Cervical Spine Surgery: Standard and Advanced Techniques: Cervical Spine Research Society - Europe Instructional Surgical Atlas [1st ed.] 978-3-319-93431-0;978-3-319-93432-7

This comprehensive, up-to-date textbook of modern cervical spine surgery describes the standard and advanced techniques

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Cervical Spine Surgery: Standard and Advanced Techniques: Cervical Spine Research Society - Europe Instructional Surgical Atlas [1st ed.]
 978-3-319-93431-0;978-3-319-93432-7

Table of contents :
Front Matter ....Pages i-xvii
Front Matter ....Pages 1-1
Introduction: Cervical Approaches, Access Ranges and Indications (Andre Jackowski)....Pages 3-6
Upper Cervical Spine: A Surgical Challenge—Past, Present, and Future (Eva-Maria Buchholz)....Pages 7-8
Subaxial Cervical Spine: Past, Present and Future (Johannes Schröder)....Pages 9-11
Concepts of Posterior Decompressive Surgery (Ken Ishii, Tateru Shiraishi)....Pages 13-15
Positioning for Anterior and Posterior Procedures (F. Cuzzocrea, M. Ghiara)....Pages 17-19
Front Matter ....Pages 21-21
Surgical Anatomy of the Upper Cervical Spine and the Craniocervical Junction (Gergely Bodon, Bernhard Hirt)....Pages 23-32
Relevant Surgical Anatomy of the Anterior Cervical Spine, the High Retropharyngeal and the Subaxial Regions (Gergely Bodon, Andres Combalia)....Pages 33-41
Relevant Surgical Anatomy of the Posterior Subaxial Spine and the Cervicothoracic Junction (Gergely Bodon, Andres Combalia)....Pages 43-49
Front Matter ....Pages 51-51
Surgical Approach: High Anterior Cervical (Rafael González-Díaz, Rosa María Egea-Gámez)....Pages 53-58
Surgical Approach: Anterolateral High Cervical Approach (Philippe Bancel)....Pages 59-64
Standard Transoral Approach to the Craniocervical Junction and Upper Cervical Spine (Brian J. Dlouhy, Arnold H. Menezes)....Pages 65-69
Combined Transoral and Transmandibular Approach: Labiomandibular Approach with or Without Glossotomy (Brian J. Dlouhy, Arnold H. Menezes)....Pages 71-74
Endonasal Approach to the Craniocervical Junction (Jens Lehmberg, Bernhard Meyer)....Pages 75-79
Posterior Midline Approach C0–C2: How to Expose Meticulously with Less Bleeding (Takachika Shimizu)....Pages 81-88
Surgical Approach: Posterior Far-Lateral Suboccipital Approach (Gergely Bodon, Dezsö Jeszenszky)....Pages 89-96
Anterior Subaxial Approach (Jörg Klekamp)....Pages 97-101
Anterolateral Approach to Subaxial Segment of the Cervical Vertebral Artery (Abolfazl Rahimizadeh)....Pages 103-112
Posterior Median Access to the Subaxial Spine (Michael Mayer)....Pages 113-117
Transmanubrial Cervicothoracic Approach (Christian Mazel, Dominique H. Grunenwald)....Pages 119-123
Manubriotomy/Sternotomy Access to the Cervicothoracic Junction (Jan Štulík, Petr Nesnídal)....Pages 125-130
Front Matter ....Pages 131-131
Transoral Biopsy: Surgical Technique (Alexander Mushkin, Alexander Gubin)....Pages 133-138
Odontoid Fracture: Anterior Screw Fixation (Anton Kathrein)....Pages 139-143
C1–C2 Trans-Oral Release and Reduction (Chao Wang, Xu Nuang, S. Wang)....Pages 145-152
C1–C2 Anterior Transarticular Fixation and Grafting (Christoph Josten, Ulrich J. Spiegl)....Pages 153-157
Transoral Odontoidectomy for Decompression of Basilar Invagination (Brian J. Dlouhy, Arnold H. Menezes)....Pages 159-165
Transoral Odontoid Resection (Heinrich Boehm, Mootaz Shousha)....Pages 167-173
Transoral Atlantoaxial and C2 Corpectomy Cage Reconstruction Techniques (Dezsö Jeszenszky, Markus Loibl)....Pages 175-181
Total Spondylectomy of C2 (Petr Vachata, Petr Suchomel)....Pages 183-187
Congenital Muscular Torticollis Correction (Philippe Bancel)....Pages 189-193
Anterior Vertebral Artery Mobilization (Philippe Bancel)....Pages 195-200
C1-Ring Osteosynthesis for Unstable, Jefferson Burst Fractures (Jason L. Pittman, Richard J. Bransford)....Pages 201-206
Occipital Condyle Screw Placement for Occipitocervical Fixation (Scott J. Raffa, Juan Uribe)....Pages 207-212
Upper Cervical Techniques: Pediatric Wiring (Philippe Bancel, Takachika Shimizu)....Pages 213-218
Upper Cervical: Occipital‑Cervical Fixation—Median, Lateral and Multihole (Adrian Casey)....Pages 219-223
Atlantoaxial Instability: Strategy for Treatment (Atul Goel)....Pages 225-237
Posterior Transarticular Screw Fixation C1-C2 (Bernhard Jeanneret)....Pages 239-243
Transarticular Screw C1-C2 Fixation: Minimal Invasive with Percutaneous Screw Placement (Juan Barges Coll, John M. Duff)....Pages 245-251
C1 Lateral Mass Screw Fixation (Christoph E. Heyde, Yohan Robinson)....Pages 253-257
Surgical Techniques: Upper Cervical—C2 Pedicle Screw Fixation Technique (Hideki Sudo, Kuniyoshi Abumi)....Pages 259-264
C1 Posterior Arch Screw Fixation (Jin S. Yeom)....Pages 265-269
C1 Translaminar Screw Fixation (Haydn Hoffman, Heiko Koller, Daniel C. Lu)....Pages 271-276
Posterior C1–C2 Fusion with the C1 Claw Device (Anna-Lena Robinson, Claes Olerud)....Pages 277-280
C2 Laminar Screw Fixation (Ilyas Aleem, Brad Currier)....Pages 281-289
Upper Cervical Spine-Posterior Cage Reconstruction C1–C2 (Corinna C. Zygourakis, Christopher P. Ames)....Pages 291-295
C1 Posterior Arch Laminoplasty (Jin S. Yeom)....Pages 297-301
Anterior Cervical Foraminotomy (Andre Jackowski)....Pages 303-308
Anterior Decompression: Discectomy and Uncotomy–Open Technique (Meric Enercan, Azmi Hamzaoglu)....Pages 309-315
Microscopic Anterior Cervical Decompression (Sebastian Hartmann, Anja Tschugg, Claudius Thomé)....Pages 317-323
Oblique Corpectomy (Ronald H. M. A. Bartels)....Pages 325-328
Anterior Cervical Corporectomy and Fusion (Hugues Pascal-Moussellard, Caroline Hirsch)....Pages 329-335
Anterior Transpedicular Screw Plate Fixation (Zhengfeng Zhang)....Pages 337-342
Surgical Technique for a Cervical Disc Arthroplasty (Gregory D. Schroeder, Alan S. Hilibrand)....Pages 343-348
Surgical Technique, Subaxial Spine: Cervical Disc Replacement Revision Surgery (Justin A. Iorio, Stelios Koutsoumbelis, Han Jo Kim, Todd J. Albert)....Pages 349-354
Subaxial Cervical Reconstruction of Multilevel Corpectomies and Skip Corpectomies (Mena Kerolus, Vincent Traynelis)....Pages 355-359
Anterior Reconstruction with Microvascular Grafts (Tianyi Liu, Andres Rodriguez-Lorenzo)....Pages 361-365
Corpectomy: Floating Method for OPLL (Toshitaka Yoshii, Masato Yuasa, Atsushi Okawa)....Pages 367-374
Subaxial Cervical Spondylectomy (Jan Štulík, Zdeněk Klézl)....Pages 375-380
Cervical Rib Resection (Mimmie Kwong, Nasim Hedayati, Julie Anne Freischlag)....Pages 381-387
Halo-Ring and Halo-Vest Fixation and Treatment: Adult and Pediatric Patients (Bengt Lind)....Pages 389-394
Technique of Cervical Traction (Philippe Bancel, J. F. Dubousset)....Pages 395-402
Posterior Cervical Foraminotomy (Christine Boone, Thomas Mroz, C. Rory Goodwin, Timothy Witham, Daniel Sciubba)....Pages 403-410
Posterior Microdiscectomy (Bastian Storzer, Heiko Koller)....Pages 411-416
Expansive Open-Door Laminoplasty for Cervical Myelopathy (Kazuhiro Chiba, Takashi Tsuji)....Pages 417-424
French-Door Laminoplasty for Cervical Compressive Myelopathy (Yasutsugu Yukawa)....Pages 425-431
Laminectomy with Fusion for Cervical Spondylotic Myelopathy (Ronald H. M. A. Bartels)....Pages 433-435
Selective Cervical Laminectomy of Limited Width by Muscle-Sparing Technique Using Anatomical Plane Exposures (Tateru Shiraishi, Ryoma Aoyama)....Pages 437-441
Cervical Hook Fixation (Carmen L. A. Vleggeert-Lankamp)....Pages 443-448
Pedicle Screw Fixation in Cervical Spine (Yasutsugu Yukawa)....Pages 449-454
Percutaneous Pedicle Screw Fixation in the Cervical Subaxial Spine (Nils Hansen-Algenstaedt, Alf Giese)....Pages 455-464
Surgical Techniques: Subaxial Cervical—Modified Subaxial Paramedian Transpedicular Approach and Reconstruction (Vance L. Fredrickson, Martin H. Pham, Frank L. Acosta)....Pages 465-468
Lateral Mass Screw Fixation (Bruce D. Darden, Marco C. Mendoza)....Pages 469-473
Surgical Techniques: Sublaminar Wiring for Long Posterior Fixation (Takachika Shimizu)....Pages 475-481
Reduction of Locked Cervical Facets: Manual, Anterior Open, Posterior Open (T. Cloché, Y. Legallois, J. M. Vital)....Pages 483-487
Surgical Technique: Posterior Subaxial Cervical Spine, Subaxial Transarticular Screw Fixation (Stelios Koutsoumbelis, Justin Iorio, Todd Albert)....Pages 489-492
Surgical Techniques–Subaxial Cervical: Upper Thoracic Pedicle Screw Fixation (Sebastian Decker, Axel Hempfing)....Pages 493-498
Management of Anterior Durotomy in Cervical Spine (Macondo Mochizuki, Masao Koda)....Pages 499-503
Cervical Posterior Durotomy Repair (A. Tomasino)....Pages 505-510
Treatment of Acute Vertebral Artery Injury (VAI) (Jin S. Yeom)....Pages 511-515
Treatment of Pharyngoesophageal Injuries in Cervical Spine Surgery (Brandon P. Hirsch, Mark D. DeLacure, Themistocles S. Protopsaltis)....Pages 517-523
Cervical and Cervicothoracic Osteotomies: Introduction Concepts, Planning, and Performance (Heiko Koller)....Pages 525-547
Ponte Osteotomy (Pedro Berjano, Claudio Lamartina)....Pages 549-554
Surgical Techniques: Cervical Osteotomies—Anterior Osteotomy With/Without Corpectomy (K. Daniel Riew, Han Jo Kim)....Pages 555-561
Surgical Techniques: Cervical Osteotomies: Modified Cervical SPO (Hossein Mehdian, Luigi Aurelio Nasto)....Pages 563-567
C7 Pedicle Subtraction Osteotomy (PSO) (Corinna Zygourakis, Christopher P. Ames)....Pages 569-574
Osteotomy Techniques for the Cervical Spine: Correction Within the Sagittal and Coronal Plane Including Halo Traction (Tobias Pitzen, Christophe Berthold, Peter Obid, Michael Ruf)....Pages 575-586
Surgical Technique: Correction of Cervical Scoliosis and Hemivertebra Resection (Addisu Mesfin, Heiko Koller, K. Daniel Riew)....Pages 587-593
Correction of Cervical Kyphosis in Pediatric Skeletal Dysplasia Patients (Dezső Jeszenszky, Tamás Fülöp Fekete)....Pages 595-600
Cervical Osteotomies: High Thoracic Three-Column Osteotomies for Kyphosis Correction (Stephen J. Lewis, So Kato)....Pages 601-607
Surgical Techniques: Cervical Osteotomies—High Thoracic VCR for Kyphoscoliosis Correction (Alexander Tuchman, Lawrence G. Lenke)....Pages 609-615
Intradural Extramedullary Cervical Spine Tumors (IECST) (Pavel Buchvald, Petr Suchomel)....Pages 617-622
Surgical Strategy for Resection of Intramedullary Tumors (Marcus Czabanka, Peter Vajkoczy)....Pages 623-629
Vascular Malformation in the Cervical Spine (Takeshi Aoyama, Kazutoshi Hida)....Pages 631-637

Citation preview

Cervical Spine Surgery: Standard and Advanced Techniques Cervical Spine Research Society Europe Instructional Surgical Atlas Heiko Koller Yohan Robinson Editors SPINE RESEARCH S L A OC VIC IET R Y CE

EUROPEAN SECTION Founded 1983

123

Cervical Spine Surgery: Standard and Advanced Techniques

Heiko Koller  •  Yohan Robinson Editors

Cervical Spine Surgery: Standard and Advanced Techniques Cervical Spine Research Society - Europe Instructional Surgical Atlas

Editors Heiko Koller Department of Neurosurgery Klinikum rechts der Isar Technische Universität München Munich Germany

Yohan Robinson Department of Orthopaedics Institute of Clinical Sciences Sahlgrenska Academy Gothenburg University Gothenburg Sweden

ISBN 978-3-319-93431-0    ISBN 978-3-319-93432-7 (eBook) https://doi.org/10.1007/978-3-319-93432-7 Library of Congress Control Number: 2019935195 © Springer Nature Switzerland AG 2019 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Illustrations by Alexis Demetriades and Rüdiger Himmelhan This Springer imprint is published by the registered company Springer Nature Switzerland AG. The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

Preface

During residency and fellowship training, most of us had a surgical atlas we consulted for planning and technical understanding of the procedures performed. This surgical atlas was our best friend: it provided consolation before difficult approaches and gave us confidence in communication with other surgeons, and we sometimes went literally to bed with it. Subspecializing in cervical spine surgery, we lost this friend. Suddenly, we had no surgical atlas anymore. The techniques were so specialized, and the case load for certain procedures is so rare that no comprehensive surgical atlas has been written so far. While in surgical solitude, we found in the Cervical Spine Research Society a soulmate. The CSRS-Europe—founded in 1983 as a subsection of the North American CSRS—had rapidly become the educator in cervical spine surgery techniques. The biannual CSRS-Europe cadaveric dissection courses at the University of Barcelona were the training grounds of leading cervical spine surgeons throughout the world. Most importantly the CSRS provided us with a network of surgeons; we could consult whenever we needed a second opinion on a surgical technique or senior advice while encountering complications. The “CSRS-Europe book on surgical techniques (? title)” is the result of the bold project to collate the current knowledge on technical approaches in a surgical atlas, reflecting approaches and techniques applied by respected surgeons all over the world. Every chapter was written by an expert in this topic, documenting the feasibility of each approach with case reports. Collaborations across physical and philosophical borders were required, where differences between surgical schools were subordinated to educational quality. We are grateful to every one of the 150 (? exact number) coauthors, who worked hard to condense decades of surgical experience into single chapters. Furthermore, we thank the medical illustrator Alexis Demetriades, who drew complex surgical knowledge into highly pedagogical illustrations, which are now the backbone of this atlas. This book is not another textbook; it is a surgical atlas representing the technical expertise of the network of the CSRS-Europe. This book is the friend we need, when we are performing cervical spine surgery, covering even the most complicated approaches. We hope you enjoy reading this book and wish you all the best. Munich, Germany Gothenburg, Sweden

Heiko Koller Yohan Robinson v

Acknowledgments by the CSRS-E

The Cervical Spine Research Society-Europe wishes to acknowledge and thank DePuy Synthes for their generous financial support which contributed greatly in facilitating our being able to produce a large number of high-quality and detailed surgical drawings to accompany the more than 90 chapters on surgical techniques of the cervical spine. These drawings enable our readers to more accurately visualize the surgical scenes described by chapter authors and therefore enhance the understanding of the described technique.

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Acknowledgments by the CSRS-E

Acknowledgments by the CSRS-E

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Contents

Part I Introduction 1 Introduction: Cervical Approaches, Access Ranges and Indications ��������������������������������������������������������������������������������   3 Andre Jackowski 2 Upper Cervical Spine: A Surgical Challenge—Past, Present, and Future��������������������������������������������������������������������������   7 Eva-Maria Buchholz 3 Subaxial Cervical Spine: Past, Present and Future����������������������   9 Johannes Schröder 4 Concepts of Posterior Decompressive Surgery������������������������������  13 Ken Ishii and Tateru Shiraishi 5 Positioning for Anterior and Posterior Procedures����������������������  17 F. Cuzzocrea and M. Ghiara Part II Surgical Anatomy 6 Surgical Anatomy of the Upper Cervical Spine and the Craniocervical Junction����������������������������������������������������  23 Gergely Bodon and Bernhard Hirt 7 Relevant Surgical Anatomy of the Anterior Cervical Spine, the High Retropharyngeal and the Subaxial Regions������������������  33 Gergely Bodon and Andres Combalia 8 Relevant Surgical Anatomy of the Posterior Subaxial Spine and the Cervicothoracic Junction����������������������������������������  43 Gergely Bodon and Andres Combalia Part III Surgical Approaches 9 Surgical Approach: High Anterior Cervical����������������������������������  53 Rafael González-Díaz and Rosa María Egea-Gámez 10 Surgical Approach: Anterolateral High Cervical Approach��������  59 Philippe Bancel xi

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11 Standard Transoral Approach to the Craniocervical Junction and Upper Cervical Spine ����������������������������������������������  65 Brian J. Dlouhy and Arnold H. Menezes 12 Combined Transoral and Transmandibular Approach: Labiomandibular Approach with or Without Glossotomy����������  71 Brian J. Dlouhy and Arnold H. Menezes 13 Endonasal Approach to the Craniocervical Junction ������������������  75 Jens Lehmberg and Bernhard Meyer 14 Posterior Midline Approach C0–C2: How to Expose Meticulously with Less Bleeding����������������������������������������������������  81 Takachika Shimizu 15 Surgical Approach: Posterior Far-­Lateral Suboccipital Approach������������������������������������������������������������������������������������������  89 Gergely Bodon and Dezsö Jeszenszky 16 Anterior Subaxial Approach ����������������������������������������������������������  97 Jörg Klekamp 17 Anterolateral Approach to Subaxial Segment of the Cervical Vertebral Artery ���������������������������������������������������� 103 Abolfazl Rahimizadeh 18 Posterior Median Access to the Subaxial Spine���������������������������� 113 Michael Mayer 19 Transmanubrial Cervicothoracic Approach���������������������������������� 119 Christian Mazel and Dominique H. Grunenwald 20 Manubriotomy/Sternotomy Access to the Cervicothoracic Junction�������������������������������������������������������������������������������������������� 125 Jan Štulík and Petr Nesnídal Part IV Surgical Techniques 21 Transoral Biopsy: Surgical Technique ������������������������������������������ 133 Alexander Mushkin and Alexander Gubin 22 Odontoid Fracture: Anterior Screw Fixation�������������������������������� 139 Anton Kathrein 23 C1–C2 Trans-Oral Release and Reduction������������������������������������ 145 Chao Wang, Xu Nuang, and S. Wang 24 C1–C2 Anterior Transarticular Fixation and Grafting���������������� 153 Christoph Josten and Ulrich J. Spiegl 25 Transoral Odontoidectomy for Decompression of Basilar Invagination�������������������������������������������������������������������� 159 Brian J. Dlouhy and Arnold H. Menezes 26 Transoral Odontoid Resection�������������������������������������������������������� 167 Heinrich Boehm and Mootaz Shousha

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27 Transoral Atlantoaxial and C2 Corpectomy Cage Reconstruction Techniques ������������������������������������������������������������ 175 Dezsö Jeszenszky and Markus Loibl 28 Total Spondylectomy of C2 ������������������������������������������������������������ 183 Petr Vachata and Petr Suchomel 29 Congenital Muscular Torticollis Correction���������������������������������� 189 Philippe Bancel 30 Anterior Vertebral Artery Mobilization���������������������������������������� 195 Philippe Bancel 31 C1-Ring Osteosynthesis for Unstable, Jefferson Burst Fractures�������������������������������������������������������������������������������� 201 Jason L. Pittman and Richard J. Bransford 32 Occipital Condyle Screw Placement for Occipitocervical Fixation �������������������������������������������������������������������������������������������� 207 Scott J. Raffa and Juan Uribe 33 Upper Cervical Techniques: Pediatric Wiring������������������������������ 213 Philippe Bancel and Takachika Shimizu 34 Upper Cervical: Occipital‑Cervical Fixation—Median, Lateral and Multihole���������������������������������������������������������������������� 219 Adrian Casey 35 Atlantoaxial Instability: Strategy for Treatment�������������������������� 225 Atul Goel 36 Posterior Transarticular Screw Fixation C1-C2 �������������������������� 239 Bernhard Jeanneret 37 Transarticular Screw C1-C2 Fixation: Minimal Invasive with Percutaneous Screw Placement ������������������������������ 245 Juan Barges Coll and John M. Duff 38 C1 Lateral Mass Screw Fixation���������������������������������������������������� 253 Christoph E. Heyde and Yohan Robinson 39 Surgical Techniques: Upper Cervical—C2 Pedicle Screw Fixation Technique �������������������������������������������������������������� 259 Hideki Sudo and Kuniyoshi Abumi 40 C1 Posterior Arch Screw Fixation�������������������������������������������������� 265 Jin S. Yeom 41 C1 Translaminar Screw Fixation���������������������������������������������������� 271 Haydn Hoffman, Heiko Koller, and Daniel C. Lu 42 Posterior C1–C2 Fusion with the C1 Claw Device������������������������ 277 Anna-Lena Robinson and Claes Olerud 43 C2 Laminar Screw Fixation������������������������������������������������������������ 281 Ilyas Aleem and Brad Currier

