Surgical Exposures in Orthopaedics (5th Edition) PDF

Stanley Hoppenfeld, M.D. Clinical Professor of Orthopaedic Surgery Albert Einstein College of Medicine Attending Physician Jack D. Weiler Hospital of the Albert Einstein College of Medicine Montefiore Hospital and Medical Center Bronx, New York Piet de Boer, M.A., F.R.C.S. Visiting Lecturer University of Rijeka Medical School Department of Anatomy Croatia CEO Medical Education Consultants GmbH Zurich, Switzerland Richard Buckley, M.D., F.R.C.S.C. Associate Professor of Orthopaedic Traumatology University of Calgary Head, Orthopaedic Trauma Department of Surgery Division of Orthopaedics Foothills Hospital Calgary, Alberta, Canada Illustrations by Hugh A. Thomas 2 Surgical Exposures in Orthopaedics The Anatomic Approach Fifth Edition Stanley Hoppenfeld Piet de Boer Richard Buckley Illustrations by Hugh A. Thomas 3 Acquisitions Editor: Brian Brown Editorial Coordinator: Dave Murphy Marketing Manager: Daniel Dressler Production Project Manager: Bridgett Dougherty Art Director: Elaine Kasmer Artist/Illustrator: Hugh A. Thomas Manufacturing Coordinator: Beth Welsh Prepress Vendor: Aptara, Inc. 5th edition Copyright © 2017 Wolters Kluwer Copyright © 2009 Lippincott Williams & Wilkins, Copyright © 2003 Lippincott Williams & Wilkins, Copyright © 1994 J.B. Lippincott Company, Copyright © 1984 J.B. Lippincott Company. All rights reserved. This book is protected by copyright. No part of this book may be reproduced or transmitted in any form or by any means, including as photocopies or scanned-in or other electronic copies, or utilized by any information storage and retrieval system without written permission from the copyright owner, except for brief quotations embodied in critical articles and reviews. Materials appearing in this book prepared by individuals as part of their official duties as U.S. government employees are not covered by the above- mentioned copyright. To request permission, please contact Wolters Kluwer at Two Commerce Square, 2001 Market Street, Philadelphia, PA 19103, via email at [email protected], or via our website at lww.com (products and services). 9 8 7 6 5 4 3 2 1 Printed in China Library of Congress Cataloging-in-Publication Data Names: Hoppenfeld, Stanley, 1934- author. | De Boer, Piet, author. | Buckley, Richard (Richard Eric), 1958- author. Title: Surgical exposures in orthopaedics : the anatomic approach / Stanley Hoppenfeld, Piet de Boer, Richard Buckley ; illustrations by Hugh A. Thomas. Description: Fifth edition. | Philadelphia : Wolters Kluwer, | Includes bibliographical references and index. Identifiers: LCCN 2016022861 | ISBN 9781496309471 Subjects: | MESH: Orthopedic Procedures–methods | Anatomy, Regional 4 Classification: LCC RD732 | NLM WE 168 | DDC 617.5–dc23 LC record available at https://lccn.loc.gov/2016022861 This work is provided “as is,” and the publisher disclaims any and all warranties, express or implied, including any warranties as to accuracy, comprehensiveness, or currency of the content of this work. This work is no substitute for individual patient assessment based upon healthcare professionals’ examination of each patient and consideration of, among other things, age, weight, gender, current or prior medical conditions, medication history, laboratory data and other factors unique to the patient. The publisher does not provide medical advice or guidance and this work is merely a reference tool. Healthcare professionals, and not the publisher, are solely responsible for the use of this work including all medical judgments and for any resulting diagnosis and treatments. Given continuous, rapid advances in medical science and health information, independent professional verification of medical diagnoses, indications, appropriate pharmaceutical selections and dosages, and treatment options should be made and healthcare professionals should consult a variety of sources. When prescribing medication, healthcare professionals are advised to consult the product information sheet (the manufacturer’s package insert) accompanying each drug to verify, among other things, conditions of use, warnings and side effects and identify any changes in dosage schedule or contraindications, particularly if the medication to be administered is new, infrequently used or has a narrow therapeutic range. To the maximum extent permitted under applicable law, no responsibility is assumed by the publisher for any injury and/or damage to persons or property, as a matter of products liability, negligence law or otherwise, or from any reference to or use by any person of this work. LWW.com 5 Dedication To my wife Norma, my sons Jon-David, Robert, and Stephen, and my parents Agatha and David, all in their own special way have made my life full and made this book possible. S.H. To my wife Suzi, my three children James, Kate and Jan and my two grandchildren Rowan and Finn P.de B. To my wife Lois, who organizes my “whole” life and makes it manageable, whom I respect greatly, and my two children, Shannon and Andrew. R.B. 6 Preface One of the first pieces of advice given to one of the authors just before publication of the first edition of this book was not to spend too much time on the preface. He was assured that “few if any people read prefaces.” So why then create another preface for the fifth edition? The answer must be to inform potential readers of the changes that have been made—why they were made and what is in these changes for the reader. The changes that have been made fall into two categories—content and format. The first edition of his book was printed in the United States on a classical printing press. All subsequent editions have been electronic and about 50% of sales of the fourth edition were in the form of an electronic book. Research has shown1 that although younger surgeons generally prefer electronic books, large numbers of them still like a printed copy. One respondent commented that she found “navigating a printed book easier than navigating an electronic one.” We have therefore decided to make the fifth edition available as a single package—electronic and printed. One of the continuing successes of the book has been the diagrams. The ability of well-drawn diagrams to convey three-dimensional images is remarkable. Videos of surgical approaches, which are now freely available on YouTube, are often disappointing. Videos shot during live surgery with a single camera often fail to show what the viewer needs to see. The fifth edition includes videos of 17 surgical approaches. The videos were shot in HD with three different cameras on specially prepared cadaveric material. When the video is not perfectly clear we have included diagrams from the book using a split screen technique. In this way we hope to eliminate the lack of clear three-dimensional clarity that plagues most surgical approach videos. The common theme in the evolution of surgical appro-aches in orthopaedics and traumatology over the past 32 years since the publication 7 of the first edition of the book has been the development of minimally invasive surgery. There have been two major drivers for this process— preservation of as much blood supply to the fracture site and creating as little soft tissue damage as possible to facilitate patient recovery following surgery. The first edition of this book focused on subperiosteal dissection—the classic concept of orthopaedics surgery in the 1960s and 70s—“get to bone and stay there.” Subperiosteal dissection ensured that neighboring soft tissues were not damaged but came at a price—the destruction of local blood supply. The second edition of the book abandoned subperiosteal dissection except in exceptional circumstances (i.e., stripping supinator off the proximal radius) in favor of epiperiosteal dissection where the periosteum is preserved. The third edition introduced arthroscopy, which by that time had almost completely replaced open knee and much open shoulder