Corrective Osteotomies for Rigid Spinal Deformities E-Book

• Herausgeber: Thieme
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 967

Veröffentlichungsjahr: 2023

Beschreibung

The ultimate guide and surgical manual for managing patients with rigid spinal deformities

Despite attempts to detect and treat spine deformities early in younger and older populations, spine deformity surgeons encounter a wide array of complex spine pathologies in patients across the age and pathology continuum. Corrective Osteotomies of Rigid Spinal Deformities, edited by world-renowned spinal deformity specialists Leon Kaplan and Lawrence G. Lenke, features contributions from an impressive group of global experts. The superbly written compendium highlights inherent challenges of managing rigid spine deformities and provides a wide array of safe and optimal treatment solutions.

Thirty-four chapters encompass surgical and nonsurgical management strategies for congenital, neuromuscular, syndrome-associated, infection, and neoplasm-related rigid spinal deformities. Special topics include secondary correction, pitfalls and difficulties, revision surgeries, and surgical and trauma-related neurological complications. New technologies are covered, including computer-assisted robotic surgery, evaluation and treatment of spinal tuberculosis in adults and children, and biological aspects that enhance spinal fusion. Throughout the text, the authors share firsthand pearls gained over many decades of delivering surgical care.

Key Highlights

• The rational, decision-making, meticulous planning, surgical strategies, and outcomes presented for each type of spinal deformity reflect the authors' extensive clinical and surgical experience
• Step-by-step methodology for treating rigid spinal deformities, including anterior, posterior, and combined approaches
• Anesthesiological aspects of spine correction in different stages of surgery and the importance of spinal neuromonitoring
• Reader-friendly algorithms, full color photographs, and radiographic images enhance the understanding of underlying pathologies and treatment strategies

This is an indispensable diagnostic and surgical manual for advanced spine surgeons who specialize in correcting rigid spinal deformities in pediatric and adult patients. Spine surgery residents and fellows will also benefit from reading this comprehensive resource.

Leseprobe

Corrective Osteotomies for Rigid Spinal Deformities

Leon Kaplan, MD Professor of Orthopaedic Surgery Surgeon-in-Chief and Director of Spine Surgery Unit Department of Orthopaedic Surgery Hadassah-Hebrew University Medical Center Jerusalem, Israel

Lawrence G. Lenke, MD Professor of Orthopaedic Surgery Director of Spinal Deformity Surgery Columbia University Vagelos College of Physicians and Surgeons; Surgeon-in-Chief, Och Spine Hospital at New York Presbyterian Allen New York, New York, USA

With special thanks to Dr. Josh Schroeder for his contribution to the book.

543 illustrations

ThiemeStuttgart • New York • Delhi • Rio de Janeiro

Library of Congress Cataloging-in-Publication Data is available with the publisher.

© 2023 Thieme. All rights reserved.

Georg Thieme Verlag KG Rüdigerstrasse 14, 70469 Stuttgart, Germany +49 [0]711 8931 421, [email protected]

Cover design: © ThiemeCover image source: © ThiemeTypesetting by DiTech Process Solutions, India

Printed in Germany by Beltz Grafische Betriebe                    5 4 3 2 1

DOI: 10.1055/b-006-163752

ISBN: 978-3-13-173081-7

Also available as an e-book:eISBN (PDF): 978-3-13-173091-6eISBN (epub): 978-3-13-245439-2

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My work is dedicated to my lovely Innula, my wife and best friend.Thank you, from the bottom of my heart, for your everlasting love, support, and encouragement; for always standing by my side and having my back (just as a back surgeon needs).I wouldn’t dream of doing this without you.I would also like to thank my wonderful children and grandchildren.I am truly a lucky man for having all of you in my life.

Leon Kaplan, MD

I would like to dedicate this textbook to all patients suffering from severe and rigid spinal deformities, for they are the reason that all of us work so tirelessly to provide the best care possible.Also, to all the past and current spinal deformity surgeons who have helped contribute to the clinical care, research, and education of our colleagues. Our patients and our profession have benefitted tremendously from your efforts.

Lawrence G. Lenke, MD

Contents

Foreword

Preface

Introduction

Acknowledgments

Contributors

1Introduction to Anatomic Systems and Terminology

Ibrahim Obeid, Louis Boissiere, Derek T. Cawley

1.1Introduction

1.2Deciding on Surgery

1.3Prognosis

1.4Congenital Kyphosis and Kyphoscoliosis

1.5Further Perioperative Considerations

1.6Treatment Options and Principles

1.6.1Observation

1.6.2Epiphysiodesis

1.6.3Hemivertebra Resection

1.6.4Pedicle Subtraction Osteotomy

1.6.5Vertebral Column Resection

1.6.6Vertebral Column Decancellation

1.7Conclusion

2Neuromuscular Spinal Deformities

Athanasios I. Tsirikos

2.1Introduction

2.2Clinical Problems Associated with Spinal Deformity

2.3Etiology and Natural History of Spinal Deformity

2.4Patterns of Spinal Deformity

2.5Specific Types of Spinal Deformity

2.5.1Spina Bifida (Myelomeningocele)

2.5.2Neurofibromatosis

2.6Treatment Principles

2.6.1Nonoperative Treatment

2.6.2Surgical Treatment

2.7Medical Considerations—Preoperative Assessment

2.8Complications during and after Scoliosis Surgery

2.9Deformity Correction Techniques

2.9.1First- and Second-Generation Instrumentation Techniques

2.9.2Third-Generation Instrumentation

2.10Additional Surgical Considerations

2.10.1Intraoperative Management

2.10.2Levels of Fusion

2.10.3Anterior Correction

2.10.4Posterior Vertebral Column Resection

2.10.5Growth Preservation/Modulation Techniques

2.11Quality of Life Assessment/Life Expectancy after Scoliosis Surgery

2.12Conclusion

3Idiopathic Spinal Deformities Treated with Spinal Osteotomies

Paul J. Park, Eduardo C. Beauchamp, Meghan Cerpa, Lawrence G. Lenke

3.1Introduction

3.2Posterior Column Osteotomy

3.2.1Indications in Idiopathic Deformity

3.2.2Technique

3.2.3Case Illustration

3.3Pedicle Subtraction Osteotomy

3.3.1Indications in Idiopathic Deformity

3.3.2Technique

3.3.3Case Illustration

3.4Preoperative Considerations and Postoperative Complications

3.4.1PCO versus PSO

3.4.2Complications

3.5Conclusions

4The Natural History of Rigid Spinal Deformities

Jean Dubousset

4.1Definition and Measurement

4.2Natural History, Physiopathology

4.3Natural History, Assessment of Flexibility/Rigidity

4.3.1Reduction of the Deformity Will Be Checked: Locally and Globally

4.4Natural History According to the Growing Spine and Etiologies

4.5Natural History According to the Mature Spine and Etiologies

5Surgical Management of Children with Congenital Deformities of the Upper Thoracic Spine and Vertebral Malformations

Sergei Vissarionov

5.1Introduction

5.2Outcomes of Surgical Management

6Osteotomies in Children under the Age of 10 Years

Josh Schroeder, Leon Kaplan

6.1Background

6.2Overall Management of the Rigid Spine Deformity

6.3Halo Traction

6.3.1Halo Placement Technique

6.3.2Complications with Halo Frames

6.4Osteotomies for Correction of Rigid Spinal Deformities

6.4.1Partial Facet Joint Resection

6.4.2Complete Facet Joint Resection (Posterior Elementectomy)

6.4.3Three-Column Osteotomies

6.5Outcome and Complications

7Surgical Treatment of Rigid Spinal Deformities in Patients with Thoracic Insufficiency Syndrome

Leon Kaplan, Josh Schroeder

7.1Thoracic Insufficiency Syndrome

7.2Care

7.3Treatment Options

7.3.1Casting

7.3.2Surgery

7.4Conclusion

8Vertebral Column Resection as a Treatment for Neurologic Deficit in Severe Spinal Deformity