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44 Upper Cervical Spine-Posterior Cage Reconstruction C1–C2������������������������������������������������������������������������������������������������ 291 Corinna C. Zygourakis and Christopher P. Ames 45 C1 Posterior Arch Laminoplasty���������������������������������������������������� 297 Jin S. Yeom 46 Anterior Cervical Foraminotomy�������������������������������������������������� 303 Andre Jackowski 47 Anterior Decompression: Discectomy and Uncotomy–Open Technique���������������������������������������������������� 309 Meric Enercan and Azmi Hamzaoglu 48 Microscopic Anterior Cervical Decompression���������������������������� 317 Sebastian Hartmann, Anja Tschugg, and Claudius Thomé 49 Oblique Corpectomy������������������������������������������������������������������������ 325 Ronald H. M. A. Bartels 50 Anterior Cervical Corporectomy and Fusion ������������������������������ 329 Hugues Pascal-Moussellard and Caroline Hirsch 51 Anterior Transpedicular Screw Plate Fixation ���������������������������� 337 Zhengfeng Zhang 52 Surgical Technique for a Cervical Disc Arthroplasty ������������������ 343 Gregory D. Schroeder and Alan S. Hilibrand 53 Surgical Technique, Subaxial Spine: Cervical Disc Replacement Revision Surgery ������������������������������������������������������ 349 Justin A. Iorio, Stelios Koutsoumbelis, Han Jo Kim, and Todd J. Albert 54 Subaxial Cervical Reconstruction of Multilevel Corpectomies and Skip Corpectomies ������������������������������������������ 355 Mena Kerolus and Vincent Traynelis 55 Anterior Reconstruction with Microvascular Grafts ������������������ 361 Tianyi Liu and Andres Rodriguez-Lorenzo 56 Corpectomy: Floating Method for OPLL�������������������������������������� 367 Toshitaka Yoshii, Masato Yuasa, and Atsushi Okawa 57 Subaxial Cervical Spondylectomy�������������������������������������������������� 375 Jan Štulík and Zdeněk Klézl 58 Cervical Rib Resection�������������������������������������������������������������������� 381 Mimmie Kwong, Nasim Hedayati, and Julie Anne Freischlag 59 Halo-Ring and Halo-Vest Fixation and Treatment: Adult and Pediatric Patients ���������������������������������������������������������� 389 Bengt Lind 60 Technique of Cervical Traction������������������������������������������������������ 395 Philippe Bancel and J. F. Dubousset

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61 Posterior Cervical Foraminotomy�������������������������������������������������� 403 Christine Boone, Thomas Mroz, C. Rory Goodwin, Timothy Witham, and Daniel Sciubba 62 Posterior Microdiscectomy�������������������������������������������������������������� 411 Bastian Storzer and Heiko Koller 63 Expansive Open-Door Laminoplasty for Cervical Myelopathy �������������������������������������������������������������������������������������� 417 Kazuhiro Chiba and Takashi Tsuji 64 French-Door Laminoplasty for Cervical Compressive Myelopathy �������������������������������������������������������������������������������������� 425 Yasutsugu Yukawa 65 Laminectomy with Fusion for Cervical Spondylotic Myelopathy������������������������������������������������������������������ 433 Ronald H. M. A. Bartels 66 Selective Cervical Laminectomy of Limited Width by Muscle-­Sparing Technique Using Anatomical Plane Exposures ������������������������������������������������������������������������������ 437 Tateru Shiraishi and Ryoma Aoyama 67 Cervical Hook Fixation�������������������������������������������������������������������� 443 Carmen L. A. Vleggeert-Lankamp 68 Pedicle Screw Fixation in Cervical Spine�������������������������������������� 449 Yasutsugu Yukawa 69 Percutaneous Pedicle Screw Fixation in the Cervical Subaxial Spine���������������������������������������������������������������������������������� 455 Nils Hansen-Algenstaedt and Alf Giese 70 Surgical Techniques: Subaxial Cervical—Modified Subaxial Paramedian Transpedicular Approach and Reconstruction�������������������������������������������������������������������������� 465 Vance L. Fredrickson, Martin H. Pham, and Frank L. Acosta 71 Lateral Mass Screw Fixation���������������������������������������������������������� 469 Bruce D. Darden and Marco C. Mendoza 72 Surgical Techniques: Sublaminar Wiring for Long Posterior Fixation���������������������������������������������������������������������������� 475 Takachika Shimizu 73 Reduction of Locked Cervical Facets: Manual, Anterior Open, Posterior Open������������������������������������������������������ 483 T. Cloché, Y. Legallois, and J. M. Vital 74 Surgical Technique: Posterior Subaxial Cervical Spine, Subaxial Transarticular Screw Fixation���������������������������������������� 489 Stelios Koutsoumbelis, Justin Iorio, and Todd Albert

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75 Surgical Techniques–Subaxial Cervical: Upper Thoracic Pedicle Screw Fixation���������������������������������������� 493 Sebastian Decker and Axel Hempfing 76 Management of Anterior Durotomy in Cervical Spine���������������� 499 Macondo Mochizuki and Masao Koda 77 Cervical Posterior Durotomy Repair �������������������������������������������� 505 A. Tomasino 78 Treatment of Acute Vertebral Artery Injury (VAI)���������������������� 511 Jin S. Yeom 79 Treatment of Pharyngoesophageal Injuries in Cervical Spine Surgery ���������������������������������������������������������������������������������� 517 Brandon P. Hirsch, Mark D. DeLacure, and Themistocles S. Protopsaltis 80 Cervical and Cervicothoracic Osteotomies: Introduction Concepts, Planning, and Performance�������������������� 525 Heiko Koller 81 Ponte Osteotomy������������������������������������������������������������������������������ 549 Pedro Berjano and Claudio Lamartina 82 Surgical Techniques: Cervical Osteotomies—Anterior Osteotomy With/Without Corpectomy������������������������������������������ 555 K. Daniel Riew and Han Jo Kim 83 Surgical Techniques: Cervical Osteotomies: Modified Cervical SPO������������������������������������������������������������������������������������ 563 Hossein Mehdian and Luigi Aurelio Nasto 84 C7 Pedicle Subtraction Osteotomy (PSO) ������������������������������������ 569 Corinna Zygourakis and Christopher P. Ames 85 Osteotomy Techniques for the Cervical Spine: Correction Within the Sagittal and Coronal Plane Including Halo Traction������������������������������������������������������������������ 575 Tobias Pitzen, Christophe Berthold, Peter Obid, and Michael Ruf 86 Surgical Technique: Correction of Cervical Scoliosis and Hemivertebra Resection���������������������������������������������������������� 587 Addisu Mesfin, Heiko Koller, and K. Daniel Riew 87 Correction of Cervical Kyphosis in Pediatric Skeletal Dysplasia Patients���������������������������������������������������������������������������� 595 Dezso˝ Jeszenszky and Tamás Fülöp Fekete 88 Cervical Osteotomies: High Thoracic Three-Column Osteotomies for Kyphosis Correction�������������������������������������������� 601 Stephen J. Lewis and So Kato

Contents

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89 Surgical Techniques: Cervical Osteotomies—High Thoracic VCR for Kyphoscoliosis Correction ���������������������������������������������� 609 Alexander Tuchman and Lawrence G. Lenke 90 Intradural Extramedullary Cervical Spine Tumors (IECST)������������������������������������������������������������������������������ 617 Pavel Buchvald and Petr Suchomel 91 Surgical Strategy for Resection of Intramedullary Tumors���������������������������������������������������������������������������������������������� 623 Marcus Czabanka and Peter Vajkoczy 92 Vascular Malformation in the Cervical Spine ������������������������������ 631 Takeshi Aoyama and Kazutoshi Hida

Part I Introduction

1

Introduction: Cervical Approaches, Access Ranges and Indications Andre Jackowski

Approaches to the cervical spine can first be conveniently divided and considered with regard to the three readily distinguishable cervical levels: the craniocervical spine, the subaxial spine and the cervicothoracic junction (Fig.  1.1). At each of these three cervical levels, the most appropriate approach corridor, access and indications can then be further considered as regards the 360° of approach which are encompassed within the anterior, posterior, lateral, anterolateral and posterolateral approaches as conventionally described (Fig. 1.2). The individual approaches and their relevant surgical anatomy are described in more detail in the various chapters that follow. Whilst individual patient cases will clearly always require their own detailed specific consideration, there are some overall guiding principles that should first be considered when choosing the most appropriate surgical approach. These are outlined as follows: 1. The primary localisation and extent of the pathology in relation to the potential approach corridors. In general, the default position should be to choose the most direct approach to the causative pathology e.g. anterior for ventral pathology, posterior for dorsal pathology and so on.

Fig. 1.1  Craniocervical-green; subaxial-red; cervicotho­racic-blue

A. Jackowski (*) Birmingham Spinal Clinic, Birmingham, UK

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A. Jackowski

Fig. 1.2  A anterior, P posterior, L lateral, AL anterolateral, PL posterolateral

2. Avoidance of retraction or manipulation of the spinal cord and as much as possible to direct operative force away from, rather than towards, vulnerable neural structures. 3. The likely nature of the pathology to be addressed. Is it semi-solid e.g. abscess or haematoma, soft e.g. disc or certain tumours or hard e.g. ossified ligaments, osteophytes, retropulsed bone and certain tumours? Is it totally benign pathology? What is the extent of removal necessary? Has it a low recurrence or high recurrence potential? Is it a primary malignant or secondary tumour? 4. The degree of instability and/or deformity already present or likely to follow on from surgical removal of the pathology and what approach will best address this at the time of the initial surgery or will more than one approach be required? 5. The local anatomy specific to the cervical level according to the approach. This varies significantly depending upon whether the sur-

gery is at the craniocervical, subaxial spine or cervicothoracic junction. Determination of the above can only be done after careful review of all the relevant patient imaging together with a full knowledge and understanding by the surgeon of the surgical anatomy at that cervical level as well as the likely pathology that needs to be dealt with. It is important that a surgeon considers and chooses the best surgical approach based upon the five principles outlined above. Not every spinal surgeon will have the necessary case-mix, experience or resources to undertake all of the cervical approaches and procedures described in the chapters that follow. However, knowledge of all the various approaches will allow a spinal surgeon to correctly determine the optimal surgery for his or her patient and to either perform the procedure or to refer the patient to a surgeon already experienced in that particular surgical approach and technique.

1  Introduction: Cervical Approaches, Access Ranges and Indications

Craniocervical Junction Anterior approaches to the craniocervical junction include the transoral transpharyngeal approach with or without trans-maxillary or mandible splitting osteotomy approaches. The latter two procedures will require help from a maxillofacial surgeon in addition to a spinal surgeon. The transoral approach is frequently used for many lesions in the location ranging from the anterior foramen magnum to the C2 vertebral body. The craniocervical junction can also be reached by an anterior retropharyngeal approach giving an access range from the lower clivus to C3. It is essentially a superior extension of the standard anterior cervical approach and remains extramucosal. Its limitation is in giving less direct access to ventral pathology. The posterior approach to the craniocervical junction is familiar to all spinal surgeons being a relatively straightforward extension of the commonly employed posterior approach to the subaxial spine. It may be extended either in the midline to expose the occiput or curved somewhat to one side to allow posterolateral access. The craniocervical junction may, if indicated, also be approached by the far lateral approach which is a modification of the traditional lateral suboccipital approach as used in neurosurgery for removal of pathology at the foramen magnum. Lesions located laterally at the craniocervical junction potentially suitable for the far lateral approach can include primary, secondary or intradural tumours, congenital anomalies and irreducible atlantoaxial dislocations.

Subaxial Spine The subaxial cervical spine, particularly in cases of one- or two-level anterior degenerative compressive disease and in kyphotic deformity, is most appropriately approached by the anterior approach staying anterior to the carotid sheath. This is the surgical approach commonly employed for the removal of soft disc prolapse or osteophytes presenting with radiculopathy or myelopathy. It is usually the approach of choice

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for most vertebral body pathologies such as tumour and compression fractures. It readily allows the insertion of an anterior support construct and stabilisation by anterior plate-screw fixation. The anterolateral approach with its closer proximity to or actual exposure of the vertebral artery, as described by Hank Verbiest and promoted by Bernard George, although less frequently employed, is both highly effective in decompressing the cord and nerve roots and has the benefit that it does not require a fusion procedure. Cervical stenosis when there is no kyphotic deformity, from multilevel degenerative disease, most cases of ossification of the posterior longitudinal ligament and where there is mainly posterior compression e.g. by ligamentum flavum hypertrophy, is more appropriately decompressed by the posterior approach. Posterior decompression can be achieved in many cases by a laminectomy alone, either at multiple levels, by skip or split laminectomy or alternatively by one of the laminoplasty techniques. If required, supplemental instrumentation with lateral mass or other screw placements can then easily be performed. A direct lateral approach to the subaxial spine, in contrast to the craniocervical junction, is rarely necessary. However, for certain pathologies such as a lateral mass primary tumour e.g. osteoblastoma, and some recurrent pathology that necessitate a fresh surgical approach and potentially in cases where there is involvement of a vertebral artery, it may be indicated to perform the direct lateral approach.

Cervicothoracic Junction As with other spinal levels, an anterior approach is more direct and provides better exposure for ventral or ventrolateral pathology presenting at the cervicothoracic level. It will, for example, be appropriate in low cervical degenerative disease such as a patient presenting with C8 radiculopathy from C7/T1 disc prolapse. The approach is essentially a lower than normal, but otherwise standard, anterior approach performed just above the clavicle. Another ventral pathology affecting the spine at the cervicotho-

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racic junction that commonly necessitates decompression and stabilisation is compression or collapse of a vertebral body due to metastatic deposits. Such pathology is best approached by an anterior approach extended inferiorly onto the upper sternum, together with varying degrees of resection or osteoplastic flap formation involving the clavicle and manubrium. If more extensive anterior access is required, then a sternal splitting procedure can be performed. Access for anterior column reconstruction may be limited; however, the use of expandable cages or even bone cement alone should provide adequate anterior column support. The plate chosen for supplemental fixation should be one that allows divergent screw placement as this

A. Jackowski

will facilitate placement of screws in the thoracic levels. The posterior approach to the cervicothoracic junction is better known to most spinal surgeons and is logically indicated if the pathology is dorsally located. In such cases, it can be better accessed and treated from that direction rather than by the anterior approach. Examples would include cases of posterior extradural tumour, cases of tumour with mainly posterior bony element involvement and spinal infection with epidural abscess but no or minimal anterior column compromise. The posterior approach has the advantage that the achieving of a strong and stable spinal instrumentation construct is generally more easily accomplished from posteriorly than anteriorly at this level.

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Upper Cervical Spine: A Surgical Challenge—Past, Present, and Future Eva-Maria Buchholz

All pathologies affecting bone, joints, muscles, vessels, and all neural structures (spinal cord, nerves, CSF, meninges) can be present in the very small area of upper cervical spine. The reasons for these pathologies are common: trauma—infectious changes—degenerative disorders—chronic diseases with pathological changes in the spine (e.g. rheumatoid arthritis)— tumours (bone, nervous system, spinal cord, muscles). The structural changes from such pathologies in the upper cervical spine cause similar problems as they do below: we will face instabilities, deformities, spreading infections, and/or compressed/injured nerve roots, spinal cord, and/or extreme pain. The peculiarities of the upper cervical spine make basic anatomical and biomechanical knowledge necessary to understand clinical symptoms and signs, to make the right diagnosis with clinical and radiological investigations, and finally to identify the right therapeutic procedure in case of pathological changes in the upper cervical spine. If a surgical procedure becomes necessary, the extraordinary anatomical surroundings of the upper cervical spine present a serious surgical E.-M. Buchholz (*) Marien-Krankenhaus, Department of Neurosurgery, Bergisch Gladbach, Germany e-mail: [email protected]

challenge. The specific biomechanics in the upper cervical spine pose a challenge for surgical procedure, tools, and equipment—the materials used, design of screws, plates, hooks, cables, and the instruments to place them. Instruments to remove tumours in bone or by/in the spinal cord have to be adapted to the local requirements. The same applies to visual assistance by microscope or navigation. These were meant to make the procedure as safe and as adequate as possible. Historically, trauma to the upper cervical spine resulted in sudden death—only anecdotal reports of survivors exist. If survived, the injury often did lead to extreme pain or to delayed sudden death, because of missing investigation methods to diagnose the instability. Other nontraumatic pathologies of the upper cervical spine (i.e. tumour) progressed to neurological dysfunction, extreme pain, finally ending in death. Since the invention of radiography and the possibility to visualize the complete bony spine we get more direct information about traumatic impact on the spine’s bony structures with the possibility to decide about immediate treatment. The correct spine fracture analysis became possible in the upper cervical spine too. The development of investigation methods such as CT, followed by MRI, made the correct diagnosis in the upper cervical spine more and more precise. We now have 20 classifications to describe a traumatic lesion to the upper cervical spine to distinguish stable from unstable.

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Spinal surgeons fear of the instability in the cranio-cervical junction with the threat of sudden death. Subsequently the fracture management/ treatment became the initial impetus for research and development of surgical procedures/ approaches in this region. The analysis of fracture type, a timely decision on fracture stability, followed by conservative treatment with skull traction or stiff neck supports, most of them including the head in order to respect the craniocervical junction’s special biomechanical situation: a plaster-cast (Minerva jacket) and eventually halo-vest. The first surgical fixation method was the “Gallie fusion C1/2” with wire and bone grafting through a posterior approach in 1939. This is a very effective procedure with simple “hardware”—only a wire. Besides the treatment of odontoid fractures and traumatic instabilities in the upper cervical spine, the most common application worldwide for this surgical procedure was rheumatoid arthritis with atlantoaxial instability. The application for other instabilities followed: osteolysis in case of tumour, infections, and metastasis with instabilities in C1/2. This method underwent many modifications such as changing the direction and number of loops, changing of bone grafting (i.e. by Brooks and Jenkins in 1978), and changing the wire in a flexible cable, or dorsal clamps. Another method was developed by Magerl in 1981 with transarticular screws C1/2 plus Gallie fusion to improve the fusion rate. Subsequently, multiple posterior fusion methods were developed. A variety of screws, new possibilities of fixation to the occiput for better connection to rods, plates, directly instru-

E.-M. Buchholz

mented C1 and C2 via pedicle screws, which resemble a fixateur interne. Simultaneously the development of anterior fusion techniques of upper cervical spine came up. Anterior bilateral C1/2 transarticular screws were introduced by Lesoin in 1987. Fritz Magerl reported in 1978 a case of anterior odontoid screw osteosynthesis, it was first accepted by the spine surgery community after Böhler’s description in 1982. With the development of more and better tools for surgical fusion of the upper cervical spine, the research about the fundamental biomechanics, about the diagnostic procedures (myelography, CT, MRI, and further technical investigation procedures), the knowledge about the spinal cord pathologies increased. Nowadays we can visualise traumatic occipito-cervical junctional injuries, differentiate fracture types in the upper cervical spine, as well as degenerative and chronic diseases, tumours, metastases, and osteolytic infections. Still, we lack good predictors for sudden death, as a result of a compressed/injured upper cervical spinal cord. We have to carefully investigate the acutely injured, surviving patient with fractures in the upper cervical spine. If there is a “dangerous instability” which can cause sudden death, there is an absolute indication for fusion. Otherwise there could be an option for conservative treatment with similar favourable outcome. Surgical procedures in the upper cervical spine have to be performed with the utmost care, which includes both indication and surgical technique, in order to avoid catastrophic complications as high paraplegia or death.

3

Subaxial Cervical Spine: Past, Present and Future Johannes Schröder

The subaxial part of the cervical spine is the region of most of the everyday surgery of cervical spine surgeons. Due to the biomechanical load and high mobility of the subaxial cervical spine, this is where most degenerative changes and injuries are found.

