DROR PALEY PRINCIPLES OF DEFORMITY CORRECTION Springer-Verlag Berlin Heidelberg GmbH DROR PALEY

PRINCIPLES OF 0 EFOR M I TV CORRECTION

With Editorial Assistance from J. E. Herzenberg

With More Than 1,800 Separate Illustrations, Clinical Photographs, and Radiographs

i Springer DROR PALEY,MD,FRCSC ISBN 978-3-642-63953-1 ISBN 978-3-642-59373-4 (eBook) DOI 10.1007/978-3-642-59373-4 Director, Rubin Institute for Advanced Orthopedics Sinai Hospital 1st ed. 2002. Corr. 3rd printing 2005 Co-Director, The International Center for Limb Lengthening, Sinai Hospital CIP-data applied for Baltimore, MD Die Deutsche Bibliothek- CIP-Einheitsaufnahme Paley, Dror: Principles of deformity correction 1 Dror Paley.• Berlin; Heidelberg; New York; Barcelona; Hongkong; Present address: London ; Mailand ; Paris ; Singapur ; Tokio : Springer, 2002 Rubin Institute for Advanced Orthopedics Sinai Hospital This work is subject to copyright. Ali rights are reserved, 2401 West Belvedere Avenue whether the whole or part of the material is concerned, specif• Baltimore, Maryland 21215-5271, USA ically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any E-mail: [email protected] other way, and storage in data banks. Duplication of this pub• lication or parts thereof is permitted only under the provisions www.limblengthening.org of the German Copyright Law of September 9, 1965, in its cur• www.deformitycourse.com rent version, and permission for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under the German Copyright Law.

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This book is dedicated to the memory of my father, Zvi Paley, who gave so much and asked for so little. Foreword -

What is genius? Analyzing complex problems and find• are technique-centric, this tome is principle-based and ing simple ways to explain them in an understandable will therefore stand the test of time. manner. By this definition, this book is genius. The limb lengthening and deformity reconstruction center created by Drs. Paley and Herzenberg in Balti• The most dramatic progress in orthopaedic surgery more is not only the clinical laboratory where this defor• during the last 2 decades has been in the field of defor• mity correction work was developed and understood mity correction. The treatment of deformities has occu• but has also become the Mecca for students in this med• pied and challenged orthopaedic surgeons since Nicho• ical specialty, with visitors from allover the world trav• las Andry. So many brilliant people have worked in this eling to learn firsthand from these masters of deformity field. Among them, Friedrich Pauwel and Gavril Ilizarov correction. It is in this manner that I first became ex• should be individually named. Dr. Ilizarov developed posed to the CORA method of mechanical and anatom• new methods oflimb lengthening and deformity correc• ic axis planning. This has resulted in a long-standing col• tion and sparked the newfound interest and develop• laboration between our two facilities, centered on our ments in this field today. In Dror Paley, this spark be• common interest in this subspecialty. We routinely apply came a raging fire. these principles to deformity correction at our center in Dr. Paley inaugurated many innovations in the field Germany. Many of the new deformity correction devic• of deformity correction. Among them, his nomenclature es that I and others are designing are now based on the deserves special mention. Before his classification based CORA principles. on joint orientation, we had a plethora of confusing Dr. Paley'S deformity correction courses around the terminology and definitions leading to a confusion of world have popularized the planning methods and prin• language reminiscent of the Tower of Babel. Dr. Paley's ciples espoused in this book. The annual Baltimore Limb nomenclature standardizes the terminology in a man• Deformity Course is the foundation for this book, work• ner that requires little memorization. This logically book, and CD. Each of its chapters has been presented as based system has gained international recognition and lectures at this course, and the workbook and multime• acceptance as the single language of deformity analysis dia CD have been tested by live audiences at these cours• and correction. This book presents us with these con• es for many years. cepts. The principles and concepts outlined in this book I am sure this book will become the bible for the under• were not discovered or understood overnight. They rep• standing, diagnosis, and treatment of lower limb defor• resent an evolution of Dr. Paley's ideas from the past mities. 14 years of clinical work in the field of deformity correc• tion. Unlike other texts, which come and go because they Wiesbaden, Germany JOACHIM PFEIL Preface -