Eduardo C. Beauchamp, Paul J. Park, Meghan Cerpa, Lawrence G. Lenke

8.1Introduction

8.2Preoperative Evaluation

8.2.1History and Physical Examination

8.2.2Imaging

8.3Halo-Gravity Traction

8.4Surgical Technique

8.5Spinal Cord Monitoring

8.6Vertebral Column Resection for Progressive Myelopathy

8.7Case Illustration

8.8Conclusion

9Osteotomies in Syndromic Patients

Dino Colo, René M. Castelein

9.1Introduction

9.2Definition, Classification, and Indication

9.3Rigid Deformities in Syndromic Patients

9.4Choice of Osteotomy: Type and Goal

9.5PreoperativeWorkup

9.5.1Patient History and Physical Findings

9.5.2Imaging Studies

9.6Surgical Aspects and Technique

9.6.1Positioning and Perioperative Measures

9.7Surgical Technique

9.7.1Smith–Petersen Osteotomy and Ponte Osteotomy

9.7.2Pedicle Subtraction Osteotomy

9.7.3Bone–Disk–Bone Osteotomy

9.7.4Vertebral Column Resection

9.8Postoperative Care

9.9Complications

9.10Outcome

9.11Conclusion

10Rigid Spine Deformities in Early-Onset Scoliosis

Pooria Hosseini, Behrooz A. Akbarnia

10.1Introduction

10.2Clinical and Radiographic Evaluation

10.2.1History and Physical Examination

10.2.2Plain Radiographs

10.2.3EOS Imaging System/Three-Dimensional Modeling Techniques

10.2.4CT Scan

10.2.5MRI

10.3Treatment of Rigid Spine Deformities in EOS

10.3.1Nonoperative Treatments

10.3.2Operative Treatments

10.4Extra Procedures Considered in the Treatment of Rigid Curves

10.4.1Traction

10.4.2Surgical Release of Soft Tissues

10.4.3Temporary Internal Distraction Rod

10.4.4Osteotomies

10.5Discussion

11Secondary Correction of Rigid Spinal Deformity after Failed Instrumentation

Meric Enercan, Azmi Hamzaoglu

11.1Introduction

11.2Preoperative Evaluation

11.2.1History

11.2.2Physical Examination

11.2.3Imaging Studies

11.3Surgical Technique

11.3.1Correction of Scoliosis Deformity

11.3.2Correction of Kyphoscoliosis Deformity

11.3.3Correction of Kyphosis Deformity

11.3.4Correction of Lordosis/Lordoscoliosis Deformity

11.3.5Correction of Severe Rigid Pelvic Obliquity in Neglected Congenital Scoliosis

11.3.6Reconstruction Laminectomy Defect following Posterior Vertebral Column Resection

11.4Complications

11.5Conclusion

12Kyphectomy in Patients with Myelomeningocele

Josh Schroeder, Leon Kaplan

12.1Introduction

12.2Kyphectomy

12.3Surgical Technique

12.4Outcome

13Pitfalls and Difficulties in the Surgical Management of Severe Adolescent Idiopathic Scoliosis

Mario Di Silvestre

13.1Definition of Severe Idiopathic Scoliosis

13.1.1Preoperative Study

13.1.2Preoperative Halo Traction

13.2Surgical Treatment

13.2.1Introduction

13.3Posterior-Only Procedures

13.3.1Pedicle Screws

13.3.2Posterior Staged Technique

13.4Preferred Operative Technique

13.4.1Magnetically Controlled Growing Rod

13.4.2Intraoperative Monitoring of Spinal Cord Function

13.4.3First Posterior Surgery

13.4.4Second Stage of Posterior Surgery

13.5Conclusion

14Posttraumatic Spine Deformity

David B. Bumpass, Lawrence G. Lenke

14.1Introduction

14.2Epidemiology

14.3Evaluation of Posttraumatic Deformity

14.3.1Normal Thoracolumbar Alignment

14.3.2Classification

14.3.3Biomechanics and Pathology

14.3.4Presentation and Physical Exam

14.3.5Radiographic Evaluation

14.4Nonoperative Management

14.5Operative Management

14.5.1Surgical Indications and Planning

14.5.2Anterior Surgical Approaches

14.5.3Combined Anterior–Posterior Surgical Approaches

14.5.4Posterior Surgical Approaches

14.5.5Technical Considerations

14.5.6Complications

15Osteoporotic Rigid Spinal Deformities

Marco Brayda-Bruno, Andrea Luca, Gabriele Ristori, Lisa Babbi, Alessio Lovi

15.1Introduction

15.2Epidemiology and Etiology of Osteoporotic Deformities

15.3Our Philosophy of Treatment in Osteoporotic VCFs and Related Kyphotic Deformities

15.4How to Improve Pedicle Screw Stability

15.5Osteoporotic Spine Deformity Correction

15.6Complications and Conclusions

16Spinal Deformities in Patients with Parkinson’s Disease

Stéphane Wolff, Peter Upex, Guillaume Riouallon

16.1Introduction

16.2Surgical Considerations

16.3Surgical Technique

16.4Conclusion

17Surgical Planning for En Bloc Resection of Spinal Tumors: Tailoring the Osteotomy to Tumor Extensions

Stefano Boriani, Alessandro Gasbarrini, Riccardo Ghermandi, Shifra Fraifeld, José E. Cohen, Eyal Itshayek

17.1Introduction

17.2Planning En Bloc Resection

17.2.1Steps for Surgical Planning

17.2.2Essential Surgical Criteria

17.2.3Surgical Tips and Techniques

17.2.4Surgical Approach

17.2.5Osteotomy of the Spine to Finalize the En Bloc Resection

17.3Case Report

17.4Discussion and Conclusions

17.4.1Conflicts of Interest

17.4.2Acknowledgments

18Corrective Osteotomies in the Cervical Spine

Venu M. Nemani, Peter B. Derman, Han Jo Kim

18.1Introduction

18.2Clinical Symptoms and Natural History

18.3Physical Exam

18.4Radiographic Evaluation

18.5Assessment and Preoperative Planning

18.5.1Location of the Deformity

18.5.2Previous Surgery

18.5.3Curve Rigidity and Degree of Deformity

18.5.4Neurologic Status

18.6Osteotomy Types

18.6.1Anterior Osteotomies

18.6.2Posterior Osteotomies

18.6.3Combined Osteotomies

18.7Conclusion

19Junctional Corrective Osteotomies (Cervicothoracic, Thoracolumbar, Lumbosacral)

Claudio Lamartina, Riccardo Cecchinato

19.1Introduction

19.2Preoperative Evaluation

19.3Cervicothoracic Kyphotic Deformity and Corrective Osteotomies

19.3.1Patient Preparation

19.3.2Technical Considerations

19.4Thoracolumbar Corrective Osteotomies

19.4.1Patient Preparation

19.4.2Technical Considerations

19.5Lumbosacral Corrective Osteotomies

19.5.1Patient Preparation

19.5.2Technical Considerations

20Corrective Strategies and Management of Rigid Sacropelvic Pathologies

Yechiel N. Gellman, Josh Schroeder, Meir Liebergall

20.1Introduction

20.2Presenting Symptoms

20.3Radiographic Evaluation

20.4Management

20.4.1Reconstruction of the Pelvic Girdle

20.4.2Sacral Osteotomies

20.4.3Pelvic Osteotomies

20.4.4Other Salvage Procedures

20.4.5Computer-Assisted Surgery

20.5Summary

21Ankylosing Spinal Disorders

Roongrath Chitragran, Rune Hedlund

21.1Introduction

21.2Ankylosing Spondylitis with Fracture

21.3Ankylosing Spondylitis with Kyphotic Deformity

21.4Diffuse Idiopathic Skeletal Hyperostosis with Fracture

22Osteotomies in Revision Surgery

Ahmet Alanay, Çağlar Yılgör

22.1Introduction

22.2General Indications

22.3Osteotomies

22.3.1Grade 1 Osteotomies

22.3.2Grade 2 Osteotomies

22.3.3Grade 3 Osteotomies

22.3.4Grade 4 Osteotomies

22.3.5Grade 5 and 6 Osteotomies

22.4Difficulties in Performing Osteotomies in Revision Cases

22.5Conclusions

23Classification and Definition of Rigid Spine Deformity

Josh Schroeder, Janina Kueper, Leon Kaplan

23.1Introduction

23.2Definition

23.2.1Pediatric Rigid Spinal Deformity

23.2.2Idiopathic Scoliosis

23.2.3Congenital Deformity

23.2.4Neuromuscular and Paralytic Scoliosis

23.2.5Scheuermann’s Kyphosis

23.2.6Adult Spinal Deformity

23.3Classification

23.3.1Pediatric Spinal Deformity Classifications

23.4Conclusions

24Strategies in the Correction of Rigid Spinal Deformities—Controversies between Anterior and Posterior Approach

Sebastien Charosky

24.1Introduction

24.2Patient Assessment and Surgical Strategy

24.2.1Location of the Deformity

24.2.2Shape and Severity of the Deformity

24.2.3Flexibility of the Deformity and Balance of the Trunk

24.3Conclusion

25Anesthesia for Spinal Surgery

Ruth Shaylor, Benjamin Drenger

25.1Introduction

25.2Spinal Cord

25.3Blood Supply

25.4Preoperative Assessment

25.4.1Preexisting Conditions

25.4.2Airway

25.4.3Respiratory System

25.4.4Cardiovascular System

25.4.5Neurologic System

25.4.6Trauma

25.5.1Neurophysiologic Monitoring

25.5.2Bispectral Index (BIS) Monitoring

25.5.3Other Monitoring

25.6Positioning

25.7Blood Conservation Techniques

25.8Wake-Up Test

25.9Postoperative Considerations and Complications

25.10Conclusions

26Neuromonitoring in Rigid Spine Deformity Correction

Akiva Korn, Joseph Danto

26.1Introduction

26.2NIOM Tools

26.2.1Somatosensory Evoked Potentials

26.2.2Transcranial Electric Motor Evoked Potentials

26.2.3Electromyography

26.2.4Multimodality Approach

26.3Clinical Applications

26.4Conclusion

27Neurological Complications after Surgery or Trauma to the Rigid Spine

Avi Ohry, W. S. El Masri, Stephen Eisenstein

27.1Introduction

27.2Spondyloarthropathies

27.3Scoliosis

28Importance of the Sagittal Balance in Correction of Rigid Spine

Pierre Roussouly, Amer Sebaaly

28.1Introduction

28.2Pelvic Sagittal Parameters: The Plinth of Sagittal Balance

28.3Spinal Sagittal Parameters: AreWe Speaking the Same Language?

