB). An ECG with echocardiography is necessary to rule out the same.9

POSITIONING OF THE PATIENT Deformities occur in various positions of the hip. External rotational, abduction and flexion deformities are the most commonly seen deformities at our center. Bilateral abduction deformities are not uncommon. At our center, we prefer the lateral decubitus position with anterior pubic and posterior sacral supports. In cases where the spine is fused, the preopera-

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tive radiological coronal deviation would give us a clue regarding patient placement. In cases of bilateral abduction, deformity padded cushions may be placed below the dependent iliac crest and trunk to facilitate horizontal placement of the patient (Fig. 12.3). Sometimes a ‘wind-swept’ deformity is encountered, and we usually do the hip, which is fixed in abduction first. Tips and Pearls s , ATERALRECUMBENTPOSITIONGIVENWITHCARETOSUPPORTTHECONTRALATERAL limb from iatrogenic fractures. s 0ADDINGOFTHEDEPENDENTLIMBFROMPRESSURESORESANDPERONEALNERVE palsy. s (EADSUPPORTSRINGTOPREVENTFRACTURESINTHESTIFFNECK

THE APPROACH Hip joint in AS may be mobile or stiff with variable grades of ankylosis. Hip replacement in former cases follows similar protocol as any other THA. Hip joint THA in ankylosed cases requires addressing the following issues. 1. Safe clean-cut neck osteotomy without bone splintering.  0REVENTIONOFDAMAGETOTHEABDUCTORSANDACETABULARWALLS 3. Restoration of biomechanics of the hip. 4. Restoration of center of rotation of the acetabular cup and head (addressing protusio). 5. Identification of true acetabulum and preserve bone stock.

Fig. 12.3 Patient positioning and endotracheal intubation in patient with fixed hip abduction deformity in ankylosing spondylitis.

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Complete visualization of neck and soft tissue releases has been the crux for performing THA in ankylosed hips. This becomes technically difficult since majority of deformities are in abduction, external rotation and flexion. The posterior structures, viz., posterior capsule and external rotators are contracted, resulting in the inability to permit internal rotation. Also, flexion deformity puts the sciatic nerve at direct risk for injury. Various approaches have been used to access these difficult hips. The trans-trochanteric approach has been widely adopted over past three decades. Though we get a 360° exposure of the acetabulum, there are inherent complications relating to trochanteric nonunion and gait disturbances due to altered biomechanics of the hip.1,10 Similarly, anterior approaches are easy for external rotation deformities. However, there are inherent problems of femur retraction due to osteopenic bone and contracted soft tissues. Also it is not possible to release the posterior capsule and external rotator from anterior approach. Most importantly, cutting the neck without visual confirmation can cause the cut to osteotomize the posterior acetabular wall. The posterior approaches are more difficult for such hips. In externally rotated extremity, the sciatic nerve is very close to the neck-posterior acetabular wall junction, and exposure to the posterior aspect of neck is limited. Overzealous retraction during exposure and while taking the neck-cut may cause inadvertent injury to sciatic nerve and damage to the anterior acetabular wall. Lastly, another widely used approach, the trans-gluteal lateral approach can cause abductor loss and superior gluteal nerve injuries.2,11 For the past 25 years, we have been approaching these specific stiff and ankylosed hips with external rotation deformities using a single incision dual anterior and posterior approach. This is a ‘safe neck resection’ and ‘glutei-sparing’ approach. The approach has been perfected on cadavers before its practical use. The approach gives complete anterior and posterior access to the neck and safe postosteotomy maneuvering of the hip.

SURGICAL PROCEDURE The surgical skin incision is a posterior curvilinear vertical incision centered over the greater trochanter around 15–20 cm in length (Fig. 12.4). The tensor fascia lata is cut and retracted anteriorly and posteriorly so as to gain a generous exposure. The gluteus maximus is split and widely opened. The anterior part of the exposure is commenced. The patient is tilted towards the surgeon by 15°–20°. Dissection is carried out below the anterior cut margins of the tensor fascia lata, which is retracted anteriorly with a rightangled retractor. The dissection starts in the internervous plane between

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Fig. 12.4 Surgical incision (red line) and bony prominences (red dot).

Fig. 12.5 Anterior exposure to the hip and retraction of muscles, viz., gluteus medius (GM) , vastus lateralis (VL) and rectus femoris (RF).

the gluteus medius–minimus complex and vastus lateralis (Fig. 12.5). The ‘V’-shaped interval between the two muscles is opened after cutting the connecting soft tissue sleeve. This exposes the gluteus minimus along with the anterior hip capsule. The gluteus medius along with the minimus is retracted superiorly with a Hohmann retractor positioned over the superior part of the hip capsule. Similarly, the vastus lateralis is retracted inferiorly

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with a Hohmann retractor between it and the inferior hip capsule. Anterior longitudinal capsulotomy is performed and Hohmann retractors are repositioned over superior and inferior aspect of the neck. Medial subcapsular periosteal dissection is performed and another pointed Hohmann retractor is placed medial to the anterior acetabular wall. Retracting superiorly, inferiorly and medially exposes the fusion mass containing the head, neck and the acetabulum. Alternatively, a smooth 3 mm Steinmann pin can be driven into the head of the femur to act as a medial retractor. This completes the neck exposure and we can have a complete visual and tactile feel of the neck in all directions.

NECKCUT With neck being completely visible and soft tissues protected, osteotomy trajectories can be easily established using visual and tactile orientation of the neck (Fig. 12.6). A 5–10 mm sandwich cut may be taken to prevent any iatrogenic fractures during osteotomy. We start by feeling the anterior and posterior aspects of the neck and establish the trajectory. Then we perform the sandwich osteotomy entirely from the anterior to posterior along the proposed trajectory. The osteotomy should be clean cut and performed under direct vision with a sharp oscillating saw. Osteotome should be avoided to complete the cut as this may create fracture. However, osteotomes may be used to confirm the gap created. The sandwich bone is removed with a Fig. 12.6 Neck-cut through anterior narrow Roungeur. This completes approach of the dual incision. Muscles in the picture – gluteus medius (GM), vastus the neck-cut. Utmost care should be taken to avoid any maneuvering lateralis (VL) and rectus femoris (RF). of the limb until the neck is completely osteotomized and there is a visible discontinuity. Even after the complete osteotomy, the tissues surrounding may be too tight to permit movements of internal rotation. The osteotomy gives considerable free-

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dom to rotate the limb internally, which aids visualization of external rotators and posterior capsule. The rest of the procedure proceeds like the classical posterior approach THA.

POSTERIOR EXPOSURE The patient is tilted 15°–20° away from the surgeon. The hip is placed in extension and internal rotation. The trochanteric bursa is taken away and the gluteus medius is retracted anteriorly with a pointed Hohmann retractor. External rotators along with the posterior capsule are erased from the bone starting superiorly from the piriformis and ending at the insertion of the quadratus femoris caudally. We often prefer to cut the insertion of the gluteus maximus, which is attached to the superior aspect of linea aspera as a thick flat tendon. This has two advantages. First, the traction on the posteriorly placed sciatic nerve decreases. Second, the anterior retraction of the femur for acetabular reaming becomes easy. There is a perforator vessel invariably present below the tendon, which may need to be cauterized. Care has to be taken to safely isolate or safeguard the sciatic nerve during the entire procedure. The hip is internally rotated. The internal rotation needs to be successively increased by releasing tight structures like the anterior hip capsule on femur and psoas muscle insertion. The anterior swan neck retractor should rest without undue traction on the anterior acetabular wall.

FEMORAL REAMING AND STEM PLACEMENT Femoral anteversion during cementless fixation is variable and may range from 17° retroversion to 30° anteversion.3,6,12 Approaching the femur first gives idea about the femoral anteversion and subsequently acetabular anteversion. Reaming may be commenced with successive metal reamers and broaches so as to get the best fit possible. Most of the patients are young and a cementless implant is preferred. During the use of cementless stems, care should be taken to preserve as much cancellous bone as possible. Inadvertent reaming can be dealt by packing cancellous bone chips at site of loss. During trail stem insertion, care should be taken to hold the leg steady and insert the trial patiently, to prevent intraoperative fractures. Cemented fixation may be required for Dorr C canals and should always be kept on standby. Reaming and determination of the native anteversion would give a clue to the acetabular anteversion using various equations like those proposed by

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Widmer and Zurfluh or Ranawat.7,13,14 There have been reports of anterior dislocation in a few papers and the reasons are still unknown. However, an exaggerated femoral anteversion due to the inflammatory pathology can be one of the causes. Nevertheless, modular stems and long diaphyseal fit stem should be kept in case the need arises.5,6,8

Acetabular Reaming Once the femoral anteversion is set, the acetabular reaming is commenced. The challenge is to find the true acetabular floor and to not breach it. The femur is retracted anteriorly with a swan neck retractor so as to visualize the acetabular area (Fig. 12.7). We use 3 mm Steinmann pins to secure

Fig. 12.7 Posterior exposure to acetabulum. Ant – anterior , Post – posterior, TAL – transverse acetabular ligament.

soft tissues superiorly and posteriorly. This gives us a 360° wide field. The margins of the true acetabulum can be visualized around the osteotomized borders of the neck. It is advisable to start with a smaller reamer and start reaming the osteotomized neck ankylosed with the acetabulum. In most of the cases, circumferential labral cartilage can be seen after superficial reaming, reconfirming the correct direction of reaming. Successive reamings would remove trabecular bone of the head until the floor of the acetabulum is reached. The fat pad in the fossa acetabuli, the unossified ligamentum teres and the superior border of the obturator foramen can be good markers to the floor. Care should be taken to do gradual controlled reaming, so as to preserve as much bone as possible. Intraoperative radiographs are not recommended to confirm the extent of reaming, since they overestimate or underestimate the extent of the medial acetabular wall. Alternatively, a 2.5-mm drill bit may be passed through till a give way is felt. A depth gauge measurement of more than 1 cm is a good assurance to

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stop medial reaming. In hips with protrusion, the depth of reaming should be adjusted according to the preoperative planning. Alternatively, impaction bone grafting may be utilized if acetabular reaming occurs till the floor of THE ACETABULUM 0ATIENTS WITH!3 ARE YOUNG AND WOULD REQUIRE MULTIPLE revisions in their lifetime. They have trabecular continuity between the head and the acetabulum. We prefer to slightly lateralize the cup so as to preserve medial acetabular bone stock for further revisions. After the desired rim fit is obtained, the anterior and inferior osteophytes should be removed to prevent hinged dislocation.

ACETABULAR CUP PLACEMENT This step is the most important for ultimate stability of the THA in AS. The cup needs to be placed in the most appropriate inclination and anteversion. Widmer et al. have suggested a cup inclination between 40° and 42° and combined anteversion of 37°, based on 3D computer modeling in a THA.7,9,13 Ranawat and others introduced the concept of combined anteversion of the mated components, normally to be 25°–35° for adult males and 30°–45° in females for preventing instability.9,14 Subtracting the combined anteversion from the native femoral stem, ante-torsion would give us the required acetabular anteversion. Alternatively, for the determination of anatomical acetabular anteversion, the transverse acetabular ligament (TAL) or the McCollum’s line can be used as a guide. We prefer to use TAL with the cup being placed parallel to the TAL for anteversion.15 We also use TAL to evaluate the inclination of the cup. For a hip without any pelvic obliquity, the inferior margin of the acetabular cup should lie just medial to TAL. As a corollary, in cases of pelvic obliquity, the cup position may be adjusted along the plane of TAL so as to reproduce functional cup inclination (Fig. 12.8). It is important to understand the concept of functional cup anteversion. The pelvic tilt has a role to play Fig. 12.8 Acetabular cup placement and in deciding the functional anteverrelation to transverse acetabular ligament sion of the cup. In a study of normal (TAL). individuals, the posterior pelvic tilt

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(decrease in the sacral slope) was present in 56% of individuals, anterior pelvic tilt (increase in the sacral slope) in 38%, while only 6% had no pelvic TILT WHICHMEANSTHEANTERIORFRONTALPLANE!&0 WASPARALLELTOTHECOROnal plane of the body in lateral decubitus position.9,16 In majority of the cases, the sacral slope is reduced and the pelvis is fixed in flexion that does not change with positioning. Implanting the hip in anatomical anteversion in such cases would lead to anterior dislocation. Hence, the anteversion has to be decreased from the original anteversion according to the posterior pelvic tilt by a factor of 0.8 (for every 1° increase in posterior tilt the anteversion decreases by 0.8°).16,17 The same would hold true for anterior pelvic tilt, where the anteversion has to be increased by the same factor. For EXAMPLE&IG SAGITTALVIEWOFTHE,3JUNCTIONSHOWSTHE!&0POS-

Fig. 12.9 Change of anteversion with change in pelvic tilt. AFP – anterior frontal plane. See explanation in the text.

teriorly tilted (a.k.a. sacral slope decreased/sacrum extended/pelvis flexed/ inferior sacral tip pointing forward) by 15°. If the femoral ante-torsion is 20° and combined anteversion fixed by the surgeon is 45°, then instead of placing the cup in 25° (45°–20°) of anteversion, the surgeon should place the cup in 13° [25° – (15° × 0.8)°]. The combined functional version would be 33° and not 45° with respect to the long axis of the table, which

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is the coronal plane then. After the trial components are put in, the hip should be inspected for anterior and posterior instability. Cup implantation in posteriorly tilted pelvis can be a cause of anterior subluxation or frank dislocation. This requires implantation of an elevated liner in the anterosuperior position. Table 12.1 gives the guidelines regarding cup positioning. Table 12.1 Recommendations during acetabular cup placement

Flexion of the sacrum Extension of the sacrum Affected pelvis tilted inferiorly Affected pelvis tilted superiorly

Anteverting the cup to prevent posterior dislocation Retroverting the cup to prevent anterior dislocation Give more inclination Give less inclination

Bearing Surface Choice The choice of bearing is a matter of debate. We prefer to use hard-on-hard ceramic bearing in young patients. However, the bearing choice needs to be individualized depending on surgeon’s prior experience and current Hip 3OCIETY RECOMMENDATIONS (IGHLY CROSS LINKED POLYETHYLENE (80,% IS ANEXCELLENTCHOICEOFBEARING SECONDONLYTOCERAMICBEARINGS@(80,% elevated liners may be utilized to deal with anterior instabilities in AS.5,18

Closure The hip is closed in layers under a suction drainage. There is a notable loss of posterior hip capsule and external rotators are atrophic due to disuse.

Fig. 12.10 Posterior soft tissue closure with quadratus femoris in a fan-shaped fashion.

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-OSTOFTHETIME THEQUADRATUSFEMORISISTHEONLYBULKYMUSCLE0OSTERIOR soft tissue closure is achieved by translocating the quadratus femoris muscle sleeve superiorly (Fig. 12.10). Anteriorly, soft tissue is closed by simple approximation of the cut sleeve between gluteus medius and vastus lateralis. Additional soft tissue releases may be done like adductor tenotomy and the PATIENTSHOULDBEKEPTINANABDUCTIONBRACE0OSTOPERATIVE8 RAYSSHOULD be done to confirm cup and stem positioning and rule out iatrogenic fractures (Fig. 12.11).

Fig. 12.11 Postoperative anteroposterior radiograph showing bilateral uncemented total hip replacement (THR).

Prevention of Heterotrophic Ossification There is high propensity for development of heterotrophic ossification (HO) in patients with AS. Risk factors for HO formation are revision surgery and trans-trochanteric surgical approach. Tips and Pearls for Preventing HO Formation s ! TLEAST,OFSALINEWASHSHOULDBEGIVENTOREMOVEPUTATIVE(/PROgenitor cells in bone reamings and bone debris. s -USCLEINJURYBYOVERZEALOUSMUSCLERETRACTIONSHOULDBEMINIMIZED s !LLBONECUTSSHOULDBETAKENWITHSHARPNEWSAWBLADE s 5NNECESSARYPERIOSTEALSTRIPPINGSHOULDBEAVOIDED

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Once set in, the progressive HO formation may hinder the functional recovery of a patient operated with a THA. Radiotherapy is useful if a linear dose of 700 cGy is given within 48 h post surgery. The implant and gonads should be shielded during this procedure. Use of nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin (75 mg) in three divided doses for 4–6 weeks has been an easy and controllable prophylaxis for prevention of HO at our center.9,19

Fractures and Dislocations Intraoperative fracture is a known possibility. Disuse osteopenia is very common. The tendon–bone junction is mechanically stronger than the muscle and the bone. This leads to avulsion fractures of trochanter and spiral oblique fractures of the shaft of femur. Unsafe neck resection may lead to spiral fractures extending up to the acetabular wall or proximal femur. Fractures are also possible while positioning the patient. Tips for avoiding such fractures are as follows. 1. Soft tissue to be released adequately, namely, the psoas major, gluteus maximus and posterior structures. 2. Rigorous jerking movements should be avoided. Successive increase in the arc of rotation should be aimed for after progressive releases. Dislocation rate for primary THA in AS has being less than 0.5% in our hands. Identification of true acetabulum, intraoperative restoration of combined anteversion and adequate posterior soft tissue closure are the crux to achieve these results.

Bilateral vs. Unilateral Most of the cases would present with varied degrees of bilateral ankylosis. Majority of the deformities are of abduction and external rotation. Also there is a fixed coronal pelvic obliquity, which would directly dictate cup inclination. Unilateral surgery may predispose to higher chances of ipsilateral hip dislocation.20 In bilateral cases, inclination needs to be tweaked with respect to the coronal plane pelvic obliquity as described before, and we recommend bilateral simultaneous or bilateral sequential hip replacement in such cases.

Postoperative Rehabilitation Mobilization of the patient starts with successive increase in the ROM of the joint to prevent stiffness and formation of HO. Weight bearing may

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be started according to patient tolerance. At our center, immediate weight bearing is started once the drain is out. In the initial few weeks, the patient is instructed to use the abduction pillow. Due to disuse atrophy of the lower limb muscles, the patients may take time to gain adequate power. The recovery is variable and depends on preoperative duration of ankylosis. Surprisingly, these patients have preserved muscle end plates and their muscles hypertrophy once the range of movement is started. The Harris hip score should be calculated after 6 months to assess the rehabilitation success.

CONCLUSIONS 1. Taking down a spontaneous ankylosis needs an excellent three-dimensional understanding of the hip anatomy and reconstruction of the joint. 2. Minimal tissue damage and soft tissue handling can decrease the chances of HO and subsequent result in decrease in functionality. 3. Neck-cut is the most challenging part of the surgical procedure and needs to be done with caution and safe technique. 4. Use of a single incision dual approach spares the glutei and offers a safe neck resection. 5. Use of intraoperative anatomical markers like TAL and foveal fat pad may help in cup placement with regard to anteversion. 6. Alteration in the lumbosacral anatomy should be understood well to position the cup in the most appropriate functional position. 7. Combined functional anteversion should be restored at the end of the procedure.  0OSTOPERATIVE REHABILITATION AND PREVENTION OF HETEROTOPIC OSSIFICATION are crucial for long-term success.

REFERENCES 1. Chopra A, Abdel-Nasser A. Epidemiology of rheumatic musculoskeletal disorders in the developing world. Best Pract Res Clin Rheumatol 2008;22(4):583–604. 2. Longo D, Fauci A, Kasper D, Hauser S, Jameson J, Loscalzo J. Harrison’s Principles of Internal Medicine THED-C'RAW(ILL0ROFESSIONAL  6ANDER#RUYSSEN" -U×OZ 'OMARIZ% &ONT0 -ULERO* DE6LAM+ "OONEN! ETAL Hip involvement in ankylosing spondylitis: epidemiology and risk factors associated with hip replacement surgery. Rheumatology (Oxford) 2010;49(1):73–81. 4. Joshi AB, Markovic L, Hardinge K, Murphy JCM. Total hip arthroplasty in ankylosing spondylitis: an analysis of 181 hips. J Arthroplasty 2002;17(4):427–33. "HAN 3 %ACHEMPATI ++ -ALHOTRA 2 0RIMARY CEMENTLESS TOTAL HIP ARTHROPLASTY FOR bony ankylosis in patients with ankylosing spondylitis. J Arthroplasty 2008;23(6):859–66. 6. van den Berg R, Baraliakos X, Braun J, van der Heijde D. First update of the current

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evidence for the management of ankylosing spondylitis with non-pharmacological treatment and non-biologic drugs: a systematic literature review for the ASAS/EULAR management recommendations in ankylosing spondylitis. Rheumatology (Oxford) 2012;51(8):1388–96. 7. Nystad TW, Furnes O, Havelin LI, Skredderstuen AK, Lie SA, Fevang B-TS. Hip replacement surgery in patients with ankylosing spondylitis. Ann Rheum Dis 2014;73(6):1194–97. 7OODWARD,* +AM0#!!NKYLOSINGSPONDYLITISRECENTDEVELOPMENTSANDANAESTHETIC implications. Anaesthesia 2009;64(5):540–8. 9. Goodman SM, Figgie M. Lower extremity arthroplasty in patients with inflammatory arthritis: preoperative and perioperative management. J Am Acad Orthop Surg 2013;21(6):355–63. 10. Schinsky MF, Nercessian OA, Arons RR, Macaulay W. Comparison of complications after transtrochanteric and posterolateral approaches for primary total hip arthroplasty. J Arthroplasty 2003;18(4):430–4. 11. Krismer M. Total hip arthroplasty: A comparison of current approaches. European Instructional Lectures 2009;9(VI):163-75. 12. Dorr LD, Malik A, Dastane M, Wan Z. Combined anteversion technique for total hip arthroplasty. Clin Orthop Relat Res 2008;467(1):119–27. 13. Widmer KH, Zurfluh B. Compliant positioning of total hip components for optimal range of motion. J Orthop Res 2006;22(4):815–21. 14. Ranawat CS, Maynard MJ. Modern technique of cemented total hip arthroplasty. Oper Tech Orthop 1991;6(3). *AIN3 !DERINTO* "OBAK04HEROLEOFTHETRANSVERSEACETABULARLIGAMENTINTOTALHIP arthroplasty. Acta Orthop Belg 2013;79(2):135–40. 16. Zhu J, Wan Z, Dorr LD. Quantification of pelvic tilt in total hip arthroplasty. Clin Orthop Relat Res 2010;468(2):571–5. 17. Moed BR. The modified gibson posterior surgical approach to the acetabulum. J Orthop Trauma 2010;24(5):315–22. )DULHAQ - 0ARK +3 $IWANJI 32 9OON 42 7IE *3 4OTAL (IP !RTHROPLASTY FOR Treatment of Fused Hip With 90° Flexion Deformity. J Arthroplasty. 2010;25(3):498. e5–498.e9. 19. Chao ST, Joyce MJ, Suh JH. Treatment of heterotopic ossification. Orthopedics 2007;30(6):457–64–quiz465–6. 20. Kim YL, Shin SI, Nam KW,Yoo JJ, Kim Y-M, Kim HJ. Total hip arthroplasty for bilaterally ankylosed hips. J Arthroplasty 2007;22(7):1037–41.

CHAPTER 13

Total Hip Arthroplasty in Protrusio Acetabulae Javahir A. Pachore, Vikram I. Shah, Amish S. Kshatriya In acetabular prostrusio, the femoral head migrates medially. The commonest causes are due to secondary conditions associated with variety of inflammatory, metabolic and posttraumatic conditions. Primary or idiopathic forms of protrusio were described by OTTO in 1824, which we commonly refer to as OTTO pelvis.1 This condition is common in females with bilateral progressive involvement. Thirty-five to forty per cent of protrusio are related to inflammatory arthroplasty. The incidence of protrusio in rheumatoid arthritis is about 15–20%. The protrusio is also well known in ankylosing spondylitis. The incidence reported by Dholakia et al. is 7%.2 Our experience of protrusio with rheumatoid arthritis at Bombay hospital is 53%, which is very high compared to western literature. A total of 150 rheumatoid hips were analyzed, which showed 53% protrusion, and the maximum were moderate protrusio (unpublished). The most common method of the radiological measurement of protrusio is Kohler’s line, which is the ilioischial line. Any femoral head or cup medial to this line by more than 2 mm is considered as protrusio. The most accurate method for measurement is Gates’s teardrop method.3 The inter-teardrop line and perpendicular line bisecting teardrop are drawn.

Fig. 13.1 Gates’s teardrop method.

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Superior migration is measured from horizontal line, and medial migration is measured from vertical line. This method gives more accurate estimation of protrusio because of persistence of teardrop (Fig. 13.1). Even in revision cases, we are able to see the teardrop identity. Protrusio with pelvic dissociation can be identified preoperatively on radiographs and CT scan. CT scan is more valuable for quantifying the bone defect. Sotelo and Charnley classified protrusio in three varieties.4 The medial migration of 1–5 mm was called as mild, that of 6–15 mm was called as moderate and more than 15 mm was called as severe (Fig. 13.2). The medial

A

B

C Fig. 13.2 Grades of protrusion. (A) Mild. (B) Moderate. (C) Severe.

deficiency intraoperatively also has been classified according to the size of medial defect. This medial defect is always membranous. Type 1 has less than 1 cm deficiency, type 2 has 1–3 cm deficiency and type 3 has more

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than 3 cm deficiency. Type 3 often has a pelvic dissociation. Normal anatomical position of acetabulum in deformed hip is difficult. Ranawat et al.5 developed a method to locate the correct anatomical position of acetabulum and they described isosceles triangle as location of normal acetabulum position. Protrusio in joint replacement is a challenge because of abnormal bone. It is a progressive disease with disturbed remodeling. Progression is usually gradual. Hasting and Parker reported 2–3 mm/year migration. Ranawat et al. reported that it is not only 2–3 mm/year medial migration but there is also superior migration of 4 mm/year. Hasting reported 71% of protrusio for those who were on corticosteroid therapy or active rheumatoid disease for those who had progressive protrusion.6 This protrusio which is due to medial and superior migration has an oblong shape. To make it hemispherical in shape is usually a surgical challenge. The reaming of this protrusio is an art. The principal of treating protrusio is to normalize the center of rotation and healing of medial wall to give good long-term results.

SURGICAL TECHNIQUE Under anaesthesia, mobility of the hip must be assessed. This gives confidence to the surgeon if there is a good rotation and flexion. Most protrusio have only a limited flexion range. If rotations are adequate, then neck exposure and dislocation may be easy. Any approach can be considered, but in general, posterior approach is more preferred. This will allow a trochanteric osteotomy if needed. In posterior approach, one has to be careful of the sciatic nerve. Due to protrusio, the sciatic nerve is very close to the trochanter. The dissection of the posterior structures has to be close to the bone. The mini posterior approach is not recommended in moderate or severe protrusio. Fair degree of soft tissue release is required, including insertion of gluteus maximus on the proximal part of femur. Frequently, we need to release the iliopsoas from the lesser trochanter to get better exposure, which facilitates the reduction. Mild to moderate protrusio needs capsulotomy rather than capsular release. Gradual release of soft tissue with internal rotation will facilitate in seeing a part of the neck. Once a part of the neck is seen, one has to gently flex, adduct and internally rotate to dislocate the hip. To dislocate the hip, forceful internal rotation should be avoided which can lead to spiral fracture of femur. Most of these patients have an osteoporotic femur; hence, one should be careful in dislocating the hip. If one is able to

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see the part of the head in some degree of flexion, adduction and internal rotation, then only should one dislocate the hip. In moderate and severe protrusio, it is better to do the neck osteotomy in situ after exposing the part of the neck. Two spikes, placed superiorly and inferiorly to the neck, give good visualization of neck for osteotomy under vision. The neck osteotomy should be done carefully, either by using a small saw blade or doing multiple drills and then using sharp osteotomes to avoid calcar fracture. After the neck osteotomy, the anterior retractor should be placed. The placement of anterior retractor for the left hip should be around 10 to 11 O’clock position. For the right hip, it should be around 1 to 2 O’clock position. The reason for putting this retractor at this position is to avoid neuro-vascular injury; second, this is the thickest part of the acetabulum anteriorly which will avoid fracture. The posterior structures should be protected with a spike into the ischial tuberosity. The inferior retractor should be below the transverse acetabular ligament. In protrusion, the transverse acetabular ligament may not be a good anatomical landmark due to osteophytes. Once we get 360° exposure of the acetabulum, the head can be extracted. If the head is mobile in the acetabulum, only then is the extraction possible. The 6.5 mm Schanz pin can be put into the center of head to facilitate the extraction by rotating manually. If there is fibrous ankylosis of the femoral head, it is better to ream with a small acetabular reamer. Gradually, the head can be made thinner and thinner and finally a thin shell of bone can be scraped. The crucial part of the acetabulum preparation is to make the acetabulum hemispherical. The mouth of the protrusio is small and the cavity is large. Gradually, with 1 or 2 mm increments of the mouth of the acetabulum, it should be made adequately larger, but one has to be careful in keeping a watch on the anterior and posterior walls (Fig. 13.3). The direction of acetabular reaming will be according to the anteversion and the inclination. The reamer should aim around 35°–40° while loading the socket. After reaming the mouth with proper degree of anteversion, trial cup should be used. It is preferred to ream 1 mm less or same size, for the trial cup. The peripheral bone of these cases is usually sclerotic and does not have expansion capacity. Mostly, the cup has a peripheral rim fit. Advance the cup gradually until you reach the optimum position; Fig. 13.3 Acetabulum reaming.