surgery. The approaches for open menisectomy are still described in this edition reflecting the need in certain developing countries but will almost certainly be excluded from the sixth edition. The fourth edition introduced minimally invasive approaches to the proximal humerus, proximal tibia, and distal tibia as well as minimally invasive spinal approaches. What then caused us to change the contents of the book? First, our readers told us that certain existing approaches needed updating and clarification. The approaches needed for emergency decompression of a compartment syndrome of the lower leg and forearm have been enlarged and updated. We realize that this surgery needs to be performed as quickly as possible and may be done by junior surgeons who need as much help as they can get. Fixation of distal radial fractures has become routine in many countries and a classic approach has been added replacing the lower end of the AK Henry approach to the whole radius that was present in previous editions. The advent of routine CT scanning of tibial plateau injuries has greatly clarified the fracture anatomy of these difficult injuries. The appreciation of the posterior elements in these injuries has led to the creation of two new surgical approaches to the tibial plateau—the posterior and posterolateral approaches. Although acetabular surgery remains a highly specialized field that should only be done by experts or learners under expert supervision, we were aware that existing descriptions of the ilioinguinal approach were inadequate. This approach has therefore been revised to show the key 8 points especially the iliopectineal fascia—a structure that has never been adequately illustrated. The flip osteotomy of the greater trochanter described in the fourth edition had been updated to show the step technique and the surgical dislocation of the hip has been included for the first time. The lateral approach to the metatarsophalangeal joint of the hallux has been added to complement the existing dorsal and dorsomedial approaches. After much deliberation a minimally invasive anterior approach to the hip joint had been included. The literature has been confusing with regard to long-term benefit to the patient of minimally invasive hip surgery and disturbing articles have been published with regard to malposition of implants. This approach however seems to be well established and patients do seem to recover faster—hence its inclusion. Finally the whole text has been revised and numerous small corrections made. This would have been impossible without the invaluable help of Dr. Peter S. Saubermann, facilitator in the ORTP, University of Basel, Switzerland who has painstakingly examined every line of text and every diagram and who has suggested invaluable changes. The strength of this book remains what it has been since its inception —clear descriptions of surgical approaches complemented by diagrams made from the point of view of the surgeon. The classical approaches remain its most popular feature. Surgeons all around the world sometimes operate with a nurse holding the book open at a key diagram. We believe that the key to safe surgery is a sound knowledge of anatomy. Paradoxically as approaches become smaller and smaller the need for anatomical knowledge becomes greater. We feel therefore that this book with its title, Surgical Exposures in Orthopaedics—The Anatomic Approach, is more relevant today than it has ever been. 1. DE BOER PG, FOX R. Changing Patterns of Life Long Learning: A Study in Surgeon Education. Stuttgart: Thieme; 2012. 9 Preface to the Fourth Edition Surgical Exposures in Orthopaedics—The Anatomic Approach was first published in 1984, 25 years ago. The standard surgical approach textbooks at the time were out of date and the principle of linking surgical anatomy to surgical approaches using incisive text and wonderfully clear diagrams (then in black and white) was greeted favorably by orthopaedists and trauma surgeons around the world. Throughout its history, this text has remained the number one best seller in its field. It has been translated into five languages and is extensively used around the world on all five continents. On many occasions, while travelling around the world to teach, the authors have been thanked by residents who have reported how the book has helped them, often in difficult and emergency situations when working either alone or poorly supervised. It is also clear that residents particularly value those classical surgical approaches first described by A.K. Henry in his book on extensile approaches. Why, then, produce a fourth edition? Standard textbooks need to change to reflect those changes that occur within their sphere of interest. The difficulty with this is to differentiate between genuine and permanent changes in the practice of orthopaedics. The young surgeon must be presented with the subject in what can only be described as “the fashion of the time” that occurs in all branches of medicine, especially orthopaedics. In the first edition of the book, great emphasis was given to the concept of subperiosteal dissection. Subperiosteal dissection ensured that the surgical approach did not damage vital structures close to the bone, but the sacrifice was significant devitalization of the bone and its surrounding soft tissues. The preservation of the blood supply to the area to be exposed has been a consistent theme in the past 24 years. The second edition of the book saw abandonment of the concept of subperiosteal dissection and the establishment of epi-periosteal planes for surgical use. Minimal access surgery has been present in orthopaedic surgery for many years. Intramedullary nailing, through a closed technique, did not 10 expose the fracture site and preserved the fracture hematoma. Similarly, external fixation can be seen as an attempt to provide stability to a fracture site, while preserving the fracture hematoma and the natural healing processes that occur around the fracture. Arthroscopy is probably the best example of effective use of minimal access surgery, a fact recognized by the inclusion of standard arthroscopic techniques for the knee and shoulder in the third edition. The fourth edition includes many new approaches involving minimal access surgery. These approaches are used mainly in the field of traumatology and reflect the major surgical interest of two of the authors and the majority of their resident readers. New minimal access approaches are included for the humerus, distal femur, and proximal and distal tibia. New external fixation approaches are included, especially bridging fixation. New approaches for the spine and calcaneus were conspicuously absent in previous editions, now part of this revision. Minimal access surgery is a classic double edge sword. The purpose of the surgery is to preserve the biology around the site of traumatic injury and to minimize the associated soft-tissue damage in elective orthopaedic surgery. The cost of this technique is decreased visualization, and many of the techniques described require the use of imaging to be safe. C-arm technologies are now readily available throughout the world. Computer- assisted surgery is also growing rapidly, particularly in the field of joint replacement surgery. A big danger of minimal access surgery is inadvertent damage to vital structures. It follows, therefore, that sound knowledge of underlying anatomy is even more critical for minimal access surgery than it is for conventional open approaches. Readers are earnestly advised to study the anatomical sections of the new approaches along with the classic approaches to ensure patient safety. We feel that the fourth edition of the book now incorporates a comprehensive range of surgical approaches required for the treatment of patients with orthopaedic and traumatological complaints. Classic extensile surgical approaches, minimal access surgery, arthroscopy, and external fixation