28.4Spinal Balance Parameters: Metric versus Angular

28.5Spinal Shapes in the Normal Population

28.6Degenerative Spinal Evolution

28.7Surgical Strategies in Correcting Rigid Spinal Sagittal Deformity

28.7.1When the Pelvic Incidence Is Small (<50 degrees)

28.7.2When the Pelvic Incidence Is High (>50 degrees)

28.8Proximal Junctional Kyphosis: A Complication of Faulty Surgical Strategy

28.9Conclusion

29Robot-Guided Surgery in Rigid Spinal Deformities

Yair Barzilay, Sajan K. Hegde, Isador H. Lieberman, Pramod K. Sudarshan, Harel Arzi, Samuel S. Bederman

29.1Introduction

29.2Robotic Guidance in Spine Surgery

29.2.1Robotic Systems in Clinical Use

29.3Robotic Surgery in Spinal Deformity

29.4Special Considerations

29.4.1Pelvic Fixation

29.4.2Revision Spinal Surgery—Redrilling Pedicles, Retained Instrumentation

29.5Case Illustrations

29.5.1Case 1

29.5.2Case 2

29.5.3Case 3

29.5.4Case 4

29.5.5Case 5

29.6Robot-Guided Osteotomies for Rigid Deformities

29.7Conclusion

30Biological Aspects of Spine Fusion—Methods to Enhance Fusion Rates

Venu M. Nemani, Matthew E. Cunningham

30.1Introduction

30.2Fusion Formation

30.3Properties of Bone Grafts

30.4Types of Grafts

30.4.1Autograft

30.5Osteoinductive Agents

30.5.1Bone Morphogenetic Proteins

30.5.2Demineralized Bone Matrix

30.6Osteoconductive Agents

30.6.1Allograft Bone

30.6.2Synthetic Bone Grafts

30.7Osteopromotive Agents

30.8Systemic Agents

30.8.1Bisphosphonates

30.8.2Parathyroid Hormone

30.9Conclusions

31Role of Anterior Approach in the Correction of Adult Spinal Deformities

Sleiman Haddad, Ferran Pellisé

31.1Introduction

31.2Adult Spinal Deformity

31.3Reconstruction of the Lower Lumbar Spine and Lumbosacral Junction

31.3.1Access to the Lower Lumbar Spine

31.3.2Restoration of Anterior Column Support

31.3.3Reconstruction of Lumbosacral Segmental Sagittal Alignment

31.4Thoracolumbar Kyphoscoliosis and Anterior Release

31.4.1Complications of the Anterior Approaches

31.4.2Comparative Studies: Combined Approaches

31.5Case Studies

31.5.1Case 1

31.5.2Case 2

31.5.3Case 3

31.5.4Case 4

31.5.5Case 5

31.6Conclusion

32Osteotomies in Spinal Tuberculosis—Adult Care

S. Rajasekaran, Rishi Mugesh Kanna, Ajoy Prasad Shetty

32.1Introduction

32.2Pathophysiology of Kyphosis in Spinal Tuberculosis

32.2.1Kyphosis during the Acute Phase of Tuberculosis

32.2.2Healing Patterns in Spinal Tuberculosis

32.2.3Kyphosis Progression in the “Healed” Phase

32.3Surgical Treatment of Kyphosis in Spinal Tuberculosis

32.3.1Principles of Surgery in Active Tuberculosis

32.3.2Single-Stage Kyphosis Correction by Anterior Approach and Stabilization

32.3.3Single-Stage Transpedicular Approach and Posterior Correction (Posterior Closing Wedge Osteotomy)

32.3.4Single-Stage Kyphosis Correction by Posterior-Only Transforaminal Approach and Interbody Fusion

32.3.5Single-Stage Kyphosis Correction by Posterior Costotransversectomy or Anterolateral Approach and Posterior Stabilization

32.3.6Kyphosis Correction by Combined Anterior and Posterior Approach

32.4Surgery for Kyphosis Correction in Healed Tuberculosis

32.4.1Transpedicular Decancellation Osteotomy

32.4.2Pedicle Subtraction Osteotomy

32.4.3Single-Stage Kyphosis Correction through Extrapleural Approach

32.4.4Closing OpeningWedge Osteotomy (Vertebral Column Resection)

32.5Conclusion

33Osteotomies in Tuberculosis—Pediatric Care

Alexander Mushkin

33.1Introduction

33.2Diagnosis of Spinal Tuberculosis in Children

33.3Principles of Treatment

33.3.1Surgical Treatment of the Consequences of Tuberculosis Spondylitis in Children

34Osteotomies for Adult Degenerative Scoliosis

Yigal Mirovsky, Yossi Smorgick

34.1Introduction

34.2Selection of Fusion Levels

34.3Spine with Mobile Disks

34.3.1Two Main Surgical Techniques Described in This Category

34.4Spine with Decreased Disk Mobility

34.4.1Pedicle Subtraction Osteotomy

34.5Complications

34.5.1Early Complications

34.5.2Late Complications

34.6Conclusion

Index

Foreword

Advances in orthopaedics and orthopaedic surgery have a long and impressive history. From the days of primitive man and the times of the Egyptians, the Greeks, the Romans, and throughout the Middle Ages—all have studied medicine and practiced orthopaedic techniques, and applied them in healing. Spine surgery truly progressed in the 19th and 20th centuries, leading to the progression of spinal surgery toward three basic goals: decompression, stabilization, and correction of deformities.

It is a great pleasure and honor for me to write the foreword of this textbook because for almost 40 years, I struggled to put into the minds ofmy colleagues the importance of3Dalignment and balance in the treatment of spinal deformities, more than pure improvement of the Cobb angle. For this reason, this textbook is focused entirely on the correction of the most difficult spinal deformities, notably the rigid ones, typically utilizing osteotomies of various types to achieve this goal, which require sufficient expertise not only about the strategies for their use, but also about the technical skills required.

No matter the etiology, any spinal deformity can evolve into a rigid deformity not correctible in the usualways of 3D correction of spinal units, thanks to distraction, compression, and axial rotation maneuvers. In this textbook, readers will be exposed to the indications of various etiologies as well as meticulous descriptions of the technical tips and tricks to achieve proper corrections in 3D in almost any place of the spine. The difference between young children, adolescents, adults, and even elderly patients are well described here with their respective solutions. Moreover, readers will find the proper strategies to prevent complications as well as the means to treat them.

The authors of the 34 chapters of this textbook, great orthopaedists from all over theworld, in particular the main authors and initiators of this book, Leon Kaplan and Lawrence G. Lenke, have attempted to bring forth as complete a survey of the rigid spine deformities issue as possible, such as treatment solutions, various patient populations, anesthesia, robot-guided surgical techniques, and neuromonitoring, among others. Consequently, the reader will find precise, reliable answers to solve the problems presented by the status of the patients the physician has to treat.

Here is a typical textbook that any spinal surgeon dealing with rigid spine deformity patients should have in their office.

Jean Dubousset, MD Orthopaedic Spine Surgeon Professor of Spinal Pediatric Orthopaedics Académie Nationale de Médecine Paris, France

Preface

In our work, Corrective Osteotomies for Rigid Spinal Deformities, wewould like to present the natural history, surgical strategies, and tactics for managing difficult spinal pathologies. There are approximately 4000 orthopaedic surgeons and a comparable number of neurosurgeons in the United States who performspine surgery. Yet only 5 to 10% of these surgeons have specific expertise and experience in deformity correction.