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make sure that you do not excessively lateralize the cup. Once you know the depth of the trial cup, mark the peripheries on the remaining anterior and posterior rims. This guides the final placement of acetabulum. Keeping the trial cup inside, assess the amount of protrusio, which needs to be grafted. After removing the trial cup, the dome of the acetabulum should be roughened with small reamers so as to open the cancellous bone. Same procedure should be done to the posterior wall. Try and avoid anterior reaming, as in most protrusio, the anterior wall is usually very thin. The medial wall should not be reamed. The fibrous tissue on medial wall should be removed with a sharp currette but the action should be gentle, as most medial walls are very thin and papery and there are chances that one may create fractures of the medial wall. The flexible drill of either 2.7 or 3.2 mm should be used to do the multiple drilling in a controlled fashion in superior and posterior segments of the acetabulum. If cancelleous bone has been exposed well, this multiple drilling may not be required. The bone grafting of the medial wall must be done with matchstick bone graft from the patient’s own femoral head (auto graft). The technique of preparation of bone graft from the femoral head is to first take out all the cartilage and hard sclerotic bone from the femoral head. Make multiple wafery thin slices of 2–3 mm. Then with the help of a nibbler, cut these bone-like matchsticks. If you are using autograft, do not wash this graft with saline. Graft should be soaked in the patient’s own blood. If the autograft is not adequate, allograft can be used from the bone bank. This allograft is fashioned in the same way as the autograft. Then these allografts are washed with normal saline multiple times to clean bone debris fat and soft tissue. After lavaging these grafts, dry them and add the patient’s own blood from the operating field. The grafts are impacted on the medial wall of acetabulum in a step wise fashion. Do not add large amounts of graft at one go. Gradually, the grafts are added and they are impacted with hemispherical metal punch. The amount of graft will be assessed by using an acetabulum trial, which is about 2 mm smaller to see the previous anterior and posterior marks. The grafting is considered adequate with this trial when the grafts are fully touching the trial cup.

COMPONENT CHOICE The result of cemented cup in protrusio has not been very satisfactory. Bayley et al. (1987) reported 50% of loosening in uncemented cups at midterm and long term. Few centers have reported good results. Rosenberg et al.7 showed 90% survival at 12 years with impaction bone grafting and cemented cup.

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If the cemented cup is used, then the dome and posterior wall need multiple step drilling so as to open the cancellous bone for micro interlock. Acetabular cementing is technically demanding, which needs experience. The technique requires hypotensive anaesthesia, multiple anchoring holes, pulsatile lavage, medial grafting, cement pressurization and use of flanged socket. Current preference in moderate to severe protrusio has been impaction bone grafting and uncemented cup. Preferably we must use two dome screws to add extra stability to the construct, which allows medial wall healing (Fig. 13.4). After implantation, the additional posterior, inferior and anterior osteophytes must be removed. If these osteophytes are not removed

A

B

Fig. 13.4 X-rays of protrusio. (A) Preoperative. (B) Postoperative.

then there are chances of impingement leading to dislocation. Uncemented cup has encouraging results. Thomas et al. (2001) showed that uncemented cups in rheumatoid arthritis had a good result at 7.5 years follow up. Their results included two cases of aseptic loosening and 1 case of ischial osteolysis due to wear. Any pelvic dissociation will need acetabular cage for reconstruction. Two commonly used reconstructs are (1) Bush Sneider cage, which needs a cemented cup, and (2) Octopus cage, which is uncemented. While using cemented cup, one precaution that is to be taken is to keep the acetabulum cup in good anteversion and in a closed fashion. Do not look for the inclination and version of acetabular cage. The acetabular alignment is independent of cage placement. This will reduce the rate of dislocation. For uncemented technology, varieties of acetabular inserts are available such as 10°, 20° and 30° lip liners. The trial liner should be introduced and then reduction is done. The stability test should be done and depending on that the original lip liner can be rotated. The surgical aim in the treatment of protrusio is to bring the normal

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center of rotation, build the medial wall and lateralize the cup, which has been emphasized by Ranawat et al. We looked into our own series of 150 cases of rheumatoid arthritis wherein total hip replacement was done. The protrusio hips showed 25.1 mm vertical and 27.2 mm lateral distance from the inter-teardrop line. After cemented hip replacement, the vertical distance was 22.6 mm and the lateral distance was 25.8 mm. This indicated that some medialization of the cup had taken place. Average angle of acetabular inclination was 42°. In uncemented cup, our vertical distance was 19.75 mm and lateral distance was 30.34 mm. This indicated that the cups were inferiorized and lateralized with an average angle of 33° of inclination (Unpublished).

SUMMARY The key is to identify the bone deficiency on radiographs. The CT scan can be a great adjuvant tool in preoperative planning. Good exposure is needed. If there is difficulty in dislocating the hip, then neck osteotomy in situ needs to be done. Careful reaming with proper version is a key for acetabulum preparation. Adequate medial grafting is to be considered either by autograft or allograft. Cemented cups can be only considered in a mild protrusio. Uncemented cups are preferred for moderate and severe protrusio. For pelvic dissociation, acetabular cage is the only ideal way of reconstruction.

REFERENCES 1. Otto AW. Seltene Biobachtunge zur Anatomie. Physiologie und Pathogie gehorig, 2nd ed., Berlin: Andral and Lobsteitiy; 1824. 2. Dholakia KT, Saraf ML, Pachore JA. Total Hip Replacement in Ankylosing Spondylitis. Book by Richard Coombs. Butterworth; 1989. 3. Gates HS, Poletti SC, Callagahan JJ, et al. Radiographic measurement in protrusio acetabula. J Arthroplasty 1989;4:347–51. 4. Sotelo-Garza A, Charnley J. The results of Charnley arthroplasty of the hip performed for protrusio actabuli. Clin Orthop 1978;132:12–18. 5. Ranawat CS, Dorr LD, Inglis AE. Total hip arthroplasty in protrusio of rheumatioid arthritis. J Bone Joint Surg 1980;62A:1059–65. 6. Hastings DE, Parker SM. Protrusio acetabuli in rheumatioid arthritis. Clin Orthop 1975;108:i.76–83. 7. Bayley J, Christie M, Ewalde et al. Long term results of total hip arthroplasty in protrusio acetabuli. J Arthroplasty 1987:2:215–9. 8. Wout W J Rosenberg, B Willem Schreurs, Maaten C De Waal Malefijt, et al. Impacted morsellized bone grafting and cemented primary total hip arthroplasty for acetabular protrusion in patients with rheumatoid arthritis: An 8- to 18-year follow-up study of 36 hips. Acta Orthopaedica 2000;71(2):143–6.

PART 3

Total Knee Arthroplasty: Techniques and Pearls Chapters 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28.

Radiological Planning in Primary Total Knee Arthroplasty Selection of the Implant in Total Knee Arthroplasty Tips and Pearls: Tourniquets and Position in Total Knee Arthroplasty Tips and Pearls: Exposure and Retractors in Total Knee Arthroplasty Tips and Pearls: Saw Techniques in Total Knee Arthroplasty Principles: Alignment and Balancing Cementation Techniques in Total Knee Arthroplasty Patellar Resurfacing in Total Knee Arthroplasty Unicondylar Knee Arthroplasty Technique: Fixed Bearing Total Knee Arthroplasty Mobile-Bearing Total Knee Arthroplasty: Techinque and Clinical Results Management of Tibial Bone Defects Total Knee Arthroplasty in the Fixed Flexion Deformity Total Knee Arthroplasty in the Stiff Knee Total Knee Arthroplasty in Post High Tibial Osteotomy

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PART 3

Total Knee Arthroplasty: Techniques and Pearls Chapters 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28.

Radiological Planning in Primary Total Knee Arthroplasty Selection of the Implant in Total Knee Arthroplasty Tips and Pearls: Tourniquets and Position in Total Knee Arthroplasty Tips and Pearls: Exposure and Retractors in Total Knee Arthroplasty Tips and Pearls: Saw Techniques in Total Knee Arthroplasty Principles: Alignment and Balancing Cementation Techniques in Total Knee Arthroplasty Patellar Resurfacing in Total Knee Arthroplasty Unicondylar Knee Arthroplasty Technique: Fixed Bearing Total Knee Arthroplasty Mobile-Bearing Total Knee Arthroplasty: Techinque and Clinical Results Management of Tibial Bone Defects Total Knee Arthroplasty in the Fixed Flexion Deformity Total Knee Arthroplasty in the Stiff Knee Total Knee Arthroplasty in Post High Tibial Osteotomy

183 190 204 211 222 230 240 249 257 269 280 287 302 308 315

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Chapter 14

Radiological Planning in Primary Total Knee Arthroplasty Mohan Desai, Kumar Kaushik Dash

INTRODUCTION The aim of total knee replacement is to evenly distribute the load on tibia by achieving a joint line parallel to the ground. In addition to decreasing the risk of unforeseen surprises intraoperatively, preoperative planning has been shown to prolong implant survival1 and reduce duration of surgery.2 Many times, a thorough preoperative planning will prevent unnecessary additional steps during surgery. For example, identifying preoperatively the presence of any tenting osteophytes and understanding the soft tissue sleeve around the knee joint are helpful in obtaining appropriate soft tissue releases. These measures will elongate the soft tissue sleeve, thus increasing the gaps, without having to resort to additional bone cuts. Following information is obtained from preoperative radiographs: 1. Assessment of hip–knee–ankle (HKA) axis to determine the distal valgus cut in the absence of computer assisted systems (CAS). 2. Deviations from normal alignment: a. Evaluation of offset (e.g., post high tibial osteotomy (HTO) cases). b. Identifying deformity and predicting its correctability; evaluating need of releases for the deformities. c. Extra-articular deformities (e.g., posttraumatic, developmental tibia vara, etc.) to identify site of deformity, and calculate approximate contribution of that to the joint. 3. Variation in Anatomy: narrow mediolateral width of distal femur in ‘female-type’ knees may warn surgeon to consider deep-dish design over cam and post, in order to avoid box cut. However, it must be kept in mind that the width of the distal femur may not be always appreciated well in a plain X-ray (e.g., in a knee with flexion deformity, distal femur may appear broader due to the oblique projection of X-ray beams). 4. Bone loss or defects, which may demand augments, cones, metal blocks,

Chapter 14

Radiological Planning in Primary Total Knee Arthroplasty Mohan Desai, Kumar Kaushik Dash

INTRODUCTION The aim of total knee replacement is to evenly distribute the load on tibia by achieving a joint line parallel to the ground. In addition to decreasing the risk of unforeseen surprises intraoperatively, preoperative planning has been shown to prolong implant survival1 and reduce duration of surgery.2 Many times, a thorough preoperative planning will prevent unnecessary additional steps during surgery. For example, identifying preoperatively the presence of any tenting osteophytes and understanding the soft tissue sleeve around the knee joint are helpful in obtaining appropriate soft tissue releases. These measures will elongate the soft tissue sleeve, thus increasing the gaps, without having to resort to additional bone cuts. Following information is obtained from preoperative radiographs: 1. Assessment of hip–knee–ankle (HKA) axis to determine the distal valgus cut in the absence of computer assisted systems (CAS). 2. Deviations from normal alignment: a. Evaluation of offset (e.g., post high tibial osteotomy (HTO) cases). b. Identifying deformity and predicting its correctability; evaluating need of releases for the deformities. c. Extra-articular deformities (e.g., posttraumatic, developmental tibia vara, etc.) to identify site of deformity, and calculate approximate contribution of that to the joint. 3. Variation in Anatomy: narrow mediolateral width of distal femur in ‘female-type’ knees may warn surgeon to consider deep-dish design over cam and post, in order to avoid box cut. However, it must be kept in mind that the width of the distal femur may not be always appreciated well in a plain X-ray (e.g., in a knee with flexion deformity, distal femur may appear broader due to the oblique projection of X-ray beams). 4. Bone loss or defects, which may demand augments, cones, metal blocks,

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extenders, etc., depending upon the defect size. Extra inventory may have to be kept ready on the table in these scenarios. 5. Evaluation for the need of special exposures, e.g., Patella Baja requiring quadriceps snip or tibial tubercle osteotomy. 6. Reasonably accurate prediction of component size. Although the accuracy of prediction of femoral and tibial component size prediction is only 60–65% for the exact same size, it increases to 90–95% when one size smaller and larger is considered in to calculations. As mentioned previously, due to oblique projection of X-ray beams, templating in an anteroposterior (AP) X-ray may not be accurate. However, a lateral X-ray with overlapping condylar shadows may give the rough estimate of the size with templating. As far as digital vs. analog templating is concerned, the differences are equivocal. 7. Variation in femoral neck shaft angle, femoral bowing, or previously performed total hip arthroplasty may affect the distal valgus cut, hence hip and proximal femur must be screened radiographically while doing planning for total knee arthroplasty (TKA).

HOW TO PLAN Good radiological planning requires an anteroposterior, lateral and patellar (merchant/sunrise, etc.) views of knee, plus a long leg alignment film (from hip to ankle) (Fig. 14.1). Radiographs should be obtained in weightbearing position. Planning ideally should be done by visualizing the center of femoral head and then drawing the mechanical axis from that point. In cases where femoral head could not be visualized due to small size X-rays, tall patient, or technical difficulties, the anatomical axis of femur is drawn instead. The mechanical axis of femur can be derived from the anatomical axis by adding 6°. Things are simpler on tibial side, with both anatomical and mechanical axis coinciding. And what is more, the axes bisect the proximal tibial metaphysis. Thus, when you do not have a long leg film till ankle, you can still find the axes by joining midpoint of proximal tibial metaphysis with midpoint of the knee. After drawing the axes on femur and tibia, the cuts are drawn on the X-ray. The normal anatomical tibia has a 3° varus surface, with a 9° valgus on femur, resulting in a 6° effective valgus at the knee joint. But while doing TKA, the tibial cut is taken perpendicular to the mechanical axis,

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extenders, etc., depending upon the defect size. Extra inventory may have to be kept ready on the table in these scenarios. 5. Evaluation for the need of special exposures, e.g., Patella Baja requiring quadriceps snip or tibial tubercle osteotomy. 6. Reasonably accurate prediction of component size. Although the accuracy of prediction of femoral and tibial component size prediction is only 60–65% for the exact same size, it increases to 90–95% when one size smaller and larger is considered in to calculations. As mentioned previously, due to oblique projection of X-ray beams, templating in an anteroposterior (AP) X-ray may not be accurate. However, a lateral X-ray with overlapping condylar shadows may give the rough estimate of the size with templating. As far as digital vs. analog templating is concerned, the differences are equivocal. 7. Variation in femoral neck shaft angle, femoral bowing, or previously performed total hip arthroplasty may affect the distal valgus cut, hence hip and proximal femur must be screened radiographically while doing planning for total knee arthroplasty (TKA).

HOW TO PLAN Good radiological planning requires an anteroposterior, lateral and patellar (merchant/sunrise, etc.) views of knee, plus a long leg alignment film (from hip to ankle) (Fig. 14.1). Radiographs should be obtained in weightbearing position. Planning ideally should be done by visualizing the center of femoral head and then drawing the mechanical axis from that point. In cases where femoral head could not be visualized due to small size X-rays, tall patient, or technical difficulties, the anatomical axis of femur is drawn instead. The mechanical axis of femur can be derived from the anatomical axis by adding 6°. Things are simpler on tibial side, with both anatomical and mechanical axis coinciding. And what is more, the axes bisect the proximal tibial metaphysis. Thus, when you do not have a long leg film till ankle, you can still find the axes by joining midpoint of proximal tibial metaphysis with midpoint of the knee. After drawing the axes on femur and tibia, the cuts are drawn on the X-ray. The normal anatomical tibia has a 3° varus surface, with a 9° valgus on femur, resulting in a 6° effective valgus at the knee joint. But while doing TKA, the tibial cut is taken perpendicular to the mechanical axis,

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and in turn, the distal femoral valgus cut is taken at 6°. To prevent the flexion gap asymmetry, femoral cut is taken at 3° external rotation. The 6° femoral valgus is derived from the angle between the anatomical and mechanical axes of femur, and ideally, one should find the angle in every patient and reproduce it, instead of taking a 6° standard cut in all patients. The next step is identifying deformities, their correctability and possible methods to counter the deformity without additional bone cuts. For example, large tenting osteophytes should be identified and marked on the X-ray. Before doing any soft tissue releases or additional cuts during surgery, these tenting osteophytes should be removed by surgeon to reassess how much correction could be achieved. Extraarticular deformities are discussed in the next section. The next step is to look for special situations like bone loss. This will help to anticipate additional inventories like augments, cones, extenders, etc. Also certain extreme Fig. 14.1 Planning for total knee arthro- bone loss scenarios will demand plasty (TKA) on a scannogram film with specific designs like hinged knee. mechanical and anatomical axes drawn. Dynamic radiographs are very helpful in this scenario to evaluate correctability after a bone loss. Also, a large tibial defect should warn the surgeon to undercut the tibia. The final step is templating. Transparent templates are available for superimposition. These must always be compared with manual X-rays of appropriate magnification to give surgeon some idea about the component sizes. Also, in cases of high tibial osteotomy, the need for an offset

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and in turn, the distal femoral valgus cut is taken at 6°. To prevent the flexion gap asymmetry, femoral cut is taken at 3° external rotation. The 6° femoral valgus is derived from the angle between the anatomical and mechanical axes of femur, and ideally, one should find the angle in every patient and reproduce it, instead of taking a 6° standard cut in all patients. The next step is identifying deformities, their correctability and possible methods to counter the deformity without additional bone cuts. For example, large tenting osteophytes should be identified and marked on the X-ray. Before doing any soft tissue releases or additional cuts during surgery, these tenting osteophytes should be removed by surgeon to reassess how much correction could be achieved. Extraarticular deformities are discussed in the next section. The next step is to look for special situations like bone loss. This will help to anticipate additional inventories like augments, cones, extenders, etc. Also certain extreme Fig. 14.1 Planning for total knee arthro- bone loss scenarios will demand plasty (TKA) on a scannogram film with specific designs like hinged knee. mechanical and anatomical axes drawn. Dynamic radiographs are very helpful in this scenario to evaluate correctability after a bone loss. Also, a large tibial defect should warn the surgeon to undercut the tibia. The final step is templating. Transparent templates are available for superimposition. These must always be compared with manual X-rays of appropriate magnification to give surgeon some idea about the component sizes. Also, in cases of high tibial osteotomy, the need for an offset

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stem will be apparent during templating (see Fig. 14.2). Digital templating softwares are now available in some places and their popularity will increase in coming years.

EXTRAARTICULAR DEFORMITIES Extra-articular deformities can occur due to trauma or developmental disorders. The distance of the site of deformity determines how much it contributes to the deviation at the joint. For example, a 10° varus deformity in tibia which is at the junction of proximal one-fourth and distal three-fourths of tibia will conFig. 14.2 Templating of tibia in a post high tribute 7.5° varus at knee joint. In tibial osteotomy (HTO) scenario showing other words, the influence of extraneed for an offset stem. articular deformity is inversely proportional to the distance from knee – the farther it is, the less influential it becomes. By calculating this contribution, the correction of deformity can be planned. For further details, the reader is referred to the monograph by Krackow and Rauh.3 While correcting deformities, the osteotomy can be done at the apex of the deformity (CORA). Instead, the deformity can also be corrected nearer to the articular surface after first calculating the contribution of the extra-articular deformity to the deviation at the knee joint.

CT vs. XRAY The advantage of CT over X-ray for preoperative planning involves (a) the ability to measure angles and distances in three dimensions, and (b) greater accuracy. In addition, the problems associated with plain X-ray (e.g., perspective distortion, magnification errors, orientation uncertainties) are overcome with CT scan. However, concern has been raised because of the amount of radiation dose. The traditional long leg radiograph leads to

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stem will be apparent during templating (see Fig. 14.2). Digital templating softwares are now available in some places and their popularity will increase in coming years.

EXTRAARTICULAR DEFORMITIES Extra-articular deformities can occur due to trauma or developmental disorders. The distance of the site of deformity determines how much it contributes to the deviation at the joint. For example, a 10° varus deformity in tibia which is at the junction of proximal one-fourth and distal three-fourths of tibia will conFig. 14.2 Templating of tibia in a post high tribute 7.5° varus at knee joint. In tibial osteotomy (HTO) scenario showing other words, the influence of extraneed for an offset stem. articular deformity is inversely proportional to the distance from knee – the farther it is, the less influential it becomes. By calculating this contribution, the correction of deformity can be planned. For further details, the reader is referred to the monograph by Krackow and Rauh.3 While correcting deformities, the osteotomy can be done at the apex of the deformity (CORA). Instead, the deformity can also be corrected nearer to the articular surface after first calculating the contribution of the extra-articular deformity to the deviation at the knee joint.

CT vs. XRAY The advantage of CT over X-ray for preoperative planning involves (a) the ability to measure angles and distances in three dimensions, and (b) greater accuracy. In addition, the problems associated with plain X-ray (e.g., perspective distortion, magnification errors, orientation uncertainties) are overcome with CT scan. However, concern has been raised because of the amount of radiation dose. The traditional long leg radiograph leads to

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absorbed dose of 0.7 mSv, whereas the lower limb CT Perth protocol leads to absorption of 2.7 mSv. The recently developed Imperial Knee Protocol (Henckel et al.)4 further defined an algorithm to reduce the amount of absorbed dose to 0.7 mSv in females and 0.5 mSv in males. Decreased radiation dose, shorter scanning time and cheaper cost of scanning will be the factors that will drive more adoption of CT for planning and outcome measurement in TKA.

ROLE OF MRI Compared to CT scannogram, which had a place in TKA planning since a long time, MRI has not been traditionally used for preoperative planning. However, things are changing with patient-specific instrumentation (PSI). CT scans or MRIs are utilized for manufacturing patient-specific instrumentation, and in some cases, patient-specific implants too. Not all patients are suitable for MRI-based planning (e.g., patients with pacemakers). The cost and scanning time are also on the higher side. With the advent of patient-specific surgeries, the role of MRI is poised to grow.

ANALOG vs. DIGITAL TEMPLATING Preoperative planning has traditionally been done on analog true size films. The facilities of digital templating may not be as widely available everywhere, particularly in developing countries. Nonetheless, the other benefits of digital imaging (i.e., easier to store and archive, view across multiple terminals, etc.) are going to drive the adoption of digital templating in future. As far as the accuracy between digital and analog templating is concerned, the difference is equivocal.5

SPECIAL RADIOGRAPHIC VIEWS BEFORE UNICOMPARTMENTAL KNEE ARTHROPLASTY In addition to standard radiographs, preoperative stress X-rays are essential before a unicompartmental knee arthroplasty. The X-rays are taken with patient being supine, with knee in 20° flexion. The X-ray beam is angled 10° cranially. This ensures that the X-ray beams are parallel to the tibial joint surface (Fig. 14.3). It must be ensured that the knee remains in neutral rotation with patella at the center, facing forward. Valgus and varus

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absorbed dose of 0.7 mSv, whereas the lower limb CT Perth protocol leads to absorption of 2.7 mSv. The recently developed Imperial Knee Protocol (Henckel et al.)4 further defined an algorithm to reduce the amount of absorbed dose to 0.7 mSv in females and 0.5 mSv in males. Decreased radiation dose, shorter scanning time and cheaper cost of scanning will be the factors that will drive more adoption of CT for planning and outcome measurement in TKA.

ROLE OF MRI Compared to CT scannogram, which had a place in TKA planning since a long time, MRI has not been traditionally used for preoperative planning. However, things are changing with patient-specific instrumentation (PSI). CT scans or MRIs are utilized for manufacturing patient-specific instrumentation, and in some cases, patient-specific implants too. Not all patients are suitable for MRI-based planning (e.g., patients with pacemakers). The cost and scanning time are also on the higher side. With the advent of patient-specific surgeries, the role of MRI is poised to grow.

ANALOG vs. DIGITAL TEMPLATING Preoperative planning has traditionally been done on analog true size films. The facilities of digital templating may not be as widely available everywhere, particularly in developing countries. Nonetheless, the other benefits of digital imaging (i.e., easier to store and archive, view across multiple terminals, etc.) are going to drive the adoption of digital templating in future. As far as the accuracy between digital and analog templating is concerned, the difference is equivocal.5

SPECIAL RADIOGRAPHIC VIEWS BEFORE UNICOMPARTMENTAL KNEE ARTHROPLASTY In addition to standard radiographs, preoperative stress X-rays are essential before a unicompartmental knee arthroplasty. The X-rays are taken with patient being supine, with knee in 20° flexion. The X-ray beam is angled 10° cranially. This ensures that the X-ray beams are parallel to the tibial joint surface (Fig. 14.3). It must be ensured that the knee remains in neutral rotation with patella at the center, facing forward. Valgus and varus

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Fig. 14.3 Position for imaging for ensuring that X-ray beams are parallel to tibial joint surface.

Fig. 14.4 Valgus stress view before a unicompartmental knee arthroplasty.

Fig. 14.5 Varus stress view before a unicompartmental knee arthroplasty.

stress views are obtained (Figs 14.4 and 14.5). The valgus stress view gives information about the correctability of the deformity and the involvement of lateral compartment. The varus stress view should reveal bone on bone disease. In valgus view, varus should be correctible in 20° of flexion and lateral joint space should not close completely. This suggests that lateral compartment cartilage is relatively intact and no release is needed to correct the varus deformity. If the varus is not correctible in valgus stress X-ray

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Fig. 14.3 Position for imaging for ensuring that X-ray beams are parallel to tibial joint surface.

Fig. 14.4 Valgus stress view before a unicompartmental knee arthroplasty.

Fig. 14.5 Varus stress view before a unicompartmental knee arthroplasty.

stress views are obtained (Figs 14.4 and 14.5). The valgus stress view gives information about the correctability of the deformity and the involvement of lateral compartment. The varus stress view should reveal bone on bone disease. In valgus view, varus should be correctible in 20° of flexion and lateral joint space should not close completely. This suggests that lateral compartment cartilage is relatively intact and no release is needed to correct the varus deformity. If the varus is not correctible in valgus stress X-ray

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in 20° of flexion or lateral joint space closes completely, then the case is unsuitable for unicompartmental knee arthroplasty.

PLANNING FOR PATIENTSPECIFIC INSTRUMENTS AND IMPLANTS Patient-specific instrumentation and implants shift the time and effort of computer navigation from inside the OT to preoperative period. The process involves submission of preoperative CT/MRI by the surgeon to the manufacturer, usually using a specific protocol. The manufacturer analyzes the data with the help of specialized computer programs and creates a surgical plan for the approval of the surgeon. The manufacturer then fabricates single-use instruments (cutting jigs/ custom cutting blocks) for femoral and tibial resections specific to that patient (e.g.,Visionaire System of Smith and Nephew, Signature System of Biomet).

REFERENCES 1. Schwartz JT, Mayer JG, Engh CA. Femoral fracture during non-cemented total hip arthroplasty. J Bone Joint Surg 1989;71-A:1135. 2. Blackley HR, Howell GE, Rorabeck CH. Planning and management of the difficult primary hip replacement: preoperative planning and technical considerations. Instr Course Lect 2000;49:3. 3. Krackow K, Rauh MA. The Measurement and Analysis of Axial Deformity at the Knee. Buffalo, NY: Kaleida Health System, 2001. 4. Henckel J, Richards R, Lozhkin K, Harris S, Rodriguez y Baena FM, Barrett AR, Cobb JP. Very low-dose computed tomography for planning and outcome measurement in knee replacement. The imperial knee protocol. J Bone Joint Surg Br 2006;88(11):1513– 18. PubMed PMID: 17075100. 5. Miller AG, Purtill JJ. Total knee arthroplasty component templating: a predictive model. J Arthroplasty 2012;27(9):1707–09. doi:10.1016/j.arth.2012.03.055. Epub 2012 May 23. PubMed PMID: 22633103.