My prediction: this book will become a classic. Brave pathological abnormalities that come under the pur• words, but I can safely make this statement because this view of the adult and pediatric orthopaedist. book is not about the latest surgical operation or about It has been my privilege and honor to be associated our knowledge of certain pathologies, which is constant- professionally with Dr. Dror Paley for the past 10 years, 1y changing. Rather, this book presents a system of de• and I probably know him better than anyone else does. I formity analysis that is universal and applicable to any have therefore been in a unique position to observe how past, current, or future surgical osteotomy techniques he developed the CORA method and to contribute as a and hardware. One needs only to think back to medical co-developer, editor, and author. Dr. Paley has an uncan• school and realize that most of the textbooks that we so ny knack of clearly seeing and understanding ortho• carefully studied are now "of historic interest only:' paedic deformities. More importantly, he has a unique Grant's Atlas ofAnatomy is perhaps the only book from ability to then process and integrate this information to my medical school days that I still use. I predict that Pa• make it accessible to the less clairvoyant. We have ley's Principles of Deformity Correction will also have a striven to make this method practical and teachable. It long shelflife. The treatment of skeletal deformity is the is not hard to learn, but it does take some effort and heart of our specialty. Indeed, the very name of our spe• practice. The method is mercifully low-tech: the only cialty, orthopaedics, was coined by Nicholas Andry in tools required are a pencil, ruler, and goniometer. We 1741 as a word derived from two Greek words, orthos have honed our ability to teach this method during the (meaning straight) and paedis (meaning child) to indi• past 10 years at our annual Baltimore Limb Deformity cate his goal "to teach the different methods of prevent• Course, and many of the figures and cases illustrated in ing and correcting deformities of children" (from Mer• this book have been used in the course. The case studies cer Rang's Anthology of Orthopaedics, 1966). and the artists' diagrams are all derived from our own Since Andry's writings 260 years ago, little progress practices and are representative of deformities that we has been made in understanding, analyzing, and quan• have treated. In this regard, we are greatly indebted to tifying the types of limb deformities. Rarely do we come our patients for providing us with both typical and atyp• across an orthopaedic surgeon who is truly an artist (or ical problems to study and illustrate. sculptor). Such an individual does not require accurate Interestingly, the CORA method of deformity analy• preoperative planning to execute a flawless corrective sis began simply as an attempt to make some sense of the osteotomy. However, for the rest of us journeymen or• Ilizarov apparatus. As the orthopaedic surgeon who in• thopaedic surgeons, achieving such beautiful artistic troduced this method in Canada and the USA, Dr. Paley and aesthetic outcomes is elusive. We tend to take a struggled to understand the concept of the Ilizarov wedge here or there, by eyeball estimation, and then hinge, which is what made the Ilizarov fixator so unique rationalize the less than perfect appearance of the final in its ability to correct deformities in a controlled fash• X-ray. "It's not bad" or "it should remodel:' True, there ion. In his early experience, he observed some of the sec• have been attempts by notable surgeons, such as Fried• ondary deformities that arose from mismatching the lo• rich Pauwels and Maurice Mueller, to be more precise in cation of the hinge and the CORA. In his effort to more our planning. Although we may have received training accurately identify the level for the Ilizarov hinge, he de• in the precise repositioning of fracture fragments with rived the CORA method of mechanical and anatomic plates and screws and accurate preoperative planning axis planning described in this text. and templating for hip osteotomies, what has eluded us He quickly realized that the concept of the CORA and until now is a universally applicable lower extremity de• the osteotomy rules were not unique to the Ilizarov de• formity planning system that takes into account the en• vice but much more universally applicable to deformity tire limb, including associated joint compensation and correction by any method. Indeed, with the CORA meth• lever arm considerations: a unified or universal system od, one can understand and plan surgery for any lower that is equally applicable to the diverse range of ages and extremity deformity from the hip to the foot. The gener- al principle of this book is to first analyze, understand, Will the CORA method be supplanted by future tech• and quantify the deformity. Only then should you begin nology? We think not. Even computer-dependent math• to plan your surgical method and approach. Regardless ematical modeling of six-axis deformity correction (see of which type and brand of fixation is selected (plates, Chap. 12) is first dependent on the surgeon to accurate• rods, or external fixator), the basic principles of defor• ly understand, analyze, and quantify the radiographic mity analysis and planning are the same. Failure to ob• deformity. We therefore think that the CORA method serve these principles frequently results in less than per• complements rather than competes with such sophisti• fect alignment and often in secondary deformities that cated deformity correction methods. may be more difficult to correct than the original defor• mities. Ultimately, the surgeon must decide which de• Is this book the final word on the topic? Clearly not. The vice works best in his or her hands. The first step of pre• CORA method is still a work in progress, and there is operative planning, however, is universally required and room to extend its application to the upper extremity, beneficial. Chap. 11 includes a discussion of some of the spine, pelvis, and perhaps even maxillofacial deformity vagaries of selected hardware devices, and it is this chap• correction. It has recently been incorporated into com• ter that will most likely require updating and revision in puter planning software. This book has already been a future edition as new device innovations become avail• lO years in the making, and these other expansions will able. The bulk of the book, however, encompasses prin• have to wait for the second edition. We welcome readers' ciples and concepts that will not change because they are comments, criticisms, and feedback to help us improve based on simple geometry. future editions.

Baltimore, Maryland JOHN E. HERZENBERG The Story Behind This Book and the CORA Method -