In this book, we didactically address the different surgical approaches, including anterior, posterior, and combined approaches for correction of rigid deformities. We also address the anesthesiological aspects of spine corrections in different stages of surgery, and the importance of spinal neuromonitoring that is becoming a gold standard, allowing surgeons to make more impressive corrections with greater confidence.

Specific surgical approaches to the various types of rigid spine deformities are presented with the rationale, techniques, and results for each.

In addition,we present new technologies like computerassisted robotic surgery, evaluation and treatment of tuberculosis in children and adults, biological aspects that speed up spine fusion, complications of cord injuries and rehabilitation approach, and others.

All contributors to this work are recognized experts in the evaluation and treatment of various spinal deformities and pathologies. In this work, they present their own personal experiences through many years of practice in clinical evaluation and surgical treatment in spine disorders.

Scoliotic surgery, especially osteotomies of rigid spinal deformities, is, without doubt, a unified part of general spine surgery and otherwise includes the philosophy of meticulous planning, execution, and management.

This book, as a surgical manual, was created and meant for advanced spine surgeons in the field of spine deformity correction in children, youth, and adults with various spine pathologies.

Iam certain that many spine surgeons, and especially the more experienced ones, will highly benefit from the didactic review of our experts.

We hope you enjoy reading our textbook and gain much from reading it.

Leon Kaplan, MD

Introduction

The field of spinal deformity has evolved markedly over the past few decades. With increasing clinical and research efforts worldwide, most patients undergoing spinal deformity reconstructions are obtaining far better correction with less or no reliance on any external immobilization postoperatively along with far fewer intraoperative and postoperative complications, leading to better overall outcomes. Within spinal deformity surgery, further subspecialization includes pediatric deformity, adult deformity, cervical deformity, and application of minimally invasive surgical techniques to many conditions as well. During this time, spinal surgeons taking care of patients with deformity have also recognized that there is a subset of patients who have stiff or “rigid” spinal columns that present a greater challenge than those with flexible deformities, as would be somewhat intuitive. Thus, the rationale for this new novel textbook is to further highlight the inherent challenges and complexities, and provide solutions for safe and optimal treatment of those patients with rigid spine deformities. In this compendium of advanced and expertly written chapters, the multiple senior authors, all leading spinal deformity specialists, provide their own insight gained through many decades of surgical care of these types of patients. Important topics covered includethe natural historyof these rigid deformities, and those associated with common diagnoses such as: congenital, idiopathic,neuromuscular, early-onset, osteoporotic, post-traumatic, Parkinson’s related, and ankylosing conditions. Anatomic-based considerations are covered in chapters on rigid deformities, including the cervical spine, the upper thoracic spine, and junctional regions of the cervicothoracic, thoracolumbar, and lumbosacral regions. In addition, other more esoteric, but still essential, topics such as kyphectomies for spina bifida patients, surgery for patients younger than 10 years, those who have preexisting neurologic deficits due to their rigid and angular deformities, and those with tumors of the spinal column are expertly presented as well. Lastly, a common scenario of patients with rigid deformities undergoing revision surgery along with various spinal osteotomies are covered in two separate chapters.

The content of this textbook is complete and detailed, and is recommended for any orthopaedic or neurosurgical spinal surgeon or trainee involved in the care of these specific types of patients. I congratulate Prof. Leon Kaplan on his vision and efforts to create and complete this incredibly educational textbook.

Lawrence G. Lenke, MD

Acknowledgments

There were many people involved in getting this book together and making sure it would see the light of day. But there are two, in particular, without whom you would not be reading these lines…

Shelly Tannenbaum, my editor. Shelly is the backbone of this book. On top of doing the standard editorial work, she has also handled all the coordination with the other book contributors and managed the various book logistics. I would like to thank her for her endless help and professionalism, her immense talent, and the sheer magic powers she has showndriving this book to its completion. Shewas a pleasure to work with, and has played a key role without which this book would not have been published.

Noa Bineth, my medical student. Noa, at her young age, excelled in every aspect of her life and education. She has offered her talents in support of this book and showed once again how everything she touches turns to gold. She managed the majority of the cooperation between me and the other doctors, and has helped drive the work on this book forward. I would like to thank Noa for her support and help throughout this process.

Ladies, this book would not have happened without you.

Leon Kaplan, MD

Contributors

Behrooz A. Akbarnia, MD Clinical Professor Department of Orthopaedic Surgery University of California, San Diego; Medical Director Emeritus San Diego Center for Spinal Disorders San Diego, California, USA

Ahmet Alanay, MD Professor of Orthopaedics and Traumatology Pediatric and Adult Spinal Disorders Acıbadem University School of Medicine Department of Orthopaedics and Traumatology Comprehensive Spine Center at Acıbadem Maslak Hospital,    Acıbadem University Istanbul, Turkey

Harel Arzi, MD Spine Surgeon Director of Pediatric Spine Unit Spine Surgery Unit Department of Orthopaedic Surgery Shaare Zedek Medical Center Jerusalem, Israel

Lisa Babbi, MD Junior Fellow Spine Surgery III - Scoliosis Unit IRCCS Galeazzi Orthopaedic Institute Milan, Italy

Yair Barzilay, MD Spine Surgeon Director of Spine Surgery Unit Department of Orthopaedic Surgery Shaare Zedek Medical Center Jerusalem, Israel

Eduardo C. Beauchamp, MD Adult and Pediatric Spine Surgeon Department of Orthopaedic Surgery Columbia University Medical Center The Daniel and Jane Och Spine Hospital at New York    Presbyterian/The Allen Hospital New York, New York, USA

Samuel S. Bederman, MD, PhD, FRCSC Scoliosis and Spine Surgeon RESTORE Orthopedics and Spine Center Orange, California, USA

Louis Boissiere, MD Orthopaedic and Spine Surgeon Bordeaux University Hospital Clinique du Dos-Bordeaux Orthopole Bordeaux, France

Stefano Boriani, MD Orthopaedic and Spine Surgeon Professor of Orthopaedic Surgery Director of Oncologic, Degenerative and Spine Surgery    Departments Rizzoli Institute Bologna, Italy

Marco Brayda-Bruno, MD Orthopaedic and Spine Surgeon Chief Spine Surgery GSpine III – Scoliosis Director of Spine Care Group Coordinator, Spinal Research IRCCS Galeazzi Orthopaedic Institute Milan, Italy

David B. Bumpass, MD Vice Chair of Orthopaedic Research Associate Professor of Orthopaedic Surgery & Neurosurgery UAMS Department of Orthopaedic Surgery Arkansas Children’s Hospital Little Rock, Arkansas, USA

René M. Castelein, MD, PhD Orthopaedic and Spine Surgeon Professor of Orthopaedic Surgery Chair, Department of Orthopaedics University Medical Center Utrecht Utrecht, The Netherlands

Derek T. Cawley, MMedSc, MCh, FRCS Orth Consultant Spine Surgeon Mater Private Hospital Dublin, Republic of Ireland

Riccardo Cecchinato, MD Specialist in Orthopaedics, Traumatology, and Vertebral    Surgery Medical Director of the GSpine4 Operational Unit IRCCS Galeazzi Orthopaedic Institute Milan, Italy

Meghan Cerpa, MPH Research Coordinator Department of Orthopaedic Surgery Columbia University Medical Center The Daniel and Jane Och Spine Hospital at New York    Presbyterian/The Allen Hospital New York, New York, USA

Sebastien Charosky, MD Orthopaedic and Spine Surgeon Centre Toulousain du Rachis Clinique La Croix du Sud Quint-Fonsegrives, France

Roongrath Chitragran, MD Spine Surgeon Chief of Spine Surgery Unit Department of Orthopaedics Phramongkutklao Hospital and College of Medicine Bangkok, Thailand

José E. Cohen, MD Neurosurgeon Professor of Neurosurgery Department of Neurosurgery Hadassah-Hebrew University Medical Center Jerusalem, Israel

Dino Colo, MD Otrhopadeic Surgeon Department of Orthopaedic Surgery University Medical Center Utrecht Utrecht, The Netherlands

Matthew E. Cunningham, MD, PhD Associate Attending Orthopaedic Surgeon Associate Professor of Orthopaedic Surgery Weill Cornell Medical College Hospital for Special Surgery New York, New York, USA

Joseph Danto, PhD Director Surgical Monitoring Services Beit Shemesh, Israel

Peter B. Derman, MD, MBA Spine Surgeon Texas Back Institute Plano, Texas, USA

Benjamin Drenger, MD Professor of Anesthesiology President of Israeli Anesthesiology Society Department of Anesthesiology and Critical Care Medicine Hadassah-Hebrew University Medical Center Jerusalem, Israel