Chapter 15

Selection of the Implant in Total Knee Arthroplasty H.P. Bhalodiya, Somesh P. Singh There has been no consensus regarding the preferable features in a knee prosthesis over several past decades in spite of multiple design philosophies being available to the surgeons. Also there has been continuous debate regarding which philosophy is better while choosing, namely, a cruciate retaining (CR) implant or posterior stabilizing implant or selection based on case to case. Whether to choose a fixed-bearing implant or a rotating platform implant? Whether to choose a cemented fixation or an uncemented fixation. One of the reasons for continuous debate may be because of the multiple variables involved in the evaluation of knee prosthesis, making it difficult to compare with each other in terms of proving superiority of one over the other. The implants we use now are different in important ways from those reported in most long-term follow-up studies. These longer-term studies also reflect a significantly different patient population than that currently presenting for knee replacement.1 Also surgeons must be aware that data reflected in the literature is from a completely different set of population and different design philosophy than what one is facing during the day-today practice. The patients are more younger, more active and with high demand on knee joint. There has been a systematic improvement in quality and consistency of performance of total knee replacement surgery due to continuous improvement in design philosophies, better material availability, better surgical technique and improvement of postoperative care. These advances have given surgeons the confidence to offer knee replacements to younger and less severely affected individuals who were not previously considered sufficiently debilitated or aged to undergo total knee arthroplasty (TKA). In addition, we are getting better at mobilizing our patients by reducing postoperative pain.2

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POSTERIOR CRUCIATE RETAINING TOTAL KNEE REPLACEMENT FIG. 15.1 In the early 1980s, CR knees dominated the market; approximately 85% of knees that were implanted were of this design. The development of universal instruments allowed surgeons outside of specialized joint centers to implant these knees. This knee design provided patients with better motion compared to the early total condylar knee. However, there were problems with the early CR designs of this era. This was a period when problems with polyethylene manufacturing had yet to be recognized. The polyethylene in this implant Fig. 15.1 Posterior cruciate retaining knee. was thin with a flat-on-flat design. Metal-backed patellae were also commonly used in this era. Not surprisingly, these characteristics led to early osteolysis, loosening and polyethylene failure. With more CR knees being implanted than posterior stabilized (PS) during this time period, the relative number of CR knees that failed was much higher than the PS knees. Consequentially, the PS knee began to increase in surgeon preference. In the meantime, design changes addressing the issues that led to early failure of the early CR implants were made. The implants we now use today are direct descendants of the original duocondylar and total condylar knee systems. Both the PS and CR knees have been modified to provide improved flexion and longevity of the implants. Today, most of the differences between the two knee designs are of historical interest. Long-term follow-up has shown no difference in survivorship of the two designs. Supporters of posterior cruciate ligament (PCL) retaining design showcase the concept of simply resurfacing the joint that sounds an appealing one. The bone loss is less, the loads are transferred to a central ligamentous structure rather than a mechanical one, natural femoral rollback is recreated and joint line is maintained, specific PS knee complications like patellar clunk syndrome and post wear are avoided and

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there is better proprioception from the joint and stair climbing ability. Recent reports have shown it to be equally effective in correction of large deformities and even in inflammatory arthritis such as rheumatoid arthritis. However, proper surgical technique and balancing of PCL are essential prerequisite as is protection of PCL from intraoperative inadvertent damage. Rasquinha et al.3 has published 12-year followup data on 150 consecutive PS knees with a 94.6% survivorship. This compares to Dixon et al.,4 who reported 92.6% 15-year survivorship on 139 CR knees, as well as Rodricks et al.,5 who reported 92.9% overall survival in a report of a 17-year follow-up on 160 CR knees.4,5 Outcomes are similar between implant designs even when the surgery is performed at nonacademic institutions and in younger patients. Gioe et al.6 reviewed outcomes of 1047 patients aged 55 and younger in a community registry database, there was no difference in revision rates between the PS and CR knees. They report an overall 84.5% 14-year survival for cemented total knee replacement in this relatively young patient population.6 Multiple comparative studies have shown no difference in functional outcome scores between the two implant designs.7–9 However, there is still some debate as to whether there are real differences in range of motion between CR and PS knees. A meta-analysis in 2005 of eight well-designed randomized studies found a statistically significant 8° increase in range of motion (ROM) for PS knees with a cam and postdesign.10 This finding has not been universally true in all studies. For example, Tanzer et al.11 compared 40 knees of PS and CR design and found no statistical difference in ROM, with average motion of 112° ± 13° for the CR and 111° ± 17° for the PS. In contrast, Maruyama et al.12 reviewed 20 bilateral knees and found an average ROM in CR knees of 112° ± 15° compared with 131° ± 13° in PS knees, a statistically significant difference. However, with such a wide range of measured motion in both designs, the clinical significance that an average 8° difference in flexion has is debatable, as both designs allow for more than 105°, which is what is needed to successfully climb stairs and arise from a seated position.13,14 To study the effect on proprioception with retention or substitution of PCL, Swanik et al.15 compared proprioception and balance before and after TKA randomized to a PS or CR knee. Although both proprioception and balance improved following knee replacement, there was no significant difference between the two implant designs.

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POSTERIOR STABILIZING TOTAL KNEE REPLACEMENT FIG. 15.2 Indications of PS knee: 1. Severe deformities (more than 20°) 2. Inflammatory arthritis 3. Postpatellectomy 4. Altered geometry of femur and/or tibia (previous osteotomy) 5. PCL-deficient knee Contraindication: Contraindication is when one or both of the collateral ligaments are significantly lax or disrupted. Failure to obtain balanced extension and flexion gaps after PCL resection necessitates conversion to a varus–valgus constrained implant. A posterior CR design TKA provides minimal constraint and relies on an intact, well-balanced PCL to create proper femoral rollback. Proponents of a CR design cite potential advantages such as more normal knee kinematics, increased quadriceps strength due to the increased moment arm of the extensor mechanism, improved stairclimbing ability, preserved proprioception, decreased patellar complicaFig. 15.2 Posterior stabilizing knee. tions, diminished shear forces at the tibial component bone interface and maintenance of distal femoral bone stock.1,2,16,17 However, all these claims are predicated on an intact and properly tensioned PCL. A posterior cruciate substituting a PS design removes the PCL and relies on a more conforming articular surface, as well as a polyethylene tibial post and femoral cam to provide restraint against posterior translation of the tibia and proper femoral rollback. Potential advantages of a PS design include more predictable restoration of knee kinematics, improved ROM, decreased polyethylene wear because of more congruent articular surfaces, easier correction of severe deformities and easier ligament balancing.1 While eliminating the reliance on a wellfunctioning PCL, a PS design introduces the risk of component dislocation with flexion instability, tibial post and femoral cam impingement, creating polyethylene wear, patellofemoral problems and increased bone resection of the distal femur.16,18

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POSTERIOR STABILIZING TOTAL KNEE REPLACEMENT FIG. 15.2 Indications of PS knee: 1. Severe deformities (more than 20°) 2. Inflammatory arthritis 3. Postpatellectomy 4. Altered geometry of femur and/or tibia (previous osteotomy) 5. PCL-deficient knee Contraindication: Contraindication is when one or both of the collateral ligaments are significantly lax or disrupted. Failure to obtain balanced extension and flexion gaps after PCL resection necessitates conversion to a varus–valgus constrained implant. A posterior CR design TKA provides minimal constraint and relies on an intact, well-balanced PCL to create proper femoral rollback. Proponents of a CR design cite potential advantages such as more normal knee kinematics, increased quadriceps strength due to the increased moment arm of the extensor mechanism, improved stairclimbing ability, preserved proprioception, decreased patellar complicaFig. 15.2 Posterior stabilizing knee. tions, diminished shear forces at the tibial component bone interface and maintenance of distal femoral bone stock.1,2,16,17 However, all these claims are predicated on an intact and properly tensioned PCL. A posterior cruciate substituting a PS design removes the PCL and relies on a more conforming articular surface, as well as a polyethylene tibial post and femoral cam to provide restraint against posterior translation of the tibia and proper femoral rollback. Potential advantages of a PS design include more predictable restoration of knee kinematics, improved ROM, decreased polyethylene wear because of more congruent articular surfaces, easier correction of severe deformities and easier ligament balancing.1 While eliminating the reliance on a wellfunctioning PCL, a PS design introduces the risk of component dislocation with flexion instability, tibial post and femoral cam impingement, creating polyethylene wear, patellofemoral problems and increased bone resection of the distal femur.16,18

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Correction of preoperative deformities is possible with both a CR and PS total knee. While a CR design mandates optimal balance of the PCL, a PS design offers possible easier correction of coronal deformities, especially when combined with a flexion contracture.19,20 A flexion contracture often requires a larger distal femoral resection so as to restore the extension space. Although both CR and PS knees require creation of symmetric extension and flexion gaps, the joint line must be restored in a CR knee to properly balance the PCL.21 Since a larger distal femoral resection will raise the joint line, a CR knee relies on an increased tibial resection to address a flexion contracture. This increased tibial resection may place the tibial component on weaker metaphyseal bone.21 Av PS knee provides more freedom to raise the joint line, which aids in the correction of a flexion contracture. However, improper gap balancing places the PS knee at risk for dislocation. The PCL often contributes to severe deformities, and its function can be significantly diminished if it requires an extensive release for balancing.19 An extensive PCL release also introduces the risk of late instability or rupture.21 Removal of the PCL creates at least a 1.0–1.3 mm increase in both extension and flexion gaps.22 Therefore, PCL resection offers the advantage of more straightforward gap balancing, improved access to the posterior aspect of the knee and improved exposure to the proximal tibia while avoiding the need for subjective release of the PCL, especially with severe deformities.19–21

MOBILEBEARING OR FIXEDBEARING FIG. 15.3

Fig. 15.3 Mobile-bearing knee.

In 1998, John Insall stated, ‘The kinematic conflict between low stress articulations and free rotation cannot be solved by any fixed bearing design. …Fixed-bearing knee designs have reached their ultimate expression; often, this stage of development indicates impending obsolescence.’ Mobilebearing knees offer an attractive avenue for future development.23 Mobilebearing knee replacement systems were designed to prevent mechanical loosening and wear, the two primary shortcomings of early knee replacement systems. Doug Noiles, an engineer with

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US Surgical Corporation, was one of the pioneers in recognizing that a dual articulation rotating-platform prosthesis would resolve the kinematic conflict between low stress articulation and high bearing conformity. He postulated that the high stresses at the tibial bone interface in conforming fixed-bearing implants would be significantly reduced by allowing rotation through the polyethylene tibial base plate interface. Forces generated during normal ambulation were ‘not transmitted to the prosthesis bone interface.’ This also allowed greater conformity between the femoral component and polyethylene, increasing contact areas and minimizing contact stresses. In 1976, Noiles obtained a patent for the PS rotating platform knee and revision system. Richard ‘Dickey’ Jones performed many of the early clinical trials on the system and helped develop the P-ROM, a press-fit condylar (PFC) femoral component, and a primary S-ROM tibial component with a mobile-bearing. With extensive European experience and clinical trials, the Noiles PS rotating platform knee eventually evolved into the PFC Sigma rotating-platform prosthesis (DePuy Orthopaedics Inc.). Following their design of the ‘floating-socket’ total shoulder, Fred Buechel, an orthopaedic surgeon, and engineer Michael Pappas were convinced that the mobile-bearing concept could resolve the dilemma. Between congruency and constraint in TKA designs,24–26 the New Jersey Integrated Knee Replacement System was developed with a large radius of curvature in extension that was symmetrical in the sagittal and coronal planes and a narrower radius in the posterior condyle. This design maximized contact areas in extension where loading is highest and allowed for improved flexion. In the early 1980s, DePuy Orthopaedics developed the low contact stress (LCS) knee from the New Jersey Knee System. The LCS knee again maximized conformity with a matching coronal and sagittal radius of the femoral component and the radii of the tibial polyethylene. There was also high conformity between the patella and the anterior flange of the component. This all contributes to very LCSs, potentially minimizing polyethylene wear. The evolution of the LCS implant eventually offered a variety of surgical options. Meniscal bearings allowed the surgeon to retain the cruciate ligaments, and the rotating-platform option allowed sacrificing the cruciate ligaments whenever appropriate.

Indications and Contraindications Patients with disabling knee pain unresponsive to conservative measures are good candidates to receive a mobile-bearing TKA. Patient selection is guided

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by patient expectations. Patients implanted with a mobile-bearing TKA may benefit from potential increase in ROM over fixed-bearing conventional knee systems, especially with higher flexion requirements.27 Since the patients are younger, heavier and more active, along with having increased life expectancy, there is a need for increased TKA implant survivorship, functional performance and load tolerance. Patients with significant coronal deformity, 20° of valgus, and 25–30° of varus may not have the adequate remaining soft tissues needed to create well-balanced flexion and extension gaps necessary to prevent instability and possible spinout. A more constrained polyethylene should be available for these cases as well as a fixed-bearing component.

Advantages of Mobile-Bearing Mobile-bearing total knee replacement offers two distinct advantages over fixed-bearing total knee replacement prosthesis. First is that it has better wear characteristics with higher surface contact area as compared to fixed-bearing with flat-on-flat design.This has been proven by multiple large retrieval studies. Second is that it avoids the possibility of malalignment of tibial component in terms of appropriate rotation of the component. The knee has the normal function of tibial internal rotation that occurs with flexion of the joint. Diseased state of the joint along with anatomical variations gives very few reliable landmarks to attain proper rotation of the tibial component in a fixed-bearing TKA. On the other hand, in mobile-bearing, the insert can attain proper rotation independent of tibial base plate position.

Results of Mobile-Bearing No published outcome study has demonstrated superior results of mobilebearing TKA over fixed-bearing TKA.28,29 Callaghan30 has stated, however, that the results of mobile-bearing TKA should be at least equivalent to the results of fixed-bearing TKA. Callaghan et al.31 reported 97% survival of the low contact stress mobile-bearing knee at 15 years. Sorrells et al.32 reported 88% survival at 13 years in younger patients, under the age of 65, using the same system. Long-term studies of the low contact stress mobile-bearing knee system by Beuchel et al.33,18 reported 98% survival at 20 years. None of these studies found more than 1% periarticular osteolysis at mediumand long-term follow-up, validating the concept of minimal surface wear with mobile-bearing TKA. The scientific basis of mobile-bearing TKA is now firmly established. Wear testing data and dynamic kinematic motion studies highlight potential advantages of mobile-bearing TKA. These

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include decreased contact stresses and wear on the polyethylene inserts and reduced stresses transmitted to the implant–bone interface. Further clinical studies are ongoing.

ALL POLY OR METAL BACK TIBIAL COMPONENTS FIG. 15.4 Metal back designs are traditionally considered gold standard and time tested for all types of total knee replacements. Advantages include options for insert modularity, stem extension and wedges, cementless fixation and possibility of insert change in setting of infection or late isolated liner wear out.

Fig. 15.4 All poly or metal backed tibia.

However, the issues of backside wear and increased osteolysis have been observed. In modern era, all poly tibia components have been shown to be equivalent and even superior in some aspects vis-à-vis metal back component. Advantages include increased polythelene thickness, avoidance of locking mechanisms issues and backside wear, less osteolysis and lower cost. Disadvantages include limitations in term of options of wedges, stem extensions and cementless fixation, no possibility for liner exchange in cases of infection and instability and relatively difficult surgical technique.

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include decreased contact stresses and wear on the polyethylene inserts and reduced stresses transmitted to the implant–bone interface. Further clinical studies are ongoing.

ALL POLY OR METAL BACK TIBIAL COMPONENTS FIG. 15.4 Metal back designs are traditionally considered gold standard and time tested for all types of total knee replacements. Advantages include options for insert modularity, stem extension and wedges, cementless fixation and possibility of insert change in setting of infection or late isolated liner wear out.

Fig. 15.4 All poly or metal backed tibia.

However, the issues of backside wear and increased osteolysis have been observed. In modern era, all poly tibia components have been shown to be equivalent and even superior in some aspects vis-à-vis metal back component. Advantages include increased polythelene thickness, avoidance of locking mechanisms issues and backside wear, less osteolysis and lower cost. Disadvantages include limitations in term of options of wedges, stem extensions and cementless fixation, no possibility for liner exchange in cases of infection and instability and relatively difficult surgical technique.

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CONDYLAR CONSTRAINED KNEE FIG. 15.5 Condylar constrained knee designs are made to give coronal plane (varus–valgus) stability to the implant. They have a large reinforced post in tibial insert sitting in a corresponding deep femoral cam. Stem extensions are added to transmit the load stresses from fixation interface to the diaphysis. They are indicated in severe valgus deformity of knee, collateral deficiency, bone defects, posttraumatic arthritis or instability created by irreconcilable flexion–extension gap balancing in PS knees. In cases of flexion instability where increased flexion gap Fig. 15.5 Condylar constrained knee. allows for posterior translation of tibial component, use of a constrained condylar knee (CCK) implant may provide stability by increasing the jump distance. However, the long-term results are under study and increased bone loss and osteolysis are potential disadvantages (Fig. 15.6).

A

B

Fig.15.6 Preoperative (A) and postoperative (B) X-rays of condylar constrained knee.

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ROTATING HINGED KNEE PROSTHESES FIG. 15.7 They have a linked system, which allows for both varus–valgus as well as translational stability. They are indicated for severe degrees of collateral insufficiency and cases of severe bone loss.

SPECIAL SITUATIONS Complex primary cases in warranting TKA may present with severe ligamentous laxity, posttraumatic stiffness or flexion contracture or malunion in proximal part of tibia or distal part of femur with hardware Fig.15.7 Rotating hinge knee. in situ. The challenge in such cases for the surgeon is to achieve rectangular well-balanced flexion–extension gap. This situation can be best addressed by using modular system that allows continuum constrain. With these system options of constrain, augments and stem are available to surgeons intraoperatively so that best outcome can be offered to the patient. Also it is better to use posterior stabilizing knee prosthesis in these situations. In case of a valgus knee where the medial collateral ligament is stretched out and even after getting a rectangular flexion extension gap, the medial side continues to remain lax on valgus strain, and a constrain type of knee is recommended. Higher constraints are reserved to cases where it is not possible to obtain final satisfactory balance: less than 5° of residual frontal laxity in extension in each compartment, and a tibio-femoral gap difference not in excess of 3 mm between flexion and extension. Girard et al.34 in their study showed that ‘in choosing the level of constraint to be applied in arthroplasty of a valgus knee deformity of more than 5°, it is important to undertake preoperative radiographic quantifications of convex laxity, the only independent parameter. The four other classical factors, identified by univariate analysis (excessive tibial slope, low patella, valgus severity, valgus of tibial origin), were not independent but their association should warn even more surgeons about problems of ligament balancing. Respecting these conditions should allow us to foresee, preoperatively with serenity,

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the use of high-constraint prostheses for the treatment of knee arthropathy with valgus deformity.’ Bone loss in total knee replacement provides a big challenge for the surgeon and has to be addressed carefully. Thoughtful preoperative evaluation and planning is most important as it will help to determine bone graft and implant requirements, although provisions should always be there for any change required on table. Extent and location of defect should be assessed using radiography and even 3D CT scans if required. Depending on the extent and location of the deficiency, there are many methods to deal with them ranging from the use of PMMA cement with or without screws for additional support, modular TKA systems with metal blocks and wedges, augments and stems, constrained or rotating hinge prostheses to mega or tumor prosthesis. Bone graft can be used as morcellised or structural grafts using autograft or allograft material or bone substitutes. Engh35,36 suggested that on the whole, choice of implant should be as simple and unconstrained as possible. Where bone resection has restored the stability, i.e., Anderson Orthopedic Research Institute (AORI) I, and with a surface defect of less than 25% (50% of either tibial plateau or either femoral condyle), primary implants can be used. However, whenever in doubt, addition of a stem extension is always preferred. Use of a constrained or hinged prosthesis is usually limited to severe soft tissue sleeve deficiency. There are some proponents for uncemented implants, but general consensus is for cemented implants. Augments are bone substitutes and space fillers. They provide rotational stability in femur condylar or tibial plateau deficiency or to restore the joint line. Stems provide about 20–30% of the resistance to axial loading and help maintain rotational and axial stability. They protect the bone graft material from excessive stresses and promote incorporation. Metaphyseal sleeves and cones may be required in cases of large central defects and give rotational stability, and in uncontained lesions with deficient rim, they provide additional longitudinal and angular stability. Use of highly porous coated sleeves is gaining popularity to fill defects and facilitate biological fixation. Pre-existing femoral or tibial extra-articular fracture deformity has to be addressed with asymmetrical intra-articular resection or with correctional osteotomy performed prior to or at the time of primary TKA. Careful preoperative planning is must. For fracture nonunion away from the joint and presenting with arthritis of knee, the nonunion must be addressed first followed by total knee replacement arthroplasty. For nonunions within the vicinity of the knee and presenting with knee arthritis

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warranting knee replacement surgery, a modular press-fit stem should be used. It should serve two purposes: first, to bypass the fracture and pass the load distally and second, to achieve optimal mechanical alignment. Tumor replacement type of prosthesis is reserved for patients with significant bone loss with very limited demand on the knee joint,where bone reconstruction is neither possible nor feasible.

SUMMARY AND CONCLUSION Selection of implant should be based on the age of the patient, type of disease, amount of deformity, proper pre-op planning and anticipating intraoperative difficulties. One should stick to a system in which the surgeon is trained. Since PS metal back implants offer modularity and are more forgiving, the consensus is shifting towards the trend of using it more commonly. The ultimate goal is to provide pain-free near-normal ROM with longevity and long-term survival of implant.

REFERENCES   Crowninshield RD, Rosenberg AG, Sporer SM. Changing demographics of patients with total joint replacement. Clin Orthop Relat Res 2006;443:266.   Buvanendran A, Kroin JS, Tuman KJ, et al. Effects of perioperative administration of a selective cyclooxygenase 2 inhibitor on pain management and recovery of function after knee replacement: a randomized controlled trial. JAMA 2003;290:2411.   Rasquinha VJ, Ranawat CS, Cervieri CL, et al. The press-fit condylar modular total knee system with a posterior cruciate-substituting design. A concise follow-up of a previous report. J Bone Joint Surg Am 2006;88:1006–10.   Dixon MC, Brown RR, Parsch D, et al. Modular fixed-bearing total knee arthroplasty with retention of the posterior cruciate ligament. A study of patients followed for a minimum of fifteen years. J Bone Joint Surg Am 2005;87:598–603.   Rodricks DJ, Patil S, Pulido P, et al. Press-fit condylar design total knee arthroplasty. Fourteen to seventeen-year follow-up. J Bone Joint Surg Am 2007;89:89–95.   Gioe TJ, Novak C, Sinner P, et al. Knee arthroplasty in the young patient: survival in a community registry. Clin Orthop Relat Res 2007;(464):83–7.   Clark CR, Rorabeck CH, MacDonald S, et al. Posterior-stabilized and cruciate-retaining total knee replacement: a randomized study. Clin Orthop Relat Res 2001;(392):208–12. 8. Pereira DS, Jaffe FF, Ortiguera C. Posterior cruciate ligament sparing versus posterior cruciate ligament-sacrificing arthroplasty. Functional results using the same prosthesis. J Arthroplasty 1998;13:138–44. 9. Udomkiat P, Meng BJ, Dorr LD, et al. Functional comparison of posterior cruciate retention and substitution knee replacement. Clin Orthop Relat Res 2000;(378):192–201. 10. Jacobs WC, Clement DJ, Wymenga AB. Retention versus removal of the posterior cruciate ligament in total knee replacement: a systematic literature review within the Cochrane framework. Acta Orthop 2005;76:757–68. 11. Tanzer M, Smith K, Burnett S. Posterior-stabilized versus cruciate retaining total knee arthroplasty: balancing the gap. J Arthroplasty 2002;17:813–19.

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12. Maruyama S, Yoshiya S, Matsui N, et al. Functional comparison of posterior cruciate-retaining versus posterior stabilized total knee arthroplasty. J Arthroplasty 2004;19(3):349–53. 13. Itokazu, M, Uemura, S, Aoki, T, et al. Analysis of rising from a chair after total knee arthroplasty. Bull Hosp Jt Dis 1998;57:88–92. 14. Rowe PJ, Myles CM, Walker C, et al. Knee joint kinematics in gait and other functional activities measured using flexible electro goniometry: How much knee motion is sufficient for normal daily life? Gait Posture 2000;12:143–55. 15. Swanik CB, Lephart SM, Rubash HE. Proprioception, kinesthesia, and balance after total knee arthroplasty with cruciate-retaining and posterior stabilized prostheses. J Bone Joint Surg Am 2004;86A:328–34. 16. Morgan H, Battista V, Leopold SS. Constraint in primary total knee arthroplasty. J Am Acad Orthop Surg 2005;13:515–24. 17. Karrholm J, Saari T. Removal or retention—Will we ever know? The posterior cruciate ligament in total knee replacement. Acta Orthop 2005;76:754–56. 18. Pollock DC, Ammeen DJ, Engh GA. Synovial entrapment: a complication of posterior stabilized total knee arthroplasty. J Bone Joint Surg Am 2002;84:2174–78. 19. Sculco TP. The role of constraint in total knee arthroplasty. J Arthroplasty 2006;21(Suppl 1):54–6. 20. Laskin RS. The Insall Award. Total knee replacement with posterior cruciate ligament retention in patients with a fixed varus deformity. Clin Orthop Relat Res 1996;331:29–34. 21. Pagnano MW, Cushner FD, Scott WN. Role of the posterior cruciate ligament in total knee arthroplasty. J Am Acad Orthop Surg 1998;6:176–87. 22. Baldini A, Scuderi GR, Aglietti P, et al. Flexion–extension gap changes during total knee arthroplasty: effect of posterior cruciate ligament and posterior osteophytes removal. J Knee Surg 2004;17:69–72. 23. Insall JN: Adventures in 1998; mobile-bearing knee design: a midlife crises. Orthopedics 1998;21:1021–23. 24. Buechel FF: The LCS story. In: Hamelynk KJ, Stiehl JB, eds. LCS Mobile Bearing Knee Arthroplasty: A 25 Year Worldwide Review. Heidelberg, Germany: Springer, 2002; pp. 19–25. 25. Pappas MJ: Engineering design of the LCS knee replacement. In: Hamelynk KJ, Stiehl JB, eds. LCS Mobile Bearing Knee Arthroplasty: A 25 Year Worldwide Review. Heidelberg, Germany: Springer, 2002; pp. 39–52. 26. Pappas MJ, Makris G, Buechel FF. Wear in prosthetic knee joints. Presented at the 72nd Annual Meeting of the American Academy of Orthopaedic Surgeons, February 23–27, 2005, Washington, DC. 27. Komistek RD, Dennis DA, Mahfouz MF, et al. In vivo polyethylene mobility is maintained in posterior stabilized total knee arthroplasty. Clin Orthop Rel Res 2004;428:207–13. 28. Kim YH, Kook HK, Kim JS. Comparison of fixed-bearing and mobile-bearing total knee arthroplasties. Clin Orthop Rel Res 2001;392:101–15. 29. Pagnano MW, Trousdale RT, Stuart MJ, et al. Rotating platform knees did not improve patellar tracking: a prospective randomized study of 240 primary total knee arthroplasties. Clin Orthop Rel Res 2004;428:221–27. 30. Callaghan JJ. Mobile bearing knee replacement: clinical results—a review of the literature. Clin Orthop Rel Res 2001;392:221–25. 31. Callaghan JJ, O’Rourke MR, Iossi MF, et al. Cemented rotating platform total knee replacement. A concise follow-up, at a minimum of fifteen years of a previous report. J Bone Joint Surg Am 2005;87:1995–98. 32. Sorrells RB, Stiehl JB, Voorhorst PE. Midterm results of mobile bearing total knee arthroplasty in patients younger than 65 years. Clin Orthop Rel Res 2001;390:182–89. 33. Beuchel FF Sr, Buechel FF Jr, Pappas MJ, et al. Twenty year evaluation of the New

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Jersey LCS rotating platform knee replacement. J Knee Surg 2002;15:84–9. 34. Girard J, Amzallag M, Pasquier G, et al. Total knee arthroplasty in valgus knees: predictive preoperative parameters influencing a constrained design selection. Orthopaedics & Traumatology: Surgery & Research 2009;95(4):260–66. 35. Engh GA, Parks NL. The management of bone defects in revision total knee arthroplasty. Instr Course Lect 1997;46:227–36. 36. Engh GA, Ammeen DJ. Classification and preoperative radiographic evaluation: knee. Orthop Clin North Am 1998;29(2):205–17.

Chapter 16

Tips and Pearls: Tourniquets and Position in Total Knee Arthroplasty Kumar Kaushik Dash, Shrinand V. Vaidya, Arvind Arora

TOURNIQUETS Introduction From the days of the screw device of French surgeon Louis Petit in the 18th century (‘tourner’ being the French verb, meaning to turn) and the rubber bandage of Johann von Esmarch, we have come a long way with more refined calibrated and digitalized tourniquets with autoclavable cuffs. Gone are the days when the pressure was increased blindly and there were no guidelines for inflation duration. The advances in modern tourniquet design and calibration have significantly reduced the amount of pressure and the fluctuation from the set value. Improvements in surgical technique and instruments have reduced the duration of surgery in most cases. And finally, better understanding of human physiology under tourniquets has enabled us to formulate significantly better guidelines regarding tourniquet use. Like any medical appliance, tourniquet has certain risks and benefits. Tourniquet provides a bloodless field, and a better cement bone interface.1 The risks include neuro-vascular injury, delay in recovery of muscle power, postoperative swelling and stiffness, and cardiorespiratory complications in patients with poor reserve.1 For beginners in arthroplasty, the authors recommend using tourniquets in order to achieve a good exposure and to be able to identify structures and cement–bone interface easily. The tourniquet should be applied high up in the thigh, well padded and with occlusive dressing at its margin, at a pressure of 250–300 mm Hg, for a duration of 2–2.5 h. Tourniquet use may alter the evaluation of patellar tracking because inflated cuff of tourniquet pushes quadriceps against the femur and impairs its mobility. Hence, at the end of the surgery, the tracking should be evaluated both before and after the release of tourniquet. Certain surgeons use tourni-

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quet only during cementing. Here tourniquet is used only for providing better cement–bone interface and not for exposure of soft tissues. However, in the absence of hypotensive anaesthesia, this approach is difficult for beginners. Local tissue metabolites accumulated during tourniquet use can cause worsening of postoperative pain. Using comparatively lower inflation pressure will decrease its incidence. Using lower pressure is also important in patients with nonelastic calcified atherosclerotic femoral vessels in order to avoid chance of vascular injury, which should be seen on pre-op plain X-ray. Finally, tourniquet use may alter the balance of coagulation mediators. Authors recommend surgeons to be vigilant about this complication and administer appropriate prophylaxis to prevent coagulation-related complications.