are all tools that a competent surgeon must be able to use to fully help patients. Stanley Hoppenfeld, M.D. Piet de Boer, M.A., F.R.C.S. Richard Buckley, M.D., F.R.C.S.C. 11 Preface to the Third Edition Since its publication in 1984, Surgical Exposures in Orthopaedics—The Anatomic Approach has been the standard textbook for surgical approaches in orthopaedics and traumatology, regularly consulted by trainees as well as by experienced surgeons throughout the world. Its enduring success is evidence that it continues to meet a need in the practice of orthopaedics and traumatology. Why, then, a third edition? The field of orthopaedics continues to evolve at a rapid rate. The previous edition introduced the concept of preserving blood supply and minimizing soft-tissue damage in fracture surgery in order to preserve the biological envelope of the injured bone as much as possible. In this edition we introduce three minimal access approaches to allow the surgeon to perform intramedullary nailing of the femur, tibia, and humerus. Again, we emphasize that “you should make every effort to preserve the soft-tissue attachments of the bone wherever possible. Only expose what you actually need to see to ensure an adequate surgical procedure.” A significant development in the field has been the enormous increase in arthroscopic procedures, which have largely replaced open operations within the knee joint. Arthroscopy of the shoulder joint, similarly, is a rapidly developing approach. Therefore, this new edition introduces arthroscopic approaches to these joints—specifically the anteromedial and anterolateral approaches to the knee joint, and the anterior and posterior approaches to the shoulder joint, which allow the surgeons to examine the joint and have proved acceptable to large numbers of surgeons for some time. Although arthroscopic procedures have largely superseded open procedures and surgery in the developed world, surgeons still need to incorporate the classic surgical approaches to the knee. These approaches and knowledge of their underlying anatomy are useful when a surgeon has to deal with an open wound with associated ligament damage or when operating in countries where arthroscopy is not readily available. 12 The third edition also contains changes in the section on acetabular approaches, particularly in the posterior approach to the acetabulum, which has become the standard approach for these complex and challenging injuries. In addition, full color has been added to all the illustrations, enhancing their attractiveness as well as their verisimilitude. Piet de Boer, M.A., F.R.C.S. Stanley Hoppenfeld, M.D. 13 Preface to the Second Edition How do you make a good book better in a radically changing orthopaedic environment? By keeping to basics and heeding the requests of our fellow surgeons who have written to us over these past nine years, since the publication of the first edition. The emphasis on the concept of internervous planes remains a hallmark of the book. The basic principle of “do not cut round structures” is further reinforced by adding color to the nerves, arteries, and veins, which enhances the clinical dimensions of the illustrations. New surgical approaches have been added, such as the anterolateral approach to the shoulder, the anterolateral approach to the tibia, and an improved lateral approach to the hip. A whole new section on approaches to the acetabulum and pelvis is presented. The chapter is enriched with numerous original detailed surgical and anatomic drawings. A new chapter on safe routes for percutaneous insertion of external fixators into the long bones is offered. The illustrations with their insets provide three-dimensional clarity and location of the important neurovascular structures. Although anatomy has clearly not changed in the past nine years, more emphasis has been given to the preservation of the blood supply to the bone during orthopaedic surgery. This concept is of particular importance in fracture surgery where the blood supply to the bone has often been disrupted by the original injury. Preservation of blood supply is achieved by maintaining the soft tissue envelope of the bone. The approaches described in this book necessarily describe exposure of the whole anatomical site; the illustrations demonstrate this. In clinical practice you will often only need part of the approach described. You should make every effort to preserve the soft tissue attachments of the bone wherever possible. Do not fall into the trap of stripping bone extensively to allow complete exposure of all sides of a fracture; dead bone does not unite in 14 the fracture situation. Only expose what you actually need to see to ensure an adequate surgical procedure. The concept of “biological fixation” of fractures relies on these principles. Stanley Hoppenfeld, M.D. Piet de Boer, M.A., F.R.C.S. 15 Preface to the First Edition It has often been said that successful orthopaedic procedures are based on a simple principle: Get to bone and stay there. Surgical Exposures in Orthopaedics: The Anatomic Approach, the product of an anatomy course for orthopaedic surgeons that has been run at the Albert Einstein College of Medicine for the past 15 years, expands on the principle. The book explains the techniques of commonly used orthopaedic approaches and relates the regional anatomy of the area relevant to the approach. Safety in surgery depends on knowledge of anatomy and technical skill. The two go hand in hand; one is useless without the other. Surgical skill can be learned only by practical experience under expert supervision. But the knowledge that underlies it must come from both book and dissection. Structurally, this book is divided into 11 chapters, each dealing with a particular area of the body. The most commonly performed approaches are described; we have omitted approaches designed only for one specific procedure—they are best understood in the original papers of those who first described them. Nevertheless, the vast majority of orthopaedic procedures can be safely and successfully accomplished through the approaches we have included. Orthopaedics is a rapidly evolving field. New procedures are appearing at a prodigious rate; some are discarded in a comparatively short time. Thus, any book that concerns itself with the specifics of operative surgery inevitably becomes dated, sometimes even before publication. To avoid this problem, we have concentrated on getting to the bone or joint concerned, and not on what to do after. When applicable, we have included references to individual surgical procedures but without incorporating their details into our textbook. The key to Surgical Exposures in Orthopaedics is a consistent organization throughout (see Table 1). Each approach is explained; then the relevant surgical anatomy of the area is discussed. When one or more approaches share anatomy, they are grouped together, with the relevant 16 anatomical section at the end. The idea is for the surgeon to read the approach and anatomy sections together before attempting a given procedure, because once the anatomical principles of a procedure are fully understood, the logic of an approach becomes clear. SURGICAL APPROACHES The crucial element in successful surgical approaches is exploiting internervous planes. These planes lie between muscles—muscles supplied by different nerves. Internervous planes are helpful mainly because they can be used along their entire length without either of the muscles involved being denervated. These approaches can generally be extended to expose adjacent structures. Virtually all the classic extensile approaches to bone use internervous planes—a concept first described by A. K. Henry, who believed that if the key to operative surgery is surgical anatomy, then the key to surgical anatomy is the internervous plane. The approach sections are structured as follows. The introduction to each approach describes indications and