Jean Dubousset, MD Orthopaedic and Surgeon Professor of Spinal Pediatric Orthopaedics Académie Nationale de Médecine Paris, France

Stephen Eisenstein, MB BCh, PhD, FRCS (Edin) Emeritus Professor Consultant Spine Surgeon Robert Jones & Agnes Hunt Orthopaedic Hospital Oswestry, Shropshire, United Kingdom

Meric Enercan, MD Professor of Orthopaedics Department of Orthopaedics and Traumatology Faculty of Medicine Demiroglu Science University Istanbul, Turkey

Shifra Fraifeld, MBA Medical Writing and Editing Jerusalem, Israel

Alessandro Gasbarrini, MD Orthopaedic and Spine Surgeon Oncologic and Degenerative Spine Surgery Unit Rizzoli Institute Bologna, Italy

Yechiel N. Gellman, MD, MSc Senior Orthopaedic Surgeon Foot and Ankle, Sports and Reconstructive Senior Surgeon Orthopaedic Department Complex Hadassah-Hebrew University Medical Center Jerusalem, Israel

Riccardo Ghermandi, MD Orthopaedic and Spine Surgeon Oncologic and Degenerative Spine Surgery Unit Rizzoli Institute Bologna, Italy

Sleiman Haddad, MD, PhD, FRCS Orthopaedic and Spine Surgeon Spinal Surgery Unit Department of Orthopaedic Vall d’Hebron University Hospital; Spine Unit, Quiron Hospital Barcelona, Spain

Azmi Hamzaoglu, MD Orthopaedic and Spine Surgeon Professor of Orthopaedic Surgery Surgeon-in-Chief and Head of Istanbul Spine Center Istanbul Florence Nightingale Hospital Istanbul, Turkey

Rune Hedlund, MD Orthopaedic and Spine Surgeon Professor of Orthopaedic Surgery Sahlgrenska University Hospital Göteborg, Sweden

Sajan K. Hegde, MD Orthopaedic and Spine Surgeon Surgeon-in-Chief and Head of Spine Apollo Institute of Spine Surgery Centre for Robotic and Complex Spine Surgeries Apollo Hospitals Chennai, India

Pooria Hosseini, MD, MSc Research Fellow San Diego Spine Foundation San Diego, California, USA

Eyal Itshayek, MD Spine Neurosurgeon Professor of Neurosurgery Surgeon-in-Chief and Director of Spine Surgery Unit Department of Neurosurgery Rabin Medical Center Petah Tikva, Israel

Rishi Mugesh Kanna, MS, MRCS, FNB Associate Consultant Spine Surgeon Department of Orthopaedics, Traumatology, and Spine    Surgery Ganga Hospital Coimbatore, India

Leon Kaplan, MD Professor of Orthopaedic Surgery Surgeon-in-Chief and Director of Spine Surgery Unit Department of Orthopaedic Surgery Hadassah-Hebrew University Medical Center Jerusalem, Israel

Han Jo Kim, MD Associate Professor of Orthopaedic Surgery David B. Levine Endowed Chair Spine Fellowship Director Hospital for Special Surgery New York, New York, USA

Akiva Korn, MMedSc, D-ABNM Surgical Monitoring Services Ltd Beit Shemesh, Israel; Division of Neurosurgery Tel Aviv University and Medical Center Tel Aviv, Israel

Janina Kueper, MD Department of Orthopaedic Surgery Spine and Scoliosis Service Hospital for Special Surgery Weill Cornell Medical College New York, New York, USA

Claudio Lamartina, MD Orthopaedic Surgeon Professor of Orthopaedics EFM Universities of Milan and Turin; Chief of Department of Spine Surgery G4Spine 4, IRCCS Galeazzi Orthopedic Institute Milan, Italy

Lawrence G. Lenke, MD Professor of Orthopaedic Surgery Director of Spinal Deformity Surgery Columbia University Vagelos College of Physicians and    Surgeons; Surgeon-in-Chief, Och Spine Hospital at New York    Presbyterian Allen New York, New York, USA

Meir Liebergall, MD Orthopaedic Surgeon Professor of Orthopaedic Surgery Surgeon-in-Chief and Director of Orthopaedic Complex Hadassah-Hebrew University Medical Center Jerusalem, Israel

Isador H. Lieberman, MD, MBA, FRCSC Orthopaedic and Spinal Surgeon President of Texas Back Institute Plano, Texas, USA

Alessio Lovi, MD Senior Fellow Spine Surgery III - Scoliosis Unit IRCCS Galeazzi Orthopaedic Institute Milan, Italy

Andrea Luca, MD Spine Fellow Spine Surgery III - Scoliosis Unit IRCCS Galeazzi Orthopaedic Institute Milan, Italy

W. S. El Masri, FRCS Ed, FRCP Emeritus Clinical Professor of Spinal Injuries Keele University; Consultant Surgeon in Spinal Injuries Midlands Centre for Spinal Injuries (MCSI) Robert Jones & Agnes Hunt Orthopaedic Hospital Oswestry, Shropshire, United Kingdom

Yigal Mirovsky, MD Orthopaedic Spine Surgeon Professor of Orthopaedic Surgery Director of Department of Orthopaedic Surgery and the    Spine Unit Assaf Harofeh (Shamir) Medical Center Zerifin, affiliated to the Sackler Faculty of Medicine Tel Aviv University Tel Aviv, Israel

Alexander Mushkin, MD Orthopaedic Surgeon Professor of Orthopaedic Surgery Surgeon-in-Chief and Doctor of Science Chief of the Spine Center-Pediatric Surgeryand Orthopaedic    Clinic Research Institute of Tuberculosis Saint Petersburg, Russia

Venu M. Nemani, MD, PhD Spine Surgeon Center for Neurosciences and Spine Virginia Mason Medical Center Seattle, Washington, USA

Ibrahim Obeid, MD Orthopaedic and Spine Surgeon Director of Spine and Scoliosis Surgery Clinique du Dos-Bordeaux Terrefort Bordeaux, France

Avi Ohry, MD Emeritus Professor Rehabilitation Medicine, Faculty of Medicine Tel Aviv University Tel Aviv, Israel

Paul J. Park, MD, MMS Adult & Pediatric Comprehensive Spine Fellow Columbia University Irving Medical Center The Daniel and Jane Och Spine Hospital at New York    Presbyterian/The Allen Hospital New York, New York, USA

Ferran Pellisé, MD, PhD Orthopaedic Surgeon Professor of Orthopaedic Surgery Surgeon-in-Chief of Spinal Surgery Unit Department of Orthopaedics Vall d’Hebron University Hospital; Spine Unit: Quiron Hospital Barcelona, Spain

S. Rajasekaran, MS, MCh, FRCS, FACS, PhD Director and Head Department of Orthopaedics, Traumatology, and Spine    Surgery Ganga Hospital Coimbatore, India

Guillaume Riouallon, MD Spine Surgeon Spine Surgery Unit Saint Joseph Hospital Paris, France

Gabriele Ristori, MD Spine Resident Spine Surgery III - Scoliosis Unit IRCCS Galeazzi Orthopaedic Institute Milan, Italy

Pierre Roussouly, MD Spine Surgeon Professor of Orthopaedic Surgery Surgeon-in-Chief of Spinal Surgery Unit Chief of Spine Surgery Department Department of Orthopaedic Surgery Massues Medicosurgical Clinic Lyon, France

Josh Schroeder, MD Senior Spine Surgeon Senior Lecturer Director of Spinal Deformities Surgeries Department of Orthopaedic Complex Hadassah University Hospital Jerusalem, Israel

Amer Sebaaly, MD Spine Surgeon Department of Orthopaedic Surgery Clinique médicochirurgicale des Massues Lyon, France

Ruth Shaylor, BMBS, BMSc, DESA Division of Anesthesia, Intensive Care, and Pain    Management Tel-Aviv Medical Center Tel Aviv University Tel Aviv, Israel

Ajoy Prasad Shetty, MS (Ortho), DNB (Ortho) Consultant in Spine Surgery Department of Orthopaedics, Traumatology and Spine    Surgery Ganga Hospital Coimbatore, India

Mario Di Silvestre, MD Orthopaedic Surgeon Professor of Orthopaedic Surgery Chief of Spine Surgery Department Santa Corona Hospital Pietra Ligure (SV), Italy

Yossi Smorgick, MD Orthopaedic and Spine Surgeon Department of Orthopaedic Surgery and the Spine Unit Assaf Harofeh (Shamir) Medical Center Zerifin, affiliated to the Sackler Faculty of Medicine Tel Aviv University Tel Aviv, Israel

Pramod K. Sudarshan, MD, MS Ortho Fellow in Spine Surgery (ASSI) Fellow in Spinal Deformity Surgery (IGASS, SICOT) Consultant Spine Surgeon Aster MIMS Calicut Kerala, India