Method of Application Hip should be widely abducted and flexed while applying tourniquet to the thigh so that it goes as proximal to the base of the thigh as possible. In patients with arthritic or ankylosed hips, this may be challenging. The tourniquet should be applied with adequate padding between the cuff and the skin. There should be no areas without padding or with uneven folds. The position should be as proximal as possible in order to have more freedom during the surgery. The quadriceps should be pulled distally while applying the tourniquet so as to make retraction and exposure during surgery easier. Occlusive dressing should be used to seal off edges of tourniquet. This prevents liquid seeping under the edge of tourniquet, which might cause chemical burns. Leg is flexed before inflation of the tourniquet to ensure relaxed quadriceps (Figs 16.1–16.4).

Fig. 16.1 Soft cotton roll is applied on proximal thigh with hip being held in wide abduction.

Fig. 16.2 Tourniquet applied snuggly around the thigh, as proximal as possible, ensuring that it is separated from the skin at all sites by the soft padding.

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Fig. 16.3 The tubing-attachment site on the cuff must be positioned laterally and directed cranially.

Fig. 16.4 The cuff is covered and secured by additional bandage rolls.

Dimension and Design With inputs from new research studies, a debate has arisen on shape and size of tourniquets.2 Newer data has implicated pressure gradient at the edge3 of tourniquet as the cause of nerve damage, suggesting that a narrower cuff might lead to lesser risk. This has also sparked interest towards the use of narrow, nonpneumatic silicone ring tourniquets.4,5 On the other hand, some surgeons prefer wider cuff because it stops the flow of blood at a relatively lower inflation pressure.6,7 As far as design or shape of tourniquet is concerned, there are no research studies demonstrating benefit with any particular type over others. There are many commercially available tourniquet systems. Stryker offers SmartPump tourniquet system (both single and dual channel), which has three main features. First, it continuously monitors and controls tourniquet pressure. Second, it communicates with OR software. And finally, it allows pressure data collection that can be printed or added to patient records. Zimmer also has similar products (e.g., A.T.S. 3000) which calculate limb occlusion pressure (LOP) through a sensor in index finger and sets the pressure accordingly. All reputable manufacturers provide color-coded cuff sizes ranging from small to large (8–42 inches). A battery backup of 3–4 h is available for emergency power failure. Modern cuffs are made of latex-free material, and are available in both reusable and disposable format. They have 90° ports for keeping hoses out of surgical site. Zimmer offers contour cuffs for better optimization to conical limb sites. Hemaclear (OHK Medical Devices, Inc.) provides single use all-in-one sterile exsanguinating tourniquet made up of stockinette and silicon ring. The advantages are ease of use, narrow profile, smaller footprint in OR and no risk of contamination.

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Special Situations The authors recommend the readers to develop their tourniquet protocol as per clinical needs. In a short limb, a narrow tourniquet applied high up in the thigh is appropriate. When that cannot be achieved, sterile tourniquets or modern nonpneumatic silicone rings are other option. Disposable sterile exsanguination tourniquet consists of a silicon ring wrapped by a stockinette, which is rolled up from foot all the way up to the upper end of thigh by pulling two straps. At the end of the surgery, the elastic ring at the proximal end is cut with a scalpel to restore blood flow.8 In extremely obese patients with conical thighs, banana-shaped tourniquets are better. In bilateral simultaneous total knee arthroplasty (TKA), the tourniquet cuff on both sides can be connected to the machine which has an in-built mechanism to inflate the right and left cuff separately as and when required. In this situation, the patient is positioned at the center of the table and side supports of both sides are rotated slightly inwards so that both limbs remain vertical in knee and hip-flexed position, and there is no sideway tilting of the limb. This also helps to maintain the proper asepsis during surgery.

Inflation Time and Deflation Interval The authors recommend inflation time to be set approximately at 2 h. The decision regarding further continuation should be taken at the end of 2 h. If based on the intraoperative scenario, the surgeon feels that the anticipated duration is going to be approximately less than 2 h, he/she may choose to continue the inflation. On the other hand, if duration longer than 2 h is anticipated, it is best to deflate the tourniquet for an interval of 10 min, and repeat the deflation at every further 1 h intervals.

Inflation Pressure The authors recommend a tourniquet pressure between 250 and 300 mm Hg for TKA if the anticipated surgery duration is approximately less than 2 h. For situations where surgery may last longer, it is best to first measure the LOP either by a commercial device or by a Doppler stethoscope, and then use an inflation pressure that is 50–75 mm Hg higher than the LOP. Newer tourniquet systems have an LOP sensor, which is applied to second toe and it provides a recommended tourniquet pressure after 30 s. The surgeon has the choice to accept the recommended pressure or change it. The limb girth is also to be considered while deciding on inflation pressure, with higher pressure required for wider girth.

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Special Situations The authors recommend the readers to develop their tourniquet protocol as per clinical needs. In a short limb, a narrow tourniquet applied high up in the thigh is appropriate. When that cannot be achieved, sterile tourniquets or modern nonpneumatic silicone rings are other option. Disposable sterile exsanguination tourniquet consists of a silicon ring wrapped by a stockinette, which is rolled up from foot all the way up to the upper end of thigh by pulling two straps. At the end of the surgery, the elastic ring at the proximal end is cut with a scalpel to restore blood flow.8 In extremely obese patients with conical thighs, banana-shaped tourniquets are better. In bilateral simultaneous total knee arthroplasty (TKA), the tourniquet cuff on both sides can be connected to the machine which has an in-built mechanism to inflate the right and left cuff separately as and when required. In this situation, the patient is positioned at the center of the table and side supports of both sides are rotated slightly inwards so that both limbs remain vertical in knee and hip-flexed position, and there is no sideway tilting of the limb. This also helps to maintain the proper asepsis during surgery.

Inflation Time and Deflation Interval The authors recommend inflation time to be set approximately at 2 h. The decision regarding further continuation should be taken at the end of 2 h. If based on the intraoperative scenario, the surgeon feels that the anticipated duration is going to be approximately less than 2 h, he/she may choose to continue the inflation. On the other hand, if duration longer than 2 h is anticipated, it is best to deflate the tourniquet for an interval of 10 min, and repeat the deflation at every further 1 h intervals.

Inflation Pressure The authors recommend a tourniquet pressure between 250 and 300 mm Hg for TKA if the anticipated surgery duration is approximately less than 2 h. For situations where surgery may last longer, it is best to first measure the LOP either by a commercial device or by a Doppler stethoscope, and then use an inflation pressure that is 50–75 mm Hg higher than the LOP. Newer tourniquet systems have an LOP sensor, which is applied to second toe and it provides a recommended tourniquet pressure after 30 s. The surgeon has the choice to accept the recommended pressure or change it. The limb girth is also to be considered while deciding on inflation pressure, with higher pressure required for wider girth.

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Calibration, Checking and Safety Most modern tourniquet systems allow presetting of inflation pressure and time. A microprocessor autoregulates the flow of compressed air in order to self-compensate and constantly maintain the inflation pressure. Safety mechanisms include a system to prevent inflation to very high pressures (e.g., >600 mm Hg), and a failsafe method that maintains cuff pressure when a leak occurs or gas supply is interrupted. Failure of inflation and abnormal high pressure can occur if the valves and pressure gauges are faulty. Routine calibration checks (preferably daily) and monthly performance assurance tests should be done on all components of a tourniquet system to ensure safe and effective functioning.

Complications Postoperative local thigh pain is a minor but the most common complaint, which usually settles after 2–3 days postoperative. Two factors are involved in pathogenesis of tourniquet-related complications. Ischaemia causes metabolic complications, whereas the mechanical compression causes nerve and muscle damage. Nervous tissue is less vulnerable to tourniquet injury compared to skeletal muscle, but the impairment is more long lasting compared to similar injury in skeletal muscle. The incidence of peroneal and tibial nerve palsy is more if inflation time is greater than 2.5 h. Metabolic parameters affected by tourniquet use include lactic acid, reactive oxygen metabolites, pH and glucose. After routine inflation durations, most of the parameters return to normalcy within 2–3 h. While there is a higher chance of electromyography (EMG) changes and decreased strength in quadriceps after 4 and 12 weeks from surgery, there is no difference between tourniquet and tourniquet-less groups at 1-year follow-up.2

Future of Tourniquets Two main avenues of research are available in order to improve the tourniquet system. First is ‘better design’. For example, curved tourniquets better fit the conical limbs and achieve occlusion at a lower inflation pressure. Second is ‘smart tourniquets’. These incorporate microelectronics to detect arterial flow and auto-adjust the inflation pressure. The other areas of active research lie in better understanding of tissue physiology. Role of n-acetylcysteine and similar compounds for preconditioning of tissues to prevent ischaemia and reperfusion injury (IRI) is being evaluated.

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POSITION The operating table should be parallel to the ground with patient comfortably supine. The patient should be brought to the edge of the bed on the operating side. Safety restraining strap should be in place. The side support should be near the level of tourniquet. The vertical height of the side support should be slightly higher in order to ensure that the knee stays stable during flexion (Figs 16.5 and 16.6). The horizontal foot sup-

Fig. 16.5 The position of side-clamp is adjusted with knee in flexion. Notice that the patient is at the edge of the table.

Fig. 16.6 The foot support is positioned ensuring a 90° flexion at the knee joint.

port should be fixed in a position that keeps the knee in 90° of flexion. This offers steady limb position in most of the maneuvers during total knee replacement (TKR), e.g., full knee flexion (heel to buttock), which delivers tibial upper surface, or thigh up for femoral procedures.

REFERENCES 1. Wakankar HM, Nicholl JE, Koka R, D’Arcy JC. The tourniquet in total knee arthroplasty. A prospective, randomised study. J Bone Joint Surg Br 1999;81(1):30–3. PubMed PMID: 10067997. 2. Fitzgibbons PG, Digiovanni C, Hares S, Akelman E. Safe tourniquet use: a review of the evidence. J Am Acad Orthop Surg 2012;20(5):310–19. doi: 10.5435/JAAOS-20-05310. Review. PubMed PMID: 22553103. 3. Ochoa J, Fowler TJ, Gilliatt RW. Anatomical changes in peripheral nerves compressed by a pneumatic tourniquet. J Anat 1972;113(pt 3):433–55. 4. Gavriely N. Surgical tourniquets in orthopaedics. J Bone Joint Surg Am 2010;92(5): 1318–23. 5. Drosos GI, Stavropoulos NI, Kazakos K, Tripsianis G, Ververidis A, Verettas DA. Silicone ring versus pneumatic cuff tourniquet: A comparative quantitative study in healthy individuals. Arch Orthop Trauma Surg 2011;131(4):447–54. 6. Crenshaw AG, Hargens AR, Gershuni DH, Rydevik B. Wide tourniquet cuffs more effective at lower inflation pressures. Acta Orthop Scand 1988;59(4):447–51.

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POSITION The operating table should be parallel to the ground with patient comfortably supine. The patient should be brought to the edge of the bed on the operating side. Safety restraining strap should be in place. The side support should be near the level of tourniquet. The vertical height of the side support should be slightly higher in order to ensure that the knee stays stable during flexion (Figs 16.5 and 16.6). The horizontal foot sup-

Fig. 16.5 The position of side-clamp is adjusted with knee in flexion. Notice that the patient is at the edge of the table.

Fig. 16.6 The foot support is positioned ensuring a 90° flexion at the knee joint.

port should be fixed in a position that keeps the knee in 90° of flexion. This offers steady limb position in most of the maneuvers during total knee replacement (TKR), e.g., full knee flexion (heel to buttock), which delivers tibial upper surface, or thigh up for femoral procedures.

REFERENCES 1. Wakankar HM, Nicholl JE, Koka R, D’Arcy JC. The tourniquet in total knee arthroplasty. A prospective, randomised study. J Bone Joint Surg Br 1999;81(1):30–3. PubMed PMID: 10067997. 2. Fitzgibbons PG, Digiovanni C, Hares S, Akelman E. Safe tourniquet use: a review of the evidence. J Am Acad Orthop Surg 2012;20(5):310–19. doi: 10.5435/JAAOS-20-05310. Review. PubMed PMID: 22553103. 3. Ochoa J, Fowler TJ, Gilliatt RW. Anatomical changes in peripheral nerves compressed by a pneumatic tourniquet. J Anat 1972;113(pt 3):433–55. 4. Gavriely N. Surgical tourniquets in orthopaedics. J Bone Joint Surg Am 2010;92(5): 1318–23. 5. Drosos GI, Stavropoulos NI, Kazakos K, Tripsianis G, Ververidis A, Verettas DA. Silicone ring versus pneumatic cuff tourniquet: A comparative quantitative study in healthy individuals. Arch Orthop Trauma Surg 2011;131(4):447–54. 6. Crenshaw AG, Hargens AR, Gershuni DH, Rydevik B. Wide tourniquet cuffs more effective at lower inflation pressures. Acta Orthop Scand 1988;59(4):447–51.

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7. Reilly CW, McEwen JA, Leveille L, Perdios A, Mulpuri K. Minimizing tourniquet pressure in pediatric anterior cruciate ligament reconstructive surgery: a blinded, prospective randomized controlled trial. J Pediatr Orthop 2009;29(3):275–80. 8. Demirkale I, Tecimel O, Sesen H, Kilicarslan K, Altay M, Dogan M. Nondrainage decreases blood transfusion need and infection rate in bilateral total knee arthroplasty. J Arthroplasty 2014;29(5):993–7. doi: 10.1016/j.arth.2013.10.022. Epub 2013 Oct 29. PubMed PMID: 24275263.

Conflict of Interest: The names of commercial parties mentioned in this chapter are purely for educational purpose; and authors do not recommend or condone any particular manufacturer.

Chapter 17

Tips and Pearls: Exposure and Retractors in Total Knee Arthroplasty Shrinand V. Vaidya, Kumar Kaushik Dash

EXPOSURE Basics of Knee Exposure There are many ways to expose the knee. There are three layers, viz., skin incision, capsular incision (arthrotomy) and quadriceps mechanism incision. Essentially, all the approaches described in the literature revolve around combination of these (see Figs 17.1 and 17.2). Approaches to Knee

Lateral Arthrotomy Approach*

Non-MIS (Medial Parapatellar Von Langenbeck/Modified Langenbeck)

MIS

Subvastus

Medial Arthrotomy Approach

Trivector

Midvastus

*Some surgeons prefer it in valgus knees. Fig. 17.1 Classification of knee approaches.

Quad Sparing

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Von Langenbeck 1879 Non-MIS

Skin

Standard

Capsule

Quadriceps

Medial

1/3rd-2/3rd

Variations

In presence of scars

Fig. 17.2 Skin, capsule and quadriceps breakdown of Von Langenbeck incision.

Medial parapatellar approach is the most common approach, originally described by Von Langenbeck in 1879. It has demonstrated excellent track record and has proven its reliability, safety and reproducibility over the last four decades. Its advantages are excellent visualization, extensile, easy release of medial structures in severe varus deformity, very reliable and reproducible. The disadvantage is violation of extensor mechanism. Skin incision, when restricted to 5 inches or less1 is called MIS or minimally invasive surgery. Depending upon the way the suprapatellar part of quadriceps mechanism is handled, the MIS approaches are divided into subvastus, midvastus, trivector and quadriceps sparing. Incidence of wound complications in some series is 22%. It occurs more in knees because of precarious blood supply. Vascular anatomy of knee involves terminal branches of peripheral anastomosis between superior lateral genicular artery (SLGA), inferior lateral genicular artery (ILGA), superior medial genicular artery (SMGA) and inferomedial genicular artery (IMGA). Saphenous branch of descending geniculate and lateral geniculate are the main venous drainage of the area. No underlying muscle or intermuscular septae makes this area highly susceptible to wound complications. Because the anastomoses are superficial to fascia, subfascial dissection is required to preserve blood supply.

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Risk factors for wound complication are:2–4 1. Decreased fibroblast proliferation 2. Reduced collagenase clearance and reduced tensile strength 3. Rheumatoid arthritis 4. Smoking 5. Diabetes 6. Obesity 7. Vigorous retraction 8. Malnutrition 9. Albumin less than 3.5 g/dL 10. Total lymphocyte count (TLC) less than 1500/mm3 11. Chemotherapy 12. Burned irradiated skin 13. Previous surgical incision We will describe the Langenbeck approach with standard anteromedial arthrotomy, because it is largely followed world over by most of the arthroplasty surgeons.

Surgical Technique Knee is prepped and draped as shown in the diagram (Fig. 17.3), and important anatomic surface landmarks are marked. The three important points are the tibial tuberosity, patella and its centre. Usually, this is very easily identifiable, but in an obese patient, it may be difficult to find the exact location of the tibial tubercle. Skin incision can be taken erroneously as per guided by the drape by many young surgeons, and this will lead to totally off-center incision, only to locate tibial tubercle somewhere else, resulting into messy retractions, and badly extended skin incision, to visualize inner landmarks. While choosing the single anterior incision, midline incision causes least disruption of the blood supply.5 When

Fig. 17.3 Knee prepped and draped with markings of landmarks and skin incisions. Note previous parallel scars 7 and 8 cm away on either side.

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there are previous surgeries done, it is best to utilize the previous incisions.6 It is safe to ignore short peripatellar longitudinal incisions of arthroplasty.7 Transverse incisions may generally be crossed at right angles with impunity.8 If more than one longitudinal incisions exist, choose the most lateral incision. Large laterally based skin flaps should be avoided.9 Hence, if scar is far from midline, consider a new midline incision. For intersecting incisions, always try to maximize the angle of intersection (should be more than 60°). Acute or suddenly changing angles should be avoided. The width of skin bridge between incisions should be adequate (8 cm – Mont, 5 cm – Ranawat, 2.5 cm – Rand).10–12 Excessive tension in incision should be avoided and in this regard, longer skin incisions are better than shorter. Retraction of skin should be gentle to protect fasciocutaneous perforators. Large flaps should be avoided. Mark the center of tibial tuberosity and center of patella and join them. Proximally, the incision, as originally described, goes 7 cm proximal to upper pole of patella. However, many now prefer to keep it shorter, and extend as per requirement. The distal end of the skin incision is extended distally, as per the convenience of surgeon than the fixed predecided length. Scuderi has clearly talked about the V sign.13 If you feel that both ends of the skin are getting so much taut that there is an obtuse angle (U Sign) (see Figs 17.4 and 17.5), the tension is high enough to damage the blood flow to edge of the skin, increasing the potential for problems of wound healing. Surgeon should be at liberty to increase the size of the skin incision depending on the patient and pathology, so as to facilitate better introduction

Fig. 17.4 Lower end of the incision getting stretched after putting retractors – ‘U’ sign.

Fig. 17.5 After extending lower end of incision till ‘V’ appears as marked.

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of the jigs and saw. Above all, he is able to close the wound that is going to heal with primary intension without any problems. After the incision, without much undermining, try to clearly define the following points: the fleshy belly of patellar tendon, the medial margin of patella and the central tendon (note the fibers of vastus medialis coming from all angles and getting inserted on the central tendon, i.e., superior, superomedial and medial). The bulk and direction and insertion angle of vastus medialis can differ from patient to patient. Suffices to say that the whitish central tendon should be clearly defined. Marking should be done before incising quads to help with closure (prevents dogears). Most of the times, there is extension lag because of the failure to approximate the margins of quads as per the preoperative anatomic status. Arthrotomy should be performed, around medial edge of patella, leaving about 5 mm of reticular attachment, to the medial border, with skin knife at 30° angle to coronal plane, with knee joint flexed at 60°. Incision is carefully extended up, between medial one-third and lateral two-thirds of the central tendon of quadriceps. We have stopped incising the central tendon since last decade or so, and instead spared the central tendon, by going midvastus, keeping 5 mm of fleshy belly of vastus intact on medial side. The incision may be extended up to about 5–7 cm proximal to the upper pole of patella. Sparing of the quadriceps, central tendon has definitely resulted in early recovery without extension lag. The proximal extent is kept about 7 cm above the superior pole of patella, which again may differ from surgeon to surgeon. Distally, after curving around, patella may go down till periosteum of tibia, making sure that there is always 3–4 mm of cuff of retinacular soft tissue adjoining the patellar tendon. Authors’ Choice We have shortened skin incision, much less than Langenbeck, and is usually 5–6 inches (see Fig. 17.6). Fig. 17.6 Figure showing authors’ choice of skin incision with length of 5 inches.

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The length is kept adequate so that the ‘U’ sign at the ends of the incision is avoided. We also liberally elongate the incision, as per the demand in the obese patients. After the arthrotomy is complete, keep on going medially in the subcapsular plane of the tibia while asking the assistant to externally rotate the tibia, and proceed with a cutting cautery at the edge along subperiosteal plane. Introduce the tip of medial collateral ligament (MCL) retractor (see Figs 17.7 and 17.8) subperiosteally and underneath the MCL in the plane of semimembranosus bursa. Hold and pull the anterior horn of the medial meniscus with a menisFig. 17.7 Specially designed and curved cal holding forceps (see Fig. 17.9), to medial collateral ligament retractor. detach it carefully from the meniscotibial ligament, on its periphery all around, with utmost care, not to let the cutting err on the outer side, i.e., the side of MCL. Many a times, it may not be possible to remove medial meniscus completely, as it may be ejected in the posteromedial corner of the tibia, as a part of arthritic process. Complete the ‘Ransall maneuver’ (named after Dr Ranawat and Dr Insall). Take a curved, three-eighths-inch osteotome and pass it around the medial corner of the tibia using mallet to tap it back until it drops into the semimembranosus bursa. The interval is at the joint line between the tibial bone and the deep MCL. Osteophytectomy is done starting from 6 O’clock position, all around from medial side, and then posteromedially, both on the tibial as well Fig. 17.8 Medial collateral retractor, introas femoral side, in a typical varus duced subperiosteally along semimebraarthritis. The retractor can be repo- nosus bursa between medial collateral sitioned along the medial edge of ligament (MCL) and medial edge of tibia.

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tibia, underneath the superficial MCL, which by now is completely decompressed from the tenting effect of the osteophytes. This step safely protects it from saw blade and facilitates cementing. The shape of the retractor, which author uses, is kept such, so as to have assistant’s hands holding this retractor, away from the surgical field, almost at the back of the knee, in coronal plane. Next anterior cruciate ligament is removed (if intact), and the tibia is rotated externally and dislocated forward in relation to femoral condyles. A retractor with the angle around 60° (see Figs 17.10 and 17.11 ) comes very handy. Because the angle, when lessened from 90° to 60°, offers better offset to jack tibia anteriorly, even in the obese patients. The tip of the posterior retractor is inserted at the back of the tibial margin, leveraging against the intercondylar area of the femur, to get full view of the tibia from the top. Using a no. 15 blade, a stab wound is made just outside the lateral menis-

Fig. 17.9 Anterior horn of the medial meniscus detached and being held with forceps.

Fig. 17.10 Lateral retractor with 60° angle.

Fig. 17.11 View from the top showing medial, lateral, posterior retractors with 360° exposure of tibia.

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cus at the mid-coronal plane of the tibia. A modified Hohmann retractor (see Fig. 17.12) specially modified is used for this purpose. With shortened tooth and narrower vertical arm, we feel it lessens the postoperative pain in this area, and thus, is less traumatic. After identifying the lateral inferior geniculcar artery, which is located on the outer rim of the meniscus at about mid coronal plane, it is coagulated. Patellar articular surface is inspected. If there are too many osteophytes, spontaneous decision is taken to nibble the osteophytes, but in no case should the patella be everted, as it used to be before. There is evidence that tells us that noneverted patella is associated with less pain, less extension lag and early rehabilitation.14 In case there is a difficulty to retract patella without everting, a narrow fold of synovium, ‘patello femoral ligament’ (see Fig. 17.13) is released with a cautery. Effort should be made to keep the lateral retractor vertical, and not to try and over stretch it, as this may put pressure on the patellar tendon insertion. If there is a stretch on patellar tendon insertion, very commonly in osteoporotic patients, it is worthwhile transfixing it with a pin. Next step is to remove the lateral meniscus, starting from the anterior tip, which is pulled centrally, while cautery goes all around the lateral meniscotibial ligament (see Fig. 17.12). Caution on the lateral side is to avoid any injury to the popliteal tendon, which may be hypertrophied and can be cut by mistake. Now, with these three retractors in place (Fig. 17.11 ), we have 360° exposure of the tibia, as well as femur. Surgeon may proceed with either femoral or tibial cut first, as per the individual choice. In case, femoral cut is done

Fig. 17.12 Lateral retractor in place after the stab in midcoronal plane and lateral meniscus detached.

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Fig. 17.13 Lateral patellar retractor in place and showing patellofemoral ligament at cautery tip.

first, especially with minimally invasive surgery (MIS) instruments, patella is best protected and retracted out with the retractor shown in Fig. 17.13. MIS approaches, namely, subvastus, midvastus, trivector and quadriceps sparing (see Fig. 17.14), essentially were conceptualized with the premise that it will reduce the postoperative pain and bleeding and will allow the patient to ambulate faster, and result in early discharge.15,16 The key element is the suprapatellar extension of the arthrotomy and the direction surgeon may have to take to elevate and rotate the quadriceps bulk, from medial to lateral side. Though conceptually appealing, there

Fig. 17.14 The different capsular incision extending into quadriceps mechanism is shown. From left to right: Langenbeck, subvastus, midvastus, quad-sparing.

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have been significant disadvantages. The torque generated during retraction in the quadriceps mechanism may compel jigs to rotate and cause malalignment. The space constraint may also damage the nerve fibres supplying the quadriceps mechanism. These reservations together with lesser blood loss because of tranexamic acid and injecting locally for pain management have lessened the initial enthusiasm for MIS.17 Since this book is recommended for beginners, we advise the readers to go through the recommended reading at the end of the chapter, as a guidance to expose the knee joint through smaller incisions. The set of retractors that the author uses has been shown in Figure 17.15.

Fig. 17.15 Set of retractors, which the authors use.

REFERENCES 1. Lin TC, Wang HK, Chen JW, Chiu CM, Chou HL, Chang CH. Minimally invasive knee arthroplasty with the subvastus approach allows rapid rehabilitation: a prospective, biomechanical and observational study. J Phys Ther Sci 2013;25(5):557–62. doi: 10.1589/jpts.25.557. Epub 2013 Jun 29. PubMed PMID:24259801; PubMed Central PMCID: PMC3804974. 2. Carroll K, Dowsey M, Choong P, Peel T. Risk factors for superficial wound complications in hip and knee arthroplasty. Clin Microbiol Infect 2014;20(2):130–35. doi: 10.1111/1469-0691.12209. Epub 2013 Apr 10. PubMed PMID:23573834. 3. Vince KG, Abdeen A. Wound problems in total knee arthroplasty. Clin Orthop Relat Res 2006;452:88–90. Review. PubMed PMID: 17079990. 4. Galat DD, McGovern SC, Larson DR, Harrington JR, Hanssen AD, Clarke HD. Surgical treatment of early wound complications following primary total knee arthroplasty. J Bone Joint Surg Am 2009;91(1):48–54. doi:10.2106/JBJS.G.01371. PubMed PMID: 19122078. 5. Johnson DP, Houghton TA, Radford P. Anterior midline or medial parapatellar incision for arthroplasty of the knee. A comparative study. J Bone Joint Surg Br 1986;68(5):812– 14. PubMed PMID: 3782252. 6. Ayers DC, Dennis DA, Johanson NA, Pellegrini VD. Instructional course lectures: The American Academy of Orthopaedic Surgeons. Common complications of total knee

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arthroplasty. J Bone Joint Surg Am 1997;79:278–311. 7. Klein NE, Cox CV. Wound problems in total knee arthroplasty. In: Fu FH, Harner CD, Vince K, eds. Knee Surgery. Baltimore: Williams & Wilkins, 1994; pp.1539–52. 8. Windsor RE, Insall JN, Vince KG. Technical considerations of total knee arthroplasty after proximal tibial osteotomy. J Bone Joint Surg Am 1988;70(4):547–55. PubMed PMID: 3356722. 9. Clarke HD, Scuderi GR. Revision total knee arthroplasty: planning, management, controversies, and surgical approaches. Instr Course Lect 2001;50:359–65. Review. PubMed PMID: 11372334. 10. Sanna M, Sanna C, Caputo F, Piu G, Salvi M. Surgical approaches in total knee arthroplasty. Joints 2013;1(2):34–44. ISSN: 2282-4234. 11. Garbedian S, Sternheim A, Backstein D. Wound healing problems in total knee arthroplasty. Orthopedics 2011;34(9):e516–18. doi:10.3928/014774. 12. Vince KG, Abdeen A. Wound problems in total knee arthroplasty. Clin Orthop Relat Res 2006;452:88–90. 13. Scuderi GR. Patient-based MIS TKA: for everything there is a season. Orthopedics 2008;31(9):923–24. 14. Majima T, Nishiike O, Sawaguchi N, Susuda K, Minami A. Patella eversion reduces early knee range of motion and muscle torque recovery after total knee arthroplasty: comparison between minimally invasive total knee arthroplasty and conventional total knee arthroplasty. Arthritis 2011;2011:854651. doi:10.1155/2011/854651. Epub 2010 Dec 29. PubMed PMID: 22046526; PubMed Central PMCID: PMC3195321. 15. Li C, Zeng Y, Shen B, Kang P, Yang J, Zhou Z, Pei F. A meta-analysis of minimally invasive and conventional medial parapatellar approaches for primary total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2014. [Epub ahead of print] PubMed PMID: 24448689. 16. Tasker A, Hassaballa M, Murray J, Lancaster S, Artz N, Harries W, Porteous A. Minimally invasive total knee arthroplasty; a pragmatic randomised controlled trial reporting outcomes up to 2 year follow up. Knee. 2014;21(1):189–93. doi: 10.1016/j. knee.2013.07.010. Epub 2013 Aug 2. PubMed PMID: 23972565. 17. Unnanuntana A, Pornrattanamaneewong C, Mow CS. Minimally invasive and standard total knee arthroplasty result in similar clinical outcomes at a minimum of five-year follow-up. J Med Assoc Thai 2012;95(Suppl 9):S29–35. PubMed PMID: 23326979.