My first exposure to orthopaedics was as a medical stu• affect the growth and development of the skeleton. My dent learning physical examination. My patient had a se• teachers at the Hospital for Sick Children, Drs. Norris vere limp, which I attributed to weakness of his gluteus Carroll, Colin Moseley, Mercer Rang, Walter Bobechko, medius. What today I would recognize as an obvious Robert Gillespie, and Robert Salter, provided my initial Trendelenburg's gait, in 1977 was the pivotal event that exposure and understanding of the growth plate and the sparked my interest in orthopaedic surgery. I began to pediatric skeleton. The training I received from them read the works of Rene Caillet (The Biomechanics of during my residency and fellowship prepared me to Joints) and of LA. Kapandji (Physiology ofJoints). Their challenge many well-established practices and beliefs in books made human mechanics easy to comprehend, pediatric orthopaedics. Of all these, I received the great• even for a medical student. With Principles of Deformity est support from Dr. Norris Caroll, who always had faith Correction, I attempt to do the same regarding deformi• in me and invested his time and patience to teach me ty analysis and treatment. meticulous surgical technique and who encouraged me at times of despair. I am grateful to the many great teachers from my ortho• I acknowledge the support of two of pediatric ortho• paedic residency at the University of Toronto. They laid paedics' elder statesmen, Drs. Lynn Staheli and Mihran the foundation for my interest in orthopaedics. Profes• Tachdjian. Dr. Staheli, as editor of the Journal of Pediat• sor Robert Salter set the tone, teaching in a Socratic ric Orthopedics, invited me to write about current tech• manner. Dr. Alan Gross of Mt. Sinai Hospital first taught niques of limb lengthening in 1988 UPO 8:73-92, 1988) me the concept of the mechanical axis of the lower limb and more recently to write an editorial on deformity as well as the importance of preoperative planning for correction in the twenty-first century UPO 20:279-281, osteotomies of the hip and knee. He frequently quoted 2000). Both of these publications helped introduce and Renato Bombelli's Osteoarthritis of the Hip: Classifica• heighten awareness to deformity correction principles. tion and Pathogenesis - The Role of Osteotomy as a The late Dr. Tachdjian involved me in his international• Consequent Therapy (Springer-Verlag, 1983) and Paul ly renowned pediatric orthopaedic review course since Maquet's Biomechanics of the Knee: With Application to 1988 and included my deformity planning method in his the Pathogenesis and the Surgical Treatment of Osteoar• textbooks (Pediatric Orthopedics, 1990; and Atlas of Pe• thritis (Springer-Verlag, 1984), which stimulated me to diatric Orthopedic Surgery, 1994). Dr. Charles Price, who read these books on the biomechanics of the hip and took over this pediatric course, has included deformity knee, respectively. Drs. David MacIntosh and Ian Har• planning by the CORA method as an important theme rington taught me controversial concepts of high tibial of the new course. osteotomies and alignment. Dr. Harrington's book on In November 1983, when I was a third-year ortho• biomechanics (Biomechanics of Musculoskeletal Injury; paedic resident in Toronto, I met Renato Bombelli who Williams & Wilkins, 1982) and his often misunderstood was a visiting professor. Dr. Bombelli was a disciple of article on high tibial osteotomy UBJS 65(2):247-259, Friedrich Pauwels and a contemporary of Maquet, an• 1983] greatly influenced my understanding of concepts other of Dr. Pauwels' disciples. Through their writings, I in this field. Drs. Marvin Tile, Joseph Schatzker, Robert began to understand that complicated joint mechanics McMurtry, and James Kellam are responsible for teach• could be reduced to simple principles. While in Toronto, ing me to think in terms of universal principles rather Dr. Bombelli briefly mentioned the Ilizarov method. than specific surgical techniques. Principles to ortho• This offhand comment sparked my interest in a field to• paedics are like laws to physics: they remain constant, tally unknown in North America. Upon completing my whereas specific operations and techniques come and residency in 1985, I visited Dr. Maurizio Catagni in Italy go. to learn more about the Ilizarov method. The next year, The widest spectrum and complexity of deformity I took my family to Europe and spent 6 months in Italy occur in pediatric orthopaedics in that many conditions and the USSR studying limb reconstruction with exter- nal fixation. I learned that deformities could occur in lowship in Toronto in 1987, I came across an article by multiple planes and that hinges could act as the axis of Dr. Ken Krackow (Adv Orthop Surg 7:69,1983). This ar• correction. I learned to consider not only angulation but ticle introduced me to the concept of joint orientation also translation, rotation, and length when analyzing a angles and was pivotal in my developing the malalign• deformity. I also learned that deformities could be cor• ment test. rected gradually or acutely and that there were virtually With this foundation upon which to build, the CORA no limits to how much angulation could be corrected. method was developed. Placing hinges on the Ilizarov I visited Kurgan three times during the Soviet era, and device involved putting the hinge just below the ring for I am greatly indebted to Professor Gavril Abramovich metaphyseal deformities and at the apex of diaphyseal Ilizarov for the opportunity to study at his institute. Al• deformities. It did not make sense that the hinge should though I learned a great deal from Dr. Ilizarov's lectures, always be the same distance from the ring for all meta• articles, and books, he was personally at his best when physeal deformities. For diaphyseal deformities, we al• examining patients. Physical examination was a skill ways drew two mid-diaphyseal lines and placed the emphasized in my training in Toronto during the annu• hinge at the intersection of the two lines. In the meta• al physical examination courses by Mr. Alan Graham physis, it was not possible to draw a mid-diaphyseal line Aply. Learning Russian facilitated the learning process for the metaphyseal bone segment. I struggled with this and allowed me to speak to the Soviet doctors directly problem until March 1988, when I had to place hinges for without going through interpreters. Many people in a supramalleolar osteotomy for ankle varus where the Kurgan contributed to my education, and some deserve joint line was clearly tilted around the lateral cortex of special mention. Igor Kataev taught me the principle of the joint yet the osteotomy was much more proximal. In• hinges and of oblique plane deformity. Mr. Kataev was stead of placing the hinges just proximal to the distal tib• not a physician but was in charge of the patent office at ial ring, I placed the hinge distal to the ring in what is Ilizarov's institute. Vladimir Shevtsov, Ilizarov's succes• now recognized as a juxta-articular hinge construct (see sor, answered the questions that I would not dare ask Ili• Chap. 11). To my fascination, the osteotomy site correct• zarov. He was direct and not evasive. Victor Makushin's ed with angulation and translation. The osteotomy rules ability to clinically evaluate nonunions was uncanny but were born together with the CORA method. The basic could be divined only by reversing the Socratic method concepts in this book were developed over the next I learned from Dr. Tile and the others in Toronto. Arnold 2 years, based to the greatest extent on the clinical cases Popkov is a master at limb lengthening. He took the mid• I had the privilege and the challenge to treat but also on dle-of-the-road approach, allowing me to learn by an• a potpourri of ideas stimulated by colleagues with sim• swering my own questions and acknowledging when I ilar interests. Most notably, Stuart Green from California hit upon the correct answers. Others helped in a clandes• was my sounding board, especially when it came to post• tine fashion to overcome the cold war Soviet secrecy of traumatic deformities. Together, we solved the mystery the institute. The best example is Dr. Yaakov Odesky, who of the relationship between the planes of angulation and is now in Israel. He allowed me to see treatments and translation. I was privileged to have Dr. Kevin Tetsworth, concepts that no Westerners had seen before. Finally, who has a brilliant mathematical mind, work with me as Galena Dyachkova's openness helped me to understand a fellow between 1989 and 1990. In 1990, we published the basic science of the field of distraction, especially the malalignment test and the first version of the CORA regarding soft tissues. method, although it was not yet called that (Clin Orthop In contrast to the struggle to learn in the USSR, Italy 280:48-64; 65-71). Dr. Natsuo Yasui from Osaka, Japan, presented a refreshing sense of openness. The team, coined the term CORA method, and it stuck. comprised of Roberto Cattaneo, Maurizio Catagni, and The initial concept of writing a book about deformity Angelo Villa in Lecco, Fabio Argnani in Bergamo, and correction originated in 1991 through discussions with Antonio Bianchi-Maiocchi in Milan, welcomed me with Darlene Cooke, who was then a book editor at Williams sincerity, kindness, and warmth and did everything to & Wilkins. The syllabus for the first annual Baltimore help me learn. I will forever be indebted to them. Of Limb Deformity Course served as an outline for the these outstanding teachers, Dr. Catagni is most respon• book. This course began in 1989, with Ilizarov as a fea• sible for my current understanding of deformities. He tured guest speaker, and has continued ever since. The possesses an intuitive understanding of deformities and success of this annual course led me to add more mate• essentially computes a CORA analysis in his head as well rial and to incorporate the concepts of some very inno• as I can on paper. My goal with this book was to codify vative contributors who participated in our course. Ms. Dr. Catagni's intuitive approach into the objective CORA Cooke thought that I would never finish the book be• method that can be performed in a step-by-step fashion cause I was a perfectionist and continued to add new by all. One more important event occurred before all the material every year. In many respects, she was right. On pieces were in place. When I returned home from Italy the other hand, the book was not ready to be finished. and the USSR and began my pediatric orthopaedic fel- There were several concepts that were on the verge of being clarified and that needed to be included in the aged me to continually strive to simplify my concepts to book to make it complete. For example, the six-axis de• make them teachable and practical. He has been my Co• formity correction concepts introduced by Dr. J. Charles Chairman in the Deformity Course and my loyal partner Taylor and the lever arm deformity concepts presented in practice. It is often impossible to separate who origi• by Dr. James Gage. In 1998, Williams & Wilkins and I nated which ideas. Therefore, this book is as much a tes• agreed to drop the book project. Without Ms. Cooke as tament to his work as it is to mine. Second is Anil Bhave, my editor, the external push to complete the book was PT. Mr. Bhave has directed our gait laboratory and gone. I saw 10 years of work to produce this book going served as clinical research coordinator since 1992. He to waste. I decided upon a new strategy: finish the book has contributed immeasurably to my understanding of on our own, and then look for a publisher. With the help gait and dynamic deformities. The rest of the loyal staff of our in-house publishing team, Senior Editor Dori of the MCLLR have also contributed to this book in one Kelly, Medical Illustrator Joy Marlowe, and Multimedia way or another. Kernan Hospital and the Department of Specialist Mark Chrisman, this became a reality. It was Orthopaedics have given me tremendous support and a now time to seek a new publisher. This was easier said wonderful environment for my work during the past than done. I could not get an American publishing com• 14 years. lowe them all a great debt of gratitude. pany to share my vision of the importance of this book. Finally, I would like to acknowledge my family. My The project was finally salvaged by Dr. Joachim Pfeil, my wife, Wendy Schelew, and our children, Benjamin, friend and colleague from Wiesbaden, Germany. Dr. Jonathan, and Aviva, have stood beside me all these years Pfeil has promoted the CORA method in Europe for and tolerated my single-minded devotion to completing years and has co-authored an article on this subject in this project. This book is a testimony to their patience, the German language. He introduced me to Gabriele love, and support. It is also a testimony to my parents. Schroeder, Senior Medical Editor for Springer-Verlag in From my mother, a school teacher, I inherited ambition, Heidelberg in April 2000. This book has finally come to love for the life sciences, and my skill of teaching. My fruition with the enthusiastic support of Springer-Ver• greatest sadness is that my father, who was my role lag. model, will never see this book. He was a holocaust sur• This history and my acknowledgments would not be vivor who at age 38 (when I was 10) completed his PhD. complete without mentioning a few more people. First is He was a mechanical engineer who specialized in metal• Dr. John E. Herzenberg, without whose editorial assis• lurgy, working as a research scientist in Ottawa, Canada, tance this book would not have been possible. Dr. Her• until his untimely death from cancer at age 54. My father zenberg has been my colleague and friend since we were was a Renaissance man who spoke nine languages and fellows together in Toronto in 1985 and 1986. We contin• who stimulated my interest in many fields. Most of all, he ued to correspond and collaborate at a distance until taught me to think critically. He grew up approximately 1991, when Dr. Herzenberg moved to Maryland to help 100 miles from Kurgan in the Soviet Union. He never got achieve our common dream of developing a limb to see me complete my residency, raise a family, learn lengthening and deformity correction center. The Mary• Russian, or achieve the publication of this book. It is to land Center for Limb Lengthening & Reconstruction his memory that I dedicate this book. (MCLLR) was born. John has been a valuable sounding board for my ideas for more than 10 years. He encour- Baltimore, Maryland DROR PALEY Contributing Authors