Athanasios I. Tsirikos, MD Senior Spine Surgeon Professor of Orthopaedic Surgery Director of Spinal Neuromuscular Department Royal University Hospital Edinburg, Scotland

Peter Upex, MD Spine Surgeon Spine Surgery Unit Saint Joseph Hospital Paris, France

Sergei Vissarionov, MD, PhD, DSc Orthopaedic and Spine Surgeon Professor of Traumatology and Orthopaedic Surgery Surgeon-in-Chief of Spinal Pediatric Surgery Department Corresponding Member of the Russian Academy of Sciences H. Turner National Medical Research Center for Children’s    Orthopaedics and Trauma Surgery Saint Petersburg, Russia

Stéphane Wolff, MD Spine Surgeon Spine Surgery Unit Saint Joseph Hospital Paris, France

Çağlar Yılgör, MD Spine Surgeon Comprehensive Spine Center at Acibadem Maslak Hospital Department of Orthopaedics and Traumatology Acıbadem University Istanbul, Turkey

1Congenital Spinal Deformities

Ibrahim Obeid, Louis Boissiere, Derek T. Cawley

Abstract

Congenital spinal deformities are a fascinating area of the science of the vertebral column. Their diagnoses and management require a deep understanding of the growth patterns, starting from intrauterine vertebral formation and segmentation to causes of pain and disability. Abnormalities of formation and segmentation apply here as much as in any endochondral growth environment. Decisions on the role and timing of surgery are best made as part of a multidisciplinary process. In particular, it is important to recognize how inherently different congenital kyphosis can behave compared to congenital scoliosis in causing neurologic deficit if left untreated. Once the goals of surgery have been identified, it requires careful planning to execute an optimal procedure. The described procedures depend on the deformity, the compensatory curves, and the potential for further deformity. The treatment options include epiphysiodesis to balance an asymmetric physis, and hemivertebral resection or pedicle subtraction osteotomy in unbalanced primary curve progression. In severe and complex deformities, vertebral column resection and vertebral column decancellation are usually the accepted options. However, one must recognize limitations including the patient’s physiologic and spinal cord tolerance, availability of surgical and technical skills, and perioperative considerations. Image-guided navigation is a new tool to help implant insertion and in particular to control vertebral resection, which improves correction while decreasing risk. In most cases, we have the privilege of developing a rich relationship with the patients and their relatives over multiple visits.

Keywords: congenital spinal deformities, congenital scoliosis, hemivertebra, butterfly vertebra, congenital concave bar, vertebral column resection, pedicle subtraction osteotomy, convex growth arrest

1.1Introduction

Congenital spinal deformity is defined as a deviation of the spine from its normal planes associated with one of a broad range of congenital vertebral malformations (CVMs) that form in utero. While the deformity may not be present at birth, the vertebral anomaly is present and may be isolated or part of a syndromic abnormality. Congenital spinal deformity occurs only where growth asymmetry from a CVM occurs. At least 40 syndromes of CVMs have been described, accounting for 61% of cases.1,​2 It is commonly accepted that disruption of somatogenesis at approximately 5 to 8 weeks of gestation is the overriding cause of CVMs from genetic predispositions or teratogenic exposures. Thus the diagnosis of and management decisions for CVMs must be made in the context of a comprehensive analysis of affected individuals—their growth, their expectations, their prognosis and potential pain or disability.

Vertebral growth depends on multiple ossification centers (Fig. 1.1), from uterine life to the end of puberty. During childhood and puberty, vertebral growth depends on growth from the secondary ossification centers. The growth plates of the vertebral body are located at the upper and lower vertebral end plates. Growth can be separated into its coronal and sagittal planes. In the sagittal plane, the anterior and posterior growth patterns should reflect the normal contour of the spine, with physiological lordotic cervical, kyphotic thoracic, and lordotic lumbar curves. The coronal plane reflects symmetric growth between the left and right sides.

Fig. 1.1 Primary ossification centers (black), growth areas from primary ossification centers (dark gray) and secondary ossification centers (light gray).

Up to 38% of CVMs have been shown to have an intraspinal anomaly, particularly cervical and thoracic, with half displaying clinical evidence of this.3 The vertebral anomalies* that result in the development of a kyphosis are fully established at birth, developing during a later stage of chondrification than scoliosis, which is thought to develop at an earlier mesenchymal stage.4 This may explain why the incidence of intraspinal abnormalities is higher in congenital scoliosis than in congenital kyphosis.5,​6 These must be fully investigated with MRI of the whole spine prior to surgery.

Tolerance for blood loss in these patients is often low, and this must be included in the decision-making process prior to the surgery. Identifying how much surgery a patient with CVM can tolerate is guided by comorbidities. The morbidity of increased spinal deformities is largely related to pulmonary effects, including alveolar multiplication and truncal constriction. When compared to a similar idiopathic scoliotic deformity, CVM has a 15% higher loss in vital capacity.

1.2Deciding on Surgery

Patients with CVM present with radiological abnormalities (usually from chest or abdominal radiographs), cosmetic deformities, pain, or neurological sequelae. The goals of surgery are to stabilize the spine, adjust for growth asymmetry, and correct the deformity so that patient-related outcomes are met.

Eighty percent of spinal deformities are caused by congenital scoliosis, with 15% causing kyphoscoliosis and kyphosis in 5%, depending on the type of vertebral anomaly and its position. A posterior hemivertebra (HV) and/or anterior unsegmented bar will leave a kyphotic deformity. An anterior HV (very uncommon) or posterior bar will leave a lordotic deformity. A lateral-sided HV or a contralateral bar will leave a scoliosis, with its convex apex at the HV or concavity at the site of the bar. Depending on the relative anterior or posterior nature of a lateral-sided HV or bar, the deformity will be either a kypho- or a lordoscoliosis.

Biplanar radiographs have been the foundation for classification and prognostication for CVMs. More recently, three-dimensional systems such as CT have been used to generate a more comprehensive picture of the deformity and to help surgical planning given their ability to demonstrate bony architecture for resectional purposes and pedicle morphology to aid pedicle screw insertion.7

* Associated spinal cord anomalies include diastematomyelia (most common), intraspinal lipoma (thickened and fatty filum—second most common), tethered cord, Chiari malformation, syringomyelia, dermoid or epidermoid cyst, arachnoid cyst, Dandy–Walker malformation, and a low conus.

The most useful and predictive classification system, which outlines failures of formation, failures of segmentation, or combinations of malformations, was designed by Winter et al,8 then modified by McMaster and Ohtsuka.9 Thus these descriptions capture the potential for asymmetric growth in any plane, creating abnormal lordosis, kyphosis, or scoliosis. Deformity progression occurs most rapidly during the most rapid periods of growth, from 0 to 5 and 10 to 14 years. Rapid prepubertal progression carries a poor prognosis, and surgical intervention is recommended. In general, defects of segmentation carry a poorer prognosis, with greater potential for deformity than defects of formation.

1.A failure of formation consists of an HV, wedge, and butterfly vertebra, where the abnormality is an aplasia of a part of the vertebra. This allows formation of a unilateral pedicle with a hemilamina, or the presence of either the anterior or posterior elements. Formation of one pedicle usually accompanies an attached rib, leaving an unequal number of ribs. The three types of HV, in order of reducing deformity potential, include a fully segmented HV (most common), a semisegmented HV, and a nonsegmented (or incarcerated) HV.

○The fully segmented HV has a normal disk above and below, with longitudinal growth occurring on the upper and lower surfaces. As the HV grows, it acts as an enlarging wedge, producing a scoliosis, progressing at approximately 1 to 2 degrees per year. The affected HV will protrude slightly at the apex as it grows. This is more problematic with a posterior HV where the dura and spinal cord may be draped over the kyphosis, potentially culminating in a neurologic deficit. Two adjacent unilateral HVs have four unopposed growth plates, invariably exceeding 50 degrees at maturity. Conversely, opposing HV may cause deformity, depending on the number of levels between them. When close together (one or two interposed vertebrae), they tend to balance each other with small curvatures, whereas when occurring at different regions, they may create unbalanced deformities.

○A semisegmented HV is fused to an adjacent vertebra, either above or below, and there is only one disk space. The two growth plates are obliterated on the convex side, and, theoretically, there is a balanced spinal growth. However, the slight wedge can maintain a tilt at the apex, which can slowly progress. At maturity, the curve does not usually exceed 40 degrees. Prognosis is usually good except at the lumbosacral junction, where there is an oblique takeoff of the spine from its base at the sacrum and a long compensatory curve at the thoracolumbar junction.