Chapter 18

Tips and Pearls: Saw Technique in Total Knee Arthroplasty Shrinand V. Vaidya, Kumar Kaushik Dash Saw technique is the key element of total knee replacement surgery. Wrong or inefficient saw cut can lead to erroneous seating of any one or all the three components, which in turn can lead to error in the knee joint alignment and/or balancing. The surgeon who masters the saw technique (both in understanding the way it cuts and also in learning how to protect ligaments and neurovascular structures) can optimize the surgical time of the knee replacement surgery. This has a major effect on his result, as the time required to finish off a surgery has direct bearing on the surgical site infection. It is important to understand the concept of effective sharpness and cutting efficiency.1 The saw speed, which is controlled by the grip button, and oscillatory movements of the teeth require continues monitoring. The surgeon should decide the forward progress based on the tactile feedback that he gets on his grip during the passage of the cut in bone. There is very little scientific literature on the saw technique apart from the information provided by manufacturers. But it is important to understand that saw technique itself is a different kind of bio-skill. A newcomer requires some guidance as to how to handle the saw, which blades to use for a particular cut and how to be efficient but safe, as the saw can endanger major ligaments, if handled carelessly. Hence, it is very important that beginners master the saw techniques quickly. A dedicated bio-skill workshop, with ample practice bones can be a great facilitator, before operating independently. Essentially there are two types of saw handles – pneumatic and power or battery saws. Pneumatic saws were first to arrive in the marketplace and supposed to be safer, as they ideally should not damage the soft tissue. However, because of cumbersome handling, with long pneumatic hoses causing hindrance for surgeon’s efficient hand movements, batteryoperated saws have largely been preferred over the pneumatic by most of the users world over. There are dos and don’ts for the maintenance of disposable batteries and charger units, and autoclaving and sterile

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techniques, which can best be understood by talking to the company’s product specialist. From the surgeon’s perspective, it is important to start surgery only after knowing that at least four to six batteries are fully charged before starting the surgery. There are certain saw blade numbers that are very popular (e.g., Stryker Blade No. 2108-102, 2108-118, 2108-109, 2108-150, 2108-155, 2108-185). These denote different types of teeth configuration, thickness of the blade, and length and width of the blade. Stryker Corporation, Kalamazoo, MI, USA offers three types of sagittal blades, viz., System 6, Dual Cuts and 2108. Three patented tool mounts are available – System 6, System 5/4 and System 2000.

BLADE SHAPE The shape of the cutting edge has a huge influence on the stability and controllability of the blade. Kicking or grabbing causes loss of accuracy in the cut from sudden, unpredictable movements of the saw and causes increased surgeon fatigue because of the greater tension that the surgeon must maintain in his hands and arms in the anticipation of receiving this kicking or grabbing motion. A blade that is kicking back is neither safe nor accurate (see Fig. 18.1). It is easy to cut chamfer/notch cuts with the narrow blade, as narrower blades work effectively and sharply. Longer blades work less effectively at their tips as the work arm length increases. However, with a powerful battery, they can make a very meaningful and efficient cut in one stroke. Depending on the kind of jigs available (slit jigs with saw capture is less likely to give rise to an error than platform jig), one can cut the anterior and posterior chamfer cuts with narrow saw blade. The recommendations by the manufacturers (Stryker Inc., USA) for various knee systems, which match their latest saw system, are as per the chart (see Fig. 18.2). Another important tip is for deciding the type of saw blade to be used for a particular cut. It is much like a golfer choosing an appropriate club, suitable for a particular shot! Some surgeons are very fond of reciprocating saw blade, especially for cutting the intercondylar notch (and the author is part of this group) which is the key-cut, prone to an error in the PS knee design. If the cut goes in extension or flexion, one can land up with a massive error in component positioning and then balancing. It is important to watch the progress of the saw from the profile and front to catch errors, before any wrong cut is made. Nonoperating hand can help to monitor the

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progress and guide the direction of the saw blade. Warning! The surgeon’s skill in saw technique is tested to the maximum when the bone is either marble hard or very soft and osteoporotic. Many a times, we experience marble hard bone on the medial side in case of varus deformity, which is the load bearing side. This tough resistance by the bone will not allow the saw to progress smoothly and the saw tip may move away in an altogether different direction than the intended one – often referred to as ‘skiving.’

Blade Shape

Convex

Straight

Concave

Least Stable

Intermediate. Better than Convex

Most Stable

All teeth engage bone at the same time. This causes the tendency for the blade to kick out during the cut.

Progressive engagement of cutting teeth. Reduces cutting force and kick out. Allows user better control of saw. Improved control allows faster cutting

Concave shape creates a cutting face that keeps blade centred at all times and allows the smoothest cut possible. Fewer teeth engaged means blade does not grab or kick.

Fig. 18.1 Different configuration of saw tips (Courtesy: Stryker Inc., USA).

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Capture

System 6 Recommendation

Dual Cut Recommendation

Precision

Thickness mm (inch) AESCULAP TKR SYSTEMS Columbus

1.27 (.050)

6113-127-090

6118-127-090

4125-127-090

4118-127-090

Yes

1.37 (.054)

6125-137-090

6118-137-090

4125-137-090

4118-137-090

Yes

Repicci

1.37 (.054)

6125-137-090

6118-137-090

4125-137-090

4118-137-090

Yes

Vanguard

1.37 (.054)

Performance

1.07 (.042)

6113-107-090

4111-107-090

No

1.47 (.058)

6125-147-090

4125-147-090

4118-147-090

Yes

Nuffield

1.27 (.050)

6113-127-090

4125-127-090

4118-127-090

Yes

Rotaglide

1.27 (.050)

4118-119-090

No

BIOMET TKR SYSTEMS AGC Maxim Asent Vanguard Finn UNI SYSTEMS

BIOPRO TKR SYSTEMS Townley CORIN TKR SYSTEMS 6118-127-090

DEPUY TKR SYSTEMS P.F.C. Sigma

1.19 (.047)

6118-119-090

4111-119-090

LCS Complete

1.47 (.058)

6125-147-090

4125-147-090

Yes

UNI SYSTEMS Preservation

1.27 (.050)

6113-127-090

6118-127-090

4125-127-090

4118-127-090

Yes

AMK, RHK, S-ROM

0.89 (.035)

6113-089-090

6118-089-090

4111-089-090

4118-089-090

No

S-ROM

0.89 (.035)

ENCORE (DJO) TKR SYSTEMS Foundation

1.0 (.039)

3D Knee

1.0 (.039)

6125-097-090

6118-097-090

4125-127-090

4118-127-090

No

UNI SYSTEMS Mitus

CONTAINS NO CAPTURES

Fig. 18.2 Manufacture-wise compatibility of saw blades (Courtesy: Stryker Inc., USA).

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A

B

Fig. 18.3 (A) Skiving at posterior edge of the femoral condyle. (B) Skiving corrected by engaging saw blade.

Skiving can cause a variety of problems; commonest amongst them can be: 1. Distal femoral cut: the component can malposition in extension because of the hard resistance offered by the edge of the posterior condyle of the femur (see Fig. 18.3A and B). 2. Residual tibial varus due to hard bone ridge left on the lateral tibial margin, when saw skives up during tibial cut as it reaches lateral border (see Fig. 18.4A and B). Warning! The skiving is mainly due to three reasons: 1. The hardness of the bone, which offers significant resistance. 2. The mismatch between the diameter of bone to be cut, and the width of saw blade tip. 3. The poor saw power, due to an exhausted battery.

A

B

Fig. 18.4 (A) Skiving of the saw blade at lateral tibial edge. (B) Skiving corrected by reengaging the blade.

Tips and Pearls: Saw Technique in Total Knee Arthroplasty

Fig.18.5 Potato-grating effect comparable to progress of saw blade.

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Fig. 18.6 Efficient saw progress by approaching ‘acute angle.’

The trick to mitigate this problem is called ‘forward-backward technique.’ When facing abnormal resistance in the bone, it is important to remember that one of the angles of the saw blade, instead of the whole of the front toothed edge of the blade, should be introduced by rotating the saw handle – something which is like a ‘potato-grating effect’ described by Krackow1 (see Fig. 18.5). When a potato is peeled, the cook does not shove the sharp edge of the peeler directly on the previous cut. Instead, to continue peeling smoothly, the sharp edge of the peeler is brought at an acute angle (half the breadth of the peeler on the cut surface and the rest half on the uncut) to the raw surface, which minimizes the force required to proceed effortlessly. This is done subconsciously as a matter of practice and is worth implementing in the saw technique.The essence of this idea is to approach the area to be cut at an acute angle, edge between already cut and newer cut by rotating the potato (Fig. 18.6) to decrease the resistance. So it is important to not frustrate your effort by banging saw blade’s blunt end against the part when there is no progress. Instead, retract backwards and reset the blade on the jig. Go on one side at an angle so that one of

Fig. 18.7 Rotating saw handle laterally and medially so that angle of the tip of the blade causes efficient progress.

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the angles of the edge, and not the full breadth of the teeth, is introduced. Go to the opposite direction, in a Y-fashion and finally the center mound (see Fig. 18.7A and B). This little trick makes the progress surprisingly smoother and cut as desired. Also, steady stream of saline at the cut site lubricates and minimizes the heat-related necrosis of bone. It also increases the life of the saw by reducing the back thrust on the gears of saw. Progress of a saw blade is not done by brute force in a linear fashion. Instead, go on either side alternately by rotating the saw grip in coronal plane, roughly by about 45°, and making repeated Y cuts, almost like a Christmas tree.This guarantees headway even in the most stubborn bones. Finally, whenever the saw blade is approaching a blind alley, it is important to protect the area with either readymade metal protectors or simply a broad osteotome or a retractor. This is particularly important in osteoporotic patients because an unwarranted cut in either of the condyles due to unchecked progress of the blade can lead to condylar fractures. In general, once a surgeon realizes that bone is too soft and osteoporotic, saw power should be toned down by releasing the power grip button appropriately. Using the saw on patella demands special care, and it is strongly recommended that the beginners use patella holders provided by the manufacturers, as control is better and the patella is stable. Free hand technique with the help of towel clips needs a lot of practice and can be erroneous if one has to recreate the patellar thickness. Efficient saw technique can significantly reduce the operating time and can easily differentiate between a master and a commoner! For further reading, the author recommends young surgeons to refer to other related articles.2–6

REFERENCES 1. Krackow KA. The technique of total knee arthroplasty. Mosby 1990:220–37. 2. Hofmann AA, Bachus KN, Wyatt RW. Effect of the tibial cut on subsidence following total knee arthroplasty. Clin Orthop Relat Res 1991;(269):63–9. PubMed PMID: 1864058. 3. Bäthis H, Perlick L, Tingart M, Perlick C, Lüring C, Grifka J. Intraoperative cutting errors in total knee arthroplasty. Arch Orthop Trauma Surg 2005;125(1):16–20. Epub 2004 Nov 9. PubMed PMID: 15538589. 4. Plaskos C, Hodgson AJ, Inkpen K, McGraw RW. Bone cutting errors in total knee arthroplasty. J Arthroplasty 2002;17(6):698–705. PubMed PMID: 12216022. 5. Tsukeoka T, Tsuneizumi Y, Lee TH. The effect of a sagittal cutting error of the distal femur on the flexion-extension gap difference in total knee arthroplasty. J Arthroplasty. 2013;28(7):1099–102. doi: 10.1016/j.arth.2012.12.017. Epub 2013 Mar 20. PubMed PMID: 23523491.

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6. Tsukeoka T, Tsuneizumi Y, Lee TH. The effect of the posterior slope of the tibial plateau osteotomy with a rotational error on tibial component malalignment in total knee replacement. Bone Joint J. 2013;95-B(9):1201–03. doi:10.1302/0301-620X.95B9.31775. PubMed PMID: 23997132.

Conflict of Interest: The names of commercial parties mentioned in this chapter are purely for educational purpose; and authors do not recommend or condone any particular manufacturer.

Chapter 19

Principles: Alignment and Balancing Hemant Wakankar

INTRODUCTION Total knee arthroplasty (TKA) is one of the most successful surgical procedures with over 90% survival rate at 10 to 15 years.1–4 However, the incidence of early failure following TKA is as high as 4% to 20%.5,6 Excluding infection, malalignment and instability are the two most important causes of an early revision. It is therefore important to address the issues related to achieving the alignment and balance during the surgical procedure of TKA.

BASIC PRINCIPLES OF ALIGNMENT The mechanical axis of lower limb is the line joining the center of the hip joint to the center of the ankle joint and normally passes through the center of the knee joint (Fig. 19.1). In a well-aligned normal knee, both medial and lateral knee compartments do get loaded almost equally. Biomechanically, such a knee has equal distribution of forces over both knee compartments and as a result is less likely to wear due to mechanical imbalance. In patients who have a varus deformity, medial compartment of the knee gets loaded excessively and is a major contributing factor, leading to medial compartmental arthrosis. Similar situation exists in a valgus knee where lateral compartment gets loaded excessively and develops lateral compartment arthrosis. The aim of TKA is to reproduce the mechanical axis that passes through the central third of the knee. Many studies assessing the alignment following TKA have shown the overall distribution to be the bell curve. The outlier beyond the 3° of neutral axis have shown higher rate of revisions due to wear. Normal tibia has 3° of physiological varus and the mechanical axis is at 3° to the vertical axis (Fig. 19.1). Some surgical techniques describe recreating this varus deformity during surgery; however, this runs the risk of excessive load on the medial compartment, leading to an early failure. It is,

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Fig. 19.1 Mechanical axis passes through the center of the knee.

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therefore, not attempted to reproduce the anatomical tibial resection but the tibial resection is done perpendicular to its long axis.

Surgical Considerations of Mechanical Axis The mechanical axis can be considered to have three segments: femoral part, intra-articular part and tibial part. Every step of the surgical procedure aims to get this mechanical axis correct. The distal femoral resection is perpendicular to the mechanical axis. Most instrumentation systems use medullary canal as reference (anatomical axis of femur), and therefore, the angle between the medullary canal and the mechanical axis can be measured and set during surgery for distal femoral resection. In most instances this ranges from 5° to 7° (Fig. 19.2). A long leg standing scanogram that shows hip, knee and ankle anteroposterior (AP) view in one picture allows measurement of the resection angle (Fig. 19.3). Practical Tip It is important to assess the rotation of the leg on scanogram before considering the angle of resection. Any external rotation of the leg will abnormally indicate higher resection angle due to femoral bowing. This is easily judged by assessing the position of patella on AP view.

Tibial resection is based on the long axis of tibia with the center of the tibial plateau and the center of the ankle joint being the two reference points. The center of the tibial plateau is fairly easy to localize and usually is the point just medial to the lateral tibial eminence. The center of the ankle joint is medial to the mid malleolar point as the lateral malleolus is more posterolaterally placed. Most instrumentation systems have an ankle clamp that allows adjustment mediolaterally. If the tibial resection is to be done with a posterior slope as demanded by the implant design, it is important to set the rotation of the jig aligned to the junction of central and medial third of the tibial tubercle. Once the distal femoral resection and tibial resection are done perpendicular to the mechanical axis, extension gap balancing restores the mechanical axis. So balancing and alignment have to be considered complimentary to each other.

PRINCIPLES OF BALANCING Normal knee has certain degree of laxity that is necessary to have free motion. In terminal extension, there is no mediolateral laxity, and no dis-

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Angle between the mechanical axis and anatomical axis (5-7 degrees) Anatomical axis of femur Mechanical axis

Distal femoral resection perpandicular to mechanical axis

Tibial resection perpandicular to long axis of tibia

Center of ankle joint Fig. 19.2 Scheme of distal femoral and tibial resections to get mechanical alignment.

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traction between medial or lateral joint surfaces is possible. In this position, posterior capsule along with medial and lateral structures is tight. At about 10° flexion and onwards, posterior capsule is relaxed and only medial and lateral structures provide mediolateral stability. Medially, medial collateral ligament (MCL) provides stability in both flexion and extension, with posterior fibers being tight in extension and anterior fibers being tight in flexion. The lateral stability is provided by multiple structures and is a lot more dynamic depending on the position of flexion. The lateral collateral ligament extends from lateral epicondyle, which is a knuckle-shaped structure over lateral femoral condyle, about 30 mm from the joint line. It diverts away from the lateral femoral condyle to insert in the fibular head with no attachment to tibia. The iliotibial tract provides lateral stability only from full extension to about 30° of flexion, beyond which it ceases to provide stability laterally. The popliteus is an important lateral Fig. 19.3 Long leg scanogram. stabilizer in flexion. All deformities that are not correctable have a significant element of soft tissue contracture, with tissues on the concave side of the deformity being contracted and tissues on the convex side being stretched to varying degrees.

The Basic Rule of Balancing Elongated structures cannot be contracted or restored to their original length; therefore, the contracted or relatively contracted structures on the contralateral side need to be released and elongated in a graduated manner so as to match the elongated structures on the opposite side of the joint.

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Technique of Balancing The basic aim is to get both extension and flexion gaps rectangular, equal and balanced. The distal femoral cut influences only the extension gap, the posterior condylar cut influences only the flexion gap, while proximal tibial cut influences both extension and flexion gaps. While distal femoral and proximal tibial resections are done perpendicular to the mechanical axis, extension gap balancing is done depending on the deformity and the tight structures. The posterior condylar cuts can vary, both depending on the femoral sizing and the rotation of the femoral component. Most systems use anterior referencing for sizing whereby the anterior level of resection remains constant and any downsizing leads to increase in flexion gap. In systems that use posterior referencing for sizing, the anterior cut changes with size, so downsizing can lead to notching of the anterior cortex of femur. Rotation of the femoral component largely influences the flexion gap balancing. It is useful to distract the joint in flexion to assess the flexion space, prior to posterior resection.

Balancing in Varus Knee First step is to check whether the deformity is correctable. If the deformity is fully correctable, no significant medial release is necessary and minimal medial subperiosteal release is done to allow forward subluxation of tibia. If the deformity is not correctable, a graduated medial release is necessary. The initial medial dissection is subperiosteal and includes the release of capsule on the posteromedial corner of tibia along with deep part of MCL. Pes anserinus tendon insertions are generally not released and the superficial MCL insertion is released only over the proximal 3 cm of tibia at this stage. The thickness of the proximal tibial resection needs to be reduced if there is any stretching of lateral structures as indicated by the lateral compartment distraction on weight bearing AP X-ray. Once the extension gap is created after the resection of distal femur and proximal tibial resection, the balance is checked using rectangular spacer blocks. There should be 1 to 2 mm opening on both medial and lateral sides on the application of varus and valgus stress. If at this stage, there is tightness on medial side, one needs to employ following techniques that can achieve balancing without having to release the superficial MCL completely. 1. Resection of medial femoral osteophytes: In most varus knees, there is medial femoral osteophyte that tents the MCL and needs to be

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excised. The medial edge of resected medial femoral condyle is traced posteriorly and the osteophyte medial to it is resected with a straight narrow osteotome without injuring the MCL attachment to medial epicondyle (Fig. 19.4).

Fig. 19.4 Medial femoral osteophyte that is tenting the medial collateral ligament (MCL) needs resection.

2. Size the femur and posterior capsular release: At this stage of surgery, it is useful to know the femoral size, which essentially depends on the AP dimensions of the distal femur. Most modular systems allow size mismatch between the femoral and tibial components. By knowing the femoral size, one can determine the smallest tibial size that will be compatible. At this stage, the joint is distracted in flexion to judge the extent of tightness on the medial side. If there appears to be significant tightness medially, one can increase the external rotation of the femoral component from 3° to 5° based on the posterior condylar line. At this stage, it is useful to resect only the posterior condyles of femur without the anterior or the chamfer cuts, and the jig is removed. If there is any preoperative flexion deformity, the posterior capsule is released from the back of the femur with a curved osteotome or electrocautery. It is useful to bend the tip of electrocautery and work anteriorly against the femoral cortex with knee in acute flexion. The curved osteotome is used to protect the important structures posteriorly. 3. Undersizing the tibia: Tibia is then sized, and the compatible smallest size that will cover the lateral tibial plateau and be aligned to the junc-

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tion of medial and middle one-third of the tibial tubercle is selected. This normally leaves overhanging bone medially and posteromedially. This overhang is resected flush with the medial edge of the tibial component. This technique is called ‘reduction osteotomy’ (Fig. 19.5).

Fig. 19.5 Tibial downsizing and lateralization allow excision of medial and posterior excess bone. This in turn helps with medial balancing.

4. MCL piecrusting: If despite above two steps, medial side is still tight, careful MCL piecrusting can stretch the medial side by another 2–3 mm. With joint distracted, multiple punctures are made in the length of the MCL using 18-gauge needle mounted on a syringe (Fig. 19.6). The number of punctures needs to be graduated, as excessive punctures can make the MCL incompetent. The usual number of punctures ranges from 10 to 16.

Fig. 19.6 Medial collateral ligament (MCL) pie-crusting with 18-gauge needle.

Fig. 19.7 Complete superficial medial collateral ligament (MCL) release can be done subperiostealy keeping pes tendons intact.

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If the medial side remains tight despite all the above measures, which can happen in severe fixed deformity, the superficial MCL needs to be completely released subperiosteally from the tibia to almost 10 cm from joint line. This is best done with a sharp curved osteotome or periosteal elevator. The pes tendon attachments can be kept intact (Fig 19.7). At the end of the release, if the medial side is lax, constrained prosthesis has to be used.

Balancing in Valgus Knee Since lateral side of knee has multiple structures providing stability, the valgus knee correction and balancing are considered more challenging. The distal femoral and proximal tibial resections based on principles mentioned earlier present an asymmetrical extension gap that is tight laterally. It is useful to place a lamina spreader or a distractor with flat discs in the joint and apply distraction force. With distractor in place, tight structures can be palpated. There are a variety of sequences of soft tissue release described in literature. We describe our sequence of soft tissue release here: 1. Pie-crusting of ilio-tibial band: A distractor is placed in the joint to get lateral structures under tension. Using a 15 number knife blade, multiple punctures are made in the distal 5 cm of IT band. The tight bands can be palpated and pie crusted. The distractor is removed and the balance checked. If not balanced yet, the distractor is reapplied and posterolateral corner and lateral structures are palpated. 2. Posterolateral capsule: With distractor in place, posterolateral capsule is carefully released using 15 number knife. 3. Lateral collateral ligament (LCL): If the lateral side is still tight, it is possible to palpate the tight LCL in the posterolateral corner of the knee. Using the 15 number knife, a couple of stab incisions are made in the length of the LCL. This usually releases the tight lateral side adequately as one can feel a snap, and balance is achieved. With these releases, the lateral side is usually still not incompetent, and standard posterior stabilized prosthesis can be used without additional constraints. Balancing the Flexion Gap In a nondeformed knee, not much soft tissue releases are necessary. Most systems use extension gap first technique and the techniques described above are used to get extension gap balancing. Flexion gap is determined next and is largely influenced by the degree of external rotation of the femoral component. Posterior condyles are commonly taken as reference points, but need careful attention to the ensuing flexion gap. Trans-

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epicondylar axis (TEA) is considered a better landmark to judge femoral component rotation and normally TEA is on average at about 3° externally rotated to the posterior condylar line in a normal knee (range 2° to 11°). In a deformed knee, especially valgus knee, the lateral femoral condyle is worn and hypoplastic. In such a situation, if posterior condyles are taken as a reference line, the femoral component will possibly be in internal rotation, leading to patellar maltracking. It is, therefore, useful to mark the TEA in valgus knee. In a varus knee, there may be some wear of the posterior condyle medially. In such a knee, one can still take posterior condyles as reference, as the femoral component will be in slightly more external rotation. This in fact improves the patellar tracking.

SUMMARY Alignment and balancing are the two most crucial aspects of TKA that determine the long-term outcome. Restoration of normal alignment needs careful clinical and radiological assessment before surgery to determine the distal femoral resection angle and determination of the soft tissue releases necessary for deformity correction and balancing.

REFERENCES 1. Ranawat CS, Padgett DE, Ohashi Y. Total knee arthroplasty for patients younger than 55 years. Clin Orthop Relat Res 1989;248:27–33. 2. Rand JA, Trounsdale RT, Ilstrup DM, et al. Factors affecting the durability of primary total knee prostheses. J Bone Joint Surg Am 2003;85-A(2):259–65. 3. Scuderi GR, Insall JN, Windsor RE, et al. Survivorship of cemented knee replacements. J Bone Joint Surg Br 1989;71(5):798–803. 4. Gioe TJ, Killeen KK, Grimm K, et al. Why are total knee replacements revised? Analysis of early revision in a community knee implant registry. Clin Orthop Relat Res 2004;428:100–06. 5. Fehring TK, Odum S, Griffin WI, et al. Early failures in total knee arthroplasty. Clin Orthop Relat Res 2001;392:315–18. 6. Sharkey PF, Hozack WJ, Rothman RH, et al. Insall Award paper. Why are total knee arthroplasties failing today? Clin Orthop Relat Res 2002;404:7–13.

Chapter 20

Cementation Techniques in Total Knee Arthroplasty Justin Duke, Douglas A. Dennis

INTRODUCTION Cemented total knee arthroplasty (TKA) is widely accepted as the gold standard fixation method for TKA.1,2 Despite numerous design variations of the tibial and femoral components (full keels, multiple lugs, etc.), the goal is to obtain rigid fixation to the corresponding bone. Numerous reports demonstrate aseptic loosening rates of near 2% at intervals of greater than 10 year follow-up duration with cement fixation.3–5 A properly executed cementation technique not only provides long-term stable fixation, but also serves as a barrier to the ingress of debris particles into the cancellous bone that can result in osteolysis.6 This chapter will focus on the ideal cementing technique and conditions that will yield the best long-term survival and outcome.

BONE CEMENT COMPOSITION Various types of bone cement are available which can differ in viscosity, tensile and compressive strength, and time of polymerization. Various chemicals are present in powder and liquid form (Table 20.1), which are mixed together, resulting in an exothermic reaction and subsequent polymerization. Antibiotics may be added to the powder by the manufacturer or surgeon to prevent or treat an active periprosthetic infection. Surgeon addition of antibiotics can reduce cost and allow custom tailoring of the Table 20.1: Chemical composition of a standard bone cementa

Powder: > 50% Polymethyl methacrylate 1-3% Benzoyl peroxide 10-15% Barium sulfate Liquid: >50% Methyl methacrylate < 1.5% N,N-Dimethyl-p-toluidine aDepuy CMV 1 Bone Cement, Blackpool, England

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spectrum of antibiotic coverage. For optimum therapeutic benefit, the chosen antibiotic should be thermally stable to avoid loss of activity from the exothermic reaction of the polymer and monomer (Table 20.2).7, 8 Table 20.2: Antibiotics added to bone cement8 Acceptable antibiotics

Decreased antibiotic activity due to the heat of polymerization

Amikacin Amoxicillin Ampicillin Bacitracin Cefamandole Cefazolin Cefuroxime Cefuzanam Cephalothin Ciprofloxacin Clindamycin (powder) Colistin Daptomycin Erythromycin Gentamicin (powder) Lincomycin Methicillin Novobiocin Oxacillin Penicillin Polymymyxin B Streptomycin Ticarcillin Tobramycin Vancomycin

Chloramphenicol Colistimethate Tetracycline Liquid gentamicin, clindamycin, or any aqueous suspension Rifampin

OPERATIVE TECHNIQUE There are several factors influencing the tensile and shear strength of the bone–cement interface. These include the preparation of the bone surface,9,10 method of cement preparation,11–13 application of the cement to the bone14–18 and the depth of cement penetration.9,10,13,15,16,19 It is important to understand that bone cement is not a glue, and does not chemically bond with either implant or bone. It functions as a ‘grout’ that forms an intimate sleeve between the implant and interdigitates into the

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cancellous structure of the bone.11,20 Poor cementation techniques risk premature implant loosening. Careless removal of excess cement results in micro and macroscopic third body particles, which can entrap within the joint articulation and cause catastrophic polyethylene wear.21 In contrast to total hip arthroplasty, there is no definitive consensus on the preferred method of TKA cementation, and wide variations in technique have been utilized. The following section discusses the available published literature and the authors’ favored method of cementing a TKA.