Anterior In contrast to the lumbar spine, the anterior approach to the cervical spine is the simpler and less invasive one (Ref Chap. 11). Routinely used since the 1950s, first historical descriptions by Chipault are dating back from 1895. In 1955, Robinson and Smith [1] published their technique of disc removal and insertion of a tricortical iliac crest graft for cervical fusion, in the original technique without removal of the posterior longitudinal ligament thus with only indirect decompression (Ref Chap. 46). Cloward [2] went a step further and removed with a special half-­ inch twist drill both endplates including dorsal osteophytes facilitating throughout decompression of the cervical spinal canal. Fusion was achieved by a round bone dowel (Fig. 3.1). One of the main concerns about iliac bone grafting is donor site morbidity, which led to dif-

J. Schröder (*) ZW-O Spine Center, Osnabrück, Germany e-mail: [email protected]

Fig. 3.1 Historical fusion technique according to Cloward [2]. Reprinted with courtesy of the Journal of Neurosurgery Publishing Group

© Springer Nature Switzerland AG 2019 H. Koller, Y. Robinson (eds.), Cervical Spine Surgery: Standard and Advanced Techniques, https://doi.org/10.1007/978-3-319-93432-7_3

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ferent developments of alternative graft-like implants in Europe and America. Allografts are popular especially outside Europe avoiding a second access for bone harvesting from the iliac crest. Frozen human cadaveric bone, especially banked fibula, offers the advantage of greater strength and of versatility in the size and shape of the graft. New bone formation and revascularisation are known to be delayed compared to autograft. Therefore in many cases, a plate fixation is added. In the late 1960s, the use of poly-methyl-­ methacrylate (PMMA) instead of a bone graft was published. After decompression, the disk space is filled with the still liquid material, with the dura being protected with a foam sponge. This method has been left in favour of industrially manufactured implants, making the time-­ consuming PMMA-component handling superfluous. Titanium implants offer the advantage of a strong bond between the implant surface and the adjacent bone. The development went from spacers like the roughened-surface Kaden implant via hollow screws like the BAK to cage-type implants to accommodate filling materials. Titanium cages have a high fusion rate, but are interfering with postoperative MRT investigations. Poly-ether-ether-ketone (PEEK) solved this problem but earned a bad reputation for delayed union and non-fusion of treated segments. The anterior plates developed by Böhler [3] started a new era of implant engineering for anterior cervical spine stabilisation especially useful for trauma treatment or degenerative instability. Allograft and plate remain the gold standard outside Europe. Interestingly, leaving the disc space empty can produce comparable results to fusion. Considerable surgical skill is required for anterior cervical root treatment leaving the disc intact. For isolated uncovertebral degeneration causing besides cervico-brachial neuralgia also cervico-­ encephalic symptoms, uncoforaminotomy was developed by Jung et al. [4]. Trying to preserve segmental motion, the first cervical arthroplasty devices entered the market

in the 1960s. Despite the initial prospects of superior results, many designs disappeared. Only a few reasonable long-term results are available. The future has to prove if cervical disc replacement reduces adjacent segment disease, a pathology not yet scientifically proven and unknown before the advent of spinal endoprosthetics. Since moving material contact surfaces are prone to wear, one should expect long-term complications related to wear debris inflammation.

Future The future of anterior implant technology is not clear. With PEEK although excellent for MRI follow-up, but disappointing in fusion rate, titanium cages are coming into focus again. Titanium coatings of PEEK implants can possibly combine the advantages of both materials. Trabecular metal is used as an alternative to PEEK and titanium. Resorbable cages are available but are not well investigated, yet. Lately, 3D printing technology enables individualised implant manufacturing. Artificial grafting materials are still struggling to prove their effect on quicker bone formation.

Posterior Frykholm contributed enormously to the understanding of cervical nerve root anatomy and their dorsal decompression [5]. His foraminotomy is still widely used especially for more lateral pathologies (Ref Chap. 60). An important step to posterior stabilisation came with plate screw constructs attached to the lateral mass in the more straightforward orientation according to Roy-­Camille [6] or the lateral upward orientated screws according to Magerl (Ref Chap. 70). It is interesting to know that in the absence of special implants a small fragment third tubular plate would do the trick as described in older AO trauma manuals. Polyaxial screw rod systems replaced plate screw construct nowadays entirely.

3  Subaxial Cervical Spine: Past, Present and Future

Multisegmental cervical spinal stenosis and myelopathy can be effectively treated by laminectomy (Ref Chap. 4). The subsequent posterior element weakening with development of kyphotic deformity is addressed by a wide variety of laminoplasty techniques or prevented by additional instrumentation.

Conclusions The time for solving all subaxial spinal pathologies with one technique or one approach is over. The spine surgeon needs to know a wide variety of techniques and has to tailor the approach to the individual requirements of his or her patient. This can range from tiny decompression to 3D navigated anterior–posterior deformity corrections. It’s not the tool available that decides the procedure, it’s the pathology that’s leading. Decades of surgi-

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cal development have crystallised most effective procedures to treat subaxial pathologies. To distribute this knowledge is what this section is about.

References 1. Robinson RA, Smith GW. Anterolateral cervical disk removal and interbody fusion for cervical disk syndrome. Bull Johns Hopkins Hosp. 1955;96:223–4. 2. Cloward RB.  The anterior approach for removal of ruptured cervical disks. J Neurosurg. 1958;15:602–17. 3. Böhler J, Gaudernak T.  Anterior plate stabilization for fracture-dislocations of the lower cervical spine. J Trauma. 1980;20:203–5. 4. Jung A, Kehr P, Hamid M. The uncoforaminotomy in lesions of the arteria vertebralis and the cervical nerve roots. Z Orthop. 1974;112:736–40. 5. Frykholm R. Deformities of dural pouches and strictures of dural sheaths in the cervical region producing nerve root compression. J Neurosurg. 1947;4:403–13. 6. Roy-Camille R, Saillant G, Laville C, Benazet JP. Treatment of lower cervical spinal injuries—C3 to C7. Spine. 1992;17:S442–6.

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Concepts of Posterior Decompressive Surgery Ken Ishii and Tateru Shiraishi

Countries in East Asia have a high prevalence of myelopathy related to spinal canal narrowing or ossification of the posterior longitudinal ligament (OPLL). Due to an severe compression of the spinal cord from either anterior or posterior, progressive cervical myelopathy results in a high level of disability. In the 1960s, cervical laminectomy that completely removes laminae with attached ligamentous structures was the only available surgical procedure for cervical myelopathy. Decompression was achieved with a posterior shift of the spinal cord by removing posterior elements of the cervical spine. However, the surgical outcomes were rather unpredictable due to various complications, such as iatrogenic spinal cord injury and recurrent myelopathy caused by the epidural scar formation or development of postoperative kyphosis. In 1968, Kirita developed a technique for extensive laminectomy. In this procedure, the laminae were carefully thinned and divided at the midline using a high-speed drill, followed by simultaneous resection of left-right laminae to achieve decompression of the spinal cord.

K. Ishii (*) Department of Orthopaedic Surgery, School of Medicine, International University of Health and Welfare (IUHW), Otawara, Japan T. Shiraishi Department of Orthopaedic Surgery, Tokyo Dental College Ichikawa General Hospital, Ichikawa, Japan

Although the high-speed drill provided a disruptive technique in spinal surgery, the complications that were found after conventional laminectomy still remained. In 1973, Hattori devised an expansive Z-plasty in which the spinal canal was reconstructed by preserved laminae (Fig.  4.1c). In 1977, Hirabayashi introduced a procedure which is called “expansive open-door laminoplasty (ELAP)” (Fig.  4.1a). This technique is simpler and safer than that used in the Z-plasty. This technique is extensively described in a following chapter. The complications of cervical laminoplasty were iatrogenic stenosis due to re-closure of the expanded laminae, injury to the spinal cord or nerve roots by dislodgement of the rotated laminae at the pivoting edges and unintentional bony fusion between the preserved laminae. To cope with re-closure or dislodgement of the expanded laminae, recent laminoplasties have been frequently combined with instrumentation using expensive small screws and lamina plates to hold the expanded laminae. In 1980, Kurokawa developed a double-door laminoplasty (Fig. 4.1b). The main concept of this procedure is to expand the spinal canal symmetrically while preserving the mobility of the cervical spine, and it is described in a following chapter. Also, this procedure has been widely used for the resection of intramedullary spinal cord tumours at the cervical level. Today, both ELAP and double-door laminoplasty are widely employed as posterior decompression techniques for cervical myelopathy, particularly for multilevel stenosis, congenital spinal stenosis,

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a

b

c

Fig. 4.1  Basic types of expansive laminoplasty: (a) open door (ELAP), (b) double door and (c) Z-plasty (courtesy of Dr. Hirabayashi)

disc herniation and ossification of the posterior longitudinal ligament (OPLL) [1]. Unfortunately, both types of laminoplasty have several complications: (1) In ELAP and double-door laminoplasty, lateral exposure usually extends from the spinous process to the facet joints. Laminoplasty in particular needs ample space laterally to expand the affected laminae. Since the joint is anatomically covered by the rotators and the multifidus, these laminoplasties may cause damage not only to the joint capsules but also to both origin and insertion of the rotators and the multifidus. Such damage could give rise to postoperative malalignment or instability. (2) C5 palsy after laminoplasty could lead to muscle weakness, brachialgia and numbness of the upper limbs. Although the aetiology of C5 palsy has been poorly understood, the most possible pathologic mechanisms are the intraoperative nerve root injury, nerve root traction, spinal cord ischemia, backward shifting of the spinal cord and reperfusion injury of the spinal cord.

In 2002, Shiraishi introduced a less-invasive technique for exposure of cervical spine laminae, which is described in one of the following chapters. By applying the technique to posterior decompression, deep extensor muscles and cervical alignment could be preserved, resulting in the maintenance of cervical sagittal alignment, cervical ROM and reduction of postoperative neck pain [2]. The “skip” laminectomy, using the lessinvasive approach on multilevel stenosis, has become popular in western countries, where OPLL is rare and degenerative myelopathy more common [3]. Many patients with myelopathy due to cervical spondylosis or OPLL can be treated successfully by applying posterior decompression methods. The key to surgical success is minimising soft-tissue trauma after meticulous preoperative planning to optimise decompression. Laminoplasty and less-invasive laminectomy are both established techniques in this regard. The current evidence is insufficient to give recom-

4  Concepts of Posterior Decompressive Surgery

mendations on which methods to favour [4]. Recent studies reveal that timing of surgery for cervical spinal myelopathy is probably more important than the applied surgical techniques [5]. Although sufficient operative outcomes are not always achieved in some patients because of inevitable preoperative risk factors or technical intraoperative issues, careful operative planning and early operative intervention may be necessary to obtain good clinical results.

References 1. Chiba K, Ogawa Y, Ishii K, Takaishi H, Nakamura M, Maruiwa H, Matsumoto M, Toyama Y. Long-term results of expansive open-door laminoplasty for cer-

15 vical myelopathy—average 14-year follow-up study. Spine (Phila Pa 1976). 2006;31(26):2998–3005. 2. Nori S, Shiraishi T, Aoyama R, et  al. Musclepreserving selective laminectomy maintained the compensatory mechanism of cervical lordosis after surgery. Spine (Phila Pa 1976). 2018;43:542. 3. Yuan W, Zhu Y, Liu X, Zhou X, Cui C. Laminoplasty versus skip laminectomy for the treatment of multilevel cervical spondylotic myelopathy: a systematic review. Arch Orthop Trauma Surg. 2014;134(1):1–7. 4. Phan K, Scherman DB, Xu J, Leung V, Virk S, Mobbs RJ.  Laminectomy and fusion vs laminoplasty for multi-level cervical myelopathy: a systematic review and meta-analysis. Eur Spine J. 2017;26(1):94–103. 5. Vidal PM, Karadimas SK, Ulndreaj A, Laliberte AM, Tetreault L, Forner S, Wang J, Foltz WD, Fehlings MG.  Delayed decompression exacerbates ischemiareperfusion injury in cervical compressive myelopathy. JCI Insight. 2017;2(11):92512.

5

Positioning for Anterior and Posterior Procedures F. Cuzzocrea and M. Ghiara

Introduction Spine surgery is inundated with potential pitfalls, and the key is to address the many risk-­generating factors; the patient’s position on the operating table and the preoperative identification of high-­ risk patients are two that must not be underestimated [1]. Partial or total loss of sight, a worsening of the deformity being treated and peripheral nerve compression [1] are among the serious, and at times irreversible, complications. Consequently, every little detail of a patient’s position (supine, prone or lateral) must be carefully planned to ensure the optimal choice of head fixation. Mayfield (Fig. 5.1) [2, 3] notably reduces the risk of damage to the sight, the likes of which is possible in the prone position; however, it can give rise to other complications such as skull fractures and subdural hematomas [4]. Instead, the Caspar head positioner for the supine, and more rarely, prone position, avoids screwing into the skull bone; ancillary fixation of the head to head positioner is done using surgical plasters or adhesive tape. Both approaches require taping of the shoulders to pull them down, in order to optimize radiographic visualization of the

F. Cuzzocrea (*) · M. Ghiara Clinica Ortopedica e Traumatologica, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy

Fig. 5.1  Mayfield is an optimal choice of head fixation for posterior approach

c­ ervico-thoracic passage. The layout of the operating theatre, intending the position of the operating theatre fluoroscopy, microscope and neurophysiological monitoring equipment, is also an important aspect to be considered. The patient must always be prepared with surgical stockings, and gel pads are used at strategic points to reduce nerve compression. The whole surgical team is involved in the positioning of the unconscious patient; the theatre nurses assist the surgeon and anaesthetist in ensuring that the patient assumes the best position for execution of surgery and monitoring of patient parameters.

© Springer Nature Switzerland AG 2019 H. Koller, Y. Robinson (eds.), Cervical Spine Surgery: Standard and Advanced Techniques, https://doi.org/10.1007/978-3-319-93432-7_5

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Anterior Approach Supine, in the reverse Trendelenburg position, the patient must be distally fixed with a foot support to avoid him/her sliding downwards and causing increased traction of the cervical spine (Fig.  5.2). This position reduces blood pressure and bleeding at the surgical site. When fixing the head with Mayfield or using a horseshoe head pad, a rigid lordotic neck support is needed due to the considerable force exerted at the vertebral bodies during introduction of Cloward distractor pins [5]. The spine must not be subjected to excessive traction or extension to ensure that the anterior structures (trachea and oesophagus) remain mobile. Excessive extension makes it difficult to perform blunt dissection of tissue and increases the risk of damage to the structures (e.g. recurrent laryngeal nerve). The shoulders must always be immobilized in a downward position using adhesive/stretch tape to prevent wrist traction and subsequent stretching of the nerve structures (plexus, radial nerve and ulnar nerve). Neuropathies are not only caused by prolonged compression against a hard surface, they also result from excessive traction along the nerve at rest which damages the axon and the vasa nervorum [1]. Compression of the nerve, on the other hand, increases both intra- and extra-neural pressure which leads to increased perfusion pressure, nerve ischaemia and, subsequently, reduction in

Fig. 5.2  Positioning for anterior approach: the patient is supine in the reverse Trendelenburg position and he must be distally fixed with a foot support

the fibre’s conduction speed [1]. The legs must be adducted and secured to the table using straps or bandages. A cushion can be placed beneath the buttocks to facilitate access to the iliac crest should autologous bone be needed for cervical spine graft. Correct positioning makes it easier for the anaesthetist to access and monitor the patient during surgery; it is the anaesthetist’s job to check that the patient maintains the chosen position throughout. The surgeon can benefit from the use of an endotracheal tube, an anaesthesiologic device, which serves as a guide during access. Once the antistatic retractor is positioned, the anaesthetist deflates the endotracheal tube pilot balloon and inflates it again once the retractor is opened; in so doing, the pressure on the anterior structures of the neck is minimized. Neurophysiological monitoring is the gold standard when treating deformities and using spinal instruments; it is an extremely important aspect to which time and care must be dedicated.

Posterior Approach The prone position is associated with a high risk of complications [1]. Mayfield or Trippi-Wells tong is mandatory for all procedures carried out in this position as it allows the cervical spine to be manoeuvred while intraoperatively correcting the deformity. Rotational control is necessary when treating the axial spine; this is only possible using Mayfield. Horseshoe head positioners can be used, but are not recommended; the head needs to be restrained with adhesive tape, and the consequent compression of the eyes against the head support can lead to corneal lesions, and/or central retinal artery occlusion, and/or ischaemic optic neuropathy [5]. The latter is extremely serious and rarely treatable, even by an eye surgeon whose intervention can only be, by course of events, performed late. The incidence is 1/3000 cases [5]; using Mayfield, the risk can be dramatically reduced, if not eliminated. A foot support is used to prevent the patient sliding down the table when in the reverse Trendelenburg position. Keeping the knees flexed has the same effect. Tilting the table is

5  Positioning for Anterior and Posterior Procedures

important because the head is elevated, and reduces bleeding since the legs are lower than the head. Also in this case, the nerves must be protected from compression or stretching; soft gel pads (or soft frame) must be placed at the bony prominences, in particular at the sternum, chest and iliac crests, preserving the abdomen’s range of motion so as not to interfere with diaphragmatic excursion. If this is not done, venous deflux through the Batson venous plexus is obstructed; this equates to increased intraoperative bleeding and decreased blood oxygenation due to altered respiration. The shoulders are positioned in a downward direction using adhesive/elastic taping (traction with straps is to be avoided due to risk of damage to nerves and brachial plexus roots) in order to ensure that visualization of the cervico-thoracic passage is not impaired upon ­ intraoperative radiographic examination. Finally, the position must provide the anaesthetist access to the airways and the possibility to frequently and repeatedly check the position of the patient’s head.

Precautions and Recommendations One of the main problems associated with the positioning of a patient is the visualization of the occipital–cervical and cervical–thoracic passages because the shoulders are in the way and interfere. Navigation, intraoperative CT and specific tables, though not always available, represent the solution. In the case of the cervical–thoracic passage, for example, the problem of the shoulder can be avoided by tilting the fluoroscopy 45°; in so doing, the pedicles are visible, and the shoulders do not interfere with the radiographic image (Fig. 5.3). Possible risks can be also contained by preoperative planning. Accurately positioning the patient using aids such as gel pads, cotton wool and head positioners can reduce the occurrence of serious complications such as optic nerve ischaemia or peripheral neuropathies. Two concepts: –– Pinpointing risk factors for peripheral neuropathies and opthalmic vascular incidences: hypertension, smoking, diabetes mellitus and old age. Intraoperative factors: hypovolaemia,

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Fig. 5.3  In the case of the cervico-thoracic passage, the problem of the shoulder can be avoided by tilting the fluoroscopy 45°; in so doing, the pedicles are visible, and the shoulders do not interfere with the radiographic image

dehydration, hypoxia, electrolytic disorders, hypothermia and anaemia. –– Identification of high-risk patients: middle-­ aged, long periods of hospitalization, long, multilevel surgery [2] and spinal fractures related to ankylosing spondylitis (high risk of dislocation during positioning). The three key ingredients for success are: knowledge, planning and teamwork.

References 1. Kamel I, Barnette R.  Positioning patients for spine surgery: avoid uncommon position-related complications. World J Orthop. 2014;5(4):425–43. 2. Sawier RJ, et al. Peripheral nerve injuries associated with anaesthesia. Anaesthesia. 2000;55:980–91. 3. Practice advisory for perioperative visual loss associated with spine surgery: a report by the American Society of Anesthesiologists Task Force on Perioperative Blindness. Anesthesiology. 2006;104:1319–28. 4. Baerts WD, de Lange JJ, Booij LH, et al. Complications of the Mayfield skull clamp. Anesthesiology. 1984;61:460–1. 5. Denaro L, et  al. Pitfalls in cervical spine surgery. Berlin: Springer; 2010. https://doi. org/10.1007/978-3-540-85019-9_6.

Part II Surgical Anatomy

6

Surgical Anatomy of the Upper Cervical Spine and the Craniocervical Junction Gergely Bodon and Bernhard Hirt

The craniocervical junction is probably the most complex region of the entire spine. Familiarity with the anatomy of this region is of paramount importance to avoid disastrous surgical complications. The craniocervical junction consists of the occipital bone, the atlas, and the axis vertebras. Motion among these three bones is determined by the shape and orientation of their joint surfaces and guided by their ligaments. The medulla oblongata is found at the level of the clivus and the foramen magnum; the lower levels contain the spinal cord. This chapter focuses on the bony anatomy, the relevant ligamentous structures of the craniocervical junction, and the suboccipital muscles.