○An anteroposterior discordance or anteroposterior dissociated HV occurs when the supplementary hemiposterior arch does not correspond to the supplementary hemianterior body. It is best to visualize this on a three-dimensional (3D) CT reconstruction, or in some cases, a 3D printout if one is planning surgery. It is helpful to work out the anterior and posterior relations of the affected pedicle during resection planning (Fig. 1.2).

○Nonsegmented or incarcerated HVs are fused to the vertebrae above and below, thus set in a niche, scalloped out of the adjacent compensatory vertebrae. There is a low growth potential with low deformity progression, usually less than 20 degrees at maturity.

○Wedge vertebrae are a result of partial failure of formation on one side of the vertebra (hypoplastic), containing two pedicles, and demonstrate slow longitudinal growth on the wedged side of the vertebra, with low progression of the curve. Depending on the location of the wedge, it may still require surgical deformity correction, especially if there is a compensatory curve.

○Butterfly HV is a failure of midline fusion that results in two side-by-side HVs (Fig. 1.3). These are often posterior, with a defect of formation of the anterior body, and mainly lead to a kyphotic deformity. They may be asymmetric, thereby producing a kyphoscoliotic deformity.

2.Growth inhibition is due to a failure of segmentation because separate diskovertebral units did not form, and thus a bar extends across adjacent vertebrae, tethering them together. Coexistent rib fusions are often found at the same site. Growth then occurs at the opposite side. Curves progress at approximately 5 degrees per year, frequently resulting in a final deformity of over 50 degrees if left untreated. These mainly occur at the thoracic or thoracolumbar spine. A block vertebra will not usually create a deformity because there is bilateral or circumferential failure of segmentation and uniformly reduced potential for growth across the involved vertebrae, progressing at 0.5 degrees per year.6

3.Some (10–20%) are unclassifiable. These often present with multiple curves. Thoracic curves are prevalent but are more common on the left side (unlike adolescent idiopathic scoliosis).10

Fig. 1.2 Two cases of anteroposterior discordance as shown on three-dimensional CT reconstructions. The upper case involves the thoracic and the lower involves the lumbar spine.

Fig. 1.3 A T12 butterfly vertebra with central and anterior failure of formation causing thoracolumbar junction kyphosis.

1.3Prognosis

The prognosis depends on three main factors:

1.The type of vertebral anomaly (growth imbalance magnitude).

2.The site of the anomaly.

3.The age of the patient at the time of diagnosis

Other prognostic factors include the risk of neurologic complications, mostly with kyphosis and kyphoscoliosis, and associated extraspinal congenital anomalies. The risks of curve progression beyond 40 degrees vary from 37 to 84%.5,​11,​12

Prognosis based on the CVM, from worst to best (approximately), is as follows:

1.Fully segmented HV (two growth plates) with a contralateral bar (10 degrees/year).

2.Double HV with a unilateral bar, especially if fully segmented.

3.Unilateral unsegmented bar.

4.Two consecutive fully segmented HVs.

5.Fully segmented HV.

6.Semisegmented HV.

7.Wedge vertebra (corresponding to a partial failure of formation).

8.Incarcerated HV.13

Prognosis based on the site of the anomaly, from worst to best, is as follows:

1.Lumbosacral junction.

2.Thoracolumbar junction.

3.Lower thoracic segment.

4.Lumbar segment.

5.Upper thoracic segment.

The effects of age on deformity progression are not constant. Acceleration of the progression is seen the year before and during puberty during the adolescent growth spurt. Progression of the curve will also depend on the severity of the spinal growth imbalance. Compensatory curves outside the CVM also become stiff with time. This is largely due to the asymmetric load placed on the concavities at the apex and contralateral compensatory curve apices, adhering to the Hueter–Volkmann principle: growth is retarded by increased mechanical compression and accelerated by reduced loading in comparison with normal values.14

Severe deformities lead to severe vertebral rotation and distortion of the rib cage. Fused, hypoplastic, or supplementary ribs can result, depending on the level of the CVM. These usually occur within the concavity, but they may occur on both sides of the deformity. While fused ribs may be observed within the concavity, they accompany (as opposed to cause) the spinal deformity and are therefore not considered when deciding on the curve prognosis. The presence of a rib anomaly increases the likelihood of a renal abnormality.15

1.4Congenital Kyphosis and Kyphoscoliosis

This is an abnormal posterior convex angulation, secondary to a slow anterior column growth, and is often asymmetric, later leading to combined coronal and sagittal deformities. This is observed later in intrauterine growth, mostly at thoracic or thoracolumbar segments. Progressive spinal cord compression causes progressive neurologic deficit.

Multiple HVs have been shown to occur most frequently (44%), followed by anterior segmentation defects (32%) and single HVs (18%).2 While congenital kyphosis can occur in any part of the spinal column, the apex is often located between T10 and L1. The anterior aspect of the spine fails either in formation (65%) or in segmentation (20%) or a combination of both (10%). Inherently different from congenital scoliosis is the potential for congenital kyphosis to cause neurologic deficit if left untreated. This is especially true if the kyphosis is located in the narrow high or midthoracic spine or the lower thoracic spine, where the blood supply is poor.16 This is the main indication for prophylactic surgery with CVMs. Patients with a preoperative neurologic deficit have a higher potential for intraoperative neurologic complications. HVs, butterfly vertebrae, and wedge vertebrae occur due to the formation failure of the vertebral body.4

Winter et al classified these anomalies as failures of formation, segmentation, and combinations thereof, types 1, 2, and 3, respectively.17

•Type 1 (anterior failure of formation) can cause rigid annular deformity, with posterolateral quadrant HVs progressing at 2.5 degrees per year until age 10, then increasing to 5 degrees, causing spinal cord compression in 25% of cases.18 The pathogenesis of these anomalies is thought to occur because of a localized failure of vascularization of the developing cartilaginous centrum. Because the posterior arch develops separately, this is relatively unaffected.

•Type 2 (anterior or anterolateral failure of segmentation) have a smoother kyphosis, often extending over multiple segments. Given the smooth contour and stable configuration conferred by the bar, neurologic deterioration has not been seen in the series by McMaster or Winter et al.5,​18 These are thought to occur because of bone metaplasia changes at the anterior annulus fibrosis and ring apophysis during late chondrification and ossification.19 The anterior bars progress at ~1 degree per year before 10 years and can be variable after this time. Thicker bars can approximate a block-type anomaly, thus displaying less potential to progress.

•Type 3 mixed anomalies display a sharp angular kyphoscoliosis, usually like kyphosis, and are least common.

1.5Further Perioperative Considerations

With surgery for deformity correction, it is very important to preserve the periosteal layer beyond the operative site, to avoid spontaneous fusion and allow for normal growth.

If using pedicle screws, allow for availability of sizes smaller than the standard range given the young age of the patient and the morphology of congenitally abnormal anatomy.

Congenital vascular anomalies will usually accompany congenital vertebral anomalies.20 This is particularly relevant when considering anterior approaches. Noordeen et al concluded that in congenital kyphotic deformities, the blood supply is possibly compromised by three factors:

1.Elongation and compression of the longitudinal arterial trunks, with kinking or stretching of the sulcal arteries.

2.Instability causing microcirculatory perfusion deficits.

3.Congenitally deficient segmental blood supply at the level of the deformity.21

Intraoperative scanning with navigation-guided surgery is a helpful conventional technique for inserting pedicle screws in these cases of abnormal anatomy and also for checking bone resection margins. The instrumentation should be compliant with the navigation system. In cervicothoracic kyphosis cases, the head may be positioned on a Mayfield frame that, given the relative anterior positioning of the head on the body, may be much lower on the operating table than the body. This is an important consideration for positioning the reference frame for navigation to allow placement of difficult pedicle screws. A scoliotic hyperlordotic lumbosacral spine may mean that screw placement is deep, and with abnormal anatomy, navigation is helpful here also. Revision surgery is a further justification for navigation surgery (Fig. 1.4, Fig. 1.5).

Fig. 1.4 A 13-year-old boy with a lumbosacral junction right hemivertebra. Two insufficient previous resections were performed (late, incomplete correction, implant failure). Progression of the oblique takeoff of the spine is observed with a lumbar compensatory curve that has since become structural. Global coronal malalignment is also present. CT coronal and sagittal images demonstrate lumbosacral oblique takeoff (coronal) and kyphosis (sagittal).

Fig. 1.5 Revision surgery by combined anterior and posterior approach allowed correction of the coronal and sagittal malalignment. At 4-year follow-up the result is maintained despite the right iliac screw fracture (image on the right). Correction of the compensatory curve remains partial because of the old age of the patient at the time of the surgery.