Bone Preparation Smooth and precise bone resections are important as irregularities of the bone surface will prevent a uniform cement mantle. Areas of sclerotic bone limit interdigitation of cement with cancellous bone and should be perforated with a small drill bit to a depth of 3 mm to enhance cement interdigitation (Fig. 20.1 ). This is most commonly required on the worn side of the tibia and the lateral patellar facet. The authors prefer to use a tourniquet at least for cementation and component insertion. This allows the surgeon to achieve the driest possible bone surface and decreases the influence of fluids, blood and fat from mixing with cement which has been shown to decrease the cement strength.10 Additionally, high bleeding pressure can inhibit cement penetration into trabecular bone. The use of pulsatile lavage has been shown to facilitate improved debris removal from the interstices of cancellous bone, resulting in reduced postoperative radiolucent lines and improved survivorship22 as well as better depth of cement penetration.13,23,24 Once the blood, fat and marrow have been removed via pulsatile lavage, it is imperative to dry the bone. A dry laparotomy sponge is placed down the tibial canal and onto the surfaces to be cemented until the time of cement

A

B

Fig. 20.1: Intraoperative photograph of a sclerotic lateral patellar facet perforated with a small drill bit (A) to enhance cement penetration (B).

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application. At this stage of washing and drying the bone, it is wise to inspect the posterior capsule for any residual boney debris that requires removal.

Cement Preparation Cement preparation occurs concurrently with bone preparation. The surgeon must be aware of the mixing and working time of the chosen cement as variations exist among the multiple chemical formulations of bone cement. Additionally, an increased operating room temperature can accelerate the speed of curing of the cement. Evidence supporting superiority of one type of cement over another is lacking. Lutz et al. demonstrated no difference in cement penetration or incidence of radiolucent lines in TKAs cemented with low-viscosity cement using a cement gun compared with standard-viscosity cement applied via a pressurizing syringe.25 The current technique for cement mixing involves mixing under conditions of a vacuum. This technique reduces the volume of noxious fumes in the operating theater and the pore size of the cement, which increases its yield strength.26

Cement Application and Component Insertion The goal of cement application to the bone is to create a uniform cement mantle that interdigitates with the cancellous bone to assure long-term fixation. Some controversy exists regarding the required depth of cement penetration. Biomechanical studies suggest a depth of penetration of 3 mm is desired.27,28 Due to the exothermic reaction of cement polymerization, a mantle that is excessively thick can lead to adverse thermal necrosis of the bone.29,30 The tibial component is initially cemented. Histologic evaluations of the bone–cement interface typically demonstrate excellent interdigitation of cement centrally but often poor penetration of cement peripherally due to the lack of pressurization from escape of the cement peripherally. It is our opinion that good penetration peripherally is paramount to create a barrier to ingress of microparticulate debris and subsequent osteolysis. Therefore, the authors’ preferred technique is to peripherally pressurize the tibia plateau using a cement gun to ensure good peripheral interdigitation (Fig. 20.2).16,19 Additional controversy exists regarding the need to cement the stem of tibial trays.14 Maloney and Clohisy evaluated 97 TKAs fixed with surface cementation only and observed a 14.4% (11 of 97) loosening rate at a 2–8 years’ follow-up duration.31 A comparative evaluation of component migration of TKAs fixed with surface vs. complete cementing using

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Fig. 20.2: Intraoperative photograph demonstrating pressure injection of the periphery of the proximal tibia using a cement gun.

radiostereometry demonstrated increased migration in the surface only cemented group.32 For these reasons, the authors favor complete cementation with hand pressurization of the tibial canal before component insertion. The tibial component is then carefully inserted, keeping the plateau portion parallel to the resected tibia to ensure a uniform cement mantle and firmly impacted with a component driver. The method of removal of excess cement is critical to avoid creation of microparticulate cement debris fragments, which can be left in the knee joint, embed within the polyethylene bearing and accelerate wear. A sharp elevator is used to cut the excessive cement at its junction with the component and the excess is removed in large fragments (Fig. 20.3A and B). Scraping away the cement with curettes is to be avoided as it typically creates residual small cement fragments which can later serve as third body wear particles. Lastly, a wet laparotomy sponge is used to wipe the tray periphery to remove any attached cement not removed using the cutting procedure described above.

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A

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B

Fig. 20.3: Intraoperative photograph demonstrating cutting of the excess cement (A) with a sharp elevator and removal as a large fragment (B).

The femoral component is then cemented using the same principles used with tibial cementation. In addition to pressure injecting the bone, cement is applied to the backside of the component to decrease fat intrusion into the prosthesis–cement interface.17 Cement penetration into the posterior condyles is often not ideal and consideration of hand pressurization of this region before component insertion is wise. Flexion of the femoral component during insertion is common and not desirable, particularly in posterior stabilized TKA designs in which flexion can lead to impingement of the top of the intercondylar box on the anterior aspect of the tibial spine. Initial impaction on the top of the intercondylar box to drive the component out of flexion can avoid this problem (Fig. 20.4). The tibial polyethylene insert trial is then inserted and the knee is the brought into full extension to further pressurize the cement as the patella is prepared. As discussed previously, the lateral facet of the patella is often sclerotic and perforation of sclerotic bone is wise (Fig. 20.1 ). Hand pressurization of the lug holes and sclerotic bone is performed before component insertion. A locking clamp is applied to the patella until the cement is cured. After all components have been implanted and cement is cured, the knee is dislocated anteriorly, the posterior compartment inspected and cleaned and any excess cement is removed from all components. The final modular tibial polyethylene bearing is inserted. The knee is then reduced and the wound copiously irrigated to remove any residual bone or cement debris. A substantial amount of nonvisible debris is often generated during

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Fig. 20.4: Intraoperative photograph demonstrating femoral component impaction applied via the top of the intercondylar box to avoid flexion of the component.

a TKA. It has been shown that irrigating with 5L of pulsatile lavage (3 L before and 2 L after component insertion) was effective at removing 95% of debris.21

SUMMARY Use of cement fixation for primary TKA demonstrates excellent long-term fixation. Meticulous cementation technique is important to optimize clinical outcomes.

REFERENCES 1. American Joint Replacement Registry. Available at: www.teamwork.aaos.org/ajrr/. Fall 2013 Update. 2. National Joint Registry for England, Wales, and Northern Ireland. Available at: http:// www.njrcentre.org.uk/. 10th Annual Report, 2013. 3. Dixon MC, Brown RR, Parsch D, Scott RD. Modular fixed-bearing total knee arthroplasty with retention of the posterior cruciate ligament. a study of patients followed for a minimum of fifteen years. J Bone Joint Surg Am 2005;87(3):598–603. 4. Font-Rodriguez DE, Scuderi GR, Insall JN. Survivorship of cemented total knee arthroplasty. Clin Orthop Relat Res 1997;345:79–86. 5. Rasquinha VJ, Ranawat CS, Cervieri CL, Rodriguez JA. The press-fit condylar modular total knee system with a posterior cruciate-substituting design. A concise follow-up of a previous report. J Bone Joint Surg Am 2006;88(5):1006–10. 6. Engh GA, Parks NL, Ammeen DJ. Tibial osteolysis in cementless total knee arthroplasty. A review of 25 cases treated with and without tibial component revision. Clin Orthop Relat Res 1994;309:33–43.

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7. Arora M, Chan EK, Gupta S, Diwan AD. Polymethylmethacrylate bone cements and additives: a review of the literature. World J Orthop 2013;18;4(2):67–74. 8. Joseph TN, Chen AL, Di Cesare PE. Use of antibiotic-impregnated cement in total joint arthroplasty. J Am Acad Orthop Surg 2003;11:38–47. 9. Dorr L, Lindberg JP, Claude-Faugere M, Malluche HH. Factors influencing intrusion of methylmethacrylate into human tibiae. Clin Orthop Relat Res 1984;183:147–52. 10. Krause R, Krug W, Miller J. Strength of cement–bone interface. Clin Orthop Relat Res 1982;163: 290–99. 11. Cooke FW, Cipolletti GB, Lunceford EM, Sauer BW. The Influence of Surgical Technique on the Strength of Cement Fixation. Dallas, Texas: ORS, 1978. 12. Lindberg J, Dorr L, Malluche H. Cement Fixation of the Total Condylar Tibial Component. New Orleans, LA: ORS, 1982. 13. Majkowski RS, Miles AW, Bannister GC, Perkins J, Taylor GJ. Bone surface preparation cemented joint replacement. J Bone Joint Surg Br 1993;75:459–63. 14. Galasso O, Jenny JY, Saragaglia D, Miehlke RK. Full versus surface tibial baseplate cementation in total knee arthroplasty. Orthopedics 2013;36:e151–e158. 15. Halawa M, Lee AJ, Ling RS,Vangala SS. The shear strength of trabecular bone from the femur, and some factors affecting the shear strength of the bone cement interface. Arch Orthop Trauma Surg 1978;92:19–30. 16. Mann KA, Ayers DC, Werner FW, Nicoletta RJ, Fortino MD. Tensile strength of the cement-bone interface depends on the amount of bone interdigitated with PMMA cement. J Biomech 1997;30: 339–46. 17. Vainbroukx M, Labey L, Innocenti B, Bellemans J. Cementing the femoral component in total knee arhtroplasty: which technique is the best? The Knee 2009;16:265–68. 18. Vertullo CJ, Davey JR. The effect of a tibial baseplate undersurface peripheral lip on cement penetration in total knee arthroplasty. J Arthroplasty 2001;16:487–92. 19. Macdonald W, Swarts E, Beaver R. Penetration and shear strength of cement–bone interfaces in vivo. Clin Orthop Relat Res 1993;286:283–88. 20. Kusleika R Stupp SI. Mechanical strength of poly(methyl methacrylate) cement-human bone interfaces. J Biomed Mater Res 1983;17: 441–58. 21. Helmers S, Sharkey PF, McGuigan FX. Efficacy of irrigation for removal of particulate debris after cemented total knee arthroplasty. J Arthroplasty 1999;14:549–52. 22. Ritter MA, Herbst SA, Keating EM, Faris PM. Radiolucency at the bone–cement interface in total knee replacement. The effects of bone-surface preparation and cement technique. J Bone Joint Surg Am 1994;76:60–5. 23. Maistrelli GL, Antonelli L, Fornasier V, Mahomed. Cement penetration with pulsed lavage versus syringe irrigation in total knee arthroplasty. Clin Orthop Relat Res 1995;312:261–65. 24. Norton M, Eyres K. Irrigation and suction technique to ensure reliable cement penetration for total knee arthroplasty. J Arthroplasty 2000;15:468–74. 25. Lutz MJ, Pincus PF, Whitehouse SL, Halliday BR. The effect of cement gun and cement syringe use on the tibial cement mantle in total knee arthroplasty. J Arthroplasty 2009;24:461–67. 26. Macaulay W, DiGiovanni C, Restrepo A, Saleh K, Walsh H, Crossett L, Peterson M, Li S, Salvati E. Differences in bone–cement porosity by vacuum mixing, centrifugation, and hand mixing. J Arthroplasty 2002;17:569–75. 27. Bert JM, McShane M. Is it necessary to cement the tibial stem in cemented total knee arthroplasty? Clin Orthop Relat Res 1998;356:73–8. 28. Peters CL, Craig MA, Mohr RA, Bachus KN. Tibial component fixation with cement: full-versus surface-cementation techniques. Clin Orthop Relat Res 2003;409:158–68. 29. Banwart JC, McQueen DA, Friis EA, Graber CD. Negative pressure intrusion technique for total knee arthroplasty. J Arthroplasty 2000;15:360–67.

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30. Dipiso JA, Sih GS, Berman AT. The temperature problems in total hip replacements. Clin Orthop 1976;121:95–8. 31. Maloney WJ, Clohisy J. Premature Failure of Surface Cementation Technique in Primary Total Knee Arthroplasty. Proceedings of the Annual Meeting of the American Academy of Orthopedic Surgeons; Paper 65, 2002, p. 624. 32. Saari T, Li MG, Wood D, Nivbrant B. Comparison of cementing techniques of the tibial component in total knee replacement. Int Orthop 2009;33:1239–42.

Chapter 21

Patellar Resurfacing in Total Knee Arthroplasty Brian K. Daines, Douglas A. Dennis

INTRODUCTION Total knee replacement (TKA) surgery is a predictable and successful surgical intervention for end-stage arthritis. Controversy remains whether to resurface or not to resurface the patella. Arguments for not resurfacing the patellar include fewer complications, more physiologic patellofemoral kinematics and superior remaining bone stock, should revision of the patellar component be required.1–5 The rationale for patellar resurfacing includes less anterior knee pain, higher patient satisfaction and lower revision rates.1, 3–12 With precise surgical technique and good prosthetic design, complication rates in patellar resurfacing should be low. This chapter will explore the literature regarding patellar resurfacing and provide our rationale and surgical technique for advocating patellar resurfacing.

LITERATURE REVIEW The current literature is inconclusive regarding whether or not to resurface the patella, as both options have supporting data. Thorough analysis of the literature is limited because of the variable length of follow-up duration, with many of the comparative analyses demonstrating short-term followup.6,7 Also, the status of the patellofemoral joint at the time of TKA is poorly documented. Within these limitations, it appears that short-term comparative data is similar. The Swedish Knee Arthroplasty Registry (1998–2007) demonstrated that nonresurfaced patellar total knee arthroplasty (TKA) subjects had a 1.23 times higher risk of revision vs. subjects with a patellar resurfacing.13 The Australian Orthopaedic Association National Joint Replacement Registry demonstrated that the risk of revision is 1.32 times higher if the patella is not resurfaced (p < 0.001).14 They showed that the risk is 1.52 higher in posterior stabilized TKAs. Several recent meta-analyses of TKA with patellae

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resurfaced vs. nonresurfaced demonstrate a higher incidence of anterior knee pain patients who did not have the patella resurfaced.11,12,15 Studies supporting resurfacing the patella show increased anterior knee pain in subjects without patella resurfacing.1–4 They also demonstrate that secondary patellar resurfacing results are inferior to primary resurfacing.1,10 In studies evaluating mixed (one knee resurfaced and one knee unresurfaced) bilateral TKAs, the resurfaced side is favored over the nonresurfaced side.3,8,16 The literature supports resurfacing in rheumatoid arthritis,9,17 which suggests that nonresurfaced patellae may deteriorate clinically over time,4,7,18 and notes that reoperation rates are higher if the patella is not resurfaced.6,11,12 There also appears to be poor correlation between cartilage condition at the time of surgery and postoperative patellofemoral pain and function.19 Meticulous surgical technique is critical, however, to achieve satisfactory results with patellar resurfacing.

SURGICAL TECHNIQUE Due to the reasoning discussed above, it is the authors’ practice to resurface the patella in all TKAs if possible. Cases in which the patella is not resurfaced include patients with insufficient bone stock to gain adequate fixation and those with severe patellar baja. In both of these clinical situations, we favor performing a patellar arthroplasty in which the articular surface is removed and smoothed, leaving a patellar thickness of approximately 12 mm. Excellent clinical results can be obtained if a precise operative technique is used. Sophisticated cuttings jigs are widely used for femoral and tibial resections. However, the traditional technique of everting the patella and performing a free-hand resection often leads to error. Operative goals of patellofemoral resurfacing include an accurate patellar resection, maintenance of patellar vascularity, proper positioning of components, avoidance of soft tissue impingement and assurance of central patellar tracking.20 The authors typically resect the patella after the femoral and tibial resections have been completed to avoid retractor damage (compression) from pressure applied to osteopenic patellar cancellous bone exposed after patellar resection. If patellar subluxation is difficult due to extensor mechanism tightness, the patella can be resected first to loosen the extensor mechanism and facilitate surgical exposure. Large hypertrophic patellar osteophytes are also debrided before any bone resections are performed to facilitate patellar subluxation and exposure of the femur and tibia. Resection of the patella can be successfully accomplished using a freehand method or with use of

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a patellar resection guide as long as the following principles are followed. Patellar resection must result in a symmetric patellar remnant with equal medial and lateral facet thicknesses. Since the patella is asymmetric in shape (medial thicker than lateral), this requires resection of more bone medi). Typically, the resection proceeds ally than laterally (Fig. 21.1A and B through the subchondral bone of the lateral facet with minimal lateral facet removal. Asymmetric patellar facet thicknesses (medial versus lateral) following articular surface resection must be avoided as it increases the risk of patellofemoral instability and patellar fracture.

A

B

Fig. 21.1 (A) Intraoperative photograph of a patellar resection guide applied to the patella demonstrating the plan to remove more medial than lateral (hemostat) facet. (B) Intraoperative photograph of the resected patellar article surface demonstrating minimal lateral facet resection through the subchondral bone to assure residual facet thickness symmetry.

It is important to duplicate native patellar thickness, which requires measurement of native patellar thickness before resection. The surgeon must be aware of the exact thickness of the chosen patellar component. The articular surface thickness removed should equate with the thickness of the implanted component to duplicate patellar thickness. The quadriceps and infrapatellar tendons are excellent anatomic landmarks for patellar resection and restoration of patellar height.21 ‘Overstuffing’ of the patellofemoral joint is thought to result in poor biomechanics of the extensor mechanism, often leading to decreased range of motion and anterior knee pain. This can result from a number of factors including over-sizing or anterior translation of the femoral component, distal joint line position, or increasing the patellar thickness.21 Any factor that excessively increases the tension in the patellar retinaculum may lead to pain, decreased range of motion and poor function. An excessive patellar resection results in increased patellar strain and an increased fracture risk.22

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Efforts to preserve vascularity include maintaining the fat pad,23,24 preservation of the superolateral genicular artery during a lateral retinacular release procedure25–27 and avoidance of patellar components with large central anchoring holes, which cause a greater reduction in the intraosseous blood supply than with use of components with smaller peripheral lugs.25,27,28 All three TKA components require accurate positioning. Medial shift and internal rotation of both femoral and tibial components, as well as lateral positioning of the patellar component, must be avoided to prevent patellar maltracking. Medialization of the patellar component and utilization of patellar Fig. 21.2 Photograph of a patellar compocomponents in which the apex of the nent with the apex medialized 3 mm to component is medialized (Fig. 21.2) facilitate central patellar tracking. facilitate central patellar tracking. Patellar component medialization can result in the uncoverage of the lateral facet and lateral facet pain postoperatively. The authors routinely resect any uncovered lateral patellar facet to avoid this problem (Fig. 21.3A and B). Following tourniquet release, central patellar tracking must be obtained using the no-thumb technique. If patellar subluxation is initially present, realignment procedures are performed until a balanced extensor mechanism is obtained.29,30 The indications for lateral retinacular release are influenced by the ‘no thumbs’ and ‘towel clip’ tests. Surgical goals should include centralizing the patellar tracking throughout the range of motion. The role of the vastus medialis obliquus muscle is simulated by the towel clip test and can influence the

A

B

Fig. 21.3 Intraoperative photographs demonstrating exposed lateral patella that will not be covered by the patellar component (A) which is removed with a rongeur (B) before component implantation to avoid lateral facet pain.

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postoperative presence of patellar tilt and subluxation, dislocation and the rate of lateral release.31 Due to premature failure of many metal-backed patellar component designs,32–35 use of cementless patellar components has become infrequent. Excellent long-term fixation with cemented patellar components can be expected23,36 if good fixation techniques are utilized. Since the articular surface resection often extends through the subchondral bone of the lateral facet, cement penetration into this region can be compromised. It is wise to perforate any sclerotic subchondral bone numerous times to enhance cement penetration (Fig. 21.4A and B) and hand-pressurize the component lug holes.

A

B

Fig. 21.4 Intraoperative photographs demonstrating drilling of the sclerotic bone of the lateral facet (A) to enhance interdigitation of bone cement (B).

Lastly, it is important to avoid patellofemoral soft tissue impingement. This most commonly involves the fat pad or fibrosynovial proliferation surrounding the patellar component. The senior author routinely debulks the fat pad, leaving one centimeter of fat pad covering the patellar tendon to facilitate tendon gliding. At completion of the procedure, any proliferative fibrosynovial tissue on the posterior aspect of the quadriceps tendon is debrided to lessen the incidence of postoperative patellar crepitus (Fig. 21.5).

SUMMARY Satisfactory results have been reported for both patellar resurfacing and nonresurfacing in TKA. Recent randomized studies suggest reoperation rates to convert nonresurfaced patellae to resurfaced patellae exceed reoperation rates from complications associated with primary patellar resurfacing. The incidence of patellofemoral pain and reoperation rates are greater in subjects in which the patella is not resurfaced. Long-term studies suggest

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Fig. 21.5 Intraoperative photograph demonstrating debridement of proliferative fibrosynovial tissue (arrow) on the posterior aspect of the distal quadriceps tendon to lessen the incidence of postoperative patellar crepitus.

that results of nonresurfaced patellae deteriorate over time both clinically and radiographically. One should expect minimal complications and satisfactory long-term function with use of a meticulous patellofemoral resurfacing surgical technique.

REFERENCES 1. Boyd AD, Jr, Ewald FC, Thomas WH, Poss R, Sledge CB. Long-term complications after total knee arthroplasty with or without resurfacing of the patella. J Bone Joint Surg Am 1993;75(5):674–81. 2. Khatod M, Codsi M, Bierbaum B. Results of resurfacing a native patella in patients with a painful total knee arthroplasty. J Knee Surg 2004;17(3):151–55. 3. Levitsky KA, Harris WJ, McManus J, Scott RD. Total knee arthroplasty without patellar resurfacing. Clinical outcomes and long-term follow-up evaluation. Clin Orthop Relat Res 1993(286):116–21. 4. Mayman D, Bourne RB, Rorabeck CH, Vaz M, Kramer J. Resurfacing versus not resurfacing the patella in total knee arthroplasty: 8- to 10-year results. J Arthroplasty 2003;18(5):541–45. 5. Soudry M, Mestriner LA, Binazzi R, Insall JN. Total knee arthroplasty without patellar resurfacing. Clin Orthop Relat Res 1986(205):166–70. 6. Badhe N, Dewnany G, Livesley PJ. Should the patella be replaced in total knee replacement? Int Orthop 2001;25(2):97–9. 7. Bourne RB, Rorabeck CH, Vaz M, Kramer J, Hardie R, Robertson D. Resurfacing versus not resurfacing the patella during total knee replacement. Clin Orthop Relat Res 1995(321):156–61. 8. Enis JE, Gardner R, Robledo MA, Latta L, Smith R. Comparison of patellar resurfacing versus nonresurfacing in bilateral total knee arthroplasty. Clin Orthop Relat Res 1990(260):38–42.

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9. Kajino A,Yoshino S, Kameyama S, Kohda M, Nagashima S. Comparison of the results of bilateral total knee arthroplasty with and without patellar replacement for rheumatoid arthritis. A follow-up note. J Bone Joint Surg Am 1997;79(4):570–74. 10. Karnezis IA, Vossinakis IC, Rex C, Fragkiadakis EG, Newman JH. Secondary patellar resurfacing in total knee arthroplasty: results of multivariate analysis in two casematched groups. J Arthroplasty 2003;18(8):993–98. 11. Nizard RS, Biau D, Porcher R, et al. A meta-analysis of patellar replacement in total knee arthroplasty. Clin Orthop Relat Res 2005(432):196–203. 12. Parvizi J, Rapuri VR, Saleh KJ, Kuskowski MA, Sharkey PF, Mont MA. Failure to resurface the patella during total knee arthroplasty may result in more knee pain and secondary surgery. Clin Orthop Relat Res 2005;438:191–96. 13. Knutson K, Robertsson O. The Swedish Knee Arthroplasty Register (www.knee.se). Acta Orthop 2010;81(1):5–7. 14. Graves SE, Davidson D, Ingerson L, et al. The Australian Orthopaedic Association National Joint Replacement Registry. Med J Aust 2004;180(5 Suppl):S31–4. 15. Pakos EE, Ntzani EE, Trikalinos TA. Patellar resurfacing in total knee arthroplasty. A meta-analysis. J Bone Joint Surg Am 2005;87(7):1438-–45. 16. Waters TS, Bentley G. Patellar resurfacing in total knee arthroplasty. A prospective, randomized study. J Bone Joint Surg Am 2003;85-A(2):212–17. 17. Picetti GD, 3rd, McGann WA, Welch RB. The patellofemoral joint after total knee arthroplasty without patellar resurfacing. J Bone Joint Surg Am 1990;72(9):1379–82. 18. Shih HN, Shih LY, Wong YC, Hsu RW. Long-term changes of the nonresurfaced patella after total knee arthroplasty. J Bone Joint Surg Am 2004;86-A(5):935–39. 19. Han I, Chang CB, Lee S, Lee MC, Seong SC, Kim TK. Correlation of the condition of the patellar articular cartilage and patellofemoral symptoms and function in osteoarthritic patients undergoing total knee arthroplasty. J Bone Joint Surg Br 2005;87(8):1081–84. 20. Dennis DA. Extensor mechanism problems in total knee arthroplasty. Instr Course Lect 1997;46:171–80. 21. Briard JL, Hungerford DS. Patellofemoral instability in total knee arthroplasty. J Arthroplasty 1989;4(Suppl):S87–97. 22. Reuben JD, McDonald CL, Woodard PL, Hennington LJ. Effect of patella thickness on patella strain following total knee arthroplasty. J Arthroplasty 1991;6(3):251–58. 23. Ranawat CS. The patellofemoral joint in total condylar knee arthroplasty. Pros and cons based on five- to ten-year follow-up observations. Clin Orthop Relat Res 1986(205):93–9. 24. Dorr LD, Boiardo RA. Technical considerations in total knee arthroplasty. Clin Orthop Relat Res 1986(205):5–11. 25. Clayton ML, Thirupathi R. Patellar complications after total condylar arthroplasty. Clin Orthop Relat Res 1982(170):152–55. 26. Lynch AF, Rorabeck CH, Bourne RB. Extensor mechanism complications following total knee arthroplasty. J Arthroplasty 1987;2(2):135–40. 27. Dennis DA, Clayton ML, O'Donnell S, Mack RP, Stringer EA. Posterior cruciate condylar total knee arthroplasty. Average 11-year follow-up evaluation. Clin Orthop Relat Res 1992(281):168–76. 28. Scott RD, Turoff N, Ewald FC. Stress fracture of the patella following duopatellar total knee arthroplasty with patellar resurfacing. Clin Orthop Relat Res 1982(170):147–51. 29. Merkow RL, Soudry M, Insall JN. Patellar dislocation following total knee replacement. J Bone Joint Surg Am 1985;67(9):1321–27. 30. Scott RD. Prosthetic replacement of the patellofemoral joint. Orthop Clin North Am 1979;10(1):129–37. 31. Archibeck MJ, Camarata D, Trauger J, Allman J, White RE, Jr. Indications for lateral retinacular release in total knee replacement. Clin Orthop Relat Res 2003(414):157–61. 32. Leblanc JM. Patellar complications in total knee arthroplasty. A literature review. Orthop

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Rev 1989;18(3):296–304. 33. Bayley JC, Scott RD. Further observations on metal-backed patellar component failure. Clin Orthop Relat Res 1988(236):82–7. 34. Bayley JC, Scott RD, Ewald FC, Holmes GB, Jr. Failure of the metal-backed patellar component after total knee replacement. J Bone Joint Surg Am 1988;70(5):668–74. 35. Brick GW, Scott RD. The patellofemoral component of total knee arthroplasty. Clin Orthop Relat Res 1988(231):163–78. 36. Doolittle KH, 2nd, Turner RH. Patellofemoral problems following total knee arthroplasty. Orthop Rev 1988;17(7):696–702.

Chapter 22

Unicondylar Knee Arthroplasty Ashok Rajgopal, Himanshu Gupta, Attique Vasdev

HISTORY The concept of unicondylar replacement of only one compartment of the knee joint came from Duncan Mc Keever in the 1950s, followed up by both Mc Keever and MacIntosh1 who introduced metallic tibial components that resurfaced only the tibial plateau. These were associated with high complication rates and unacceptable functioning. John Charnley developed a convex ultra-high-molecular weight polyethylene (UHMWPE) femoral component to articulate against a flat metallic plateau, which did not have a prolonged life due to loosening, deformation and wear of the plastic femoral component.2,3 Following this, in 1972, Dr Leonard Marmor4 developed a prosthetic design and showed good results in his series.