I am indebted to the chapter contributors, without MICHAEL MONT,MD whose input this book would be deficient. These select Co-Director, Joint Preservation and Replacement authors were invited because of their original ideas and Center, Sinai Hospital contributions to the field of deformity correction. The Baltimore, MD numbers and titles of the chapters to which they con• CHAPTER 23: Total Knee Replacement and Total tributed are listed below their names. For the consis• Hip Replacement Associated with tency of this book, I have edited and added to each of Malalignment these chapters to better incorporate these authors' ideas. I especially thank my partner, John E. Herzenberg, who MICHAEL SCHWARTZ, PHD in addition to contributing as an author to two chapters Director of Bioengineering Research in the book helped me to develop and also originated Gillette Children's Hospital, St. Paul, MN many of the deformity concepts presented herein. John Assistant Professor of Orthopaedics acted as this book's content editor for both the text and University of Minnesota the figures. This laborious task has refined and clarified Minneapolis, MN the theoretical and practical principles that this book CHAPTER 22: Dynamic Deformities and Lever Arm presents. Considerations DROR PALEY, MD, FRCSC SHAWN C. STANDARD, MD Pediatric Orthopedic Surgeon ANIL BHAVE,PT The International Center for Limb Lengthening, Director of Rehabilitation and Gait Laboratory Sinai Hospital The International Center for Limb Lengthening, Baltimore, MD Sinai Hospital CHAPTER 12: Six-Axis Deformity Analysis Baltimore, MD and Correction CHAPTER 21: Gait Considerations J. CHARLES TAYLOR,MD JIM GAGE,MD Orthopedic Surgeon, Specialty Orthopedics Medical Director, Gillette Children's Hospital Memphis, TN St. Paul,MN CHAPTER 12: Six-Axis Deformity Analysis Professor of Orthopaedics, University of Minnesota and Correction Minneapolis, MN CHAPTER 22: Dynamic Deformities and Lever Arm KEVIN TETSWORTH,MD Considerations Director of Orthopaedics, Royal Brisbane Hospital Brisbane, Queensland, Australia JOHN E. HERZENBERG, MD, FRCSC CHAPTER 13: Consequences of Malalignment Co-Director, The International Center for Limb Lengthening, Sinai Hospital Chief of Pediatric Orthopedics, Sinai Hospital Baltimore, MD CHAPTER 9: Rotation and Angulation-Rotation Deformities CHAPTER 12: Six-Axis Deformity Analysis and Correction CHAPTER 20: Growth Plate Considerations Senior Editor DORI KELLY,MA