points out the major advantages or disadvantages of the proposed surgery. Significant dangers are also outlined in this section. Table 1 Chapter Outline 17 The position of the patient is critical to clear, full exposures, as well as to the comfort of the operating surgeon. Surgical landmarks form the basis for any incision; they are described with instructions on how to find them. The incision follows these key landmarks. Although the incisions described are generally straight, many surgeons prefer to use curved or zigzag incisions because they heal with less tension than do equivalent straight incisions. The approaches often allow exposure of the whole length of a bone; usually, only part of an exposure is required for any given operation. The surgical dissection has been divided into superficial and deep surgical dissections for teaching purposes to reinforce the concept that each layer must be developed fully before the next layer is dissected. Adequate exposure depends on a systematic and deliberate technique that exploits each plane completely before deeper dissection begins. The dangers of each approach are listed under four headings: nerves, vessels, muscles and tendons, and special points. The dangers are described, along with how to avoid them. The approach section concludes with a description of how to enlarge 18 the approach. All too often, the surgeon discovers that the incised exposure is inadequate. There are two ways in which the exposure can be enlarged: Local measures include extending skin incisions, repositioning retractors, detaching muscles, or even adjusting the light source; and extensile measures are ways in which an approach can be extended to include adjacent bony structures. In approaches through internervous planes, extensile measures may permit the exposure of the entire length of the bone. ANATOMICAL SECTIONS The anatomy of each approach begins with a brief overview of the muscular anatomy, along with the arrangement of the neurovascular structures. The anatomy of the landmarks relates these structures to their surroundings. The anatomy of the skin incision describes the angle between the incision and the natural lines of skin cleavage first described by Langer—a relationship that may influence the size and prominence of the resultant scar. Nevertheless, the site of a skin incision must be determined largely by safety and effectiveness and not by cosmetic considerations. Skin incisions generally avoid cutting major cutaneous nerves; where they might, the danger is clearly stated. The anatomy of the superficial and deep surgical dissection discusses the regional anatomy encountered during the approaches—not only the anatomy of the plane to be used but also that of adjacent structures that may appear if the surgeon strays out of plane. Perhaps the greatest value of knowing topographical anatomy is in cases of trauma, where the surgeon may explore wounds with confidence, aware of the potential dangers created by any given wound. Relevant clinical information on the anatomical structures is offered, but a comprehensive clinical picture is beyond the scope of this book. The origins, insertions, actions, and nerve supplies of relevant muscles are listed in legends under the muscles’ illustrations. The anatomical and surgical illustrations are drawn from the surgeon’s point of view whenever possible, with the patient on the operating table, so that the surgeon can see exactly how the approach must look when he operates. The anatomical terms used in Surgical Exposures in Orthopaedics are generally those used in modern anatomical textbooks. Terms now in 19 orthopaedic usage sometimes differ from them; when that occurs (for instance, with the flexor retinaculum/transverse carpal ligament), both terms are given. Variation also occurs in usage on either side of the Atlantic; we have used those terms on which the authors (one American and one English) have reached consensus. It has been said that all of orthopaedic surgical approaches can be reduced to one line: “Avoid cutting round structures.” This book has been written to tell you how. Stanley Hoppenfeld, M.D. Piet de Boer, M.A., F.R.C.S. 20 Acknowledgments This book reflects the accumulated experience of many people over many decades. We should like to thank those in particular who helped us during the writing of this book. To Richard Hutton, my long-term friend and editor, who adds organization and reality to our writings. His love of the English language is reflected in this book. To Hugh Thomas, my long-term friend and medical illustrator, who added clarity to the book by his imaginative original illustrations, which reflect anatomic knowledge and clinical detail. In preparing the artwork for Surgical Exposures in Orthopaedics—The Anatomic Approach, he managed to draw beautifully on two continents. To Ray Coomaraswamy, M.D., for his help and guidance in writing the transabdominal and thoracotomy approaches to the spine. He has furthered his life experience by becoming a psychiatrist. To David M. Hirsh, M.D., for his detailed, expert review of the chapter on the hip and for his guidance in its presentation and clinical details. To Barnard Kleiger, M.D., for reviewing the chapters on the tibia and fibula and on the foot and ankle. He has been a source of inspiration to us during these years. We miss him. To Roy Kulick, M.D., 21 for reviewing the chapter on the hand several times and for giving it that little extra to help its clinical tone. To Martin Levy, M.D., for his multiple reviews of the chapter on the knee and for his valuable suggestions and clarity of thought. To Eric Radin, M.D., for reviewing parts of our book in its early stages, encouraging us, and making valuable suggestions. To Arthur Sadler, M.D., for his review of the chapter on the femur. To Leonard Seimon, M.D., for reviewing the medial approach to the hip and sharing his unusual surgical experiences with us. To Neil Cobelli, M.D., Chairman of the Department of Orthopaedic Surgery at the Montefiore Medical Center and Director of Orthopaedic Surgery of the Albert Einstein College of Medicine, for his continued interest in teaching anatomy and surgical approaches to the resident staff. To Jerry Sosler, M.D., for demonstrating and reviewing the retroperitoneal approach to the spine and his positive suggestions. To Morton Spinner, M.D., for reviewing the chapters on the elbow and forearm, helping us with clinical details, and for sharing a lifetime of clinical and surgical experience. To Keith Watson, M.D., for reviewing the chapter on the shoulder. To the British Fellows, who visit the Albert Einstein College of Medicine from St. Thomas 22 Hospital in England each year. Each has made a major contribution to the educational program and to our Anatomy course: Clive Whaley, Robert Jackson, David Grubel-Lee, David Reynolds, Roger Weeks, Fred Heatley, Peter Johnson, Richard Foster, Kenneth Walker, Maldwyn Griffith, John Patrick, Paul Allen, Paul Evans, Robert Johnson, Martin Knight, Robert Simonis, and David Dempster. To the Anatomy Department of the Albert Einstein College of Medicine—in particular. To France Baker-Cohen, who worked closely with us in establishing the course each year, and whom we miss. To Michael D’Alessandro, who has kept the rooms and cadaver material for us. To Dr. M. Bull, Dr. E.M. Chisholm, and the Examiners of the primary fellowship in London, who convinced me that topographical anatomy was worth learning. To Ronald Furlong, Eric Denman, and David Reynolds, for their efforts in teaching me and others operative surgery. To Marianne Broadbent, Ken Peel, and the nursing staff and ODAs at the York District Hospital and the Purey Cust Nuffield Hospital, York, for making surgery not only possible and safe, but also for their endless good humor, which makes surgery a pleasure. To the operating staff and technicians of Princess Margaret Hospital, Swindon, and St. Thomas Hospital, London—and especially