Bony Anatomy The main importance of the occipital bone (Fig. 6.1) is its use as an anchor in occipito-cervical fusion procedures. The foramen magnum has a round (58%) or oval (42%) form [1]. The occipital bone consists of a basal, paired condylar and a squamous part. Basal part of the occipital bone G. Bodon (*) Department of Orthopaedic Surgery, Klinikum Esslingen, Esslingen am Neckar, Germany B. Hirt Clinical Anatomy Tübingen, University of Tübingen, Tübingen, Germany e-mail: [email protected]

forms the clivus, which is located anterior to the foramen magnum. It is 42.8  mm long measured from the basion to the midpoint of the sella [2] and ascends anterocranially at an angle of 45°. The pons and part of the medulla oblongata are found at the level of the clivus. The paired condylar parts are situated lateral to the foramen magnum, bearing the occipital condyles. The occipital condyles have an oval form, their long axes are oriented anteriomedially, with their articular surfaces facing inferiorly and laterally, and their posterior pole reaches the middle of the foramen magnum. The length of the condyles is 23.26 and 20.85  mm, width is 12.54 and 11.51  mm, and height is 9.63 and 9.03  mm, while the convergence is 27.34° and 29.05° in males and females, respectively [3]. The hypoglossal canal opens on the occipital bone about 9.5 mm cranial from the articular surface of the condyle [3], the medial border of the hypoglossal canal being 21.3  mm from the midline [4]. The rough medial surface of the occipital condyle serves as attachment for the alar and the accessory ligaments (Fig. 6.1c) [5, 6]. Behind the condyles, the condylar fossa is found, sometimes perforated by an emissary vein (Fig.  6.1a). The squamous part of the occipital bone forms a concave plate; it is located posterior to the foramen magnum. Its outer surface serves as attachment for muscles and ligaments (Fig.  6.1a). The external occipital protuberance (EOP) is the most prominent and important bony landmark marking the midline. There is a crest

© Springer Nature Switzerland AG 2019 H. Koller, Y. Robinson (eds.), Cervical Spine Surgery: Standard and Advanced Techniques, https://doi.org/10.1007/978-3-319-93432-7_6

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a

the inferior nuchal line is found. The insertion of the semispinalis capitis muscle is located between the superior and inferior nuchal lines medially, and the obliquus capitis superior muscle is attached laterally. The area between the inferior nuchal line and the foramen magnum serves as attachment point for the rectus capitis posterior minor muscle medially and the rectus capitis posterior major muscle laterally. The thickness of the occipital bone shows considerable individual variability. The thickest bone stock is found at the level of the EOP with an average of 17.5 mm in males and 15.3 mm in females (Fig. 6.3). It is possible to place 8 mm long screws in the area extending 2  cm laterally from the EOP at the level of the superior nuchal line and approximately 3 cm inferior to the center [7]. The atlas vertebra (Fig. 6.2) is ring shaped; it consists of two lateral masses connected by an anterior and a posterior arch. The transverse processes project lateral from the lateral sides of the lateral masses. The anterior arch bears an anterior tubercle, serving as an attachment point for the anterior longitudinal ligament and the longus colli muscles. This tubercle is an important surgical and radiological landmark. On the posterior aspect of the anterior arch, a facet joint is found which articulates with the odontoid process. The posterior arch shows greater variations, and together with the posterior roots of the transverse processes, it forms a continuous bony arch. This bony arch consists of segments of various thickness and shape. The middle of the posterior arch is marked by a single, double, or irregular posterior tubercle (forming a groove), or it can be absent [8], which serves as an attachment for the rectus capitis posterior minor muscle and the nuchal ligament. The thick middle part of the posterior arch is limited laterally by the groove for the vertebral artery on both sides, the indentation where the vertebral artery crosses the superior aspect of the posterior arch. The intersection of the vertebral artery and the outer cortex of the posterior arch is 20  mm from the midline [9]. Below and lateral to the groove for the vertebral artery, the thinnest part of the arch is found. If we consider the medial angulation of the lateral mass, this part of the arch is situated

b

c

Fig. 6.1  Figure (a) shows the external landmarks of the occipital bone. (b) shows the structures located at the inner surface of the occipital bone. (c) occipital bone cut in the medial sagittal plane, viewed from medial. Below the external occipital protuberance, the bone stock is considerably thicker because of the external and internal occipital crests

running caudal from the EOP in the midline to the foramen magnum serving as an attachment for the ligamentum nuchae. The superior nuchal line extends lateral to the EOP and serves as attachment for the trapezius muscle in the midline and the sternocleidomastoid and below the splenius capitis muscles on the lateral part of the occipital bone. About halfway down between external occipital protuberance and the foramen magnum,

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Fig. 6.2  Macerated atlas vertebra viewed from above (upper left) and below (upper right) in the upper row. Lower left shows direct posterior view, and lower right

shows the posterior aspect of the posterior arch parallel with the axis of the lateral mass on the right side. The arch posterior to the lateral mass (APLM) is marked

posterior to the lateral mass and therefore was named as arch posterior to the lateral mass (APLM) [10]. The importance of this bone stock is that the ideal entry point for a posterior arch lateral mass screw is located here [10], while the entry point for a lateral mass screw is located below. Lateral to the APLM, the thickness of the arch increases, being made up by the posterior root of the transverse process. A complete or incomplete ponticulus posticus is formed when the posterior atlanto-occipital membrane is partly or completely ossified, in this latter case forming a foramen around the vertebral artery. In some patients an open or closed oval accessory hole (sometimes seen only as an indentation) can be found posterior to the transverse foramen of the atlas. This is the retrotransverse foramen or groove [11] containing an anastomotic vein connecting the venous sinuses above (suboccipital

cavernous sinus) and below the posterior arch of the atlas (vertebral artery venous plexus) (Fig. 6.5a) [12]. The lateral mass of the atlas is an oval bony cylinder, which is covered superiorly and inferiorly by joint surfaces and connected by the anterior and posterior arches. Its long axis converges anteriorly at 18.6° (range 15.5°–21.8°) [13]. Its superior articular surface is rather irregular, bean shaped, and concave, facing medially to form a cradle for the occipital condyle. The inferior articular surface is smaller, round shaped, and slightly concave. Both joints are tilted resulting in a lateral mass height of 12.9 mm (range 8.7–17.3 mm) laterally, but only 4.1 mm (range 1.4–6.7 mm) medially, while the medial wall of the lateral mass is found 10.2 mm (range 8.9–12.8  mm) from the midline [13]. Modeling the bone stock available for a lateral mass screw measured below the APLM is

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slightly greater at its long axis than the width of the lateral mass measured perpendicular to this long axis (17.55  mm and 17.15  mm, respectively) [14]. The working area for placement of a lateral mass screw on the posterior surface of the lateral mass inferior to the APLM is 4.4 mm high and 8.4 mm wide [15]. There are different results published on the height of the groove/C1 posterior arch/pedicle analog/posterior-lateral arch. According to these, the percentage of the arch below 4  mm is 8% [16]/12% [17]/53.8% [18]/19.2% [19], respectively. We found the height of the APLM to be below 4 mm in 40.5% of the cases [10]. The cortical bone of the atlas vertebra is thickest at its inner ring at the junction of the lateral mass and the posterior arch (up to 3.5  mm). The medial surface of each lateral mass bears a small tubercle, which serves as an attachment for the transverse atlantal ligament. In some specimens a bony crest can be found running posteriorly from below this tubercle (a few mms cranial from the inferior joint surface) on the medial aspect of the lateral mass to the ­posteromedial margin of the superior joint surface. The accessory atlantoaxial ligaments attach to this crest (Fig. 6.4d). The spinal canal at the level of the atlas is capacious, the anterior third is occupied by the dens axis, while the posterior two thirds form the spinal canal. This latter was measured on MRIs from the tectorial membrane to the anterior aspect of the posterior arch of the atlas, measuring 10.7–19.7 mm, and was proportional to body height and greater in males than in females. The spinal cord at the level of C1 was measured 7.9–8.5 mm and was inversely proportional to the height of the individual [20]. The second cervical vertebra, the axis, is also special (Fig.  6.3). From its vertebral body, the odontoid process projects cranially to form a pivot around which the atlas vertebra (bearing the skull) rotates. The vertebral body is asymmetric and has a concave endplate with a pronounced lip anteroinferiorly. The body is widest at its base, being 15.9 mm (12.2–20.1 mm) wide in the coronal and 16.7  mm (13.6–20.00  mm) in the sagittal plane [13]. The height of the vertebral body up to the base of the dens is 22.13 mm (17– 26 mm). The dens is 15.8 mm (9–21 mm) high

G. Bodon and B. Hirt

[21]; its mean maximal width is 10.8 mm in the coronal and 10.9 mm in the sagittal plane [13]. It is composed of thick cortical bone with a thin inner spongiosa of 4.3–6.2 mm [22]. The dens is tilted posteriorly 0–30° relative to the axis body [21]. On the anterior surface of the dens, there is a joint to articulate with the atlas, while the posterior surface bears a transverse groove for the transverse atlantal ligament. Lateral to the vertebral body, the two lateral masses are found bearing the oval superior articular facets on their upper surface. From the sides of the axis body, two “lateral bony pillars” run craniolaterally in the coronal plane to support the lateral masses. The use of the “C2 pedicle” in the literature is blurred by the fact that the true anatomical and surgical pedicles are truly different anatomical structures. Besides this, the surgical pedicle is often erroneously used for the pars interarticularis region of the C2. The true anatomical pedicle of the axis is the bone stock connecting the base of the dens with the lateral mass, leaving the body in the coronal plane (Fig.  6.3 middle picture) [23, 24]. The surgical pedicle is defined as the hemitubular structure connecting the inferior articular process to the vertebral body; it is located below the posteromedial part of the ­superior articular process, medial to the vertebral artery groove and medial to the transverse foramen [25]. Precisely, it is the bone stock running from the anteriormost part of the inferior articular process to the lateral bony pillar of the vertebral body (Fig.  6.3 lower left picture). The surgical pedicle forms the cranial border of the inferior vertebral notch of C2. The pars interarticularis connects the superior and inferior articular facets (Fig.  6.3 lower right picture). According to this, the surgical pedicle and the pars interarticularis have the same origin—anterior to the inferior articular process—and their medial walls are common, forming the medial wall of the spinal canal. The vertebral artery groove of the axis is a bony canal through which the vertebral artery enters running cranially, making a lateral turn to exit through the transverse foramen. The bony components of the vertebral artery groove have an intimate contact with the vertebral artery. The groove is bordered postero-

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Fig. 6.3  Macerated axis vertebra. The relevant regions, the anatomical pedicle, the surgical pedicle, as well as the pars interarticularis regions are marked

medially by the surgical pedicle, medially by the lateral bony pillar of the vertebral body, anterosuperiorly by the lateral mass, and posterosuperiorly by the pars interarticularis. An increase in the dimensions of this groove in any direction will cause a decrease in the bone stock of the surrounding structures and thus the bone stock available for screw purchase. A “high-riding” arch extending cranially or posteriorly will narrow the pars interarticularis [26], while an extension medially will reduce the size of the surgical ped-

icle and the lateral bony pillar. Usually in case of a high-riding vertebral artery, a combination of these, medial and cranial increase in extension of the groove exists. The limiting factor for screw placement into the pedicle of the axis is its thickness in the horizontal plane. It was measured a mean 6.38 mm (2.09–12.62) between the medial border of the pedicle to the medial border of the groove [27] using CT angiographies or 5.18 mm (2.2–9.2) in a different study [28] using CT scans. The height of the pedicle is 9.7  mm/8.7  mm in

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males/females [28]. The mean pedicle transverse angle is 43.9° [29]. The superior joints slope inferiorly in the coronal and sagittal planes. The inferior joints are facing inferiorly and have a slightly anterolateral orientation. The transverse processes are small lateral projections originating on the anterolateral aspect of the lateral mass and at the lateral aspect of the pars interarticularis, just anterior to the inferior articular facet. Its tip serves as muscle attachment for the splenius cervicis and scalenus medius muscles (inferiorly) and the intertransversarius muscle (superiorly). The lamina of the axis is well pronounced; it is taller and thicker than the other cervical laminas. It is thicker at its inferior half, on average 5.77 mm (1.35–9.77) [30]. The bifid spinous process of the axis is also pronounced, providing attachments on its craniolateral aspect for the rectus capitis posterior major superiorly and the obliquus capitis inferior muscles below, while on its inferior aspect, the nuchal ligament and the multifidus and semispinalis cervicis muscles attach.

Joints, Ligaments, and Membranous Structures (Fig. 6.4) Motion among these bones is determined by the shape and orientation of their joints and guided by their ligaments. The convex occipital condyle, protruding anteriorly and medially, fits into the concave, bean-shaped superior facet of the atlas, allowing for flexion-extension and minimal lateral flexion. The slightly convex, oval-shaped inferior facet of the atlas faces medially and articulates with the convex superior facet of the axis that is sloping inferiorly. In these joints sliding over long or short distances is possible while the atlas rotates around the dens, which fits into the ring formed by the anterior arch of the atlas and the transverse ligament. The weight of the head is transmitted through the two lateral masses of the atlas to the superior articular processes of the axis. This two-column load is converted to three-column loading at the C2–C3 level as the weight is divided among the end plate of the axis and its two inferior articular processes. This three-column load sharing (disc

G. Bodon and B. Hirt

with end plate and two facet joints) is typical at the lower levels of the entire spine. The main ligaments of the craniocervical junction are the cruciform ligament consisting of the transverse atlantal ligament and the vertical part of the cruciform ligament, the paired alar and accessory ligaments, and the apical ligament. These ligaments are covered posteriorly by the tectorial membrane. See Fig. 6.4. The cruciform ligament (Fig. 6.4b) is composed of a horizontal and a vertical part, forming a cross behind the odontoid process. The horizontal part is composed of the pronounced transverse atlantal ligament that is bond by the weaker vertically oriented longitudinal fibers (Fig. 6.4b). The superior part of the longitudinal fibers attaches cranially to the anterior edge of the foramen magnum in the midline (where it is fused to the tectorial membrane), while its inferior part is attached to the posterior surface of the axis body. The transverse atlantal ligament (Fig.  6.4c, d) is attached to the small tubercle found on the medial aspect of the atlas lateral masses on both sides. This ligament is round after its origin but widens and flattens out to cover the posterior aspect of the odontoid process, locking it in the ring formed by the ligament and the anterior arch of the atlas. It is approximately 10 mm wide in the midline, 18 mm long, and 2 mm thick [31]. The alar ligaments (Fig.  6.4b–d) are strong rounded ligaments originating on the posterolateral surfaces of the upper third of the dens. They run horizontally and slightly cranial to insert on the rough medial surface of the occipital condyles. Mean length of the alar ligament is 8.8 mm, while mean diameter is 7.3 mm [32]. They have a close relationship and are partly covered from behind by the transverse atlantal ligament. The transverse occipital ligament is formed by the posteriormost fibers of the alar ligaments, connecting the two occipital condyles without having contact to the odontoid process. It is present in 8.3–77.8% according to different authors and can be considered as a separate ligament [33]. The accessory atlantoaxial ligaments (Fig.  6.4b–d) or lig. Collaterale atlantoaxiale mediale [34] were considered as medial reinforcements of the C1–C2 joint capsules according to Arnold (Arnold’s ligaments) [35]. In our sample, the accessory ligaments were Y-formed, and the base of the Y originated at the

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a

c

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b

d

Fig. 6.4  This picture shows the ligaments of the craniocervical junction from behind in a formalin-fixed specimen. The posterior part of the foramen magnum and the posterior arch of the atlas are removed. (a) the middle part of the tectorial membrane (tm) is visible, covering the odontoid process (OP) together with its lateral parts (lp). C clivus, AOJ atlanto-occipital joint, AAJ atlantoaxial joint, * marks the spinous process of C2. (b) after removal of the tectorial membrane, the cruciate ligament (cl) with

its vertical bands (vb), alar ligaments (a), and the accessory ligaments (acc) become visible. (c) after removal of the vertical bundles of the cruciate ligament, the transverse atlantal ligament (tal) becomes visible. C2B C2 vertebral body, OC occipital condyle. (d) on the right side of the picture, right half of the transverse atlantal ligament (tal) is removed; its origin is marked with purple. The origin and bony attachments of the accessory ligament are marked with green on the right

posterior aspect of the C2 vertebral body between the base of the dens and the superior articular surface (we found a tubercle at this location in some specimens). The lateral arm of the Y was attached to the medial aspect of the atlas lateral mass on a line starting from below the tubercle of the transverse ligament, ascending posteriorly to the posteromedial margin of the superior articular facet. In some specimens a bony crest can be found along this line, marking the attachment of the accessory ligaments. The medial arm of the Y, forming the cranial extension of the accessory ligament, was

blended with the lateral part of the alar ligament and attached to the medial aspect of the occipital condyle just above and posterior to the attachment of the alar ligament (Fig. 6.4d). Probably the main function of the accessory ligaments together with the alar ligaments is to restrict rotation and limit flexion in the C1–C2 joint. This ligament was examined and named accessory atlantal-axialoccipital ligament by Tubbs, its size being 29 mm long and 5.5 mm wide based on a cadaver study [6]. The mean dimensions of the C1–C2 segment of the ligament measured 2.8 × 1.8 mm on MRIs;

G. Bodon and B. Hirt

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the thinner C0–C1 part’s mean dimensions were 1.6 × 1.2 mm on the right and 1.8 × 1.4 mm on the left side [36]. The apical ligament extends from the tip of the dens to the anterior margin of the foramen magnum, crossing the supraodontoid space, located just anterior to the superior portion of the cruciform ligament. It has no biomechanical function and, as recently revealed, lacks notochordal tissue in adults [37]. It is 2–5 mm wide and only 10–12 mm long and was present in 80% of the cadavers studied [5, 33, 34]. The tectorial membrane (Fig.  6.4a) is a wide and flat square-shaped ligament covering the entire craniocervical junction and upper cervical spine from behind. It is wider cranially, originating on the clivus between the hypoglossal canals; it reaches the posterior aspect of the axis and the third vertebral body caudally where it fuses with the posterior longitudinal ligament. It could be divided into three parts, one medial and two lateral bands. The medial band runs vertically, from the posterior aspect of the body of the axis to the anterior rim of the foramen magnum where it blends with the cranial dura. It is about 1 cm wide and covers the posterior aspect of the dens. The two lateral parts are diverging running cranially; they originate inferi-

a

Fig. 6.5  Formalin-fixed specimen shows the relevant anatomy of the suboccipital region. (a) on the left side of the picture, the suboccipital muscles are shown, and the right side shows the suboccipital cavernous sinus and the

orly at the lateral walls of the spinal canal at the level of C2 (to the medial walls of the pars interarticularis region). The accessory atlantoaxial ligaments are found deep to the lateral parts of the tectorial membrane. The anterior atlanto-occipital membrane attaches the anterior aspect of the atlas to the anterior rim of the foramen magnum, while the posterior atlanto-occipital membrane is a broad thin ligament connecting the posterior arch of the atlas to the posterior rim of the foramen magnum. The posterior atlanto-occipital membrane is connected anteriorly with the dura mater and posteriorly with the rectus capitis posterior minor [33]. The posterior arch of the atlas and the lamina of the axis are connected by the first set of the ligamentum flavum.

 uboccipital Muscles and Nerves S (Fig. 6.5) The suboccipital muscles are covered by their own fascia, formed by fatty and connective tissue. The rectus capitis posterior minor originates on the posterior tubercle of the atlas; it runs cra-

b

vertebral artery venous plexus with their anastomotic vein. (b) shows the neural elements, joints, and V3 segment of the vertebral artery with its vertical (V3v) and horizontal (V3h) segment

6  Surgical Anatomy of the Upper Cervical Spine and the Craniocervical Junction

nial to insert on the occiput between the medial part of the inferior nuchal line and the foramen magnum. The other four muscles form the suboccipital triangle. Its cranial and medial border is formed by the rectus capitis posterior major muscle, which is originating on the spinous process of the axis; it is running cranial and lateral to insert to the occiput, on the lateral part of the inferior nuchal ligament and directly below it. The obliquus capitis superior muscle forms the cranial and lateral border of the triangle. It arises from the upper surface of the processus transversus of the atlas and runs cranial and dorsal to insert on the occiput between the superior and inferior nuchal lines (lateral from the insertion of the rectus capitis posterior major muscle). The base of the triangle is formed by the obliquus capitis inferior muscle. This muscle arises from the processus spinosus and adjacent lamina of the axis and runs cranial and lateral to reach the inferior aspect of the processus transversus of the atlas. The posterior arch of the atlas and the groove for the vertebral artery is found in the middle of the triangle. Dorsal ramus of the first cervical nerve, the suboccipital nerve, runs between the horizontal segment of the V3 vertebral artery and the groove for the vertebral artery posteriorly to innervate the four muscles of the suboccipital triangle. The C2–C3 joint lies directly below the belly of the obliquus capitis inferior muscle. The greater occipital nerve (medial branch of the dorsal ramus of the C2 nerve) emerges from below the obliquus capitis inferior muscle and runs medial and cranial on the obliquus capitis inferior muscle toward the midline to perforate the semispinalis capitis muscle. The third occipital nerve is the sensory superficial medial branch of the third cervical nerve.