PRINCIPLE Unicondylar knee arthroplasty in the real sense is resurfacing only one compartment of the knee joint. One tibiofemoral component is resurfaced in order to reduce deterioration of the joint space and to eliminate resultant pathological joint biomechanics.5–7 A unicondylar replacement cannot change the natural alignment or ligamentous balance of the knee. Slight undercorrection of the deformity with insertion of an adequate thickness of polyethylene is an important contributor to a successful outcome.8 For patients presenting with a degenerative disease involving only one compartment, the options usually are limited to arthroscopic debridement, osteotomy and changing the joint alignment and weight bearing forces or going in for a unicompartmental knee arthroplasty (UKA). Of all these options, UKA has shown to have better results compared to the other two in medium to long term. Repicci concluded that UKA minimizes physiological damage, has minimal interference with lifestyle and avoids any interference with future treatment options.9 UKA addresses single compartment disease and preserves bone and soft tissue.10

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INDICATIONS It has been proven in many studies that improper patient selection is thought to be a risk factor for early UKA failure. Classic indications described by Kozinn and Scott and others include11–15: 1. a patient with a sedentary occupation; 2. age 60 years and older; 3. minimal rest pain; 4. varus or valgus malalignment of less than 10º; 5. range of motion of at least 90º with no flexion contracture; 6. correctable medial deformity; 7. weight less than 82 kg; 8. intact ACL with a stable knee that resists femorotibial subluxation and normal articular cartilage in the opposite compartment;16 and 9. diagnosis of osteoarthritis, post-traumatic arthritis or osteonecrosis. Some indications that have been recently updated have been to include patients with monocompartmental arthritis in patients less than 60 and those with BMI less than 30 as medications for unicompartment replacement. Contraindications for UKA, traditionally, have been a diagnosis of rheumatoid arthritis or other inflammatory arthritis, knee pain including all compartments, decreased range of motion with a flexion deformity, knee instability, anterior cruciate ligament (ACL) rupture and obesity.5,12,17 All these have been identified as factors associated with unfavorable results. Preop planning includes some specific radiographs, which are essential in deciding whether the patient is an ideal candidate and also in the planning of surgery: AP views with standing (Fig. 22.1A) in full extension : in 40º flexion: Lateral view (Fig. 22.1B):

Skyline view:

To look for mechanical alignment and to assess the damage in the involved and uninvolved compartments. To assess the status of the posterior condyles. To determine the area of degeneration in the sagittal plane. Posterior degeneration indicates ACL insufficiency. For assessing degeneration in the patellofemoral joint.

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A

259

B

Fig 22.1 Medial compartment degenerative arthritis. (A) Anteroposterior (AP) radiograph. (B) Lateral radiograph.

The surgical principles in UKA surgery are stringent patient selection criteria, careful surgical technique and a proven prosthetic design. The components are placed in such a way that the tibial and femoral components are in maximum congruency in both flexion and extension. There are various different types of UKA available such as a fixed and a rotating platform UKA. We have not used a rotating platform UKA as we have experienced good results with fixed platform UKA. Also many surgeons across the world are doing bicondylar UKA as a norm in both condylar involvement, but we would recommend a TKA in such cases owing to the associated patellofemoral involvement in almost all cases of varying degrees.

Surgical Technique The patient is positioned on a routine operating table with the knee flexed at 90° with the foot resting on the table after inflating the thigh tourniquet. The length of the skin incision varies from 6 to 8 cm. The upper limit for a medial UKA would be the medial pole of the patella, extending distally towards the medial side of the tibial tuberosity. For a medial UKA, a medial parapatellar arthrotomy is done, whereas for a lateral UKA, a lateral capsular arthrotomy is performed. The anterior and mid portions of the meniscus are removed at this step. After exposure, ACL strength is evaluated at 45º of knee flexion, and

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intercondylar and medial osteophytes are removed. After the removal of these peripheral osteophytes, there is a relative lengthening of the MCL, allowing passive correction of the deformity.

Femoral Component The femoral intramedullary canal is drilled after bringing the knee to a lesser degree of flexion and then a femoral distal resection guide is positioned in the center of the mediolateral dimension of the femoral condyle. After the completion of the cuts, posterior osteophytes are removed to increase the range of flexion. The ideal anteroposterior (AP) size of the femoral component should extend far enough anteriorly to cover the weight bearing surface that comes in contact with the tibia in full extension, leaving 1–2 mm of exposed bone on the cut surface, at the junction with the trochlear groove.

Tibial Component After having completed the femoral cuts, the tibial jig is placed using the extramedullary technique. The jig is placed distally around the ankle joint with the axis of the guide lying slightly medial to the center of the ankle joint. The proximal part of the guide is translated on the anterior affected tibia. The diaphyseal part is parallel to the anterior tibial crest, and AP positioning is done to reproduce the natural posterior slope of 5°. The amount of resection is usually between 6 and 8 mm, reproducing in the horizontal plane the height of the unaffected lateral condyle. The sagittal cut is done freehand close to the tibial spine’s eminence, without violating the ACL tibial footprint. The ideal size for the tibial component is one that provides the best mediolateral coverage without overhanging medially.

Alignment Before the final preparation of the tibia, spacer blocks are used to check the balance in both the flexion and extension. After putting in the trial implant, a 1–2 mm opening of the joint space applying a valgus stress is looked for to avoid any overcorrection. The final implants are cemented in place taking care to remove any extra cement. These should be placed in the center of the compartment to avoid weak fixation or early loosening due to offset placement (Fig. 22.2A and B).

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Most failures reported with UKA surgery have been attributed to technical error (Figs 22.3–22.5).

A

B

Fig. 22.2 Postoperative radiograph showing medial unicompartmental knee arthroplasty (UKA). (A) Anteroposterior (AP) view. (B) Lateral view.

Fig. 22.3 Femoral component loosening.

Fig. 22.4 Wrong placement of femoral component.

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Fig. 22.5 Subsidence of tibial component.

POST OP REHABILITATION Before the final closure of the capsule, a drain is inserted as this avoids haematoma formation and thus decreases post op pain in return. We use low molecular weight heparin from first postoperative day onwards for a total of 10 days, which is combined with pulsatile compression stockings to minimize the chance of post op deep vein thrombosis (DVT). Quadriceps setting exercises and attempts at straight leg raising are initiated as tolerated and are achieved on postoperative Day 1 or 2. Knee flexion using a continuous passive motion machine is initiated from Day 0 itself. The patient commences walking from the next day after surgery, and in most cases, walks within 1 week with a cane and discontinues the use of cane at 2–3 weeks post op.

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RESULTS Early results of UKA were discouraging, but with recent evolution in patient selection, implant design and surgical techniques have led to much improved results in the last two decades.18–20 In patients of medial UKA, the best results have been obtained when the postoperative mechanical axis is in the center or slightly medial to the knee center. Over correction (Fig. 22.6) as well as severe undercorrection have been associated with early failures.21 In 1976, Marmor22,23 reported on 105 patients with a minimum of 2 years of follow up, and he achieved successful results with functional improvement and a stable articulation in 88% patients. After 10–13 years, patients implanted with the Marmor knee maintained satisfactory results in 70% cases, and 86.6% patients remained pain free. In 1980, Insall and Aglietti24 reported their results on 32 UKAs. They demonstrated a decrease in Fig. 22.6 Over correction of deformity in the varus angulation from the pre medial osteoarthritis knee. op period to the post op status and had 55% satisfactory results compared to 45% poor results. In 1986, Broughton et al.25 published their results on 42 UKAs and reported to have 76% (32 knees) good results and at the end of 5–6 years post surgery 57% (24 knees) did well. Similar mid- to long-term results were obtained by Bert in 1998.5 He showed 87.4% survivorship of the UKA 10 years after the procedure. Scott et al.26 reported 85% survivorship at 10 years, with the end point defined as revision arthroplasty. Stockelman and Pohl27 reported 43 satisfactory results and four revisions at an average of 7.4 years after 47 UKAs. Christensen28 reported that 7 out of a total of 575 UKAs required revision to a total knee arthroplasty at 2–11 years.

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Murray et al.29 in a comprehensive large volume series showed outcomes of 143 knees treated with a medial UKA using Oxford mobile bearing prosthesis between 1982 and 1992. Patients were followed for a mean duration of 7.6 years postoperatively and they reported 97% survivorship. The five revisions they had reported were: two for progression of degenerative disease; two for loosening; one for infection and one for an unexplained pain without any radiographic abnormality. Even functionally, UKAs have been found to be better than osteotomy that patients undergo. Ivarsson and Gillquist30 reported that patients who had UKA demonstrated better gait velocity and superior muscle strength compared with those who had undergone an osteotomy. When compared to a TKA, the various reasons in favor of a UKA are less perioperative morbidity, reduced blood loss, shorter hospital stay, increased postsurgical range of motion and reduced surgical costs.5,6,11,12,16,31 Many studies have been done comparing the results of both these. Laurencin et al.32 followed 23 patients who underwent a UKA in one knee and a TKA on the contralateral side. These patients were operated on both sides by the same surgical team, and received same inpatient care and rehab protocol in both knees. At the follow up of 81 months, postoperative range of motion improved more in the UKA side than the other. Dalury et al.33 found that in 23 patients with UKA on one side and TKA on the contralateral side, the UKA patients felt less pain and the ranges were much better than those of the TKA. Patil et al.34 also concluded that tibial axial rotation and femoral rollback more closely resemble normal anatomy in UKA compared to a TKA. The widespread use of UKA has been limited by the technical difficulty in performing the procedure. It has been found in many studies that UKA has less tolerance for unacceptable component positioning when compared to TKA, as improper component positioning by as little as 2°, can result in a failure.6,35–41 Other reasons for an early failure are medial–lateral mismatch, heterogeneous polyethylene wear, inadequate stability of components, improper patient selection, aseptic loosening (Figs 22.7 and 22.8) and tibial subsidence.5,42 With precise selection in a patient with single compartment involvement, UKA provides for better physiological function and quicker recovery as compared to TKA, with a reliable surgical technique bone stock is preserved and survivorship expected to exceed 90% at 10 years.43–45

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Fig. 22.7 Wrong placement leading to mismatch of femoral and tibial component – anteroposterior (AP) view.

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Fig. 22.8 Wrong placement leading to mismatch of femoral and tibial component – lateral view.

Our Experience Well, in our cases, we select the modality of treatment based on the scheme shown in Table 22.1. Table 22.1 Author-preferred modality of treatment in patients with unicompartmental arthritis Unicompartmental arthritis

Age < 40 years

Age > 40 years

Age > 40 years

Varus < 10°/Valgus

Varus < 10°/Valgus

Varus > 10°/Valgus

26

Full range of motion

Restricted range

No fixed deformities

of motion

Unicondylar knee

Total knee arthroplasty

High tibial osteotomy

arthroplasty

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As the knowledge about the patient selection and surgical techniques has evolved along with the prosthesis designs, even our results have shown to improve sequentially. In the last 12 years, we have done 768 cases of UKA with a mean follow up of 9.2 years and a mean age of 64 years. Of these, we have had 19 failures or conversions to a total knee arthroplasty. The various reasons we found in our series for failure were progression of contralateral compartment arthritis in 11 knees, component loosening in 6 cases, infection in 1 case and a periprosthetic femoral fracture in 1 patient. The infected case was dealt with a two stage revision arthroplasty.

CONCLUSIONS The technical demands of performing UKA, coupled with a small margin for errors, have limited the widespread use of this surgical technique. Though the results of UKA are in many cases even better than TKA, the important criteria on which these are dependent are proper patient selection, use of a good prosthesis and a surgical procedure, which is technically perfect for a long-lasting successful UKA.

REFERENCES 1. Kurtz SM. The origins and adaptations of UHMWPE for knee replacements. In: UHMWPE Biomaterials Handbook. London, UK: Academic Press; 2009:81–96. 2. Aichroth PM, Cannon WD, Jr. Revision of total knee arthroplasty. In: Knee Surgery Current Practice. London, UK: Martin Duntz Limited; 1992:709–16. 3. Minns RJ, Hardinge K. Failure of one design of surface replacement knee arthroplasty due to loosening deformation and wear of the plastic femoral component. Biomaterials 1983;4(3):147–52. 4. Marmor L. The modular knee. Clin Orthop Rel Res 1973;(94):242–48. 5. Bert JM. Unicompartmental knee replacement. Orthop Clin North Am 2005;36(4):513–22. 6. Conditt MA, Roche MW. Minimally invasive robotic arm guided unicompartmental knee arthroplasty. J Bone Joint Surg Am 2009;91(Suppl 1):63–8. 7. Lonner JH. Patellofemoral arthroplasty. J Am Acad Orthop Surg 2007;15(8):495–506. 8. Cartier P, Sanouiller JL, Grelsamer RP. Unicompartmental knee arthroplasty surgery. 10 year minimum follow up period. J Arthroplasty 1996;11:782–88. 9. Repicci JA. Mini-invasive knee unicompartmental arthroplasty: bone sparing technique. Surg Technol Int 2003;11: 282–86. 10. Repicci JA, Hartmann JF. Minimally invasive unicondylar knee arthroplasty for the treatment of unicompartmental osteoarthritis: an outpatient arthritic bypass procedure. Orthop Clin North Am 2004;35(2):201–16. 11. Bert JM. 10 year survivorship of metal backed, unicompartmental arthroplasty. J Arthroplasty 1998;13(8):901–05. 12. Lonner JH. Indications for unicompartmental knee arthroplasty and rationale for robotic arm-assisted technology. Am J Orthop (Belle Mead NJ) 2009;38(Suppl 2):3–6. 13. Grelsamer RP. Unicompartmental osteoarthrosis of the knee. J Bone Joint Surg AM 1995;77 (2):278–92.

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14. Kozinn SC, Marx C, Scott RD. Unicompartmental knee arthroplasty. A 4.5–6 year follow up study with a metal backed tibial component. J Arthroplasty 1989;4( Suppl):S1–10. 15. Kozinn SC, Scott R. Unicondylar knee arthroplasty. J Bone Joint Surg Am 1989;71(1):145–50. 16. Pearle AD, Kendoff D, Stueber V, Musahl V, Repicci JA. Perioperative management of unicompartmental knee arthroplasty using the MAKO robotic arm system (MAKOplasty). Am J Orthop (Belle Mead NJ) 2009;38(Suppl 2):16–19. 17. Cobb J, Henckel J, Gomes P, Harris S, Jakopec M, Rodriguez F, Barrett A, Davies B. Hands-on robotic unicompartmental knee replacement: a prospective, randomized controlled study of the acrobat system. J Bone Joint Surg Br 2006;88(2):188–97. 18. Goodfellow JW, Tibrewal SB, Shermsn KP, O’Connor JJ. Unicompartmental Oxford meniscal knee arthroplasty. J Arthroplasty 1987;2:1–9. 19. Laskin RS. Unicompartmental tibiofemoral resurfacing arthroplasty. J Bone Joint Surg Am 1978;60:182–85. 20. Insall J, Walker P. Unicondylar knee replacement. Clin Orthop 1976;120:83–5. 21. Kennedy WR, White RP. Unicompartmental arthroplasty of the knee. Post operative alignment and its influence on overall results. Clin Orthop 1987;221:278–85. 22. Marmor L. Unicompartmental knee arthroplasty. Ten to 13 year follow up study. Clin Orthop Rel Res 1988;226:14–20. 23. Marmor L. Unicompartmental arthroplasty of the knee with a minimum ten year follow up period. Clin Orthop Relat Res 1988;(228):171–7. 24. Insall J, Aglietti P. A five to seven year follow up of unicondylar arthroplasty. J Bone Joint Surg Am 1980;62(8):1329–37. 25. Broughton NS, Newman JH, Baily RA. Unicompartmental replacement and high tibial osteotomy for osteoarthritis of the knee. A comparative study after 5-10 years’ follow up. J Bone Joint Surg Br 1986;68(3): 447–52. 26. Scott RD, Cobb AG, Mc Queary FG, Thornhill TS. Unicompartmental knee arthroplasty. Eight to 12 year follow up evaluation with survivorship analysis. Clin Orthop 1991;27:96–100. 27. Stockelman RE, Pohl KP. The long term efficacy of unicompartmental arthroplasty of the knee. Clin Orthop 1991;271:88–95. 28. Chritensen NO. Unicompartmental prosthesis for gonoarthrosis. A nine year series of 575 knees from a Swedish hospital. Clin Orthop 1991;273:165–69. 29. Murray DW, Good fellow JW, O’Connor JJ. The Oxford medial unicompartmental arthroplasty: a ten year survival study. J Bone Joint Surg Br 1998;80:983–89. 30. Ivarsson I, Gillquist J. Rehabilitation after high tibial osteotomy and unicompartmental arthroplasty. A comparative study. Clin Orthop 1991;266:139–44. 31. Newman JH, Ackroyd CE, Shah NA. Unicompartmental or total knee replacement? Five-year results of a prospective, randomised trial of 102 osteoarthritic knees with unicompartmental arthritis. J Bone Joint Surg Br 1998;80(5):862–65. 32. Laurencin CT, Zelicof SB, Scott RD, Ewald FC. Unicompartmental versus total knee arthroplasty in the same patient. A comparative study. Clin Orthop Relat Res 1991;(273):151–56. 33. Dalury DF, Fisher DA, Adams MJ, Gonzales RA. Unicompartmental knee arthroplasty compares favorably to total knee arthroplasty in the same patient. Orthopedics 2009;32(4). 34. Patil S, Colwell CW Jr, Ezzet KA, D’Lima DD. Can normal knee kinematics be restored with unicompartmental knee replacement? J Bone Joint Surg Am 2005;87(2):332–38. 35. Banks SA, Harman MK, Hodge WA. Mechanism of anterior impingement damage in total knee arthroplasty. J Bone Joint Surg Am 2002;84-A(Suppl )2:37–42. 36. Hernigou P, Deschamps G. Alignment influences wear in the knee after medial unicompartmental arthroplasty. Clin Orthop Relat Res 2004;(423):161–65. 37. Hernigou P, Deschamps G. Posterior slope of the tibial implant and the outcome of uni-

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compartmental knee arthroplasty. J Bone Joint Surg Am 2004;86-A(3):506-11. 38. Li G, Papannagari R, Most E, Park SE, Johnson T, Tanamal L, Rubash HE. Anterior tibial post impingement in a posterior stabilized total knee arthroplasty. J Orthop Res 2005;23(3):536–41. 39. Mariani EM, Bourne MH, Jackson, RT, Jackson ST, Jones P. Early failure of unicompartmental knee arthroplasty. J Arthroplasty 2007;22(6 Suppl 2):81–4. 40. Park SE, Lee CT. Comparison of robotic-assisted and conventional manual implantation of a primary total knee arthroplasty. J Arthroplasty 2007;22(7):1054–59. 41. Whiteside LA. Making your next unicompartmental knee arthroplasty last: three keys to success. J Arthroplasty 2005;20(4 Suppl 2):2–3. 42. Borus T, Thornhill T. Unicompartmental knee arthroplasty. J Am Acad Orthop Surg 2008;16(1):9–18. 43. Argenson JN, Chevrol – Benkeddache Y, Aubaniac JM. Modern unicompartmental knee arthroplasty with cement: a three to ten year follow up study. J Bone Joint Surg Am 2002;84 A:2235–39. 44. Argenson JN, Flecher X. Minimally invasive unicompartmental knee arthroplasty. Knee 2004;11:341–47. 45. Argenson JN, Flecher X, Parratte S. Mini invasive implantation of an unicompartmental medial knee prosthesis. Rev Chir Orthop Reparatrice Appar Mot 2006;92:193–39.

Chapter 23

Technique: Fixed Bearing Total Knee Arthroplasty Hemant Wakankar

INTRODUCTION Fixed bearing total knee arthroplasty (TKA) is historically the gold standard and a well-proven concept. Fixed bearing essentially refers to the tibial component that is fixed to the bone either as a monoblock all poly tibial component or a metal tibial tray in which the polyethylene component is locked. The alternative that is becoming popular is the rotating platform in which the tibial polyethylene component is free to rotate on the metal tray. TKA evolved in 1974 with total condylar prosthesis, which originally had an all polyethylene single piece tibial component.1,2 Later, the metalbacked modular tibial component was introduced in the Insall-Burstein (IB) prosthesis. The modularity allowed the surgeon to choose the poly thickness even after the metal tibial tray was cemented in, and soon this became widely popular. The total condylar prosthesis required the sacrifice of the posterior cruciate ligament (PCL) but did not have the mechanism to reproduce the normal tibio-femoral rollback that occurs with flexion. As a result, the flexion was restricted to about 95°. The femoral rollback refers to the tibiofemoral contact point, which moves posteriorly on tibia with increasing flexion in a normal knee and is a function of PCL. With the introduction of cam and post mechanism in the articulation, the consistent rollback was ensured3–5 and the range of movement improved. This is called posterior stabilized (PS) TKA in which PCL is sacrificed. Alternatively, PCL can be preserved in TKA and can be carefully balanced to reproduce the normal rollback. This is called cruciate retaining (CR) TKA (Fig. 23.1). Essentially, PS and CR total knee arthroplasty are two philosophies with no proven superiority of one over the other.6,7 Both are types of fixed bearing TKA. There are differences in the indications, patient selection and the surgical technique of the two. PS TKA can be used universally in all cases, while CR TKA is difficult in knee deformities exceeding 20° in any plane.

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Fig. 23.1 Cruciate retaining (CR) and posterior stabilized (PS) prosthesis. Note the intact posterior cruciate ligament (PCL) with CR total knee arthroplasty (TKA).

POSTERIOR STABILIZED FIXED BEARING TOTAL KNEE ARTHROPLASTY The function of PCL is to provide proprioception and consistent femoral rollback. As the knee advances into flexion, the checkrein effect of posterior cruciate does not allow posterior shift of tibia on femur, and as a result the contact point on tibia shifts posteriorly. The same kinematics is reproduced in PS TKA in which the tibial articulating surface has a peg in the center and the femoral component has a transverse cam that articulates with the tibial peg.

Surgical Technique The TKA essentially consists of three basic bone cuts: 1. Distal femoral cut 2. Proximal tibial cut 3. Posterior femoral cut The aim of these three cuts is to achieve symmetrical, equal and balanced gaps between the femur and tibia in full extension (extension gap) and at 90° of flexion (flexion gap) (Fig. 23.2). All other femoral cuts are necessary to accommodate the femoral component fit on the distal femur. These cuts include anterior cut, anterior and posterior chamfer cuts and the box cut for peg–cam mechanism. Most common surgical technique establishes the extension gap first. One may choose to resect distal femur first and tibia later or vice versa. Other less popular technique establishes the flexion gap first, starting with tibial resection followed by posterior femoral condyles. We describe here our technique of extension gap first.

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Fig. 23.2 Balanced and equal flexion and extension gaps.

Approach Skin is incised in midline with knee in flexion, starting about 2 inches above upper pole of patella and distally to about just medial to the tibial tubercle. The most common approach is the medial parapatellar approach in which arthrotomy starts in the quadriceps tendon, leaving a small cuff of tendon attached to vastus medialis. The arthrotomy is carried around patella medially to just 2 mm medial to the edge of patellar tendon. The medial tibia is exposed by subperiosteal dissection using sharp curved periosteal dissector and the dissection is carried to the posteromedial corner of tibia. Pes anserinus insertion is not violated. The anterior cruciate ligament is cut and the tibia is subluxed forward. Warning During exposure, no dissection is done in the subcutaneous tissue as it can compromise the vascularity of skin. The medial dissection is subfascial to expose the musculotendinous junction of vastus medialis and virtually no lateral dissection is necessary. The medial soft tissue flap from proximal tibia needs to be carefully dissected and subperiosteally elevated so that it can later be closed well to get watertight closure. If this flap gets shredded or is poorly developed, good watertight closure is difficult. It is important not to force the tibia to sublux forward. If with hyperflexion, the tibia does not sublux or if the knee is stiff, put the knee in figure of four position and release the capsule and deep medial collateral ligament (MCL) from the posteromedial tibial rim. If this is inadequate, use a curved sharp osteotome to resect the posteromedial osteophyte without damaging the MCL.

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Distal Femoral Cut The femoral entry point is marked on the line joining the top of the intercondylar notch and the bottom of the trochlear groove (Whiteside’s line), 1 cm anterior to the top insertion of PCL (Fig. 23.3). The entry hole is drilled and over-reamed to accept the medullary canal rod of the jig. It is useful to lavage the medullary canal with long suction tube to reduce incidence of fat embolism. Most systems use intramedullary reference jigs. The angle of resection Fig. 23.3 Entry point for femoral canal is on is judged on the long leg scanogram Whiteside’s line 1 cm anterior to the posdone in neutral rotation, and is usu- terior cruciate ligament (PCL) attachment. ally set at 5–7° to resect perpendicular to mechanical axis. It is important to set the jig completely against the distal surface of femur. In a varus knee, the jig normally touches the lateral femoral condyle with a small gap medially (Fig. 23.4). Opposite is true in a valgus knee. The cutting block is fixed to the anterior aspect of femur with mini- Fig. 23.4 Distal femoral resection angle is mum 3 pins and the jig is taken off. set using intramedullary jig. The distal femur is cut with oscillating saw to resect 9–10 mm of distal femur on the less worn side. Warning Most cutting slots are 1.27 mm wide and recommended saw blade thickness is 1.2–1.25 mm. If a thinner saw blade is used, the resection thickness can vary significantly leading to inaccuracy. The saw should be held firmly with the flat surface of the saw blade kept flush with the distal face of cutting slot. The saw blade should be allowed to move freely without jamming.

Proximal Tibial Cut The tibia is subluxed forwards and a curved Hohmann spike with blunt

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tip is passed behind tibia in front of the PCL. This spike rests of the distal femur and it is important to cushion it with a surgical cotton sponge. One Hohmann 15 mm wide spike is passed laterally beyond the lateral rim of tibial plateau and another medially protecting the medial collateral ligament (MCL) (Fig. 23.5). Most systems use extramedullary alignment jig with ankle clamp. The jig is first placed around the ankle and rotation of the jig is aligned to the junction of medial Fig. 23.5 Proximal tibial resection. Note and central third of the tibial tuber- the use of Hohmann spikes for protection. cle. Proximally, the jig may have a spike that can be fixed to the center of the tibial plateau. The cutting block of the tibia is pushed close to bone and held there. The slope of the cut can vary depending on the prosthesis used and can be 0–7°. Most systems have the slope marked on the cutting block. The long arm of the jig is kept parallel to the shin of tibia. The ankle position of the jig is set next. The center of the ankle joint is medial to the mid-malleolar point and the position of the jig is set accordingly. Other reference landmarks that can be used include tibialis anterior tendon and the second metatarsal. However, in the presence of foot deformities or a very mobile foot, these landmarks are unreliable. After the tibial jig is locked in position, the slope of the cut is checked using angel wing depth resection guage. The level of resection is then referenced on the less worn side using a stylus. In a non-deformed varus knee, 9–10 mm is resected using the lateral side as reference. The cutting block is pinned in place and proximal tibia is resected. Resected proximal tibia is excised and thickness is measured. The tibial jig is then removed. Warning It is important not to use extra long saw blade as it can go beyond the tibia to injure vital structures. The four spikes are used to protect structures: medially protecting medial collateral ligament (MCL), posteriorly protecting neurovascular bundle, two laterally protecting patella and patellar tendon (Fig. 23.5).

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The stumps of the anterior and posterior cruciate ligaments are excised. Any bleeding points are coagulated. The knee is then placed in extension and remaining medial meniscus is excised taking care not to damage the MCL. Extension Gap With knee in extension, extension gap is first visually checked and balance is then checked with spacer blocks. The joint is stressed mediolaterally and any opening on either side is noted. Ideally, with block in extension gap, the joint should open on each side by 1–2 mm (Fig. 23.6). Femoral Sizing Anterior vs. posterior referencing system: The femoral sizing is based on the anteroposterior (AP) dimension of femur and not on mediolateral dimension. The anterior and posterior referencing refers to whether anterior or the posterior cut remains constant with up or downsizing. Majority of systems are anterior referencing Fig. 23.6. Extension gap balance and wherein anterior cut remains constant checking the alignment. and with downsizing, more posterior resection is done, increasing the flexion gap. In posterior referencing system, the posterior resection remains constant and with downsizing, more anterior bone will be resected, which may cause notching of anterior cortex. This is important in situation when the measured size is in between two sizes and one has to choose the upper or the lower size. Generally, in posterior referencing system, one should choose higher size to avoid anterior notching. In anterior referencing system, one should choose lower size so that flexion space is not too tight. Effect of resection of PCL on flexion space: Normally, with resection of PCL, flexion space tends to increase by 2–4 mm. This should be kept in mind before AP resection. If on visual inspection of flexed space, the gap appears larger, one should choose one size higher for less posterior resection (with anterior referencing). If needed, it is easily possible to go to the lower size and resect more bone posteriorly.