Jim Lovegrove, 23 for making surgery possible. To Alan Apley, not only for providing the model for teaching, but also for writing a book that teaches. To Professor Kinmonth, Fred Heatley, Malcolm Morrison, and John Wilkinson, for their generous help during my own orthopaedic training. To the fellow physicians who have participated in teaching the Anatomy course over these many years: Uriel Adar, M.D., Russell Anderson, M.D., Mel Adler, M.D., Martin Barschi, M.D., Robert Dennis, M.D., Michael DiStefano, M.D., Henry Ergas, M.D., Aziz Eshraghi, M.D., Madgi Gabriel, M.D., Ralph Ger, M.D., Ed Habermann, M.D., Armen Haig, M.D., Steve Harwin, M.D., John Katonah, M.D., Ray Koval, M.D., Luc Lapommaray, M.D., Al Larkins, M.D., Mark Lazansky, M.D., Shelly Manspeizer, M.D., Mel Manin, M.D., David Mendes, M.D., Basil Preefer, M.D., Leela Rangaswamy, M.D., Ira Rochelle, M.D., Art Sadler, M.D., Jerry Sallis, M.D., Eli Sedlin, M.D., Lenny Seimon, M.D., Dick Selznick, M.D., Ken Seslowe, M.D., Rashmi Sheth, M.D., Bob Shultz, M.D., Richard Seigel, M.D., Norman Silver, M.D., Irvin Spira, M.D., Moe Szporn, M.D., Richard Stern, M.D., Jacob Teladano, M.D., Alan Weisel, M.D., and Charles Weiss, M.D. To the residents who have participated in the Orthopaedic Anatomy course at the “Einstein,” who have been a continual course of stimulation and inspiration. To Muriel Chaleff, who spent many hours helping to organize the Orthopaedic Anatomy course at the Albert Einstein College of Medicine. We owe her a great debt of gratitude for the kindness she has shown. To Leon Strong, my first Professor of Anatomy in Medical School for a stimulating 24 introduction to anatomy. To Emanuel Kaplan, M.D., whose great fund of anatomy and comparative anatomy was passed on to many of us while we were residents. His presence is still felt. To Herman Robbins, M.D., for his professional support and teaching of anatomy during the many sessions held in the library of the old Hospital for Joint Diseases. To Dr. and Mrs. N.A. Shore, my long-term friends, who had a positive effect on my medical writings and clinical practice. We greatly miss them. To Mr. Abraham Irvings, my long-term friend and accountant, who kept the financial records, helping to make this book possible. To Ruth Gottesman, for making reading possible for all through her great endeavors at the Albert Einstein College of Medicine, Fisher Landau Center for the Treatment of Learning Disabilities. To David “Sandy” Gottesman, in appreciation of his friendship and professional dissection of the marketplace. To Marie Capizzuto, my long-term secretary and friend, for her professional help in making this book possible. To Frank Ferrieri, my long-term friend, in appreciation of his help. His loss is greatly felt. To Mary Kearney, my secretary, for help in communicating with the J.B. Lippincott Company and mailing and calling, and calling, and calling! We miss her. To Tracy Davis, 25 for English editing of the Third Edition. To Barbara Ferrari, for her friendship, positive suggestions, and typing the Third Edition of our book. To our secretarial staff, and Mary Ann Becchetti, who took hours out of their busy schedules to type, retype, retype, and retype the text until it was perfect. To J. Stuart Freeman, Jr., former Senior Editor at Lippincott Williams & Wilkins, who has befriended me over these years and has been a source of positive suggestions and inspiration. To Robert Hurley, former Executive Editor at Lippincott Williams & Wilkins, in appreciation of his friendship and professional help in structuring the Third Edition. To Eileen Wolfberg, former Developmental Editor at Lippincott Williams & Wilkins, in appreciation of her detailed work in keeping the production and editing of this book on track and for her good humor at all times. To Jacques Bouchard, a special thank you to this special spine surgeon who has updated for us all of the latest minimally invasive spine techniques for the cervical, lumbar, and thoracic regions. His organization, thoroughness, and dedication to duty are exemplary. The whole team of authors commends his work. To the Orthopaedic and Trauma Team in Geneva. A special thank you to Robin Peter, Nicolas Holzer, Jean-Yves Beaulieu, Hermes Miozzari. Panayiotis Christofilopoulos, Tedi Cicavic, and Jean Fasel for carrying out the dissections shown in the new videos. Also thanks to Toto Gali and his team for filming them and Fredie Patane and his team for editing and final production. 26 Contents Introduction Chapter One The Shoulder Anterior Approach to the Clavicle Anterior Approach to the Shoulder Joint Applied Surgical Anatomy of the Anterior Approach to the Shoulder Joint Anterolateral Approach to the Acromioclavicular Joint and Subacromial Space Lateral Approach to the Proximal Humerus Minimally Invasive Lateral Approach to the Proximal Humerus Minimally Invasive Anterolateral Approach to the Proximal Humerus Applied Surgical Anatomy of the Anterolateral and Lateral Approaches Posterior Approach to the Shoulder Joint Applied Surgical Anatomy of the Posterior Approach to the Shoulder Joint Arthroscopic Approaches to the Shoulder Posterior and Anterior Approaches Arthroscopic Exploration of the Shoulder Joint through the Posterior Portal Chapter Two The Humerus Anterior Approach to the Humeral Shaft Minimally Invasive Anterior Approach to the Humeral Shaft Posterior Approach to the Humerus Anterolateral Approach to the Distal Humerus Lateral Approach to the Distal Humerus Medial Approach to the Distal Humerus Applied Surgical Anatomy of the Arm 27 Chapter Three The Elbow Posterior Approach to the Elbow with Olecranon Osteotomy Posterior Approach to the Elbow without Olecranon Osteotomy Anteromedial Approach to the Elbow Posteromedial Approach to the Coronoid Process of the Ulna Anterolateral Approach to the Elbow Anterior Approach to the Cubital Fossa Posterolateral Approach to the Radial Head Applied Surgical Anatomy Chapter Four The Forearm Anterior Approach to the Radius Applied Surgical Anatomy of the Anterior Compartment of the Forearm Exposure of the Shaft of the Ulna Applied Surgical Anatomy of the Approach to the Ulna Posterior Approach to the Radius Applied Surgical Anatomy of the Posterior Approach to the Radius Anterior and Posterior Approaches for the Treatment of Forearm Compartment Syndrome Chapter Five The Wrist and Hand Dorsal Approach to the Wrist Applied Surgical Anatomy of the Dorsal Approach to the Wrist Volar Approach to the Distal Radius Volar Approach to the Carpal Tunnel and Wrist Volar Approach to the Ulnar Nerve Applied Surgical Anatomy of the Volar Aspect of the Wrist Volar Approach to the Flexor Tendons Midlateral Approach to the Flexor Sheaths, Proximal and Middle Phalanges Dorsal Approach to Phalanges and Interphalangeal Joints Applied Surgical Anatomy of the Finger Flexor Tendons Volar Approach to the Scaphoid Dorsolateral Approach to the Scaphoid Drainage of Pus in the Hand Drainage of Paronychia Drainage of a Pulp Space Infection (Felon) 28 Web Space Infection Anatomy of the Web Space of the Fingers Anatomy of the Web Space of the Thumb Tendon Sheath Infection Deep Palmar Space Infection Drainage of the Medial (Midpalmar) Space Drainage of the Lateral (Thenar) Space Applied Surgical Anatomy of the Deep Palmar Space Drainage of the Radial Bursa Drainage of the Ulnar Bursa Anatomy of the Hand Chapter Six The Spine Posterior Approach to the Lumbar Spine Minimally Invasive—Posterior Approach to the Lumbar Spine Applied Surgical Anatomy of the Posterior Approach to the Lumbar Spine Anterior (Transperitoneal and Retroperitoneal) Approach to the Lumbar Spine Anterior Retroperitoneal Approach to the Lumbar Spine Applied Surgical Anatomy of the Anterior Approach to the Lumbar Spine Anterolateral (Retroperitoneal) Approach to the Lumbar Spine Posterior Approach to the Subaxial Cervical Spine Applied Surgical Anatomy of the Posterior Approach to the Subaxial Cervical Spine Posterior Approach