Medical Illustrators JOY MARLOWE, MA MARY GOLDSBOROUGH,MA STACY LUND, MA

Multimedia Specialist MARK CHRISMAN,Bs Contributing Authors _

Drs. Dror Paley, MD, FReSe, and John E. Herzenberg, MD, FRese

DR 0 R PAL E Y was born in Tel Aviv, Israel, in 1956 and land Center for Limb Lengthening & Reconstruction in moved to North America in 1960. He grew up in Ottawa, Baltimore. Canada, for most of his youth. He graduated from the In 1989, Dr. Paley organized and inaugurated ASAMI• University of Toronto Medical School in 1979, complet• North America, the limb lengthening and reconstruc• ed his internship in surgery at the Johns Hopkins Hos• tion society, and served as the first president of this new pital in Baltimore in 1980, and completed his ortho• subspecialty society. The first AS AMI meeting also coin• paedic surgery residency at the University of Toronto cided with the first Baltimore Limb Deformity Course. Hospitals in 1985. After completing a hand and trauma The publication of this book will debut at the 11th An• surgery fellowship at Sunnybrook Hospital in Toronto nual Baltimore Limb Deformity Course and will be the and the AOA-COA North American Traveling Fellow• manual of this internationally recognized course. Dr. ship, he spent 6 months studying limb lengthening and Paley has been active in teaching limb reconstruction reconstruction techniques in Italy and the USSR and worldwide (more than 50 countries to date). He lectures then completed a pediatric orthopaedics fellowship at and reads in six languages (English, Hebrew, French, the Hospital for Sick Children in Toronto. This is where Italian, Spanish, and Russian). he began his limb lengthening and deformity correction In 1990, Dr. Paley was awarded a Gubernatorial Cita• experience. In November 1987, he organized the first in• tion for Outstanding Contributions in Orthopaedic Sur• ternational meeting on the Ilizarov techniques with Dr. gery by the Governor of Maryland. He was also awarded Victor Frankel, at which Professor Gavril Abramovich the Pauwels Medal in Clinical Biomechanics by the Ger• Ilizarov shared his knowledge in the United States for man-Speaking Countries Orthopaedic Association in the first time. The same month, Dr. Paley joined the or• 1997. His most cherished award, however, is the Ortho• thopaedic faculty of the University of Maryland. Many paedic Residents Teaching Award, which he has received of the original concepts for this book were developed on more than one occasion. Dr. Paley was the Chief of during the next 3 years. In 1991, Drs. John E. Herzenberg Pediatric Orthopaedics at the University of Maryland and Kevin Tetsworth joined Dr. Paley to form the Mary- until June 2001 and was Professor of Orthopaedic Sur- gery at the University of Maryland Medical System until JOHN E. HERZENBERG was born in 1955 in Spring• October 2003. He is well published in the peer-reviewed field, Massachusetts. At the age of 15, he left to attend literature and has also authored and edited several high school at Kibbutz Kfar Blum in Israel. He studied books and numerous book chapters. He considers Prin• medicine at Boston University and completed his in• ciples of Deformity Correction to be his thesis and his ternship in surgery at Albert Einstein-Montefiore Hos• most important academic achievement. On July 1,2001, pitals in New York. In 1985, he completed his residency Dr. Paley, together with Drs. John Herzenberg, Michael in orthopaedic surgery at Duke University in Durham, Mont, and Janet Conway, opened the Rubin Institute for NC, where he was drawn toward pediatric orthopaedics Advanced Orthopedics at Sinai Hospital, in Baltimore. by his mentor and chief, Dr. J. Leonard Goldner. Dr. Paley is the Director of this new orthopaedic center Dr. Herzenberg completed a pediatric orthopaedic and Co-Director of The International Center for Limb fellowship at the Hospital for Sick Children in Toronto, Lengthening. where he first met Dr. Dror Paley. He was on the faculty at the University of Michigan in Ann Arbor for 5 years, Dr. Paley is married to Wendy Schelew, and they have with Dr. Robert Hensinger. Dr. Herzenberg traveled to It• three children (Benjamin, Jonathan, and Aviva). For fun, aly' USSR, and Baltimore to study limb reconstruction he enjoys personal fitness, skiing, scuba diving, biking, techniques. This began his active collaboration with Dr. and studying history. Paley, which resulted in a joint vision to set up a nation• al center devoted to limb reconstructive surgery. In 1991, Dr. Herzenberg joined Drs. Paley and Tetsworth on the full-time faculty of the University of Maryland in Balti• more to establish the Maryland Center for Limb Length• ening & Reconstruction. Dr. Herzenberg has traveled extensively, teaching the Ilizarov techniques and the CORA method of deformity planning. He has served as president of ASAMI-North America and is active as a volunteer surgeon with Oper• ation Rainbow and Operation Smile, participating in yearly missions to Central and South Americas. He was awarded both the AOA-COA North American and ABC Traveling Fellowships. He is extensively published in many areas of pediatric orthopaedics and limb recon• struction. Dr. Herzenberg was Professor of Orthopaedic Surgery at the University of Maryland Medical System until October 2003 and is currently Co-Director of the International Center for Limb Lengthening and Chief of Pediatric Orthopedics at Sinai Hospital.