References 1. Cirpan S, Yonguc GN, Mas NG, Aksu F, Orhan Magden A. Morphological and morphometric analysis of foramen magnum: an anatomical aspect. J Craniofac Surg. 2016;27(6):1576–8. 2. Lega BC, Kramer DR, Newman JG, Lee JYK.  Morphometric measurements of the anterior

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skull base for endoscopic transoral and transnasal approaches. Skull Base. 2011;21(1):65–70. 3. Zhou J, Espinoza Orías AA, Kang X, He J, Zhang Z, Inoue N, et al. CT-based morphometric analysis of the occipital condyle: focus on occipital condyle screw insertion. J Neurosurg Spine. 2016;25(5):572–9. 4. Russo VM, Graziano F, Russo A, Albanese E, Ulm AJ.  High anterior cervical approach to the clivus and foramen magnum: a microsurgical anatomy study. Neurosurgery. 2011;69(1 Suppl Operative):ons103–14. discussionons115–6 5. Gray H. Gray’s anatomy. Philadelphia, PA: Churchill Livingstone; 1989. p. 1. 6. Tubbs RS, Salter EG, Oakes WJ. The accessory atlantoaxial ligament. Neurosurgery. 2004;55(2):400–2. discussion 402–4 7. Morita T, Takebayashi T, Takashima H, Yoshimoto M, Ida K, Tanimoto K, et al. Mapping occipital bone thickness using computed tomography for safe screw placement. J Neurosurg Spine. 2015;23(2):254–8. 8. Lin JM, Hipp JA, Reitman CA.  C1 lateral mass screw placement via the posterior arch: a technique comparison and anatomic analysis. Spine J. 2013;13(11):1549–55. 9. Yamaguchi S, Eguchi K, Kiura Y, Takeda M, Kurisu K.  Posterolateral protrusion of the vertebral artery over the posterior arch of the atlas: quantitative anatomical study using three-dimensional computed tomography angiography. J Neurosurg Spine. 2008;9(2):167–74. 10. Bodon G, Grimm A, Hirt B, Seifarth H, Barsa P. Applied anatomy of screw placement via the posterior arch of the atlas and anatomy-based refinements of the technique. Eur J Orthop Surg Traumatol. 2016;26(7):793–803. 11. Le Minor JM.  The retrotransverse foramen of the human atlas vertebra. A distinctive variant within primates. Acta Anat (Basel). 1997;160(3):208–12. 12. Arnautović KI, al-Mefty O, Pait TG, Krisht AF, Husain MM.  The suboccipital cavernous sinus. J Neurosurg. 1997;86(2):252–62. 13. Kandziora F, Schulze-Stahl N, KhodadadyanKlostermann C, Schröder R, Mittlmeier T.  Screw placement in transoral atlantoaxial plate systems: an anatomical study. J Neurosurg. 2001;95(1 Suppl):80–7. 14. Voth D, Glees P, Goethe von JW.  Diseases in the cranio-cervical junction. Berlin: Walter de Gruyter; 1987. p. 1. 15. Seal C, Zarro C, Gelb D, Ludwig S. C1 lateral mass anatomy: proper placement of lateral mass screws. J Spinal Disord Tech. 2009;22(7):516–23. 16. Tan M, Wang H, Wang Y, Zhang G, Yi P, Li Z, et  al. Morphometric evaluation of screw fixation in atlas via posterior arch and lateral mass. Spine. 2003;28(9):888–95. 17. Ma X-Y, Yin Q-S, Wu Z-H, Xia H, Liu J-F, Xiang M, et  al. C1 pedicle screws versus C1 lateral mass screws: comparisons of pullout strengths and biomechanical stabilities. Spine. 2009;34(4):371–7.

32 18. Lee MJ, Cassinelli E, Riew KD.  The feasibility of inserting atlas lateral mass screws via the posterior arch. Spine. 2006;31(24):2798–801. 19. Christensen DM, Eastlack RK, Lynch JJ, Yaszemski MJ, Currier BL.  C1 anatomy and dimensions relative to lateral mass screw placement. Spine. 2007;32(8):844–8. 20. Ulbrich EJ, Schraner C, Boesch C, Hodler J, Busato A, Anderson SE, et  al. Normative MR cervical spinal canal dimensions. Radiology. 2014;271(1):172–82. 21. Lang J.  Clinical anatomy of the cervical spine. Stuttgart: George Thieme Verlag; 1993. p. 1. 22. Heller JG, Alson MD, Schaffler MB, Garfin SR.  Quantitative internal dens morphology. Spine. 1992;17(8):861–6. 23. Borne GM, Bedou GL, Pinaudeau M.  Treatment of pedicular fractures of the axis. A clinical study and screw fixation technique. J Neurosurg. 1984;60(1):88–93. 24. Suchomel P, Choutka O. Reconstruction of upper cervical spine and craniovertebral junction. Heidelberg: Springer Science & Business Media; 2010. p. 1. 25. Ebraheim NA, Fow J, Xu R, Yeasting RA. The location of the pedicle and pars interarticularis in the axis. Spine. 2001;26(4):E34–7. 26. Neo M, Matsushita M, Iwashita Y, Yasuda T, Sakamoto T, Nakamura T.  Atlantoaxial transarticular screw fixation for a high-riding vertebral artery. Spine. 2003;28(7):666–70. 27. Moftakhar P, Gonzalez NR, Khoo LT, Holly LT.  Osseous and vascular anatomical variations within the C1–C2 complex: a radiographical study using computed tomography angiography. Int J Med Robot. 2008;4(2):158–64. 28. Ould Slimane M, Le Pape S, Leroux J, Foulongne E, Damade C, Dujardin F, et  al. CT analysis of C2 pedicles morphology and considerations of use-

G. Bodon and B. Hirt ful parameters for screwing. Surg Radiol Anat. 2014;36(6):537–42. 29. Smith ZA, Bistazzoni S, Onibokun A, Chen N-F, Sassi M, Khoo LT. Anatomical considerations for subaxial (C2) pedicle screw placement: a radiographic study with computed tomography in 93 patients. J Spinal Disord Tech. 2010;23(3):176–9. 30. Cassinelli EH, Lee M, Skalak A, Ahn NU, Wright NM.  Anatomic considerations for the placement of C2 laminar screws. Spine. 2006;31(24):2767–71. 31. Lang J.  Skull base and related structures. Stuttgart: Schattauer Verlag; 2001. p. 1. 32. Cattrysse E, Barbero M, Kool P, Gagey O, Clarys JP, Van Roy P. 3D morphometry of the transverse and alar ligaments in the occipito–atlanto–axial complex: an in vitro analysis. Clin Anat. 2007;20(8):892–8. 33. Tubbs RS, Hallock JD, Radcliff V, Naftel RP, Mortazavi M, Shoja MM, et al. Ligaments of the craniocervical junction. J Neurosurg Spine. 2011;14(6):697–709. 34. Fick R. Handbuch der Anatomie und Mechanik der Gelenke, unter Berücksichtigung der bewegenden Muskeln, von Rudolf Fick. Jena: Verlag von Gustav Fischer; 1904. 35. Arnold F.  Handbuch der Anatomie des Menschen. Freiburg im Breisgau, Herder`sche Verlagshandlung. 1851. 36. Yuksel M, Heiserman JE, Sonntag VKH.  Magnetic resonance imaging of the craniocervical junction at 3-T: observation of the accessory atlantoaxial ligaments. Neurosurgery. 2006;59(4):888–92. discussion 892–3 37. Fisahn C, Schmidt C, Rostad S, Li R, Rustagi T, Alonso F, et al. The adult apical ligament of the dens does not contain notochordal tissue: application to better understanding the origins of skull base chordomas. World Neurosurg. 2017;101:42–6.

7

Relevant Surgical Anatomy of the Anterior Cervical Spine, the High Retropharyngeal and the Subaxial Regions Gergely Bodon and Andres Combalia

The anterior approach to the cervical spine allows for exposure of the ventral aspect of the vertebral bodies, discs, ipsilateral transverse foramens, and the vertebral artery. In the present chapter, the relevant anatomic structures of the anterior neck and the anterior cervical spine are discussed, related to the high retropharyngeal and the anterior subaxial approaches. To perform a safe exposure of the anterior cervical spine, familiarity with the components of the carotid sheath, the lower four cranial nerves and their branches, as well as the five fascial layers covering all the structures of the neck is of paramount importance. Figure 7.1 demonstrates the principles of the standard anterior subaxial approach. The spine is reached by opening five subsequent fascial layers covering the structures of the anterior neck (Fig. 7.1a), while the sternocleidomastoid muscle with the underlying carotid sheath and its contents are retracted laterally; the esophagus, trachea, and larynx with the infrahyoid muscles are retracted medially (Fig. 7.1b).

G. Bodon (*) Department of Orthopaedic Surgery, Klikikum Esslingen, Esslingen a.N., Germany A. Combalia Department of Orthopaedic Surgery, Musculoskeletal Oncology Unit, Hospital Clinic Universitari de Barcelona, School of Medicine, Barcelona, Spain

Muscles of the Anterior Neck The topographic anatomy of the anterior neck is shown on Fig. 7.2. The most prominent muscle of the anterior neck is the sternocleidomastoid muscle originating from the manubrium of the sternum and the medial third of the clavicle. It traverses the neck running posterolateral to insert on the mastoid process and the lateral part of the occipital bone; it is innervated by the accessory nerve and the ventral ramuses of C2 and C3 [1]. The great auricular nerve, the branches of the external jugular vein, and the cutaneous cervical nerve cross the anterior surface of this muscle (Fig.  7.3). The deeper muscles of the anterior neck are divided to suprahyoid and infrahyoid muscles. The most superficial of the infrahyoid muscles is the omohyoid muscle. The inferior belly arises from the scapular notch, turns anteromedially and ends in the intermediate tendon which lies on the internal jugular vein at the level of the cricoid cartilage. The superior belly of the omohyoid muscle runs cranially and medially to the lower border of the hyoid bone. The superior belly is encountered when operating at the C5– C6 and C6–C7 levels at the anterior margin of the sternocleidomastoid muscle. Medial to the superior belly is the sternohyoid muscle ascending cranially from the posterior surface of the manubrium to the hyoid bone. Deep and lateral to the sternohyoid muscle are the sternothyroid (running from the posterior surface of the manubrium

© Springer Nature Switzerland AG 2019 H. Koller, Y. Robinson (eds.), Cervical Spine Surgery: Standard and Advanced Techniques, https://doi.org/10.1007/978-3-319-93432-7_7

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G. Bodon and A. Combalia

a

b

Fig. 7.1 (a) Formalin fixed specimen showing the cross sectional anatomy of the neck. (b) The principle of the standard anterior approach is shown. The anterior aspect of the cervical spine is reached by retracting the sternocleidomastoid muscle with the underlying carotid sheath laterally and the the esophagus, trachea and larynx medially

to the thyroid cartilage) and the thyrohyoid (connecting thyroid cartilage to the hyoid bone) muscles (Fig. 7.2). On the anterior aspect of the cervical spine, the longus colli and the longus capitis muscles are found. The longus colli muscle covers the anterolateral aspect of the vertebral bodies between the atlas and the third thoracic vertebra, inserting cranially on the anterior tubercle of the

Fig. 7.2  Superficial topographic anatomy is shown on the right side of the neck. The sternocleidomastoid muscle and below the common carotid artery (CCA) is visible together with the infrahyoid muscles

atlas. It is partly covered by the longus capitis muscle above C6, which is originating by tendinous slips from the anterior tubercles of the transverse processes of the third to sixth cervical vertebra and runs cranially to insert on the inferior surface of the occipital bone in front of the foramen magnum, lateral to the midline. Its muscle belly covers the anterior aspect of the lateral mass of the atlas vertebra [2]. The rectus capitis anterior muscle is a flat muscle arising from the anterior aspect of the lateral mass of the atlas and the anterior root of its transverse process and inserts to the occipital bone in front of the occipital condyle. The rectus capitis lateralis muscle arises from the cranial margin of the anterior root of the transverse foramen of the atlas and inserts on the jugular process of the occipital bone. The three scalene muscles are found lateral to the vertebral column. The anterior scalene muscle originates at the anterior tubercles of C3–C6 and attaches on the anterior aspect of the first rib (scalene tubercle). It lies deep to the sternocleidomastoid and omohyoid muscles. The vertebral artery enters the C6 foramen (in 90% of the cases [3]) between the bellies of the longus colli medially and the anterior scalene muscle laterally.

7  Relevant Surgical Anatomy of the Anterior Cervical Spine, the High Retropharyngeal and the Subaxial…

Fasciae of the Anterolateral Neck Region The superficial cervical fascia is very thin and covers the platysma (Fig. 7.1a). The four layers of the deep cervical fascia invest the neck muscles. This fascial system is composed of fibroareolar tissue filling up the empty spaces among muscles, vessels, and the viscera of the neck. This fibroareolar tissue is variable, forming thin fascial layers or loosely arranged connective tissue matrix which can be easily broken down. The superficial layer surrounds the sternocleidomastoid muscles uniting in the midline. The middle layer covers the strap muscles and forms a visceral fascia for the trachea, the esophagus, and the recurrent laryngeal nerve. The alar fascia is attached on both sides to this visceral fascia medially and to the carotid sheaths laterally. The deep layer is the prevertebral fascia, covering the anterior surface of the spine, longus colli, and scalene muscles [1].

Vessels The common carotid artery is located in the carotid sheath deep to the sternocleidomastoid muscle. It passes obliquely upward from behind the sternoclavicular joint to its bifurcation (found at the level of C4 in 68% of the cases [3]) where it divides into the internal and external carotid arteries. The cervical portion of the internal carotid artery usually runs in front of the transverse processes of the upper three cervical vertebras [1], but anatomic variations have an overall incidence of 10–40% with high-grade aberrations in 5–6% of the general population [4]. These variations include tortuosity (S- or C-shaped elongations) coiling (loop formation) or kinking (angulation with stenosis) with a higher occurrence with increasing age [2, 3]. The internal carotid artery has a highly variable course at the level of the atlas vertebra and is located in front of the C1 lateral mass in 64.4% of the cases [5]. The cervical portion of the internal carotid artery is in contact with the longus capitis muscle posteriorly; it is related to the wall of the pharynx

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medially and covered by the sternocleidomastoid muscle anterolaterally [1]. Three ventral branches of the external carotid artery are encountered during the high retropharyngeal approach. The superior thyroid artery is the first anterior branch emerging just below the tip of the greater horn of the hyoid bone. After giving off a horizontal branch to the hyoid bone and the superior laryngeal artery, it descends caudally running on the surface of the thyroid gland [6]. The lingual artery emerges at the level of the tip of the greater horn of the hyoid bone, running deep to the hypoglossal nerve. The facial artery is emerging cranial to the tip of the greater horn, running cranially and disappearing behind the posterior belly of the digastric muscle. It is crossing the mandible running cranially and helps localizing and retracting the marginal mandibular branch of the facial nerve, which runs superficial to the facial artery and vein. The medial ascending pharyngeal artery is a small branch ascending between the internal carotid artery and the pharynx on the surface of the longus capitis muscle running to the skull base [1]. The inferior thyroid artery is a branch of the thyrocervical trunk of the subclavian artery. Its origin is located at front of the medial border of the anterior scalene muscle. The inferior thyroid artery runs cranially in front of the medial border of the anterior scalene muscle and forms a loop medially to reach the thyroid gland. As it turns medially, the vertebral artery and vein are running behind and the sympathetic trunk runs in front of it. The middle cervical ganglion rests on the vessel [1]. On the left side, the thoracic duct is crossing the inferior thyroid artery anteriorly. Usually, the recurrent laryngeal nerve is running behind the terminal branches of the thyroid artery on the left side while it is found more likely at front or in between the terminal branches of the inferior thyroid artery on the right side. The internal jugular vein collects the blood from the brain, leaving the skull through the posterior compartment of the jugular foramen. It runs down the neck located in the carotid sheath laterally and posteriorly to the common and internal carotid arteries to unite with the subclavian vein behind the clavicle. It may communicate with the

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G. Bodon and A. Combalia

external jugular vein at the cranial part of the neck. It receives a pronounced tributary joining the retromandibular and facial veins, the veins of the tongue, pharynx, larynx, and cranial part of the thyroid below the level of the hyoid bone. It has a variable number of smaller tributaries below in form of the middle and inferior thyroid veins. The external jugular vein is formed by the union of the retromandibular and the posterior auricular veins beginning at the level of the angle of the mandible. It runs down the neck crossing the sternocleidomastoid muscle anteriorly and ends in the subclavian vein lateral to or in front of the anterior scalene muscle. It runs between the platysma and the superficial layer of the deep cervical fascia. The posterior external jugular vein begins in the occipital region and opens into the middle part of the external jugular vein. The anterior jugular vein drains the blood of the floor of the mouth and the submandibular region. It is usually doubled and runs down between the midline and the medial border of the sternocleidomastoid muscle, which covers the inferior part of the vein. It opens into the external jugular or the subclavian vein. These veins show great variations.

Nerves The marginal mandibular branch of the facial nerve is endangered during the high retropharyngeal approach. It makes a curve about 1.5  cm below the inferior border of the mandible close to its angle running anterior to innervate the lower lip and chin muscles [7, 8]. Its injury results in “hanging” of the lip on the affected side. It is usually injured by getting pinched between the retractor blade and the mandible. The great auricular and the transverse cervical nerves are part of the sensory portion of the plexus cervicalis and can be found crossing the sternocleidomastoid muscle anteriorly (Fig. 7.3). They innervate the ear and the skin at the angle of the mandible and the anterior neck region, respectively [9]. The motor portion of the plexus cervicalis forms the ansa cervicalis profunda (consists of a superior root formed by the C1 ventral ramus joining the hypoglossal nerve and inferior root formed by the ventral ramuses of C2 and C3) innervating the infrahyoid muscles. The glossopharyngeal, vagus, and accessory nerves

Fig. 7.3  Superficial neural structures relevant for the anterior approach are visible after removal of the platysma on the right side. SCM sternocleidomastoid muscle, EJV external jugular vein, AJV anterior jugular vein

exit the skull through the jugular foramen. The glossopharyngeal nerve is running anteriorly between the internal jugular vein and the internal carotid artery and descends at the front of the latter to enter the pharynx together with the stylopharyngeal muscle. It supplies general and taste sensation to the posterior third of the tongue. The accessory and hypoglossal nerves are located behind the posterior belly of the digastric muscle. After exiting the skull, the accessory nerve runs laterally anterior to the internal jugular vein, emerges from behind the posterior belly of the digastric muscle (just anterior to the transverse process of the atlas), and enters the sternocleidomastoid muscle about 3 cm from the tip of the mastoid process. It leaves the sternocleidomastoid muscle at its lateral border and runs lateral to enter the trapezius muscle which it innervates (Fig. 7.3). Injury to the accessory nerve results in paralysis of the sternocleido-

7  Relevant Surgical Anatomy of the Anterior Cervical Spine, the High Retropharyngeal and the Subaxial…

mastoid and trapezius muscles. The vagus nerve courses inferiorly through the neck in the carotid sheath; two of its branches are endangered during the anterior cervical approach. The superior laryngeal nerve runs anteromedially deep to the internal and external carotid arteries, emerging anterior to the external carotid artery at the level of the superior thyroid artery. Its external branch supplies motor innervation to the inferior pharyngeal constrictors and the cricothyroid muscle while its internal branch is responsible for the sensory innervation of the larynx. Injury of this nerve results in early fatigue of voice and difficulty in producing high notes as well as the loss of supraglottic sensation [8]. The right recurrent laryngeal nerve leaves the vagus nerve after it passes anterior to the subclavian artery; it loops around that artery running from anterior to posterior, turns cranial, and ascends in the groove formed by the trachea and esophagus on the right side (Fig. 7.4). The left Fig. 7.4 Deep structures of the neck shown on (a) fresh cadaver on the right side after removal of the clavicle and the omohyoid muscle, the sternocleidomastoid muscle is divided and elevated, the jugular veins are also removed. In (b) are the midline structures retracted to show the vagus nerve with its superior laryngeal and recurrent laryngeal branches

a

b

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vagus nerve passes anterior to the arch of the aorta on the left side, it gives off the left recurrent laryngeal nerve, which loops around the aorta and runs cranially in the tracheoesophageal groove. Both recurrent laryngeal nerves are related to the medial surface of the thyroid gland and disappear under the inferior constrictor muscle to enter the larynx. The recurrent laryngeal nerves innervate all muscles of the larynx (except the cricothyroid muscle). Injury to this nerve can lead to vocal cord paralysis with hoarseness, stridor and dyspnea in case of unilateral injury or aphony and dyspnea requiring tracheostomy in case of bilateral injury [8]. A feared variant of the recurrent laryngeal nerve is the nonrecurrent course of the inferior laryngeal nerve, which occurs on the right side in 0.51% of the cases [10]. In this case, the inferior laryngeal nerve does not form a loop around the subclavian artery but runs directly from the vagus nerve to the larynx accompanied by the vessels of

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the thyroid gland. In this case, the nerve could be ligated or clipped unintended with—or instead of—the inferior thyroid artery [8]. The nonrecurrent inferior laryngeal nerve is usually associated with malformations of the aortic arch resulting in an aberrant subclavian artery, which arises from the distal portion of the left subclavian artery and passes to the right behind the esophagus [11], although nonrecurrent course of this nerve without vascular anomaly has been also reported [12]. A nonrecurrent laryngeal nerve on the left is a rarity, always associated with situs inversus viscerum. The hypoglossal nerve exits the skull through the hypoglossal canal about 9.4 mm above articular surface of the occipital condyle [13], the medial border of the hypoglossal canal being 21.3  mm from the midline [14]. It runs caudally between the internal jugular vein and the internal carotid artery and appears from behind the posterior belly of the digastric muscle making a curve about 3 cm cranial to the bifurcation of the carotid artery anteriorly superficial to the internal and external carotid arteries at the level of the lingual artery and enters the tongue by passing deep to the mylohyoid muscle. It innervates the muscles of the tongue causing ipsilateral paralysis and deviation to the ipsilateral side of the tongue if injured. It gives off the superior branch of the deep ansa cervicalis formed by Fig. 7.5  After dividing and retracting the sternocleidomastoid (SCM) and omohyoid muscles and dividing and resecting the sternohyoid (black asterisk) and sternothyroid (white asterisk) muscles, the deep structures of the neck are revealed. The main vessels are the carotid artery (CA), the external carotid artery (ECA), and the jugular vein (JV). PG parotid gland, SMG submandibular gland

G. Bodon and A. Combalia

the C1 ventral ramus which joins the inferior branch from the ventral ramuses of C2 and C3 on the surface of the internal jugular vein and innervate the strap muscles (infrahyoid muscles). The sensory portion of the cervical plexus is formed by the ventral ramuses of the C2–C4 nerves forming the lesser occipital, great auricular, transverse cervical, and supraclavicular nerves. The motor portion is formed by the inferior root of the deep ansa cervicalis joining the C2–C3 nerves, running lateral to the internal jugular vein, and uniting with the superior root formed by the C1 ventral ramus (leaving the hypoglossal nerve) on the jugular vein to supply all the infrahyoid muscles except the thyrohyoid (Fig. 7.5). The phrenic nerve arises from the ­ventral ramus of C3, C4, and C5 with C4 being the most remarkable. The cervical sympathetic trunk is made up of three distinct ganglia in the neck region, the superior, middle and cervicothoracic (stellate) ganglions [9]. The superior ganglion is the most pronounced, about 2.5–3  cm long, lying on the ventral aspect of the longus capitis muscle at the C2–3 level. The middle cervical ganglion is the smallest in size and may be absent, it lies at the level of C6 transverse process on the longus capitis muscle close to the inferior thyroid artery (which is running behind the sympathetic trunk).