to the C1-2 Vertebral Space Applied Surgical Anatomy of the Posterior Approach to the C1-2 Vertebral Space Anterior Approach to the Cervical Spine Applied Surgical Anatomy of the Anterior Approach to the Cervical Spine Posterolateral (Costotransversectomy) Approach to the Thoracic Spine Anterior (Transthoracic) Approach to the Thoracic Spine Posterior Approach to the Thoracic and Lumbar Spines for Scoliosis Applied Surgical Anatomy of the Posterior Approach to the Thoracic and Lumbar Spines Approach to the Posterior Lateral Thorax for Excision of Ribs Chapter Seven Pelvis and Acetabulum Pelvis 29 Acetabulum Anterior Approach to the Iliac Crest for Bone Graft Posterior Approach to the Iliac Crest for Bone Graft Anterior Approach to the Pubic Symphysis Anterior Approach to the Sacroiliac Joint Posterior Approach to the Sacroiliac Joint Applied Surgical Anatomy of the Bony Pelvis Ilioinguinal Approach to the Acetabulum Applied Surgical Anatomy of the Ilioinguinal Approach to the Acetabulum Posterior Approach to the Acetabulum Chapter Eight The Hip Anterior Approach to the Hip Minimally Invasive Anterior Approach to the Hip Anterolateral Approach to the Hip Lateral Approach to the Hip Applied Surgical Anatomy of the Anterior, Lateral, and Anterolateral Approaches to the Hip Posterior Approach to the Hip Applied Surgical Anatomy of the Posterior Approaches to the Hip and the Acetabulum Medial Approach to the Hip Applied Surgical Anatomy of the Medial Approach Chapter Nine The Femur Lateral Approach Posterolateral Approach Anteromedial Approach to the Distal Two-thirds of the Femur Posterior Approach Minimally Invasive Approach to the Distal Femur Minimally Invasive Approach to the Proximal Femur for Intramedullary Nailing Minimally Invasive Surgery for Retrograde Intramedullary Nailing of the Femur Applied Surgical Anatomy of the Thigh Posterior Approach to the Femur Chapter Ten The Knee 30 General Principles of Arthroscopy Arthroscopic Approaches to the Knee Arthroscopic Exploration of the Knee Medial Parapatellar Approach Approach for Medial Meniscectomy Medial Approach to the Knee and Its Supporting Structures Applied Surgical Anatomy of the Medial Side of the Knee Approach for Lateral Meniscectomy Lateral Approach to the Knee and Its Supporting Structures Applied Surgical Anatomy of the Lateral Side of the Knee Posterior Approach to the Knee Applied Surgical Anatomy of the Posterior Approach to the Knee Lateral Approach to the Distal Femur for Anterior Cruciate Ligament Surgery Chapter Eleven The Tibia and Fibula Anterolateral Approach to the Lateral Tibial Plateau Posteromedial Approach to the Proximal Tibia Posterolateral Approach to the Tibial Plateau Posterior Approach to the Tibial Plateau Minimally Invasive Anterolateral Approach to the Proximal Tibia Anterior Approach to the Tibia Minimally Invasive Anterior Approach to the Distal Tibia Posterolateral Approach to the Tibia Approach to the Fibula Applied Surgical Anatomy of the Leg—Approaches for Decompression of a Compartment Syndrome Minimally Invasive Approach for Tibial Nailing Chapter Twelve The Foot and Ankle Anterior Approach to the Ankle Anterior and Posterior Approaches to the Medial Malleolus Approach to the Medial Side of the Ankle Posteromedial Approach to the Ankle Posterolateral Approach to the Ankle Lateral Approach to the Lateral Malleolus Anterolateral Approach to the Ankle and Hindpart of the Foot Lateral Approach to the Hindpart of the Foot 31 Lateral Approach to the Posterior Talocalcaneal Joint Lateral Approach to the Calcaneus Applied Surgical Anatomy of the Approaches to the Ankle Applied Surgical Anatomy of the Approaches to the Hindpart of the Foot Dorsal Approaches to the Middle Part of the Foot Dorsal Approaches to the Metatarsophalangeal Joint of the Great Toe Dorsomedial Approaches to the Metatarsophalangeal Joint of the Great Toe Dorsolateral Approach for Bunion Surgery Dorsal Approach to the Metatarsophalangeal Joints of the Second, Third, Fourth, and Fifth Toes Dorsal Approach for Morton Neuroma Applied Surgical Anatomy of the Foot Chapter Thirteen Approaches for External Fixation The Humerus The Radius, Ulna, and Wrist The Pelvis The Femur The Tibia and Fibula The Ankle Index 32 Introduction Orthopaedic Surgical Technique Surgical technique in orthopaedics varies from surgeon to surgeon; the more experienced the surgeon, the fewer instruments he uses and the simpler his technique becomes. Certain principles, however, remain constant. They are listed below as they apply to each surgical section. The position of the patient is fundamental to any approach; it is always worth taking time to ensure that the patient is in the best position and that he is secured so that he cannot move during the procedure. Operating tables are well padded, but certain bony prominences—such as the head of the fibula and greater trochanter—are not. These prominences must always be padded adequately to prevent skin breakdown and nerve entrapment during surgery. Patients who are prone must have suitable padding placed under their pelvis, chest, head, and nose to allow respiration during surgery. Many different systems ensure adequate ventilation of the patient; bolsters placed longitudinally under the side of the patient are probably the best. Ventilation of the prone patient must be adequate before surgery, since repositioning of the patient during surgery is difficult and almost inevitably contaminates the sterile field. The surgeon should be comfortable during surgery, with the patient placed at the correct height for the surgeon’s size or the table low enough to allow him to operate sitting down. In surgery on the limbs, a tourniquet is often used to create a bloodless field, making identification of vital structures easier and expediting surgery. To apply the tourniquet, empty the limb of blood, either by elevating it for 3 to 5 minutes or by applying a soft rubber compression bandage. The tourniquet should be padded with a soft dressing to prevent the wrinkles (and blisters) that inevitably occur when the skin is pinched. The tourniquet may be applied to the upper arm or thigh. Both of these areas are well muscled; the major nerves are protected from compression of the tourniquet. The inflated pressure of the tourniquet should be about 275 mm 33 Hg in the upper limb and 450 mm Hg in the lower limb, depending on the circumference of the limb. Test the tourniquet by inflating it before applying it to the patient. In children, inflate the tourniquet to 50% above their systolic pressure. In hypertensive patients, inflate it 50% more than their systolic pressure. Finally, do not leave the tourniquet inflated for longer than 1 hour in the upper limb and 1½ hours in the lower limb to minimize the risk; do not use tourniquets when the peripheral circulation of the patient is suspect or in the presence of sickle cell disease. Partial exsanguination of the limb, which can be achieved after 2 minutes of elevation, leaves blood in the venous structures. It makes for a bloodier field during surgery but does make it easier to identify neurovascular bundles—something of immense value in, for example, lateral meniscectomy, where it is safer to identify and to coagulate the lateral inferior geniculate artery than to cut it accidentally, learning about it only after the tourniquet has been deflated. Deflate the tourniquet before closure to identify and to coagulate major bleeding points. The landmarks are critical to the planning of any incision. It is often convenient to mark them on the skin with methylene blue to ensure that the skin incision lines up with them. All skin incisions heal with the formation of scar tissue, which contracts with time. For this reason, skin incisions should not cross flexion creases at 90 degrees; cutting perpendicular to flexion creases can cause contractures to develop over the involved joints. That is why incisions that cross major flexion creases are usually curved