Dr. Herzenberg is married to Merrill Chaus, and they have three daughters (Alexandra, Danielle, and Britta• ny). For fun, he enjoys personal fitness and Bible study. Contents

1 Normal lower limb Alignment 4 Frontal Plane Mechanical and Joint Orientation ... 1 and Anatomic Axis Planning ... 61

Mechanical and Anatomic Bone Axes . . . Mechanical Axis Planning ...... 61 Joint Center Points ... 5 Anatomic Axis Planning ...... 63 Joint Orientation lines 5 Determining the CORA by Frontal Plane Mechanical Ankle...... 5 and Anatomic Axis Planning: Step by Step. 64 Knee...... 5 Part I: CORA Method, Tibial Deformities. . . . . 64 Hip...... 8 Mechanical Axis Planning Joint Orientation Angles and Nomenclature ...... 8 ofTibial Deformities . . 64 Mechanical Axis and Mechanical Axis Deviation (MAD). 10 Anatomic Axis Planning Hip Joint Orientation . 12 of Tibial Deformities. . 74 Knee Joint Orientation ...... 13 Part II: CORA Method, Femoral Deformities . 76 Ankle Joint Orientation ...... 16 Mechanical Axis Planning References...... 17 of Femoral Deformities 76 Anatomic Axis Planning of Femoral Deformities 81 2 Malalignment and Malorientation Multiapical Deformities . . . . 97 in the Frontal Plane ... 19

Malalignment ...... · . 19 5 Osteotomy Concepts MAT ...... · . 23 and Frontal Plane Realignment ... 99 Malorientation of the Ankle and Hip . . 28 Orientation of the Ankle and Hip in the Frontal Plane . 28 Angulation Correction Axis (ACA) ...... 99 MOT of the Ankle ...... 28 Bisector Lines ...... 101 MOT of the Hip. . 30 Relationship of Osteotomy Type to Bisector Lines. 101 References...... 30 Osteotomy Rules ...... 102 Translation and length Displacement atthe Osteotomy Line ...... 105 3 Radiographic Assessment Opening Wedge Osteotomy. . 106 ofLower Limb Deformities ... 31 Closing Wedge Osteotomy...... 106 Focal Dome Osteotomy...... 112 Knee ...... 31 Clinical Choice of Osteotomy Level and Type 114 Ankle and Hip ...... 40 Multiapical Osteotomy Solutions . . . 140 Radiographic Examination in the Sagittal Plane .... 46 Single Osteotomy Solutions...... 140 Knee ...... 46 Multiple Osteotomy Solutions. 142 Ankle...... 51 References ...... 154 Hip ...... 53 Radiographic Examination in One Plane When There Is a Deformity Component 6 Sagittal Plane Deformities ... 155 in the Other Plane . . 57 References...... · . 60 Sagittal Plane Alignment in the lower Limb . 155 Sagittal Plane MAT ...... 157 Knee Joint Malorientation ...... 157 .. Contents

Overall Sagittal Plane MOT ...... 159 9 Rotation and Angulation-Rotation Deformities Knee Level Sagittal Plane MOT .... . 163 ... 235 Overall Sagittal Plane MOT of the Ankle. 163 Ankle Level Sagittal Plane MOT of the Ankle 165 Sagittal Plane Anatomic Axis Planning Clinical Assessment of Rotation Deformities . . 235 ofTibial Deformity Correction . . . 165 Level of Osteotomy for Rotation Deformities . . 243 Sagittal Plane Anatomic Axis Planning Frontal Plane Preoperative Planning of Femoral Deformity Correction. . 169 for Rotation Deformities ...... 249 Osteotomies in the Sagittal Plane. 169 Factoring in Rotation for Mechanical Axis References ...... 174 Planning of the Femur ...... 250 Frontal Plane Anatomic Axis Planning for Rotation Deformities ...... 252 7 Oblique Plane Deformities ... 175 Combined Angulation and Rotation Deformities . . . 252 Locating the Inclined Axis ...... 259 Plane of Angulation . . 175 Locating the Inclined Osteotomy .... 261 Graphic Method. . . . . 179 Inclined Focal Dome Osteotomy ...... 266 Graphic Method Error .. 183 Clinical Examples...... 266 Base ofTriangle Method ...... 183 References ...... 268 Axis of Correction of Angulatory Deformities . 186 Definition of Angulation. . 193 References ...... 193 10 Length Considerations: Gradual Versus Acute Correction of Deformities ... 269

8 Translation and Angulation-Translation Length Considerations for Angular Corrections. . 276 Deformities ... 195 Neurovascular Structures ...... 278 Nerves ...... 282 Translation Deformity ...... · .. 195 Vessels ...... · 287 Two Angulations Equal One Translation . . · .. 200 Muscles, Tendons, and Fascia · 287 Translation Effects on MAD ... · .. 200 Ligaments .. . · 287 Osteotomies for Correction Skin .... . · 288 ofTranslation Deformity . . . 202 References ...... 289 Combining Angulation and Translation . . · 203 a-t Deformities and MAD ..... · 205 Graphic Analysis of a-t Deformities . . · 205 11 Ha rdware and Osteotomy Considerations Type 1: Angulation and Translation ... 291 in the Same Plane...... 205 Anatomic Plane Deformity . . . . · 205 Choice of Hardware. . . . · 291 Oblique Plane Deformity ...... 208 Patient Age ...... · 291 Type 2: Angulation and Translation Osteotomy Types. . . · 291 in Different Planes ...... · 209 Closing Wedge Osteotomy. · 291 Anatomic Plane Deformity with Angulation Opening Wedge Osteotomy . . . . . · 297 and Translation 90° Apart ...... 209 Angulation-Translation Osteotomy. · 300 Oblique Plane Deformity with Angulation Dome Osteotomy. · 300 and Translation 90° Apart ...... 211 Hardware ...... · 300 One Anatomic and One Oblique Plane Plate Fixation ...... · 300 Deformity with Angulation and Translation Intramedullary Nails .. . . 307 in Different Planes Less Than 90° Apart ... 214 External Fixation . . .. 346 Oblique Plane Deformity with Angulation Order of Correction. . . · 383 and Translation Less Than 90° Apart. . 216 Lever Arm Principle .. · 387 Osteotomy Correction of a-t Deformities . . 218 Method of Osteotomy · 389 Osteotomy Correction of Angulation References ...... · 410 and Translation in the Same Plane .. 219 Correction of Angulation and Translation in Different Planes ...... 222 Multilevel Fracture Deformities...... 231 References ...... 234 Contents