7  Relevant Surgical Anatomy of the Anterior Cervical Spine, the High Retropharyngeal and the Subaxial…

The cervicothoracic (stellate) ganglion is about 2.8 cm long, is located at the base of the C7 transverse process and the neck of the first rib. These ganglia have many fibers forming the perivascular plexuses on the internal and external carotid, vertebral and subclavian arteries, furthermore laryngopharyngeal, thyroid and cardiac branches [9].

Discs Although cervical discs are chemically similar to lumbar discs, they are completely different anatomically and functionally. The cervical nucleus pulposus makes up only 25% of the disc at birth (compared to the 50% of a lumbar disc). This nucleus is going through an aging process and disappears by the age of 30, its place taken by a fibrocartilaginous core. At an early age, between 9 and 14 years, bilateral clefts start building medial to the uncovertebral joints; at 20–35  years, these clefts form dissecting tissue planes toward the midline where they finally meet. At 60 years of age, the cervical discs are bisected transversely from uncinate process to uncinate process [15]. The fibers of the cervical anulus fibrosus are not concentric. The anterior anulus is 2–3 mm thick in the midline and gets thinner toward the uncinate region; its fibers are oriented craniomedi-

a

Fig. 7.6  Detailed anatomy of the cervical neural foramen. (a) bony anatomy and (b) section through the neural foramen of a formalin-fixed specimen, right side; right side of the picture is toward anterior. (c) bony anatomy

39

ally and are interwoven in the midline. The anterior longitudinal ligament covers it anteriorly. The posterior anulus is 1 mm thick consisting of one set of vertically oriented collagen fibers between the uncinate processes, covering only the posteromedial aspect of the fibrocartilaginous core. The posterior longitudinal ligament covers the entire floor of the cervical spinal canal (covering the area between the uncinate processes), while periosteofascial tissue— consisting of unorganized fibrous connective tissue—covers the area at the lateral clefts in the uncovertebral region [16].

Neural Foramen The cervical neural foramens are oval-shaped tunnels with an approximate length of 4–6  mm, a vertical diameter of 10 mm, and an anteroposterior diameter of 5 mm. The boundaries of the real cervical neural foramens are the pedicles of the adjacent vertebras cranially and caudally, the medial aspect of the superior articular process and the lateral mass posteriorly and the posterolateral aspect of the uncovertebral joint anteriorly (Fig.  7.6). There is the equivalent of the lumbar subarticular zone located medial to the cervical neural foramen, bordered by the posterior part of

b

from above, (d) horizontal section at the level of the foramen in a formalin-fixed specimen. SAP superior articular process, UVJ uncovertebral joint, Ped pedicle, TF transverse foramen, VA vertebral artery

G. Bodon and A. Combalia

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c

d

Fig. 7.6 (continued)

a

b

Fig. 7.7  Formalin-fixed specimen shown from the front (a) and obliquely (b) after removal of the C4 and C5 vertebral bodies and opening of the dura anteriorly. P pedicle, VA vertebral artery

the uncinate process and the posterolateral part of the disc anteriorly and the yellow ligament posteriorly. Lateral to the neural foramen, the spinal nerve rests in the trough formed by the transverse process, with the spinal ganglion and the dorsal and ventral ramuses of the exiting nerve roots posteriorly and the vertebral artery ascending through the transverse foramens anteriorly. The dorsal root ganglion is located outside the neural foramen, anterior to the lateral mass and superior articular process. The ventral root of the spinal nerve is about two thirds the diameter of the dorsal root which is located posteriorly and inferiorly

in the neural foramen. The two roots occupy one fourth to one third of the neural foramen [17, 18]. Periradicular fibrous tissue covers the exiting nerve, vertebral artery, and uncovertebral joint. The neural foramens are facing about 45° from the midsagittal plane and 10° to the horizontal plane [9]. The intradural rootlets below the level of C5 pass downward and lateral with increasing obliquity to their respective neural foramen. Because of this obliquity, the nerve roots below C5 could be compressed in the central region at one disc above the respective neural foramen (Fig. 7.7) [17]. Besides the neural structures, we

7  Relevant Surgical Anatomy of the Anterior Cervical Spine, the High Retropharyngeal and the Subaxial…

find radicular arteries entering and foraminal veins leaving the neural foramen. The remaining space of the neural foramen among the neural and vascular structures is filled with areolar tissue.

References 1. Gray H. Gray’s anatomy. Philadelphia, PA: Churchill Livingstone; 1989. 2. Hong JT, Kim TH, Kim IS, Yang SH, Sung JH, Son BC, et  al. The effect of patient age on the internal carotid artery location around the atlas. J Neurosurg Spine. 2010;12(6):613–8. 3. Lang J.  Clinical anatomy of the cervical spine. Stuttgart: George Thieme Verlag; 1993. 4. Pfeiffer J, Ridder GJ. A clinical classification system for aberrant internal carotid arteries. Laryngoscope. 2008;118(11):1931–6. 5. Murakami S, Mizutani J, Fukuoka M, Kato K, Sekiya I, Okamoto H, et al. Relationship between screw trajectory of C1 lateral mass screw and internal carotid artery. Spine. 2008;33(24):2581–5. 6. Luzsa G.  X-ray anatomy of the vascular system. Philadelphia: Lippincott; 1974. 7. Batra APS, Mahajan A, Gupta K. Marginal mandibular branch of the facial nerve: an anatomical study. Indian J Plast Surg. 2009;43(1):60–4. 8. Stöhr M. Iatrogene Nervenläsionen. Stuttgart: George Thieme Verlag; 1996. 9. Cramer GD, Darby SA. Clinical anatomy of the spine, spinal cord, and ANS.  Philadelphia: Elsevier Health Sciences; 2013.

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10. Toniato A, Mazzarotto R, Piotto A, Bernante P, Pagetta C, Pelizzo MR.  Identification of the nonrecurrent laryngeal nerve during thyroid surgery: 20-year experience. World J Surg. 2004;28(7):659–61. 11. Nagayama I, Okabe Y, Katoh H, Furukawa M.  Importance of pre-operative recognition of the nonrecurrent laryngeal nerve. J Laryngol Otol. 1994;108(5):417–9. 1 2. Tateda M, Hasegawa J, Sagai S, Nakanome A, Katagiri K, Ishida E, et  al. Nonrecurrent inferior laryngeal nerve without vascular anomaly as a genuine entity. Tohoku J Exp Med. 2008;216(2):133–7. 13. Zhou J, Espinoza Orías AA, Kang X, He J, Zhang Z, Inoue N, et al. CT-based morphometric analysis of the occipital condyle: focus on occipital condyle screw insertion. J Neurosurg Spine. 2016;25(5):572–9. 14. Russo VM, Graziano F, Russo A, Albanese E, Ulm AJ.  High anterior cervical approach to the clivus and foramen magnum: a microsurgical anatomy study. Neurosurgery. 2011;69(1 Suppl Operative):ons103–14. discussions 115–6 15. Giles LGF. The clinical anatomy and management of cervical spine pain. London: Butterworth-Heinemann Medical; 2000. 16. Mercer S, Bogduk N.  The ligaments and annulus fibrosus of human adult cervical intervertebral discs. Spine. 1999;24(7):619–26. discussion 627–8 17. Tanaka N, Fujimoto Y, An HS, Ikuta Y, Yasuda M. The anatomic relation among the nerve roots, intervertebral foramina, and intervertebral discs of the cervical spine. Spine. 2000;25(3):286–91. 18. Ebraheim N, Rollins JR, Xu R, Jackson WT. Anatomic consideration of C2 pedicle screw placement. Spine. 1996;21(6):691–5.

8

Relevant Surgical Anatomy of the Posterior Subaxial Spine and the Cervicothoracic Junction Gergely Bodon and Andres Combalia

While the subaxial cervical spine consists of four typical cervical vertebrae from C3 to C6, the ­vertebrae between C6 and Th4 show special and unique characteristics. The cervicothoracic junction is the intersection between the mobile cervical spine and the rigid thoracic spine. This chapter focuses on the muscular anatomy of the posterior subaxial and upper thoracic spine and on the special bony anatomy of the vertebras forming the cervicothoracic junction.

Surface Anatomy and Bony Landmarks The landmarks of the posterior cervical spine on the occipital bone include the external occipital protuberance marking the midline of

the occipital region. Moving laterally, a small bony bridge, the superior nuchal line, can be felt. More lateral and inferior, the mastoid process can be palpated. The tip of the transverse process of the atlas lies just anteroinferior to the tip of the mastoid process. The row of spinous processes marks the posterior midline and could be palpated through the ligamentum nuchae. The cranialmost spinous process is that of the axis vertebra. It is quite large and can be easily palpated while the spinous processes of C3–C6 are bifid and located slightly more ventrally. The C7 and Th1 spinous processes are more pronounced and not bifurcated. The zygapophysial joints are found about 25  mm lateral from the midline (Fig. 8.1).

G. Bodon (*) Department of Orthopaedic Surgery, Klinikum Esslingen, Esslingen a.N., Germany A. Combalia Department of Orthopaedic Surgery, Hospital Clinic Universitari de Barcelona, Barcelona, Spain © Springer Nature Switzerland AG 2019 H. Koller, Y. Robinson (eds.), Cervical Spine Surgery: Standard and Advanced Techniques, https://doi.org/10.1007/978-3-319-93432-7_8

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G. Bodon and A. Combalia

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a

b

c

d

Fig. 8.1  Figures (a–c) show the most important muscles of the posterior cervical spine. (a) The most superficial muscle on the dorsal aspect of the neck is the trapezius muscle which is fused with the nuchal ligament and the spinous processes in the midline. (b) Deep to the trapezius muscle, the splenius capitis and splenius cervicis muscles become visible. A few centimeters from the midline, the greater occipital nerve pierces through the semispinalis capitis muscle and will be accompanied by the occipital artery which emerges between the splenius and the semispinalis capitis. (c) Removal of the splenius capitis and

 elevant Muscular Anatomy R and the Ligamentum Nuchae The posterior aspect of the cervical and the upper thoracic spine is covered by six muscle layers [1, 2]. Segmental origins and attachments of these

splenius cervicis muscles reveals the semispinalis capitis and longissimus capitis and cervicis (below) muscles (left side), while removal of the latter three muscles allows for visualization of the suboccipital muscles and the semispinalis cervicis and multifidus muscles with their cranialmost attachment on the spinous process of the axis (right side). C2SP spinous process of the axis, EOP external occipital protuberance. (d) shows cross section of the cervical spine at the C6 level. The muscle layers are visible with the ligamentum nuchae in the midline. FJ facet joint, SC spinal cord

muscles show slight variations. The first layer, deep to the skin and the subcutaneous tissue, is formed by the trapezius and the sternocleidomastoid muscles. They both are covered by the superior nuchal fascia and are both inserting to the occipital bone. The trapezius muscle is attached cranially to the external occipital protuberance

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Fig. 8.2  Picture shows the 4–6th layers of the neck muscles. On the left, the superficial muscle layers are only marked with their origin and attachments to reveal the deeper muscle layers

and to the superior nuchal lines. The sternocleidomastoid muscle is inserted to the lateral surface of the mastoid process and to the lateral half of the superior nuchal line (Figs. 8.1 and 8.2). The second layer is composed of three muscles lying deep to the trapezius muscle and inserting onto the medial border of the scapula. The levator scapulae muscle originates on the transverse processes of the atlas and the axis and on the posterior tubercles of the transverse processes of C3 and C4. It inserts onto the medial border of the scapula between the superior angle and the spine of the scapula. The rhomboid minor muscle

is running inferolaterally beginning on the inferior portion of the ligamentum nuchae and the spinous process of C7 and Th1. It is attached to the medial border of the scapula at the level of the spinal root. The rhomboid major muscle is located inferior to the previous muscle, originating on the spinous processes and supraspinous ligaments of Th2–Th5. Its fibers are running also inferolaterally to insert to the medial border of the scapula between the spine of the scapula and its inferior angle. The third layer is formed by a thin quadrangual muscle, the serratus posterior superior mus-

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cle. It is originating on the spinous processes of C7 to Th3 and the interconnecting supraspinous ligaments and inserts to the posterior aspect of the second to fifth ribs. The fourth layer is formed by the splenius capitis muscle which is covered by the deep nuchal fascia. This is a thin and flat muscle originating on the lower half of the ligamentum nuchae (below the level of C3) and from the spinous processes C7 to Th3(4) and their connecting supraspinal ligaments. Fibers of the muscle are running upward and lateral to insert on the mastoid process and on the occipital bone just below the lateral third of the superior nuchal line and deep to the sternocleidomastoid muscle. The splenius cervicis muscle originates from the Th3–Th6 spinous processes and inserts deep to the origins of the levator scapulae muscle onto the transverse processes of the atlas and axis and the posterior tubercles of the transverse processes of C3 and C4. Deep to the splenius capitis muscle, the largest group of back muscles, the erector spinae group is found, forming the fifth layer. They can be divided into three groups from lateral to medial, the group of the iliocostalis, longissimus, and the spinalis muscles. Each of them has three subgroups according to their insertion (lumborum, thoracis, cervicis, and capitis). The iliocostalis cervicis muscle is originating on the angle of the third to sixth ribs and runs cranially to insert on the posterior tubercles of the C4– C6 transverse processes. The longissimus cervicis muscle forms a flat muscle located just medial to the former muscle group. It originates on the transverse processes of Th1–Th5 and runs cranially to insert onto the articular process and posterior tubercles of the transverse processes of C3–C6 and to the transverse processes and inferior articular processes of C2. The longissimus capitis muscle originates on the transverse processes of Th1–Th5 and the articular processes of C4–C7. It runs cranially to insert close to the tip of the mastoid process on its posterior aspect deep and medial to the attachment of the splenius capitis muscle and

G. Bodon and A. Combalia

lateral to the origin of the digastric muscle. The spinalis muscle group is formed of muscles connecting the spinous processes except the spinalis capitis muscle. The spinalis thoracis muscles are most pronounced, forming two spindle-shaped muscle bellies, located on both sides lateral at the tips of the spinous processes. They originate from Th11-L2 spinous processes and are attached to the upper thoracic spinous processes from Th(1)2–9(10). The origin of the spinalis cervicis muscle is located more superficial from the spinalis thoracis. It is originated on the spinous processes of C6 to Th2(4) and runs cranial to attach to the tips of the spinous processes of C2–4. The spinalis capitis muscle is different from the other spinalis muscles as it does not originate or attach to spinous processes. Its origin and muscle fibers are blended with the more laterally lying semispinalis capitis muscle as well as its attachment on the occipital bone. The sixth layer contains the most important segmental stabilizers of the spine. They are also called the transversospinalis group as they generally originate from transverse processes and attach to spinous processes. The muscle fibers run cranially and medially, the deeper fibers connect one to two segments while the superficial fibers connect up to six segments. This muscle group is made up of the semispinalis, multifidus, and rotatores muscles. The semispinalis thoracis muscle forms thin muscle fascicles originating on the transverse processes of Th6–12 and attaches to the spinous processes of the C6-Th4. The semispinalis cervicis muscle originates on the Th(2)3–Th6(7) transverse process and runs cranially attaching to the bifid spinous processes of C2–C6. The strongest attachment is found on the inferior aspect of the C2 spinous process; this muscle belly also covers the bellies of the muscle attaching on a lower spinous process. The semispinalis capitis muscle forms two strong muscle bellies in the paramedian line, covered by a thin layer of the deep nuchal fascia. It is originating on the transverse processes of C7-Th6 and the articu-

8  Relevant Surgical Anatomy of the Posterior Subaxial Spine and the Cervicothoracic Junction

lar processes of C4–C6. The joined muscle fibers form a broad muscle, which runs cranially to insert on the occipital bone between the superior and inferior nuchal lines. The two muscle bellies are separated by the nuchal ligament in the midline. The multifidus muscles are lying deeper to the semispinalis muscle group and fill up the groove between the spinous process and the laminas. They originate on the transverse processes of the thoracic vertebras and the articular process of the lower four cervical vertebras, which run cranially and medially to attach to a spinous processes, bridging two to five vertebras, the shorter fibers lying deep. The superiormost attachment is at the inferior margin of the spinous process of C2, deep to the semispinalis cervicis, separated by a thin connective tissue layer. The attachment of these latter two muscles on the spinous process of the axis makes them biomechanically important. The rotatores muscles are best developed at the thoracic region and only poorly developed in the cervical and lumbar regions. They are lying deep to the multifidus muscles. The rotatores brevis begin on a transverse process and attach to the base of the spinous process immediately cranial while the rotatores longus insert on the spinous process of the second cranial vertebra. The ligamentum nuchae is the equivalent of the supraspinous and intraspinous ligaments of the thoracic and lumbar spine. In humans its function is to resist flexion of the cervical spine [3]. Its strong superficial part, the funicular portion, is composed of a thick fibroelastic membrane extending between the external occipital protuberance and the spinous process of C7. The funicular portion joins the superficial and deep cervical fascias and the aponeurosis of the trapezius muscle. Its deep part, the lamellar portion, forms a double-walled septum separating the multiple layers of the muscles covering the posterior aspect of the cervical spine. It is ventrally attached to the external occipital protuberance and the external occipital crest of the occiput, posterior tubercle of the atlas, and to

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the bifid spinous processes of all lower cervical vertebrae. The two layers of the lamellar portion fuse cranially at the external occipital protuberance, caudally at the C7 spinous process, and dorsally at the funicular portion. The space between the two layers is filled with areolar tissue [4]. The ligamentum nuchae, the spinous process of the axis (forming the cranialmost anchor point for the deep erector spinae muscles, the multifidi and the semispinalis cervicis muscles), and the C6 and C7 spinous processes have important biomechanical roles as part of the posterior tension band and should be protected together with their muscle attachments during surgery [5].

Bony Anatomy The bony anatomy of the four typical cervical vertebrae (C3–C6) is well known. The size and shape of the junctional vertebras go through significant changes from C6 to Th4. The width of the vertebral bodies is increasing from C6 to Th1 and decreasing at the deeper thoracic levels. The A–P diameter of the vertebral bodies is increasing from Th1 to Th4. The dimensions and convergence of the pedicles at the cervicothoracic junction show great individual variations as well as significant differences between single levels. The height of the pedicle increased from C6 (mean 6.3 mm) to Th4 (mean 10.5  mm). The width of the pedicles increased from C6 (mean 5.7 mm) to Th1 (mean 7.8 mm) and decreased below to Th4 (mean 4.7 mm). The length of the pedicles increased slowly from C6 (mean 4.7 mm) to Th4 (mean 5.8 mm). The convergence of the pedicles at the lower cervical levels is significantly higher compared to the thoracal levels with significant differences between the levels: C6 (mean 45.8°), C7 (mean 40.6°), Th1 (mean 33.7°), Th2 (mean 29.6°), Th3 (mean 21.0°), and Th 4 (mean 15.1°) [6]. The interpedicular distance is greatest at Th1 and decreases at the lower levels [7] (Figs. 8.3 and 8.4).