to traverse the crease at about 60 degrees. The techniques of the superficial and deep surgical dissections are the province of practical experience, not book knowledge. However, two techniques are frequently referred to in the book. Subperiosteal dissection protects vital structures that lie near the bone, helping to prevent their damage by instruments. The rule holds true, but vital structures often lie on the periosteum itself: The posterior interosseous nerve, for instance, lies on the periosteum of the neck of the radius. The radial nerve lies on the periosteum on the back of the humerus. In these cases subperiosteal dissection must be strictly subperiosteal, something that may not be possible if the periosteum is damaged in case of fracture. The periosteum normally detaches easily from the bone except at sites of muscle or ligament attachments where it may adhere strongly. Blunt dissection may be difficult or impossible at the sites of insertion. Note that the periosteum of children is thicker than that of adults, more easily defined, and less adherent to bone. In fracture surgery subperiosteal 34 dissection is rarely indicated except in the region of the proximal radius and the center of the humeral shaft. Subperiosteal stripping will destroy the periosteal supply of blood to the bone and if extensive will devitalize the fracture site. In such cases periosteal stripping is only permissible to allow accurate reduction of the fracture. The more experienced the surgeon becomes, the less soft-tissue damage he will need to create to allow accurate visualization and reduction of the fracture. The second technique is that of detaching a muscle from the bone. Remember to strip into the acute angle that fibers make with the bone to which they attach. This is perhaps clearest in the fibula: To detach the peroneal muscles, pass an elevator from distal to proximal; to detach the interosseous membrane, where fibers run in a different direction, strip from proximal to distal. Exposures can be improved in two ways. Local measures enhance the immediate exposure. Extensile measures allow the surgeon to expose adjacent bony structures. It is vital to appreciate that not all approaches are extensile: Specialized approaches should be used only in cases where the pathology is accurately pinpointed and where the surgeon does not have to expose any adjacent structures. Inadequate exposure is one of the most common causes of surgical failure. If the surgeon is in difficulty, one of the first things he should try is to improve the exposure either by local or by extensile means. 35 Video List Anterior Approach to the Ankle Approaches for Decompression of Lower Leg Compartment Syndrome Approach to the Cubital Fossa Dorsal Approach to the Wrist Forearm Approach Illioinguinal Approach to the Acetabulum Lateral Approach to the Calcaneus Lateral Approach to the Hip Minimally Invasive Anterior Approach to the Hip Minimally Invasive Approach to the Distal Femur Minimally Invasive Lateral Approach to the Proximal Humerus Posterior Approach to the Acetabulum with Surgical Dislocation of the Hip Posterior Approach to the Distal Humerus Posterior Approach to the Tibial Plateau Posterolateral Approach to the Ankle Volar Approach to the Distal Radius Volar Approach to the Flexor Tendons 36 One The Shoulder Anterior Approach to the Clavicle Anterior Approach to the Shoulder Joint Applied Surgical Anatomy of the Anterior Approach to the Shoulder Joint Anterolateral Approach to the Acromioclavicular Joint and Subacromial Space Lateral Approach to the Proximal Humerus Minimally Invasive Lateral Approach to the Proximal Humerus Minimally Invasive Anterolateral Approach to the Proximal Humerus Applied Surgical Anatomy of the Anterolateral and Lateral Approaches Posterior Approach to the Shoulder Joint Applied Surgical Anatomy of the Posterior Approach to the Shoulder Joint Arthroscopic Approaches to the Shoulder General Principles of Arthroscopy 37 Posterior and Anterior Approaches Arthroscopic Exploration of the Shoulder Joint through the Posterior Portal The shoulder is the most mobile joint in the body. It is surrounded by two sleeves of muscle: The outer sleeve, or deltoid muscle; and the inner sleeve, or rotator cuff, which is critical for the stability of the joint. The three most common shoulder pathologies that necessitate surgery are instability, such as recurrent anterior dislocation of the shoulder (see Fig. 1-29), degenerative lesions of the rotator cuff, and fractures of the proximal humerus. Nine surgical approaches are described in this chapter: Anterior and posterior approaches to the shoulder, anterolateral approach to the acromioclavicular joint and subacromial space, anterior approach to the clavicle, lateral and minimally invasive lateral approach to the proximal humerus, minimally invasive anterolateral approach for humeral nailing, and two arthroscopic approaches—anterior and posterior. Of these, the anterior approach is the “work-horse” incision of the shoulder, providing excellent exposure of both the joint, its anterior coverings and the proximal humerus. The anterolateral approach is used mainly to expose the acromioclavicular joint and subacromial structures, especially the rotator cuff. Use of this approach has declined with the increasing use of arthroscopic techniques. The lateral approach and minimally invasive lateral approach also expose the rotator cuff but their main use is in the treatment of fractures of the proximal humerus. The posterior approach, which is used rarely, is effective in treating recurrent posterior dislocations and is also used for open reduction and internal fixation of fractures of the posterior glenoid and fractures of the scapula neck. The arthroscopic approaches to the shoulder (anterior and posterior) provide excellent visualization of the internal structures of the joint. The surgical anatomy of the area is divided into three sections: Anterior, anterolateral, and posterior. A description of each area is found immediately after its respective operative section in this chapter. Anterior Approach to the Clavicle The anterior approach to the clavicle provides exposure of the entire bone allowing: 38 1. Open reduction and internal fixation of fractures 2. Reconstruction of the sternoclavicular and the acromioclavicular joints in case of dislocation or subluxation 3. Drainage of sepsis 4. Biopsy and excision of tumors 5. Osteotomy for malunion1 The brachial plexus and subacromial vessels can also be approached via this surgical approach. To do this an osteotomy of the clavicle is required (see page 16, Fig. 1-20). Bleeding from subcutaneous vessels and vessels in the platysma muscle is very common. Because of the proximity of great vessels, such superficial bleeding must be controlled to ensure adequate visualization of the structures (see Fig. 1-1). Position of the Patient Place the patient supine on the operating table. Break the table and elevate the head end, so as to elevate the shoulder area. Place a sandbag between the medial border of the scapula and the spine. This will allow the shoulder to drop back and often this maneuver reduces fractures of the middle third. Landmarks and Incision The sternal notch is the most medial landmark of the incision. From the sternal notch, palpate the clavicle laterally to the acromioclavicular joint, palpating its subcutaneous surface. Make an incision following the S-shaped clavicular anatomy, beginning from the medial end. The site and length of the incision depend on the clinical indication for surgery (Fig. 1-1). Internervous Plane Because the approach is directly onto the subcutaneous surface of the clavicle, there is no internervous plane. However, the incision cuts across numerous small subcutaneous nerves, branches of the supraclavicular nerve which cross the operating field from superior to inferior running in the substance of the platysma muscle. 