Perioperative and intraoperative halo-gravity traction may have a role for patients with severe deformities or those with significant intraspinal pathology.22

1.6Treatment Options and Principles

1.6.1 Observation

Deformity observation is required in isolation or before and after surgical treatment. Clinical evaluation of the child is also important for encompassing characteristics, such as sexual development, cosmetic concerns, pain, and quality of life. Repeated observation alone is appropriate for incarcerated thoracic HVs, complete block vertebrae, or adjacent bilateral HVs. Deformity observation is also very important for monitoring the fusion at the operated level and the behavior of the compensatory curve after surgery.

1.6.2 Epiphysiodesis

The goal of convex epiphysiodesis is to stop the spinal growth at the convex side anteriorly and posteriorly. This can be done with combined anterior and posterior, or posterior alone approaches, depending on the deforming factor. Convex growth arrest by unilateral epiphysiodesis can stop curve progression by canceling growth asymmetry, but cannot correct the deformity (Fig. 1.4). The use of pedicle screws and rigid posterior instrumentation enables posterior and anterior growth arrest by blocking the vertebral body cartilage as it is commonly used in long bone metaphysis by a Blount staple. In older patients, potential for slow correction with growth on the concave aspect is negligible. Epiphysiodesis is best performed before 5 years of age for optimal results or in cases where the anatomy of the location of the pathology is difficult, such as the cervicothoracic junction (Fig. 1.6, Fig. 1.7).16 Traditionally, in children who are less than 5 years of age, noninstrumented epiphysiodesis for kyphoscoliosis is appropriate if the kyphotic angle is small—less than 45 degrees according to McMaster and Ohtsuka9 or 55 degrees according to Winter et al.18 A combined strategy with growing rods and apical correction and short fusion may be used in complex situations. Short anterior instrumented fusion and posterior convex noninstrumented fusion of HV for congenital scoliosis in very young children has been described. Anterior instrumentation is a safe and effective technique capable of transmitting a high amount of convex compression allowing short-segment fusion.19

Fig. 1.6 A 7-year-old boy with a congenital unilateral, unsegmented bar at the cervicothoracic junction (a) as a result of a slightly delayed diagnosis. Convex side epiphysiodesis was performed. Four-year follow-up radiographs (b) confirmed that the deformity remained stable.

Fig. 1.7 Pre- and postoperative radiographs of a 13-year-old boy with cervicothoracic congenital scoliosis, treated with epiphysiodesis. This is performed with a unilateral posterior approach at the convex side of each curve. Pedicle screws were inserted unilaterally at the level of the hemivertebra and adjacent levels, one above and one below. In the cervicothoracic curve a unilateral growth arrest can be performed using intraoperative navigation for pedicle screw insertion. Fusion with local bone graft is then done posteriorly.

1.6.3 Hemivertebra Resection

HV resection and three-column osteotomy allow deformity correction and stop spinal growth at the fused segment. Early surgical excision has the advantage of avoiding the structural compensatory curve, particularly for two adjacent HVs or HVs at the thoracolumbar or lumbosacral junctions. Early resection may also be indicated for congenital kyphosis where there is a posterior HV with instability and potential neurologic risk. The aim of the treatment is to achieve a straight spine with respect to sagittal contour, and as short a construct as possible. This can be achieved by transpedicular instrumentation, even in very young patients down to 1 year old.23 Hedequist et al identified the optimal age range as 4 to 6 years.24

Thoracic HV resection can be treated by a posterior-only approach with short instrumentation from one level above to one level below using segmental pedicle screws (Fig. 1.8). The surgery is performed under motor-evoked potentials and somatosensory-evoked potentials neuromonitoring. After a standard midline incision, a full-thickness subperiosteal dissection running lateral to the transverse processes exposes the HV with the vertebra above and below it. Care is taken to limit dissection to the concerned levels because spontaneous fusion after exposure only is common in young children. Inferior facetectomies of the HV level and the cephalad level are performed to provide maximum flexibility to the spine. The spinous processes are also resected, and the bone recovered is prepared for use as a graft at the end of the procedure. Pedicle screws are then placed one level above and below the HV. Resection is first performed by removing the proximal part of the same-level rib and the transverse process, followed by the hemilamina. Both foramina, above and below the HV, are opened by removing the superior articular processes. After a careful and complete removal of the rib head, a Cobb elevator is placed outside the lateral portion of the HV and moved anteriorly to the anterolateral quadrant. The pedicle of the HV is then removed with a rongeur, and the nerve roots above and below are identified. The body of the HV is then removed with the use of osteotomes, including the disks above and below, which must include the concave disk material. No retraction of the dural sac is authorized in this region. Venous bleeding in the epidural space should be controlled by bipolar cautery. The convex rod is then placed into the screws. Gradual compression is done to close the resection site, with careful control of the exiting nerve roots and dura. During the closure of the resection site, either convex side pedicle above can fracture in relation to the high strains due to the important reduction needed. Pedicle fracture can be avoided by using a three-rod technique, with opposing supralaminar and infralaminar fixation involving only those vertebrae already used for pedicle screw fixation. Thus a more controlled correction can be achieved through simultaneous compression on pedicles and hooks applied on the posterior arch.16,​25,​26

Fig. 1.8 A 7-year-old girl with congenital hemivertebra with scoliosis underwent a posterior complete resection of the bone and of the disk spaces above and below. This allowed a complete and immediate correction of the scoliosis, maintained at 4-year follow-up. This underlines the importance of complete resection and correction of the deformity at a young age before the compensatory curves become structural.

When checking with fluoroscopy, the inferior end plate of the level above and the superior end plate of the level below should be parallel at the end of the correction maneuver. The posterior elements are then decorticated, and autograft from the resected vertebra is applied. Remaining bone defect at the anterior column is filled by autologous bone graft to obtain anterior bony contact and avoid pseudarthrosis. Complete disk and cartilage removal, anterior bony contact either by direct contact or by bone grafting, complete correction of the deformity, and solid fixation are key to a satisfactory long-term result. Compared to convex epiphysiodesis, HV resection allows better correction with shorter fusion. Compared to the double approach, this technique achieves the same result with less morbidity but is technically more demanding.

1.6.4 Pedicle Subtraction Osteotomy

After skeletal maturity, a three-column osteotomy is usually necessary. In the adult setting the choice either includes an osteotomy or a vertebral column resection at the apex (Fig. 1.9, Fig. 1.10).

Fig. 1.9 CT and T2-weighted MRI sagittal images demonstrate a posterolateral quadrant hemivertebra causing kyphoscoliotic deformity of the thoracic spine. The increased signal at the anterior column defect (long arrow) and within the spinal cord (short arrow) indicates spinal instability and cord myelopathy, respectively.

Fig. 1.10 A three-column osteotomy was required to decompress the spinal cord and correct the deformity as projected on the MRI sagittal section. Two-year follow-up radiographs demonstrate a stable correction.

In some cases the deformity may be so severe that one pedicle subtraction osteotomy (PSO) would be inadequate to obtain acceptable correction. Adjacent osteotomies can be performed at the same setting. This technique enables bone-on-bone contact between two PSO sites and between the proximal PSO and the level above after the closure, which significantly decreases the pseudarthrosis rate and avoids a complementary anterior approach for grafting. This technique permits use of the vertebral body between the two PSOs as a bony cage, decreasing the risk of spinal cord kinking and increasing fusion rate. The desired correction is slightly kyphotic or neutral, as opposed to lordotic, and thus is not ideal in the lumbar spine. It is preferably indicated in the thoracic and thoracolumbar junction. Furthermore, it is more difficult at the lumbar spine because of the lordotic shape of these segments.

L5 or S1 congenital deformities are difficult to correct. A transdiskal osteotomy utilizes the disk as a further source of correction.27 A working knowledge of the spinal osteotomy classification by Schwab et al is helpful.28

Like any complex surgical procedure, the execution of two-level PSO requires comprehensivepreoperative (not intraoperative) planning, given the usual average bleeding rate for a single PSO (2.4 L).29 Thus the PSO levels and types should be clearly defined, potentially using a modified PSO including the disk at the proximal level, with PSO for the level below, which allows removal of the disk between the osteotomies, thereby enabling bone-on-bone contact after closure and decreasing the pseudarthrosis rate.30 One could potentially conserve the distal part of the pedicle of the distal vertebra, keeping intact the posterior arch, without need of opening both distal foramina. This variation helps to decrease the bleeding that may come from the foramina or from the extensive opening of the canal, and extensive exposure of the dura is also avoided. As the disk above is removed, a good correction could still be reached and is not compromised by the partial removal of the pedicle. Usually, with this two-level PSO technique, a correction between 60 and 70 degrees can be achieved. The main advantage compared to vertebral column resection (VCR) is that it does not create the same level of instability, without the need for a temporary rod or for an anterior cage (Fig. 1.11, Fig. 1.12).