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Fig. 8.3  This picture shows the lower two cervical and the upper two thoracic vertebras, illustrating the morphological changes. Note the changes in form and width of the vertebral bodies as well as the thickness and angulation of their pedicles

Fig. 8.4  Picture shows the bony anatomy of the cervicothoracic junction. Left picture shows a direct posterior view, the middle picture shows a direct lateral, while the

G. Bodon and A. Combalia

The sixth cervical vertebra is considered typical except its prominent anterior tubercles of their transverse processes, the carotid tubercles. It has bifid spinous process. The seventh cervical vertebra has usually the most prominent spinous process of the cervical spine. It is not bifid, with its tip serving as muscle attachment and as attachment point for the ligamentum nuchae. It has pronounced transverse processes, while the posterior tubercles are quite large. The transverse foramens are normally small and filled with areolar tissue and accessory arteries and veins. The vertebral artery enters the transverse process of the C7 only in 3.5% of the cases [8]. The stellate ganglion is located between the base of the transverse process of C7 and the neck of the first rib, while the suprapleural membrane (cupola) is attached to the posterior tubercle of the transverse process of C7. The height of the lateral mass is on average 14.8 mm, while its average thickness is 6.8 mm [9]. The first thoracic vertebra has a bean-shaped vertebral body, which is wider in the coronal than in the sagittal plane. The vertebral bodies of the second thoracic vertebra and the vertebras below are more heart shaped viewed from above, thinner in the coronal, and wider in the sagittal planes.

right picture is made from the anterolateral direction, perpendicular to the pedicles

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References

Posterior view of the cervical spine after complete removal of the C5–C7 laminas and lateral masses. The cranialmost vertebra is C4 while the caudalmost is Th1. The row of the pedicles is marked on the right side of the picture. The vertebral artery (VA) runs anterior to the exiting nerve roots (NR)

1. Cramer GD, Darby SA. Basic and clinical anatomy of the spine, spinal cord, and ANS. Amsterdam: Elsevier Health Sciences; 2005. p. 1. 2. Gray H.  Gray’s anatomy. Edinburgh: Churchill Livingstone; 1989. p. 1. 3. Takeshita K, Peterson ETK, Bylski-Austrow D, Crawford AH, Nakamura K. The nuchal ligament restrains cervical spine flexion. Spine. 2004;29(18):E388–93. 4. Kadri PAS, Al-Mefty O.  Anatomy of the nuchal ligament and its surgical applications. Neurosurgery. 2007;61(5 Suppl 2):301–4. discussion 304 5. Riew K, Raich A, Dettori J, Heller J. Neck pain following cervical laminoplasty: does preservation of the C2 muscle attachments and/or C7 matter? Evid Based Spine Care J. 2013;04(01):042–53. 6. Stanescu S, Ebraheim NA, Yeasting R, Bailey AS, Jackson WT. Morphometric evaluation of the cervicothoracic junction. Practical considerations for posterior fixation of the spine. Spine. 1994;19(18):2082–8. 7. Resnick DK, Barr JD, Garfin SR.  Vertebroplasty and kyphoplasty. New York: Thieme Publishers; 2011. p. 1. 8. Lang J.  Clinical anatomy of the cervical spine. Stuttgart: George Thieme Verlag; 1993. p. 1. 9. Xu R, Ebraheim NA, Yeasting R, Wong F, Jackson WT.  Anatomy of C7 lateral mass and projection of pedicle axis on its posterior aspect. J Spinal Disord. 1995;8(2):116–20.

Part III Surgical Approaches

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Surgical Approach: High Anterior Cervical Rafael González-Díaz and Rosa María Egea-Gámez

This chapter shows several approaches to the high anterior cervical, used for a wide range of pathologies. The patient is traditionally positioned in supine, with extension of the cervical spine by interscapular elevation cushion or in lateral position. It is relevant to avoid hyperextension preventing medullary compression by posterior bone fragments, as well as by disc and tension of the trachea and esophagus. In those cases where great instability is presented and traction is necessary (fractures, rheumatoid arthritis, etc.), the cranial compass or the Mayfield support may be convenient to be used. An anti-Trendelenburg position of the table will facilitate a bloodless surgical field. The anatomical references to have into consideration are the following: –– The hard palate corresponds to the arc of the atlas. –– The angle of the mandible to the C2–C3 level. –– Hyoid, thyroid, and cricoid cartilages correspond to the height of C3, C4–C5, and C6 level. –– The Chassaignac tubercle (marks the entrance of the vertebral artery) in C6 is easily identifiable at the percutaneous touch.

R. González-Díaz (*) · R. M. Egea-Gámez Hospital Universitario Niño Jesús, Madrid, Spain

Nevertheless, the safest maneuver is to check the level with fluoroscopy. In the medium and lower cervical levels, the skin incision can be made transversal or longitudinal, depending on the level and the number of vertebral discs involved. While a transversal approach is more aesthetic, it is more uncomfortable for those patients with more than two levels to be approached. On the other hand, a longitudinal incision, following the anterior border of the sternocleidomastoid, gives an excellent field between C2 and up to T2 depending on the patient. Furthermore, exposing the higher cervical areas requires other approaches: high anterior cervical incision and transoral approach with transmaxillary or transmandibular extension.

 igh Anterior Cervical Incision H (Sébileau–Carréga Incision) The present approach provides direct and wide exposure for fusion and anterior decompression of the upper cervical spine in pathologies such as hangman’s fracture. A crucial issue is the position of the patient in supine, together with neck extended slightly and with 30° of rotation toward the contralateral side of the surgical approach. The skin incision is an arcuate path, from the apophysis mastoid to the submental region, 3–4 cm below the mandibular border (Fig. 9.1). The marginal

© Springer Nature Switzerland AG 2019 H. Koller, Y. Robinson (eds.), Cervical Spine Surgery: Standard and Advanced Techniques, https://doi.org/10.1007/978-3-319-93432-7_9

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a

b

Fig. 9.1 (a) High anterior cervical incision. (b) Anterior exposure C2–C3 for C3 chordoma

mandibular branch of the facial nerve runs forward, below the angle of the mandible, under cover of the platysma muscle. Maintaining the skin incision 2  cm below the inferior border of the mandible ensures its preservation, avoiding a cosmetically disturbing paralysis of the lower lip associated with salivary incontinence. The superficial cervical fascia and platysma muscle are then divided transversely. In this step, the facial artery is retracted superolaterally or scarified when better exposures are needed. The sternocleidomastoids larynx and esophagus are identified. A fascial plane between the sternocleidomastoids and the carotid sheath laterally and the hypopharynx and trachea and esophagus medially permits better exposure to the high cervical spine. A specific retractor placement, away from the tracheoesophageal groove, is critical to preventing injury to the recurrent laryngeal nerve. At this point, it is very relevant to identify the superior laryngeal nerve, superior thyroid vessels (in the paratracheal fascia, and enters the larynx at the level of the thyroid membrane), and recurrent laryngeal nerve (in an anterolateral direction in the tracheoesophageal groove). After the placement of retractors, the midline of the cervical spine must be identified between the right and left longus colli muscles. Here, the anterior longitudinal ligament appears and the surgeon will perform a subperiosteal dissection.

The exact cervical spine level is assessed fluoroscopically by using lateral cervical views.

Transoral Approach The transoral approach allows a direct exposure to the extradural structures located in the midline, allowing a ventral decompression to the brain stem and to the spinal cord, between the inferior part of the clivus and the superior part of the third cervical vertebra. The approach is limited by the patient’s ability to open the mouth; if three fingers cannot be inserted vertically, the approach will be very complicated to be carried out, and it might cause damage to the temporomandibular joint and/or teeth. Transoral access can be easily performed with retraction of the soft palate and tongue, without the need to cut such structures, avoiding potential nasal dysphagia, diffusion, or regurgitation resulting from the incompetence of velopalatine caused by the incision in these structures. This approach can be extended to cranial or caudal, producing a greater exposure but also a greater index of complications. One of the main advantages of this extradural approach is to allow access to the upper cervical region, impeding the manipulation of structures such as the cranial nerves, the spinal cord, and the

9  Surgical Approach: High Anterior Cervical

vertebral arteries. Nevertheless, a more in-depth knowledge of anatomy is necessary, essentially when facing anatomical variations during surgery. Cranially, care has to be taken in order to avoid injury to the XII nerve at its exit from the base of condyle and the jugular foramen. Anterior tubercle of the atlas is considered to be a crucial point for safe dissection.

Surgical Technique The patient is placed supine with the head in slight extension. A retractor (Crockard) is used with malleable retractors that separate cranially the soft palate, caudally the tongue, and laterally the endotracheal tube (Fig. 9.2). Then, the oropharyngeal area is cleaned with antiseptic to minimize the risks of infection. Once the area is exposed, the first step is to open the posterior wall of the pharynx in the middle raphe, from the soft palate to the base of the tongue by cauterizing. After reaching the anterior

Fig. 9.2  Transoral approach. Position of the different retractors

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part of the anterior arch of C1, the second retractor is placed. To facilitate the introduction of the retractor, the anterior longitudinal ligament must be separated slightly from both sides. This is how a good exposure is achieved in order to proceed to surgery. It seems to be very crucial to pay attention how to check the cervical level with lateral fluoroscopy. Those lesions that extend beyond the exposure provided by the standard transoral approach require an extended transoral modification. As previously mentioned, the exposure can be expanded in the sagittal and axial planes by adding mandibulotomy, mandibuloglossotomy, palatotomy, and transmaxillary approaches to the standard transoral approach. These extended modifications are explained below.

Transoral Approach with Transmaxillary Extension This approach facilitates a good exposure by removing the barrier produced by the maxillary bone. An incision is made 1 cm above the upper dental line elevating the mucoperiosteal, previous infiltration with 1% lidocaine with adrenaline to avoid bleeding. Prior to performing the osteotomy, it is recommended to place titanium miniplates to ensure alignment of the palate and teeth, preventing postsurgical malocclusion. There are two types of osteotomy in this extended approach: –– Le Fort I lateral osteotomy. A bilateral mucogingival incision is performed along the entire length of the maxilla, being careful not to damage the dental roots and therefore the loss of teeth. A facial degloving is performed subperiosteally by elevating the mucosa and muscles from the maxilla superiorly until the infraorbital nerve. After the piriform aperture is exposed, the nasal mucosa is elevated off the floor bilaterally to the level of the inferior turbinates. As mentioned, titanium miniplates are attached across the intended osteotomy lines to ensure proper reapproximation at the end of the surgery. In this point, the plates are removed, and a horizontal osteotomy is bilaterally made from the piriform aperture laterally

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R. González-Díaz and R. M. Egea-Gámez

Fig. 9.3  Transoral approach with transmaxillary extension (Le Fort I osteotomy)

Fig. 9.4  Transoral approach with transmaxillary extension (transmaxillary palatal split)

through the maxillary alveolus using an oscillating saw. The maxilla is disarticulated and down-fractured by inserting a chisel and applying downward pressure. The inferior turbinates are fractured and removed with rongeurs. The transoral retractor is placed with a palatal plate attachment and a tongue retractor holds the transected maxilla in place. The nasal mucosa is reflected off the septum, which is removed until the sphenoid base is exposed. The mucosal lining of the maxillary sinus is removed. A posterior pharyngeal wall midline incision is made and the cervical exposure is achieved (Fig. 9.3). –– Transmaxillary Palatal Split. Osteotomy between the upper incisor teeth; continue through the middle raff of the hard palate until reaching the soft palate leaving the uvula to one side of the cut (Fig. 9.4).

tor, exposing from the sella turcica to the lower part of C2. The two hemi-maxillae are retracted into the cheek and held in place with a pharyngeal retractor. A midline incision is made in the posterior pharyngeal wall and the cervical area is exposed.

Once the osteotomy is performed, the maxilla is opened as if it was a book with a specific retrac-

Transoral Approach with Transmandibular Extension (Mandibulotomy) It consists of a single and paramedial mandibulotomy without mandibulectomy. That means that the masticatory function is preserved thanks to the preservation of the majority of the masticatory muscles, as well as a consequence of the alveolar and nerves. The cutaneous incision may be cervicofacial or cervical. The cervicofacial incision involves the lip-chin section. This can be vertical or curved by avoiding the tassel of the chin. This approach is useful for localized lesions below C2. A zigzag incision is made to prevent

9  Surgical Approach: High Anterior Cervical

retraction of the lip upon healing (one of the disadvantages of this approach is the unsightly scar on the lip and chin). The osteotomy of the mandible becomes between the central incisors medial to the mental foramen with an oscillating saw, preserving the sensation of the lower lip. It has been found unnecessary to remove an incisor in this exposure. It is recommended to put miniplates before performing the osteotomy so that the reduction is easier (as in previous transmaxillary approach). The mucosa in the floor of the mouth is then divided in the midline beneath the tongue between the orifices of the submaxillary ducts. The two halves of the mandible are retracted laterally, and the tongue is depressed into the space created by relaxation of the floor of the mouth. The posterior pharyngeal wall is achieved and the cervical area will be exposed after opening the wall (Fig. 9.5). Sometimes, the tongue does not allow a wide exposure so it is necessary to divide the tongue at the level of the midline, allowing a greater exposure of the surgical field. This extension is known as mandibuloglossotomy. The tongue is incised with cautering along the median raphe (relatively avascular plane) and

Transoral Approach

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extended posteriorly toward the median glossoepiglottic fold. The nerve and vascular supply are preserved for each half of the tongue. The entire floor of the mouth is then divided sharply in the midline. Usually, a tracheostomy is performed before using this approach. Retractors are used to further separate the halves of the tongue and mandible laterally. The posterior pharyngeal wall is incised in the midline, and cervical vertebral bodies below C3 are exposed. Closure is achieved by approximating the mandible using the plates that were positioned at the beginning of the surgery. The tongue is sutured in planes, starting from the dorsum with 3–0 continue resorbable sutures from posterior to anterior, the intrinsic muscles of the tongue with 2–0 interrupted resorbable sutures, and, last, the ventral surface of the tongue and the floor of the mouth. New advances in endoscopic and microsurgery are helping to use smaller incisions to achieve treatment of the cervical area. Other approaches have been described for lower levels in the cervical spine that will be explained in other chapters.

Transoral + Palatotomy

Fig. 9.5  Schematic representation of the different transoral approaches

Transoral + Glossotomy

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Far–Lateral Approach The far-lateral approach is a well-established technique for the removal of pathology ventrolateral to the brain stem and the craniocervical junction and, however, may be too extensive for lesions limited to areas far from the midline. The patient is positioned in lateral decubitus, and the ipsilateral shoulder is gently retracted inferiorly with tape and the head is rotated 15° to the contralateral side. A hockey-stick incision is used (superior and anterior curved and lateral to mastoid tip). The platysma muscle is split longitudinally or incised in line with the skin incision. The cervical fascia is sharply dissected medially to the sternocleidomastoid muscle and the medial visceral structures. The pretracheal fascia is then divided longitudinally along the carotid sheath separating it from the visceral structures medially. Carotid pulsations are checked to identify the carotid artery, and ipsilateral temporal artery pulsations can also be palpated during exposure to help prevent excessive arterial constriction. The prevertebral fascia is incised longitudinally in the midline of the vertebrae and the longus coli muscles are stripped laterally off the anterior aspect of the cervical spine. Special careful must be taken in this approach in the dissection of the transverse process not to injure the nerve root or vertebral artery (lies anterior to the nerve root) and not to injure the cervical sympathetic chain, especially when a

R. González-Díaz and R. M. Egea-Gámez

transversal incision in the longus coli muscle is made in the transverse process (when the longus coli muscle is large).

Bibliography 1. Finn MA, MacDonald JD.  C2–C3 anterior cervical fusion: technical report. Clin Spine Surg. 2016;29(10):E536–41. 2. González Díaz R, Koller H.  Cirugía de la columna cervical. Madrid: Editorial Médica Panamericana; 2015. 3. Singh H, Harrop J, Schiffmacher P, Rosen M, Evans J.  Ventral surgical approaches to craniovertebral junction chordomas. Neurosurgery. 2010;66(3):A96–A103. 4. Martin MD, Bruner HJ, Maiman DJ.  Anatomic and biomechanical considerations of the craniovertebral junction. Neurosurgery. 2010;66(3):A2–6. 5. Ahmed R, Traynelis VC, Menezes AH.  Fusions at the craniovertebral junction. Childs Nerv Syst. 2008;24(10):1209–24. 6. Youssef AS, Sloan AE. Extended transoral approaches: surgical technique and analysis. Neurosurgery. 2010;66(3):A126–34. 7. Hsu W, Wolinsky JP, Gokaslan ZL, Sciubba DM.  Transoral approaches to the cervical spine. Neurosurgery. 2010;66(3):A119–25. 8. Neo M, Asato R, Honda K, Kataoka K, Fujibayashi S, Nakamura T.  Transmaxillary and transmandibular approach to a C1 chordoma. Spine. 2007;32(7):E236–9. 9. Menezes AH. Surgical approaches: postoperative care and complications “transoral–transpalatopharyngeal approach to the craniocervical junction”. Childs Nerv Syst. 2008;24(10):1187–93. 10. Abdullah KG, Schlenk RS, Krishnaney A, Steinmetz MP, Benzel EC, Mroz TE. Direct lateral approach to pathology at the craniocervical junction: a technical note. Neurosurgery. 2012;70:ons202–8.

Surgical Approach: Anterolateral High Cervical Approach

10

Philippe Bancel

Purpose Approach of high cervical spine particularly occipito-cervical area and atlanto-axis vertebrae remains a demanding surgery. Occipito-cervical junction may be involved in different kinds of pathologies: inflammatory, tumours, malformation and degenerative alteration. Sometimes only the anterior part of the spine must be reached. Mobilization of the vertebral artery is then necessary.

Prerequisites A perfect knowledge of the anatomy is necessary. 1. Bone Anatomy. (a) The inferior part of the occiput. (b) The lateral mass of the atlas which will be a major spatial landmark during the approach. 2. Vertebral Artery Anatomy. (a) The suboccipital segment (C2-C0) coursing from C3 to C2 foramen with a first P. Bancel (*) Spine Department, Arago Institute, Paris, France e-mail: [email protected]

loop and then joining the transverse foramen of C1. Then it winds around the lateral mass and posterior arch of C1 (second loop with an horizontal trajectory). (b) Intradural segment: leaving the atlas, the artery passes through the posterior atlanto-occipital membrane into the foramen magnum.

Planning and Diagnostics Indication for approaching the anterolateral high cervical spine varies according to pathologies to be treated. Perfect assessment must be done before surgery including: –– Clinical and neurological examination. –– X-rays, CT-scan and MRI. –– Specific vascular exploration as angiogram, CT angiogram with 3D reconstruction and angio-MRI. These explorations will help to define perfect relationship between lesion and VA, diagnose congenital or acquired anomalies, identify spinal blood supply, predominant VA and realize a vascular procedure (occlusion, embolization).

© Springer Nature Switzerland AG 2019 H. Koller, Y. Robinson (eds.), Cervical Spine Surgery: Standard and Advanced Techniques, https://doi.org/10.1007/978-3-319-93432-7_10

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Patient Positioning Under general anaesthesia and endotracheal intubation, the patient is placed in supine position and in slightly reversed Trendelenburg. The head and the intubation are turned away from the pathologic side. The ear lobe is reversed and applied on the temporomandibular joint, leaving free the mastoid process. A pillar is placed under the upper part of the thorax; the shoulder is lowered using adhesive tape.

Surgical Technique 1. A hockey-stick incision is performed : from the tip of the mastoid process, a vertical arm follow the anterior border of the sternocleidomastoid muscle (SCM) caudally, an horizontal arm follows the upper rim of the mastoid , then the superior occipital line to the external occipital protuberance. The greater auricular nerve is identified and retracted cephalad. The platysma muscle is divided. The deep cervical fascia is incised along the anterior border of the SCM. 2. Detached of the SCM: all the SCM including the anterior tendon from the tip of the mastoid and nuchal muscles are detached from the occiput to the fat tissue. Conversely the digastric muscle is respected. 3. Opening of the space anterior to the SCM: the internal jugular vein (IJV) as has to be identified at this step at two levels: (a) Upward under the inferior rim of the digastric muscle. (b) Downward: by freeing the anterior rim and then the deep part of the SCM. • The space between the SCM and the IJV is opened at the two extremities. The space is then slowly exposed in its intermediary portion. • The space between the SCM and the IJV is occupied by a flat pad. The dissection of the flat tissue (highly vascularized) must be done by using the bipolar coagulation.

P. Bancel

4. The spinal accessory nerve should be identified at its entrance to the SCM posterolaterally. The nerve will be seen entering the substance of the SCM 2–3 cm caudal to the tip of the mastoid process. As soon as the nerve has been located, it is dissected from the deep part of the SCM to mastoid (crossing upward the IJV). The fat pad may be dissected safely, and the SCM is gently retracted posterolaterally, taking care to avoid any excess traction on the spinal accessory nerve. 5. Dissection of the transverse process of C1 and C2: • The prominent transverse process of C1 and C2 is palpated by the finger. Due to the rotation of the head, the posterior arch of C1 is exposed. • Gently the muscles inserted on the transverse process of C1 are severed at the edge of the bone. • The two segments of the VA will then appear (C1–C2 and above C1).The C1–C2 segment is crossed by the anterior branch of the second cervical nerve. 6. Release of the VA from the transverse foramen of C1 and C2: • The posterior arch of C1 is dissected subperiosteally and then the upper and inferior edge of the transverse tubercle (to find the entrance and exit of the transverse foramen). • This dissection allows to protect the VA and the venous plexus surrounded by the periosteum sheath. • In this area bipolar coagulation may be possible to control venous bleeding. • With a small bone rasp, all the foramen can be prepared, and the VA is separated from all the tunnel of the foramen. • Slowly, by a small Kerisson (2 mm) or a small rongeur, the lateral part of the foramen process and then the anterior and posterior arch of the process are resected. • So the VA is freed from all surrounding bone except the lateral mass of C1. • The VA is isolated and enclosed by a soft, flexible, thread.

10  Surgical Approach: Anterolateral High Cervical Approach

• The VA can be slowly mobilized and release as the same manner upward and downward. • Acting on the bone disc is then possible as on the artery itself (Fig. 10.1d).

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Cases will illustrate the technique by the author (Figs.  10.2 and 10.3). The technique is also explained in Fig. 10.1. Common pitfalls and complications are summarized in (Table 10.1).