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Flexion Space and Femoral Preparation The knee is then distracted in 90° flexion and the flexion space is visually checked. If it appears too tight medially, more external rotation may be necessary. The routine femoral anterior and posterior resection is in 3° of external rotation with reference to the posterior condylar line and therefore more thickness of posterior medial condyle is resected than the lateral side. The femoral sizing jig is placed on distal femur, with posterior arms of the jig resting on the posterior condyles. Anterolateral ridge of femur is the anterior reference point for the sizing. Appropriate rotation is selected and reference pins are placed. The AP cutting block is fixed to the distal femur and flexion space is checked for the last time visually before resecting the anterior and posterior condyles. The chamfer cuts and trochlear cuts, if demanded by the system, are also done at this stage. The block is removed and resected bone is taken off. The knee is placed in acute flexion and posterior osteophytes are resected using a curved osteotome. Spacer block is then inserted in the flexion space at 90° of flexion to check the balance and if it is equal to the extension space. Slightly loose flexion space is acceptable but a flexion space much tighter is likely to cause loss of flexion and one should consider downsizing (in anterior referencing system) to get more flexion space. Warning It is important to protect medial collateral ligament (MCL) while resecting posterior condyles using a 15 mm Hohmann retractor placed in the axilla of MCL. It is important not to resect posterior condyles with uncontrolled saw blade exit. It can cause serious injury to posterior structures (Fig. 23.7).

Intercondylar box cut: The box cutting jig is fixed over the distal femur and using a reciprocating saw, the box cut is done. This concludes the femoral preparation. Tibial Preparation The tibia is sized to accept the baseplate that covers the lateral tibial condyle completely. The rotation is Fig. 23.7 Posterior condyle resection. set to align to junction of medial Note the Hohmann spike protecting the third and lateral two-thirds of the medial collateral ligament (MCL). tibial tubercle. Any excessive promi-

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nent bone on posteromedial side is excised. The tibia is drilled to accept stem as required and broached in correct rotational alignment. Tibial and femoral sizing compatibility: Most systems allow some size mismatch between tibial and femoral sides. However, it is important to know what degree of incompatibility is allowed. In some severely deformed varus knees, it is advisable to downsize and lateralize the tibial component so that reduction osteotomy can be done on the medial tibial flare. In such situation, it is useful to know the femoral size early in surgery, so that the smallest compatible tibial size is known. Patellar Resurfacing If patellar articular surface is worn out and if the patella is at least 20 mm thick, patellar resurfacing can be done. Using either a free hand technique or a patellar clamp, 8–9 mm of articular side of patella is resected parallel to the anterior surface of patella. The cut patellar surface is sized and prepared to accept appropriate patellar button. With the trial patellar button in place, the composite thickness is measured to make sure that there is no overstuffing of patellofemoral joint. Trial Reduction The trial tibial, femoral and patellar components are inserted in place and trial poly component is fitted. The knee is placed through range of motion and the mediolateral stability is observed. In full extension with posterior capsule being tight, there should not be any opening mediolaterally. However, the most important position to assess the stability is about 5–10° of flexion when there should be about 1–2 mm opening on either side. At 90° of flexion, the stability is checked by rocking the tibia sideways. If knee appears lax in both flexion as well as extension, a thicker poly insert is tried. Patellar stability is checked through the range of motion without the thumb on the patella. If at this stage, the patella tends to sublux laterally, tibial rotation is checked. The lateral patellofemoral ligament is released and any tight bands in the lateral retinaculum are palpated. If any such bands are present, they are released. The lateral genicular artery may pass within these bands and should be preserved if possible. Things to Check on Trial Reduction s Mediolateral stability in: Full extension

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s s s s

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90° flexion 5–10° flexion Residual flexion deformity Patellar tracking without thumb on the patella Tight lateral patellar bands Tibial component rotational alignment

Cementing the Final Implants If the trial reduction is satisfactory, the final implants are called for and opened from sterile packing. The trial prostheses are removed and the knee is thoroughly irrigated with pulsatile lavage. The cancellous surfaces are thoroughly cleaned for good cement interdigitation. It is a good protocol to have every member of the surgical team change gloves prior to handling the sterile prosthesis. Polymethyl-methacrylate bone cement is mixed as appropriate, and time since mixing is tracked. We prefer to complete cementation of all components using a single 40 g mix of cement. We start with patellar cementing at about 1 min after mixing (if patella is being resurfaced). Next we cement tibial component to be followed by femoral component. It is vital that tibial component rotation is paid attention to. While inserting femoral component, care is taken so that the posterior condyles of the prosthesis do not scratch against the tibial surface. All excess cement is removed carefully. We prefer to fit in final polyethylene tibial insert before releasing the tourniquet. The knee is maintained in full extension so that cement is pressurized. Tourniquet is then released and haemostasis is achieved. Closure is done in layers with a watertight closure of the arthrotomy. Tips for Avoiding Intraoperative Complications s Use good quality saw and drill system. s Use new saw blade of correct thickness (usually 1.2 mm) for each case. s Always measure the resected bone thickness of distal femur and proximal tibia. s Plan for the level of resection based on the ligamentous stretching. s Protect patellar tendon and medial collateral ligament (MCL) while resecting bone. s Flexion and extension gap balancing is critical for function and longterm survival of prosthesis. s Patellar tracking depends on rotational alignment of both tibial and femoral components. Internal rotation of both tibial and femoral component is strictly avoided.

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Cruciate Retaining Total Knee Arthroplasty Posterior CR TKA has certain technical variations from PS TKA and cannot be performed in all cases. If PCL is stretched or contracted significantly, it is functionally incompetent. Generally, deformities more than 20° in any plane warrant use of PS TKA. As most of the surgical procedure is same, only the differences with the PS TKA are discussed here. Technique Variations for Cruciate Retaining Total Knee Arthroplasty 1. Distal femoral resection: For CR TKA, it is useful to be conservative with distal femoral resection. As stated earlier, during PS TKA, resection of PCL can increase flexion space by 2–4 mm and to increase the extension apace, extra distal femoral resection may be beneficial. For CR TKA, such adjustment is not likely, hence, conservative resection is warranted. 2. Slope of tibial resection: PCL can act as a tether to the flexion gap and it is important to reproduce native slope of the tibia to avoid flexion gap tightness. 3. Balancing of PCL – Pull out lift off (POLO) test8: During trial reduction, with patella relocated and not everted, laxity or tightness of PCL is assessed as follows. In the pull out test, with knee in flexion, attempt is made to pull out the tibial insert from under the femur. If the tibial insert is easily pulled out, increasingly thicker inserts are tried to achieve stability in flexion. In lift off test, if the trial tibial component lifts off anteriorly, it suggests tightness of PCL. Another sign is failure of tibial component to completely locate under the femoral component. If PCL is tight, anterior and lateral fibers can be released from femur. Excessive PCL release may make it incompetent. PCL laxity can also be tested by applying posterior pressure to upper tibia to see if tibia subluxes posteriorly. Significant posterior shift would suggest laxity of PCL and may warrant the use of PS TKA.

REFERENCES 1. Insall JN, Scott WN, Ranawat C. The total condylar prosthesis: a report of two hundred and twenty cases. J Bone Joint Surg 1979;61 A:173–80. 2. Insall JN, Hood RW, Flawn LB, Sullivan DJ. The total condylar prosthesis in gonarthrosis: a five to nine year follow up of the first one hundred consecutive replacements. J Bone Joint Surg 1983;65 A:619–28. 3. Dennis DA, Komistek RD, Hoff WA. In vivo knee kinematics derived using an inverse

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perspective technique. Clin Orthop Relat Res 1996;331:107–17. 4. Ranawat CS, Komistek RD, Rodriguez JA, Dennis DA, Anderle M. In vivo kinematics for fixed and mobile-bearing posterior stabilized knee prosthesis. Clin Orthop Relat Res 2004;418:184–90. 5. Baier C, Springorum HR, Gotz J, et al. Comparing navigation based in vivo kinematics pre and post-operatively between a cruciate-retaining and a cruciate-substituting implant. Int Orthop 2013;37:407–14. 6. Becker MW, Insall JN, Faris PM. Bilateral total knee arthroplasty: one cruciate retaining and one cruciate substituting. Clin Orthop Relat Res 1990;271:122–24. 7. Swanik CB, Lephart SM, Rubash HE. Proprioception, kinesthesia and balance after total knee arthroplasty with cruciate retaining and posterior stabilized prosthesis. J Bone Joint Surg Am 2004;86A:328–34. 8. Scott RD, Chmell MJ. Balancing the posterior cruciate ligament during cruciate-retaining fixed and mobile bearing total knee arthroplasty: description of pull-out lift-off and slide-back tests. J Arthrop 2008;4:605–08.

Chapter 24

Mobile-Bearing Total Knee Arthroplasty: Technique and Clinical Results* Charlie C. Yang, Douglas A. Dennis

INTRODUCTION Early condylar total knee arthroplasty (TKA) designs were primarily implanted in elderly, low-demand patients with debilitating pain and loss of function. The excellent 10-to-15 year clinical outcomes in this patient cohort1–5 has led surgeons to perform TKA on younger patients who have higher functional demands and the need for increased implant longevity. Increased patient expectations for a longer-lasting knee replacement have driven advances in implant design and surgical technique. Many first generation TKA designs resulted in early clinical failure secondary to malalignment, instability and the use of excessive prosthetic constraint. Premature aseptic component loosening was common due to the increased stresses occurring at the fixation interface. Later iterations of TKA focused on reducing constraint and conformity at the expense of detrimental effects on the articular surface, resulting in accelerated polyethylene wear. The mobile-bearing (MB) TKA was designed with the intention of allowing increased implant conformity with reduced polyethylene loads while concomitantly reducing stresses to the fixation interface. MB TKA designs offer the theoretical advantage of increased implant conformity and contact area while minimizing stresses transmitted to the fixation interface.6 The dual articulation also reduces polyethylene cross-shear stresses and wear to subsequently decrease the rate of revision TKA.7 This uncoupled motion through the tibial tray-polyethylene bearing articulation *Acknowledgement: We acknowledge the permission granted by World Scientific Publishing Company to reproduce the parts of this chapter that appeared in “Raymond H. Kim and Douglas A. Dennis. Mobile Bearing Total Knee Arthroplasty: Technique and Results. In: Giles R Scuderi (Insall Scott Kelly Institute, USA), Alfred J Tria Jr (Robert Wood Johnson Medical School, USA) Eds.The Knee: A Comprehensive Review. pp. 467-485. Copyright© 2014 World Scientific Publishing Co.”

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theoretically minimizes the transfer of torsional stresses to the fixation interface that are present with fixed-bearing TKA prosthetic designs. This chapter addresses the surgical technique principles for implanting a MB TKA and the clinical outcomes with use of these designs.

SURGICAL TECHNIQUE Meticulous attention to symmetric ligament balancing, reproduction of neutral mechanical alignment and creation of balanced flexion and extension gaps are critical for the long-term success of both fixed-bearing and MB TKA. Proper attention to these fundamental concepts will result in more uniform loading of the articular bearing surface rather than placing excessive eccentric loads on either the medial or lateral aspects of the polyethylene surface. Failure to obtain flexion–extension gap balance is of particular importance in the use of a MB TKA due to the risk of bearing dislocation or ‘spin-out.’ The authors favor the use of a gap-balancing methodology rather than measured resection techniques when implanting MB TKA because adequate coronal plane stability is more reproducibly obtained.8 Balanced flexion and extension gaps can be achieved by several methods. The authors initially assess and balance the extension gap prior to addressing the flexion gap and establishing the femoral component rotation. After the distal femur and proximal tibial cuts are made, all remaining osteophytes must be removed due to their tensioning effect on adjacent soft tissue structures. The extension gap should then be assessed for gap height and symmetry medially and laterally. This can be performed using spacer blocks, laminar spreaders or other tensioning devices. If the extension gap is asymmetric medially compared to laterally, appropriate releases should be performed at this time to obtain a balanced extension gap. When implanting an MB TKA, a laxity of 1–2 mm medially and laterally with firm varus and valgus stress testing is desired. Appropriate rotation of the femoral component is an essential component of obtaining a balanced flexion gap. Numerous methods are available to assist in gaining correct rotation of the femoral component (Fig. 24.1).9–16 Techniques include: (i) use of cutting jigs which rotate the femoral component a predetermined amount (typically 3–5°) externally relative to the posterior condylar axis;9 (ii) femoral component placement either parallel to the trans-epicondylar axis10–12 or perpendicular to the anterior–posterior axis (Whiteside’s line);13 or (iii) by utilizing the gap-

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3° external rotation vs. the posterior condylar axis

Parallel to the transepicondylar axis

Perpendicular to the anterior-posterior axis

Fig. 24.1 Diagram demonstrating the transepicondylar (TEA), anterior–posterior (AP), and posterior condylar (PCA) axes used for determination of femoral component rotation when using a measured resection technique.

balancing method in which the femoral component is placed parallel to the tibial cut with the medial and lateral collateral ligaments equally tensioned.14–16 All methods have been shown to have potential shortcomings and combined use of all rotational landmarks is wise. The critical step in the use of gap-balancing involves positioning of the anterior–posterior cutting block, which determines the rotation of the femoral component. This block is positioned anteriorly or posteriorly to ensure that the flexion gap height is equal to the extension gap height without notching the femur. A decision about femoral component size is confirmed at this point. Using tensioning devices (laminar spreaders, spacer blocks, or a specific gap tensioning device), the rotation of the anterior–posterior cutting block is then appropriately adjusted rotationally to ensure that the flexion gap space itself is symmetric medially and laterally and parallel to the tibial cut with each Fig. 24.2 Intra-operative photograph collateral ligament equally tensioned demonstrating the gap-balancing tech). Secondary checks nique to establish femoral component (Fig. 24.2 rotation to ensure a symmetric flexion are then performed to ensure reagap medially and laterally and parallel to sonable rotational position relative to the tibial cut with the collateral ligaments the transepicondylar and anterior– equally tensioned. posterior axes. Lastly, before anterior

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and posterior femoral resections are performed, the authors remove the laminar spreaders and insert a spacer block (same width as the extension gap) between the inferior aspect of the cutting block and the resected tibia. The spacer block handle is then torqued to assure symmetry of the flexion gap (Fig. 24.3). Use of this technique facilitates obtaining balanced flexion and extension gap heights, and a rectangular flexion gap that is symmetric medially and Fig. 24.3 Intra-operative photograph laterally. If the anterior–posterior demonstrating placement of a spacer cutting block is positioned paral- block (same width as utilized in creation lel to the resected tibia and there of the extension gap) into the flexion gap is substantial divergence from the to ensure appropriate width and symmetry before performing the anterior and transepicondylar and anterior–pos- posterior femoral condylar resections. terior axes, one of three things has occurred. Either the axes have been constructed in error, there is an error in the proximal tibial resection, or the flexion gap stabilizers (superficial medial collateral ligament medially or lateral collateral ligament and popliteus tendon laterally) are incompetent. Inability to obtain flexion–extension gap balance or substantial incompetence of the collateral ligamentous structures should prompt consideration of using a fixed-bearing TKA or use a more constrained MB device to reduce the risk of polyethylene bearing spin-out. When equal flexion–extension gap balance cannot be obtained, most commonly in cases with collateral ligament insufficiency, the authors prefer the use of a constrained condylar rotating platform (RP) TKA. In scenarios with severe deformities with tibial plateau defects and as to which bone grafting or use of a modular tibial augment is required, the authors consider use of a modular stem extension in these cases. Large, posterior femoral osteophytes can impinge on the RP bearing in deep flexion and should be removed. After making the anterior and posterior condylar resections on the distal femur, the knee can be placed at 90° of flexion with the flexion gap distracted with a laminar spreader. A three-quarter-inch curved osteotome can then be used to sharply remove the posterior osteophyte at the osteochondral junction of both condyles (Fig. 24.4). The flexion and extension gaps can then be

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Fig. 24.4 Intraoperative photograph demonstrating removal of posterior femoral osteophytes using a curved osteotome.

reassessed to determine if further balancing is required. In cases with massive posterior compartment osteophytes, it is wise to attempt to remove them before extensive soft tissue releases are performed since removal of large osteophytes can have a dramatic effect on both the coronal and sagittal plane soft tissue balance. Due to the self-aligning mechanism of the RP polyethylene bearing with the femoral component, tibial component rotation can be determined based on the anatomy of the resected tibial surface rather than its position relative to the tibial tubercle. The self-aligning behavior of the rotating bearing maintains congruency of the femorotibial articulation during both flexion–extension and axial rotation of the knee,17 which is much more difficult to achieve in fixed-bearing TKA designs. An additional advantage of the self-aligning feature of RP TKA systems is facilitation of central patellar tracking.3,18 In a fixed-bearing TKA, if substantial malrotation of the tibial component relative to the femoral component is present (especially tibial component internal rotation), the tibial tubercle can become lateralized, enhancing the risk of patellar subluxation. An RP design, through bearing rotation, typically provides for greater self-correction of rotational component malalignment, allowing better centralization of the extensor mechanism. A study of over 1300 consecutive primary TKAs performed at our institution comparing the lateral release rates in fixed vs. MB TKA revealed a lateral release rate in the fixed-bearing group of 14.3% (54 of 378) compared to 5.3% (50 of 940) in the MB group (p < 0.0001).18

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CLINICAL OUTCOMES Excellent long-term clinical results with minimal loosening rates have been reported in numerous studies of MB TKA. Callaghan et al.3 evaluated the 15-year results of the LCS RP design (Depuy, Inc., Warsaw, IN) and reported no failures secondary to loosening, osteolysis, wear, or bearing instability. In the initial early combined experience with the low contact stress (LCS) meniscal bearing and RP systems, Buechel and Pappas2 reported 95.1% and 98.2% (cemented and cementless) good to excellent results at a follow-up period of up to 10 years. When evaluating only the RP LCS system, Buechel et al.19 reported survivorship rates of 97.7% at both 10 and 20 years with end-points defined as revision for any mechanical reason or a poor clinical knee score. Survivorship of the cementless LCS RP system with loosening as the end-point was determined to be 99.4% at 20 years.1 Various studies evaluating primary TKA using the RP system reported no evidence of radiographic loosening, even at 20-year radiographic follow-up and report that revision TKA was required in 0–0.2% due to aseptic loosening.1–3,19 Carothers et al.20 performed a meta-analysis of clinical results of MB TKA and found survivorship of RP designs to be 96.4% at 15 years. Mean component loosening was 0.33%. Bearing complication rate (fracture or spin-out) in studies reported after 1995 was 0.1%

SUMMARY Basic science evaluation of MB TKA demonstrates many potential advantages including reduced polyethylene wear by providing improved implant conformity, reduced cross-shear stresses and reduced stresses in the presence of femoral condylar lift-off. Additionally, lessened fixation stresses are observed. Use of a surgical technique which assists in obtaining flexion– extension gap balance and symmetry is critical to obtain successful results. Multiple studies have demonstrated excellent long-term clinical results with a very low incidence of aseptic loosening, polyethylene wear, bearing instability, or failure due to backside wear of the mobile polyethylene bearing.

REFERENCES 1. Buechel FF, Sr. Long-term follow-up after mobile-bearing total knee replacement. Clin Orthop 2002;404:40–50. 2. Buechel FF, Pappas MJ. New Jersey low contact stress knee replacement system:

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Ten-year evaluation of meniscal bearings. Orthop Clin North Am 1989;20:147–77. 3. Callaghan JJ, O’Rourke MR, Iossi MF, Liu SS, Goetz DD, Vittetoe DA, Sullivan PM, Johnston RC. Cemented rotating-platform total knee replacement. A concise follow-up, at a minimum of fifteen years, of a previous report. J Bone Joint Surg (Am) 2005;87(9):1995–98. 4. Ranawat CS, Boachie-Adjei O. Survivorship analysis and results of total condylar knee arthroplasty: Eight- to 11-year follow-up period. Clin Orthop 1998;226:6–13. 5. Schai PA,Thornhill TS, Scott RD. Total knee arthroplasty with the PFC system: Results at a minimum of ten years and survivorship analysis. J Bone Joint Surg (Br) 1998;80:850–58. 6. Bottlang M, Erne OK, Lacatusu E, Sommers MB, Kessler O. A mobile-bearing knee prosthesis can reduce strain at the proximal tibia. Clin Orthop Relat Res 2006;447:105–11. 7. Callaghan JJ, Insall JN, Greenwald AS, Dennis DA, Komistek RD, Murray DW,Bourne RB, Rorabeck, CH, Dorr, LD. Mobile-bearing knee replacement: Concepts and results. J Bone Joint Surg Am 2000;82:1020–41. 8. Dennis DA, Komistek RD, Kim RH, Sharma A. Gap balancing versus measured resection technique for total knee arthroplasty. Clin Orthop Relat Res 2010;468(1):102–07. 9. Nagamine R, Miura H, Inoue Y, Urabe K, Matsuda S, Okamoto Y, Nishizawa M, Iwamoto Y. Reliability of the anteroposterior axis and the posterior condylar axis for determining rotational alignment of the femoral component in total knee arthroplasty. J Orthop Sci 1998;3(4):194–98. 10. Berger RA, Rubash HE, Seel MJ, Thompson WH, Crossett LS. Determining the rotational alignment of the femoral component in total knee arthroplasty using the epicondylar axis. Clin Orthop Relat Res 1993;(286):40–7. 11. Griffin FM, Math K, Scuderi GR, Insall JN, Poilvache PL. Anatomy of the epicondyles of the distal femur: MRI analysis of normal knees. J Arthroplasty 2000;15(3):354–59. 12. Poilvache PL, Insall JN, Scuderi GR, Font-Rodriguez DE. Rotational landmarks and sizing of the distal femur in total knee arthroplasty. Clin Orthop Relat Res 1996; (331):35–46. 13. Whiteside LA, Arima J. The anteroposterior axis for femoral rotational alignment in valgus total knee arthroplasty. Clin Orthop Relat Res 1995; (321):168–72. 14. Dennis, DA. Measured resection: an outdated technique in total knee arthroplasty. Orthopedics 2008; 31(9):940, 943–44. 15. Fehring TK. Rotational malalignment of the femoral component in total knee arthroplasty. Clin Orthop Relat Res 2000;380:72–9. 16. Katz MA, Beck TD, Silber JS, et al. Determining femoral rotational alignment in total knee arthroplasty: reliability of techniques. J Arthroplasty 2001;16(3):301–05. 17. Stukenborg-Coleman C, Ostermeier S, Hurschler C, Wirth CJ. Tibiofemoral contact stress after total knee arthroplasty: comparison of fixed and mobile-bearing inlay designs. Acta Orthop Scand 2002;73:638–46. 18. Yang CC, McFadden LA, Dennis DA, Kim RH, Sharma A. Lateral Retinacular Release Rates in Mobile- versus Fixed-bearing TKA. Clin Orthop Rel Res 2008;466(11): 2656–61. 19. Buechel FF Sr, Buechel FF, Jr, Pappas MJ, Dalessio J. Twenty-year evaluation of the New Jersey LCS rotating platform knee replacement. J Knee Surg 2002;15:84–9. 20. Carothers JT, Kim RH, Dennis DA, Southworth C. Mobile-bearing total knee arthroplasty: a meta-analysis. J Arthroplasty 2011;26(4):537–42.

Chapter 25

Management of Tibial Bone Defects Rajesh N. Maniar, Vipan Kumar

INTRODUCTION Tibial defects are often encountered at primary knee arthroplasty, in relation to either severe deformity, osteoporotic bone, osteonecrosis, bone cyst or old injury. They pose a unique problem to achieving adequate support and fixation of the tibial component. One needs to address them effectively to obtain a uniform and successful outcome.

CLASSIFICATION Based on Location of Defect Peripheral defects: commonly seen with varus knee; they typically appear posteromedial or anteromedial in location (Fig. 25.1). Central defects: commonly seen in valgus knee and rheumatoid knee (Fig. 25.1). The significance of location of the defect is that a central defect would have a good cortical rim and would only need to be filled with either cement or cancellous bone graft, whereas the peripheral defect would need additional support without which there is a risk of implant collapse into the defect. Fig. 25.1 Radiograph showing one side varus deformity with other side valgus deformity. Corresponding cut bones in the inset show peripheral defect on varus side and central defect on valgus side.

Based on Size of Defect Rand classified these defects according to the extent of involvement of the tibia or femoral condyle

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(Table 25.1).1 Rand classification helps to grade the defect and manage it accordingly. Larger the defect, less is the support to the implant and more aggressive is the treatment needed. Table 25.1 Rand classification of bone loss1 Type a: Intact peripheral rim b: Deficient peripheral rim

Single condyle/hemiplate involvement

Depth (mm)

1.(a,b)

Minimal 90%

>10

MANAGEMENT OPTIONS There are several ways to address tibial defects effectively. First, one can consider ways to minimize the defect, and then select the best option to fill the residual defect. Finally, it is imperative to assess the need for additional support to the construct, which can be provided by a tibial stem extension.

Tricks to Minimize the Extent of Defect 1. Tibial resection through the base of defect. 2. Down sizing or Lateral translation of tibial component. Tibial Resection Through the Base of Defect Tibial resection through the base of defect is easy and therefore often a practised method to deal with eliminating bone defect. However, resection level should remain proximal to the Gerdy’s tubercle, otherwise function of the ilio-tibial band would be compromised. It should be noted that with greater tibial resection, the size of the component would also decrease, reducing contact area and increasing per unit load. Besides, the tibial surface becomes weaker if subchondral bone is completely removed. It has been documented that the strength of cancellous bone in the proximal tibia decreases rapidly 5 mm distal to the subchondral bone.13 Hence extra bone resection should not be the preferred method for managing bone deficiency (Fig. 25.2).

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Advantage

Disadvantages

1. Easy

1. Smaller size tibial tray, more load on implant and bone. 2. Weakened support for tibial tray with greater tibial resection.

A distal tibial cut should be avoided as far as possible, also because in these cases with severe deformity the knee is already lax on the lateral side. A distal tibial cut would necessitate a thicker poly. Hence, tibial cuts should be limited in depth, and one of the options described later should rather be used to deal with the residual defect left after the limited tibial cut.

Fig. 25.2 Radiographs showing the level of tibial cut. Image on the right is the preferred level.

Lateral Translation of Tibial Component Rationale

Lateralization of the smaller tibial component reduces the extent of peripheral bone defect under it (Fig. 25.3). Lotke presented a study on this technique in two groups, one had an average defect of 13.5 mm, other group had a defect of 27.5 mm. There were no failures in the either group but the overall knee score was better with lesser defect.17

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Advantages Disadvantages 1. Quick, not time consuming. 1. A smaller size tibial tray implies more 2. Easy to perform. load on implant and bone. 3. Economical. 2. Changes the axis of tibia. 3. Mechanically, it is not a sound technique. Technique

1. If suitable, select one size smaller tibial component. Place it lateral most, yet contained within the cut tibial surface. 2. There should be no overhanging of the plate on the lateral side.

Fig. 25.3 Downsizing the tibial component with lateralization done to reduce the extent of peripheral tibial defect.

OPTIONS TO FILL THE DEFECT Cementing or Cement with Screw Use of cement in filling the defect is a viable option as cement can be easily moulded to any size or dimension of the defect. Lotke et al., and Ritter and Harty have observed good medium- or long-term results with cement fill.4,16 However, the support provided by cement fill may not be mechanically adequate.3,4 Lotke et al. described reasonable results with cement but preferred bone grafting for defects greater than 20 mm.4 Elia and Lotke found no difference in short-term results between the use of cement and bone grafts for revision total knee replacement (TKR) and small defects.5

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In a cadaveric study comparing five different techniques for reconstruction of medial tibial plateau bony defects, it was reported that tibial component displacements under axial and varus-directed loads, respectively, were 100% and 100% for the cement alone construct, 70% and 72% for cement with screw augmentation, 32% and 44% for the polymethylmethacrylate (PMMA) wedge, 17% and 32% for the metal wedge, and 9% and 17% for the custom implant. The cement alone construct provided least stability.3 Cement is not a biological scaffold, it may cause thermal necrosis of the surrounding bone and damage blood supply to the bone, which could be a cause for long-term loosening of the prosthesis.8 However, cement can achieve similar stability as impaction bone grafting and structural allografting when used for a 4-mm medial tibial bone defect.2 For small bone defects, cement with screw fixation resulted in 30% less displacement of the prosthesis than cement alone in tibial wedge defect reconstruction.3,9 In 57 patients with tibial defects of mean 9 mm height, followed up for a minimum of 3 years, 25% had nonprogressive radiolucency at the cement interface, but none of the components failed.15 There was no progression of radiolucent lines in either the bone–cement or the cement–prosthesis interface after 7 years.17 The radiolucency probably existed at the time of surgery and could be due to poor penetration of the cement into sclerotic bones.18 Radiolucent lines can also occur because cement contracts on final setting. It is thus advocated to make multiple holes on the tibial bed for better penetration of the cement. Authors recommend the use of cement alone only in defects less than 5 mm (Fig. 25.4). For defects greater than 5 mm, if one opts to use cement, a stabilizing screw should be additionally used to strengthen the construct.

Fig. 25.4 Intra operative photographs showing a small (