12 Six-Axis Deformity Analysis and Correction , 6 Realign ment for Mono-com partment ... 411 Osteoarthritis of the Knee ... 479

The Taylor Spatial Frame Fixator. . · 412 Deformities in Association with MCOA . . 479 Introduction ...... · 412 Bone Deformities . . . 479 Modes of Correction. . · 416 Joint Deformities...... 479 Planning Methods . . . · 418 Customized HTO ...... 485 Fracture Method . . · 418 Malalignment Test form Mono-Compartment CORAgin Method .. .420 Osteoarthritis...... 485 CORAsponding Point Method ...... 422 Femoral versus Tibial Osteotomy...... 485 Virtual Hinge Method ...... 424 Level of Center of Rotation of Angulation. . 492 Line of Closest Approach (LOCA) . · .426 Magnitude of Correction ...... 492 Taylor Computer-assisted Design Type of Osteotomy and Fixation ...... 494 (CAD) Software...... · . 429 Considerations...... 495 Reference Concepts ...... 429 Medial Compartment Osteoarthritis Rate of Correction and Structure at Risk (SAR). 430 Varus plus Medial Collateral Parallactic Homologues of Deformity: Ligament Pseudo laxity ...... 495 Proximal versus Distal Reference Perspective . . . 433 Medial Compartment Osteoarthritis References ...... 436 Varus plus Lateral Collateral Ligament Pseudo laxity ...... 497 Medial Compartment Osteoarthritis 13 Consequences of Malalignment ... 437 Varus plus Rotation Deformity...... 497 Medial Compartment Osteoarthritis Static Considerations. . . . · 438 Varus plus Hyperextension...... 499 Dynamic Considerations . . .440 Medial Compartment Osteoarthritis Rotational Considerations . · 443 Varus plus Fixed Flexion Deformity. .. 502 Animal Laboratory Models .444 Medial Compartment Osteoarthritis Cadaver Laboratory Models .444 Varus plus Lateral Subluxation...... 503 Clinical Longitudinal Studies . . .446 Medial Compartment Osteoarthritis Summary. · 448 Varus plus Medial Plateau Depression. . . 503 References ...... 448 Lateral Compartment Osteoarthritis (LCOA) . 504 References ...... 507

14 Malalignment Due to Ligamentous Laxity ofthe Knee ... 4S 1 17 Sagittal Plane Knee Considerations ... 509

LCL Laxity. · . 451 Frontal Plane Knee Considerations . . · . 509 MCL Laxity · . 462 FFD ofthe Knee ...... · . 509 References · .464 HE and Recurvatum Knee Deformity. . · . 538 Knee Extension Contracture . . . . · . 563 Patella Baja and Alta . · . 568 1 S Knee Joint Li ne Deformity References ...... · . 569 Sources of Malalignment ... 465

References ...... 478 18 Ankle and Foot Considerations ... 571

Frontal Plane Ankle Deformities ...... 574 Supramalleolar Osteotomy for Varus and Valgus Deformities...... 579 Sagittal Plane Ankle Deformities ...... 581 Supramalleolar Osteotomy for Recurvatum and Procurvatum Deformities ...... 585 Compensatory Mechanisms and Deformities: Mobile, Fixed, and Absent...... 596 DIll Contents

Specific Ankle Malalignment Deformities...... 611 Growth Plate Considerations Relative Ankle Fusion Malunion ...... 611 to Deformity...... 705 Flattop Talus Deformity...... 611 Cause of Deformities ...... 705 Ball and Socket Ankle Joint ...... 619 Developmental Angular Deformities...... 705 Overcorrected Clubfoot and Other Lateral Angular Deformities: Gradual Correction Translation Deformities of the Heel. . . · 623 by Hemi-epiphysiodesis ...... 708 Posterior Tibial Tendon Dysfunction ...... 627 Planning for Hemi-epiphyseal Stapling for Completely Stiff Foot Treatment Angular Correction at the Knee in Children . 708 by Supramalleolar Osteotomy. . . · 627 Multiplier Method for Timing Partial Growth Arrest . . . · 630 Hemi-epiphyseal Stapling for Correction Malunion of Fibula .... · 630 of Angular Deformity ...... 710 Ankle Contractu res . . . 630 Multiplier Method for Calculating References ...... 645 When to Remove Hemi-epiphyseal Staples in Young Children. . 710 References ...... 715 19 Hip Joint Considerations ... 647