Table 10.1  Pitfalls and complications Main complication and risks Greater auricular nerve Facial nerve injury during the approach close to the superior pole of the SCM The spinal accessory nerve: Below the deep mass of the muscle close to the mastoid process Internal jugular vein

Anterior spinal branch of C2 Control of the VA

Preventive measures Recognized after incision and retracted cephalad The nerve is behind the deep portion of the digastric This muscle must not be detached, the deep portion not dissected Must be early identified and dissected throughout Located  – upward under the inferior rim of the digastric muscle  – downward by freeing the anterior rim and then the deep part of the SCM Crossing the C1–C2 VA segment, and the muscles inserted on C1 transverse tubercle By dissection subperiosteally the transverse foramen and its tunnel

a

Fig. 10.1 (a) Positioning and incision: Head turned away from the pathologic side. Incision as a hockey-stick: along the mastoid and anterior rim of the SCM (b) Important step: the fat pad is dissected to identify the spinal accessory nerve, the posterior rim of the digastric muscle, the internal jugular vein and the foramen tubercle of C1 prominent. (c) After resection of the muscles and subperiosteally dissection of the transverse process of C1 and C2,

b

a small instrument is introduced in the tunnel of the orifices and bone resected, permitting the release of the VA. (d) All the transverse process is resected, the VA is freed, the lataral mass of C1 is exposed and capsule of O-C1 and C1–C2 can be excised. The bone and joint of the condyle of the lateral mass of C1 and if extended downward the vertebral body of C2 are reached

P. Bancel

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c

d

Fig. 10.1 (continued)

a

b

Fig. 10.2  Case Example 1 A 5-year-old young kid with irreducible torticollis, cervical pain, with night majoration, stiff cervical spine, neurologic evaluation as normal. (a) X-rays interpreted as normal (b) MRI are low contributive (c) CT scan shows an osteoid osteoma at the

implantation of the right pedicle of C2 (non-reachable by a posterior approach) (d) Anterior cervical approach with mobilization of the vertebral artery permits the resection of the tumour as shown on the post-op CT scan with healing of the patient

10  Surgical Approach: Anterolateral High Cervical Approach

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c

d upper antero lateral approach

Fig. 10.2 (continued)

a

c

b

c1

c2

d

Fig. 10.3  Case Example 2 (a) 6-year-old boy: C1 lesion no biopsy (b) 7 months later: progressive tetraplegia (c) Halo cast, embolization (C1, pre-embolization; C2, after embolization), decompression, C3 front and back fusion,

c3

d

e1

e2

histology, osteoblastoma (d) Relapse around both vertebral arteries, bypass carotid-vertebral arteries, clamp above C1 (e) Embolization both vertebral arteries (e1, e2) (f) 4 years post-op (g) 15 years post-op fused and healed

P. Bancel

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f

g

Fig. 10.3 (continued)

Summary of Main Surgical Steps

Bibliography

1. Supine position, head turned away from the pathologic side. 2. Detachment of all the SCM from the mastoid. 3. Careful dissection of the anterior rim of the muscle to prepare the space between the SCM and the internal jugular vein. 4. Identification of the IJV upward and downward. 5. Control and dissection of the spinal accessory nerve . 6. Section on the edge of the transverse tubercle of all the muscles. 7. Dissection subperiosteally of the foramen and posterior arch of C1 . 8. Control of the transverse foramen. 9. Resection of the bone to release the VA. 10. The bone and joint of the condyle, lateral mass of C1, and vertebral body of C2 are exposed.

1. Bancel P. Abord antérieur de l’artère vertébrale et de la charnière occipito-cervicale. Société Française de Chirurgie Rachidienne. Paris: Laboratoire d’anatomie-­ Fer à Moulin; 2014. 2. Georges B, Laurian C.  Surgical possibilities of the third portion of the vertebral artery above C2. Acta Neurochir. 1979;28:263–9. 3. Georges B, Laurian C.  Surgical approach to the whole length of the vertebral artery with special reference to the third portion. Acta Neurochir. 1980;51:259–72. 4. Georges B, Laurian C.  Vertebro-basilar ischemia. Its relation to stenosis and occlusion of the vertebral artery. Acta Neurochir. 1982;62:287–95. 5. Georges B, Laurian C. The vertebral artery. Pathology and surgery. Berlin, Heidelberg, New  York, Tokyo: Springer. p. 1–258. 6. Georges B.  Artère vertébrale: exposition du 3e segment (segment sous occipital C2-C0). Technique neurochirurgicale, Société Française de Neurochirurgie , Sénace du 3 Mai. 2006. 7. Kamina P.  Anatomie Clinique 3e Edition. Tome 2 Tête-Cou-Dos. Maloine; 2006.

Standard Transoral Approach to the Craniocervical Junction and Upper Cervical Spine

11

Brian J. Dlouhy and Arnold H. Menezes

Purpose The transoral approaches for decompression of irreducible ventral pathology at the CVJ have become a mainstay of treatment [1–5]. In the last 10 years, the emergence of endoscopic endonasal approaches has provided more options for decompression of irreducible ventral CVJ pathology. This includes congenital and developmental basilar invagination, basilar impression, cranial settling, proatlas segmentation abnormalities, os odontoideum, tumors, and other rare congenital bony abnormalities.

Prerequisites The transoral-transpharyngeal approach provides exposure from the clivus to the C2–C3 interspace and laterally for 2 cm to either side of the midline [1–3]. Laterally situated lesions may involve the occipital condyles, as well as the lateral portions of the posterior fossa, the transverse processes of the atlas, and the axis vertebrae. A midline ventral approach allows exposure of the anterior 45° of the circumference of the foramen magnum, to

B. J. Dlouhy (*) · A. H. Menezes University of Iowa Hospitals and Clinics, Iowa City, IA, USA e-mail: [email protected]

either side of the midline, thus providing a 90° exposure. The inferior extent of the exposure, which is limited by the degree of depression of the tongue, is the C2–C3 interspace. The lateral extent of the exposure is limited by the condylar canals of the hypoglossal nerve, the Eustachian tubes, and the vertebral arteries before they enter into the intradural space. However, when a tumor, such as a chordoma, is present, the tumor displaces normal anatomy creating working space and greater exposure than normal.

Planning and Diagnostics Reduction pertains to the reestablishment of anatomical alignment to relieve compression of neural structures. If the ventral lesion is irreducible, an anterior approach is required for decompression, which then often necessitates posterior instrumentation and fusion. If the lesion is reducible, a ventral transoral approach can be avoided, and dorsal instrumentation and fixation can be performed in the reduced position with or without a posterior decompression. We prefer to divide the soft palate (transoraltranspalatopharyngeal) when needed as it increases exposure superiorly to the inferior onethird of the clivus. Many others have suggested that elevation and retraction of the soft palate provide similar access to dividing the soft palate. However, with normal clival anatomy, we have

© Springer Nature Switzerland AG 2019 H. Koller, Y. Robinson (eds.), Cervical Spine Surgery: Standard and Advanced Techniques, https://doi.org/10.1007/978-3-319-93432-7_11

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found that elevation and retraction of the soft palate usually only provide rostral access to the inferior tip of the clivus. Additionally, in congenital pathological states such as with a foreshortened clivus or basioccipital hypoplasia, the clivus tends to be more horizontal in position than vertical. Thus, it becomes essential to divide the soft palate (transoral-transpalatopharyngeal approach) and at times resect the posterior inferior portion of the posterior hard palate to gain clival exposure [2]. In this manner, the upper portion of the clivus can be visualized. Anatomical studies have confirmed our clinical findings. In general, review of imaging studies preoperatively are integral to deciding on the adequacy of clival exposure with or without a soft palate split and whether this exposure is even needed for ventral decompression.

Patient Positioning After fiber-optic oral endotracheal intubation, the patient is positioned supine on the operating table with the head and crown halo resting on a horseshoe headrest with traction being maintained at 5–7 lbs. in children and 7 lb. in adults. The endotracheal tube is secured to the skin overlying the mandible with suture and the nasal passages anesthetized with topical cocaine. A throat pack is used to occlude the laryngopharynx and oral preparation carried out with 10% povidoneiodine and hydrogen peroxide. A Dingman or Crockard mouth retractor is then set in place. This provides self-retaining exposure of the oral cavity and oropharynx.

Surgical Technique Transoral-Transpalatopharyngeal Approach After proper positioning of the Dingman or Crockard retractor, the entirety of the procedure is carried out under the operating microscope and at high power [1–3]. The soft palate is split in procedures that involve the foramen magnum and the inferior clivus. To prepare the soft palate, it is

B. J. Dlouhy and A. H. Menezes

anesthetized with 0.5% Xylocaine solution with 1:200,000 epinephrine. To divide the soft palate, an incision is made starting at the right of the uvula and extends along the median raphe up until the hard palate. Stay sutures attached to the edge of the palate and fastened between the coiled springs of the Dingman retractor hold apart the exposure. At times, it is necessary to remove a portion of the hard palate to gain exposure of the high nasopharynx. Large adenoid tissue in the nasopharynx, at times, also requires removal. After retraction or split of the soft palate, the posterior pharyngeal wall is topically anesthetized with 2% cocaine and the median raphe infiltrated with 0.5% Xylocaine solution with 1:200,000 epinephrine. An ultra-sharp angled monopolar cautery (Stryker Colorado Needle, Stryker Inc., Kalamazoo, MI, USA) is used to incise the posterior pharyngeal wall longitudinally in the midline over the inferior clivus, C1 arch, and C2 vertebral body in the case of an odontoidectomy. The mucosa is incised, and dissection with monopolar cautery proceeds through the midline raphe between the pharyngeal muscles and the anterior longitudinal ligament to the bone. The longus colli and longus capitis muscles are detached from their medial origin on the anterior surface of the cervical vertebrae and mobilized laterally in a subperiosteal fashion using bipolar electrocuting cautery and blunt dissection. These muscles can be held in place with toothbladed lateral pharyngeal retractors if needed or held in place with stay sutures. The midline is marked by the tubercle of the anterior arch of C1 and should be identified for orientation.

Transoral-Transpalatopharyngeal Closure After satisfactory decompression at the craniocervical junction, aerobic and anaerobic cultures are obtained, and bacitracin powder is placed in the wound. FloSeal, Surgicel (Johnson & Johnson, New Brunswick, NJ, USA), and Avitene may be placed in resection cavity to help eliminate dead space and help with hemostasis. The longus colli and longus capitis muscles are

11  Standard Transoral Approach to the Craniocervical Junction and Upper Cervical Spine

approximated using interrupted 3–0 Vicryl sutures. Next, the constrictor muscles of the pharynx are approximated, along with the mucosa of the posterior pharyngeal wall in a separate layer. The throat pack is removed. A nasogastric tube is placed under direct visualization for postoperative nutritional care. The anesthesiologist auscultates over the abdomen, while air is insufflated to ensure proper position of the tube. The tubing is secured to the midline columella using 2–0 Nurolon. The soft palate is closed in two layers. The nasal part of the palate is approximated with interrupted inverted sutures of 3–0 Vicryl. The oral mucosa together with the muscular layer is approximated with interrupted horizontal mattress sutures of 3–0 Vicryl. The mouth retractor is removed and the oral mucosa smeared with hydrophilic ointment with hydrocortisone (1%), and the tongue is massaged. Dorsal occipitocervi-

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cal fusion combined with posterior fossa decompression is usually mandated and performed under the same anesthetic. The patient remains orotracheally intubated postoperatively (Figs. 11.1–11.3).

a

b

Fig. 11.1  Exposure provided by the standard transoral approach

Fig. 11.2  Exposure to the anterior craniovertebral junction via the transoral-transpalatopharyngeal approach. (a) The Dingman mouth retractor is in place with the tongue depressor. The soft palate has been incised. The operation with the microscope will be carried out within the circle. (b) The soft palate has been divided. The posterior pharyngeal incision is made

B. J. Dlouhy and A. H. Menezes

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a

Table 11.1  Pitfalls and complications Main complications and risks (%) CSF leak/meningitis (0–1.1%)

Pharyngeal wound dehiscence or infection (0.7–1.1%) Velopharyngeal/ palatine incompetence (1.8–14.3%) Dysphagia (0–3.3%)

b

Preventive measures Meticulous closure, proper abx coverage pre-op and post-op, proper treatment of intraoperative CSF leak Meticulous pharyngeal closure and proper preoperative and postoperative management Meticulous pharyngeal and soft palate reapproximation

Meticulous closure

Postoperatively, the endotracheal intubation is maintained until swelling of the oral tissues, including the tongue, has receded. The endotracheal tube is left in place 3–4  days in most patients. Nystatin and Peridex to the oral cavity is maintained for 2  weeks postoperatively. In the event that the dura is opened, broad-spectrum intravenous antibiotics and spinal drainage are maintained for 10  days after the operation. Previously, in adults and children who had undergone a dorsal fixation after the anterior procedure were ambulated in a halo vest. At the present time, this is done with a custom-fitted occipitocervical Minerva-type brace or an Aspen-Minerva brace (Table 11.1).

Fig. 11.3  Closure of the transoral-transpalatopharyngeal approach. (a) The longus colli and longus capitis muscles, Summary of Main Surgical Steps the pharyngeal muscles, and the posterior pharyngeal wall mucosa are reapproximated in layers with interrupted . Divide or retract the soft palate. sutures. (b) The soft palate is reapproximated in multiple 1 2. Incise the posterior pharyngeal wall longitudilayers

Postoperative Care Nasogastric tube feedings are maintained for the first 5  days. A clear liquid diet is then started. Over several days, it is advanced to a full liquid diet and, subsequently, to a soft diet.

nally in the midline. 3. Dissection proceeds through the midline raphe between the pharyngeal muscles and the anterior longitudinal ligament to the bone. 4. The longus colli and longus capitis muscles are detached from their medial origin on the anterior surface of the cervical vertebrae and mobilized laterally.

11  Standard Transoral Approach to the Craniocervical Junction and Upper Cervical Spine

References 1. Dlouhy BJ, Dahdaleh NS, Menezes AH. Evolution of transoral approaches, endoscopic endonasal approaches, and reduction strategies for treatment of craniovertebral junction pathology: a treatment algorithm update. Neurosurg Focus. 2015;38(4):E8. 2. Menezes AH. Surgical approaches: postoperative care and complications “transoral-transpalatopharyngeal approach to the craniocervical junction”. Childs Nerv Syst. 2008;24(10):1187–93.

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3. Menezes AH, VanGilder JC.  Transoraltranspharyngeal approach to the anterior craniocervical junction. Ten-year experience with 72 patients. J Neurosurg. 1988;69(6):895–903. 4. Choi D, Crockard HA. Evolution of transoral surgery: three decades of change in patients, pathologies, and indications. Neurosurgery. 2013;73:296–303. 5. Crockard HA. The transoral approach to the base of the brain and upper cervical cord. Ann R Coll Surg Engl. 1985;67:321–5.

Combined Transoral and Transmandibular Approach: Labiomandibular Approach with or Without Glossotomy

12

Brian J. Dlouhy and Arnold H. Menezes

Purpose The emergence of the transoral approach provided exposure to a previously inaccessible region. Although this allowed proper decompression and treatment of a variety of CVJ pathology, the approach was still limited in its exposure below the C2–C3 interspace and above the 1/3 inferior aspect of the clivus. Combining the standard transoral approach with previously described techniques of craniofacial osteotomies that split the mandible and divided the tongue enhances access inferiorly to the C4–C5. We consider these to be “extended transoral approaches.”

Prerequisites A combined transoral–transpalatopharyngeal approach with a median mandibulotomy (median labiomandibular approach) allows for increased caudal exposure to the C3–C4 interspace and maintains the superior exposure to the inferior

B. J. Dlouhy (*) · A. H. Menezes University of Iowa Hospitals and Clinics, Iowa City, IA, USA e-mail: [email protected]

third of the clivus. Dividing the tongue in the midline further increases the caudal exposure to the C4–C5 interspace (median labiomandibular glossotomy (MLG) approach).

Planning and Diagnostics Indications to use the MLG approach to augment exposure of the craniocervical junction and the upper cervical vertebrae include an inter-incisor opening distance of less than 2.5 cm and when access to C3–C5 is required. In children as well as adults, adequate access to the craniocervical junction and upper cervical vertebra can usually be achieved with a transoral–transpalatopharyngeal route. In some children, however, young age and/or small size precludes adequate exposure with a soft palatal split alone. Therefore, additional exposure can be gained with the median labiomandibular glossotomy approach. However, this is a rare event. Tracheotomy allows an unobstructed view of the oral cavity and posterior pharyngeal wall and prevents upper airway obstruction secondary to tongue and pharyngeal edema in the perioperative phase. The general advantages of the MLG include a wider surgical field in both transverse and sagittal dimensions. By splitting the mandible, the surgeon also has a shorter working distance to the spine.

© Springer Nature Switzerland AG 2019 H. Koller, Y. Robinson (eds.), Cervical Spine Surgery: Standard and Advanced Techniques, https://doi.org/10.1007/978-3-319-93432-7_12

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Patient Positioning The patient is brought to the operating room with a cervical collar in place as a precaution during intubation, maneuvers, and positioning. All adults and children 10–18  years old undergo awake fiber-optic oral endotracheal intubation. However, in children less than 10  years old or in an older child who cannot tolerate the procedure, general anesthesia is utilized, and fiber-optic intubation is carried out through the mask. The patient is positioned supine on the operating table. Depending on the pathology, a crown halo may be applied for traction and the patient placed in traction at the beginning of the procedure. First, a tracheotomy is performed, using a modified oral Ring–Adair–Elwyn endotracheal tube trimmed just beyond the curvature of the tube to allow adequate intubation of the trachea when the tube is sutured flush to the chest wall. At the conclusion of the case, the tube is replaced with an age-appropriate tracheostomy tube. The patient’s face, neck, and anterior chest are prepared and draped in a sterile fashion. If a costal cartilage graft is to be harvested, this portion of the procedure is performed using a separate operative field and separate instruments.

Surgical Technique The skin incision is made full thickness in the midline at the lip and sublabial crease utilizing a notch to aid relocation at the vermillion border, and the incision is carried around the mental protuberance, in a line of relaxed skin tension, and over the lower border of the mandible, back to midline, and extends inferiorly to the level of the hyoid. To expose the mandible, the labial sulcal incision must deviate from the midline toward

B. J. Dlouhy and A. H. Menezes

the osteotomy site; the incision continues in the midline on the lingual surface at the alveolar ridge. After the stair-step osteotomy is marked, rigid fixation plates are molded to the midline mandible inferiorly and superiorly and secured in place. They are then removed and preserved for reconstruction during closure. This step preserves occlusal relationships postoperatively. Following the mandibular osteotomy, the soft-­ tissue dissection within the floor of the mouth is continued in the midline between the submandibular ducts and carried into the intrinsic tongue musculature. Special attention is taken to preserve the submandibular ducts bilaterally. Dissection of the midline tongue is then carried posteriorly along the median raphe to expose the lingual surface of the epiglottis to the level of the hyoid. Additional oropharyngeal exposure can be achieved with a tonsillectomy. If further rostral exposure of the clivus is required, a midline split of the soft palate to one side of uvula can be performed. Additionally, removal of a portion of the posterior hard palate can be removed as well for even greater rostral exposure of the clivus. At this point the mandible can be widely separated. Fluoroscopy is used to confirm the cervical level inferiorly. An ultrasharp angled monopolar cautery (Stryker Colorado Needle, Stryker Inc., Kalamazoo, MI, USA) is used to incise the posterior pharyngeal wall longitudinally in the midline over the inferior clivus, C1 arch, and C2 vertebral body and inferiorly to the inferior aspect of the pathology. The mucosa is incised and dissection with monopolar cautery proceeds through the midline raphe between the pharyngeal muscles and the anterior longitudinal ligament to bone. The longus colli and longus capitis muscles are detached from their medial origin on the ventral surface of the cervical vertebrae and mobilized laterally in a subperiosteal fashion using bipolar

12  Combined Transoral and Transmandibular Approach

electrocuting cautery and blunt dissection. These muscles can be held in place with stay sutures. The midline is marked by the tubercle of the anterior arch of C1 and should be identified for orientation. A costal cartilage graft can be placed after bony decompression if needed for anterior vertebral body reconstruction. Meticulous closure is performed using the longus colli muscles, pharyngeal musculature, and mucosa. Layered closures of the tongue and soft palate are followed by mandibular reconstruction using the prefashioned rigid fixation plate and tension band. When

Fig. 12.1  Labiomandibular skin incision and midline mandibulotomy

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closing the floor of the mouth, care must be taken to cover the osteotomy site intraorally. Layered closure of the anterior neck soft tissue and skin is performed with careful reapproximation of the vermilion—cutaneous junction. A nasogastric feeding tube is placed beyond the posterior pharyngeal incision under direct visualization and secured at the nose. After removal of traction, cervical spine precautions are maintained with placement of a cervical collar through which the tracheostomy tube is positioned (Figs.  12.1–12.3, Table 12.1).

Fig. 12.2  Midline tongue incision and midline dissection and lateralization of the pharyngeal musculature and longus coli and capitis muscles exposing the CVJ and upper cervical spine

B. J. Dlouhy and A. H. Menezes

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Summary of Main Surgical Steps

Fig. 12.3  Anterior decompression of the upper cervical spine pathology and placement of rib graft between part of C1 anterior arch and C3 vertebral body

Table 12.1 Pitfalls and complications (according to Choi, Crockard et al. 2013) Main complication and risks (%) Lingual neuropathy

Cosmetic deformity CSF leak, infection, wound dehiscence (