Limb in Neutral Alignment to Pelvis, No Intra- 21 Gait Considerations ... 717 or Periarticular Limitation of Range of Motion . 647 Varus Deformity...... 647 Gait Considerations in Association Valgus Deformity ...... 653 with Lower Limb Deformities . · ... 717 Limb in Neutral Alignment to Pelvis, Sacrifice ofJoint Motion .... · . 717 Intra-articular Limitation of Range of Motion . . . 653 Fixed Joint Position ...... · 718 Varus Deformity...... 653 Abnormal Loading ofJoints ... · 721 Valgus Deformity ...... 653 Compensatory Mechanisms . . . . · 721 Lesser Trochanter Considerations ...... 656 Frontal Plane Malalignment. . . . · 722 Greater Trochanter Considerations ...... 660 Distal Tibia Varus or Valgus...... · 722 Sagittal Plane Considerations ...... 672 Varus Deformity at the Knee . · . 725 Deformities of the Head and Neck of the Femur. . . . 673 Valgus Deformity of the Knee...... · 732 Pseudo-subluxation of the Hip ...... 684 Varus or Valgus Deformity of the Deformities Due to Hip Ankylosis and Arthrodesis Proximal Femur. . . . . · 735 between the Femur and the Pelvis. . . . 686 Sagittal Plane Deformity...... · 738 Pelvic Support Osteotomy . . 689 Ankle Equinus Deformity. . . · 739 References ...... · 694 Excessive Ankle Dorsiflexion or Calcaneus Deformity . . . · 743 Ankle Arthrodesis Deformities. · 744 20 Growth Plate Considerations ... 695 Anterior Translation of the Foot . · . 746 Fixed Flexion Deformity of the Knee. . · ... 749 LLD ...... 695 Recurvatum of the Knee...... · .. 751 Predicting LLD ...... 695 Hip Flexion Deformity...... · .. 751 Multiplier Method . . . 697 Hip Fusion...... · . 752 Additional Growth Databases...... 701 Rotational Malalignment ...... · .. 753 Relationship of Multipliers for Boys Leg Length Considerations...... · 755 to Multipliers for Girls...... 701 References ...... · ... 758 Development of the Multiplier ...... 702 Limb Length Discrepancy Prediction Formulae ...... 702 22 Dynamic Deformities and Lever Arm Prediction of Limb Length Discrepancy Considerations ... 761 at Skeletal Maturity Using the Multiplier Growth-Remaining Method for Cases Levers ...... · 761 of Postnatal Developmental Discrepancy. . 702 Mechanical Advantage. · 763 Percentage of Total Bone Growth from the Moments and Motions . · 763 Distal Femur and Proximal Tibia ...... 703 Redundancy . . . . · 765 Using the Multiplier Method to Calculate Normal Function . . . . · 766 Timing for Epiphysiodesis. . . . 703 Introduction ...... 766 Growth Prediction Controversies...... 704 Mechanics of the Ankle: First Rocker...... 766 Contents _

Mechanics of the Ankle: Second Rocker ..... 766 Mechanics of the Ankle: Third Rocker ...... 767 Force Production and Compensation . . . · 768 Pathological Function . · 768 Short Lever Arm ...... · 768 Flexible Lever Arm. . . · 771 Malrotated Lever Arm. . . · 772 Unstable Fulcrum . . . . . · 773 Positional Abnormalities · 773 References ...... · 775

23 TKR and Total Hip Replacement Associated with Malalignment ... 777

Normal Alignment Versus Malalignment in Association with Total Knee Arthroplasty. · 777 Management of Fixed Soft Tissue Deformities . · 780 Clinical Assessment ...... · 780 Radiographic Assessment ...... · 780 Intraoperative Placement of Components and Consequences of Malalignment . . . . · 782 Varus Deformities ...... · 783 Valgus Deformities...... · 783 Flexion Deformity and Contracture · . 783 Recurvatum Deformity...... · . 786 Peroneal Nerve Palsy and Operative Release . · . 786 Trial Reduction after Ligamentous Balancing. · . 786 Summary of Soft Tissue Balancing Principles . . ... 787 Extra-articular Bone Deformities ...... 788 Total Knee Arthroplasty after Failed HTO . . . . 792 Preoperative Assessment ...... 792 Proximal Tibial Osteotomy-Related Problems forTKR ...... 793 Proximal Femoral Deformities and Total Hip Arthroplasty . . . · 794 Preoperative Planning ...... · 796 Soft Tissue Balancing. . . . . · 797 Bone Deformity Correction. · 797 References ...... · 797

Subject Index .. . 799 Glossary

a anatomic LOCA line of closest approach A anterior LON lengthening over nail ACA angulation correction axis LPFA lateral proximal femoral angle ACL anterior cruciate ligament m mechanical AOTA anterior distal tibial angle M medial aJCO anatomic axis to joint center distance MAD mechanical axis deviation aJCR anatomic axis: joint center ratio MAT malalignment test aJEO anatomic axis to joint edge distance MCL medial collateral ligament aJER anatomic axis:joint edge ratio MCOA medial compartment osteoarthritis aLOFA anatomic lateral distal femoral angle MOA mid-diaphyseal angle AMA anatomic-mechanical angle mLOFA mechanical lateral distal femoral angle AP anteroposterior (for radiograph) MM medial malleolus aPPTA anatomic posterior proximal tibial angle mMOFA mechanical medial distal femoral angle ASIS anterior superior iliac spine MNSA medial neck shaft angle a-t angulation-translation MOT malorientation test CORA center of rotation of angulation MPFA medial proximal femoral angle 0 distal MPTA medial proximal tibial angle OAA distal anatomic axis NSA neck shaft angle OMA distal mechanical axis P posterior (when used in conjunction with F femur A for anterior, M for medial, and L for lateral) FAN fixator-assisted nailing P proximal FFO fixed flexion deformity PAA proximal anatomic axis GRV ground reaction vector POFA posterior distal femoral angle HE hyperextension PPFA posterior proximal femoral angle HTO high tibial osteotomy PMA proximal mechanical axis IMN intramedullary nail PPTA posterior proximal tibial angle JLCA joint line convergence angle SA surface area L lateral SAR structure at risk LAT lateral (for radiographic view only) SCFE slipped capital femoral epiphysis IBL longitudinal bisector line SO standard deviation LCL lateral collateral ligament T tibia LCOA lateral compartment osteoarthritis tBL transverse bisector line LOTA lateral distal tibial angle TKR total knee replacement LLO limb length discrepancy WBF weight-bearing force