39 Figure 1-1 The subclavian vessels are very close to the clavicle. Figure 1-2 A: Make a longitudinal incision overlying the subcutaneous surface of the clavicle. The site and length of the incision are determined by the pathology to be treated and the implant to be used. B: Deepen the incision in the line of the skin incision to expose the platysma muscle. Note the presence of several cutaneous nerves. Superficial Surgical Dissection Deepen the skin incision through the platysma to reach the subcutaneous surface of the clavicle. Take care to diathermy the numerous vessels present within this muscle (Fig. 1-2). Try to preserve as many branches of the supraclavicular nerve as possible. Safe zones exist within 2.5 cm of the sternoclavicular joint and within 2 cm of the acromioclavicular joint where 40 no branches of the supraclavicular nerve are present. The nerve usually divides into a medial and a lateral branch2 both of which cross the operative field if the incision is used for fixation of a fracture of the middle third of the clavicle. Division of a single branch may not produce any postoperative numbness due to overlap in the cutaneous distribution of the branches of the nerve. Deep Surgical Dissection Gently strip soft tissues off the subcutaneous surface of the clavicle in an epiperiosteal plane. Take care to preserve as much soft tissue attachments as possible, particularly in cases of fracture fixation. Dangers Nerves The brachial plexus with the subclavian artery has a variable relationship with the clavicle. These structures lie posterior to the bone medially and then lie immediately inferior to the clavicle in the middle and lateral thirds (Fig. 1-3). To ensure that the plexus is uninjured, remain on the subcutaneous surface of the clavicle. If dissection is required inferior to the bone, develop a plane between the periosteum of the clavicle and the subclavius muscle. Also, be aware when drilling for fixation of fractures that penetration of the bone should be minimized in its posterior surface because of the close proximity of the nerves and vessels.3 Branches of the supraclavicular nerves cross the operative field from superior to anterior. There is wide variation in the position of these nerves which should be preserved if possible. Vessels The subclavian artery and vein lie immediately inferior to the clavicle in its middle and lateral thirds. Avoid dissection inferior to the clavicle, if possible. Dissection onto the subcutaneous surface and the anterior surface is safe. How to Enlarge the Approach The exposure can be enlarged longitudinally along the whole length of the clavicle as required (see Extensile Measures in this chapter). The approach can be extended distally into the anterolateral approach 41 to the proximal humerus and midshaft of the humerus using the deltopectoral interval (see Fig. 1-20). Figure 1-3 Deepen the incision through the platysma muscle in the line of the skin incision to expose the subcutaneous surface of the clavicle. Anterior Approach to the Shoulder Joint The anterior surgical approach offers good wide exposure of the shoulder joint, allowing repairs to be made of its anterior, inferior, and superior coverings. Among its many uses, the anterior approach permits the following: 42 Figure 1-4 Position of the patient for the anterior approach to the shoulder. Elevate the table to 45 degrees. A sandbag placed under the spine at the medial end of the scapula will allow the shoulder to rotate externally and open the anterior part of the joint. 43 1. Reconstruction of recurrent dislocations4–9 2. Drainage of sepsis 3. Biopsy and excision of tumors 4. Repair or stabilization of the tendon of the long head of the biceps10 5. Shoulder arthroplasties or hemiarthroplasties which usually are inserted through modified anterior incisions11–13 6. Fixation of fractures of the proximal humerus14,15 The anterior approach is notorious for the amount of bleeding that occurs from skin and subcutaneous tissues during superficial dissection. The bleeding must be controlled before the deeper layers are dissected. Failure to do so may obscure important anatomic structures and endanger their integrity. Position of the Patient Place the patient in a supine position on the operating table. Wedge a sandbag under the spine and medial border of the scapula to push the affected side forward while allowing the arm to fall backward, opening up the front of the joint (Fig. 1-4). Elevate the head of the table 30 to 45 degrees to reduce venous pressure, and thereby decrease bleeding, and to allow the blood to drain away from the operative field during surgery. If a headrest is used, make sure that it is padded properly to prevent the development of a pressure sore on the occiput. Drape the arm free, because it will have to be moved during the approach. If image intensification is to be used during surgery, ensure that adequate images can be obtained prior to prepping and draping the patient. Landmarks and Incision Landmarks Coracoid Process. Palpate the coracoid process by dropping your finger distally about 2.5 cm from the anterior edge of the clavicle at the deepest point in the clavicular concavity. Press laterally and posteriorly in an oblique line until the coracoid process is felt. The process faces anterolaterally; because it lies deep under the cover of the pectoralis major, it can be felt only by firm palpation. Deltopectoral Groove. The deltopectoral groove is easier to see than to 44 feel, especially in thin patients. The cephalic vein, which runs in the groove, sometimes is visible. Incisions The anterior aspect of the shoulder can be approached through either of two skin incisions. Anterior Incision. Make a 10- to 15-cm straight incision, following the line of the deltopectoral groove. The incision should begin just above the coracoid process (Fig. 1-5). Axillary Incision. With the patient supine, abduct the shoulder 90 degrees and rotate it externally. Mark the anterior axillary skin fold with a sterile pen. Make a vertical incision 8 to 10 cm long, starting at the midpoint of the anterior axillary fold and extending posteriorly into the axilla.16 The skin flaps should be undermined extensively with a finger, especially superiorly in the area of the deltopectoral groove, using the cephalic vein as a guide to ensure correct position in the vertical plane. Retract the skin flaps upward and laterally so that the incision comes to lie over the deltopectoral groove (Figs. 1-6 and 1-7). 45 Figure 1-5 Make a straight incision in the deltopectoral groove, starting at the level of the coracoid process. 46 Figure 1-6 Make an incision in the axilla. Dissect subcutaneously to mobilize skin. The axillary incision has a significant cosmetic advantage over the anterior incision, both because it is hidden in the axilla and because the resulting scar is covered by hair. In addition, the suture line remains free from tension while it heals; thus, the scar has little opportunity to spread. The incision may be contraindicated when, in extremely muscular patients, the skin flaps cannot be moved enough to allow adequate exposure of the muscular structures that lie in front of the shoulder. If adequate exposure cannot be obtained through the axillary incision, it should be extended 47 superiorly into the deltopectoral groove. This skin incision is not recommended for fracture fixation surgery. Internervous Plane The internervous plane lies between the deltoid muscle, which is supplied by the axillary nerve, and the pectoralis major muscle, which is supplied by the medial and lateral pectoral nerves (Fig. 1-8). Figure 1-7 Retract the axillary incision cephalad to expose the cephalic vein and the deltopectoral groove. 48 Figure 1-8 The internervous plane lies between the deltoid muscle (axillary nerve) and the pectoralis major muscle (medial and lateral pectoral nerves). 49 Figure 1-9 Develop the groove between the fascia overlying the pectoralis major and the fascia overlying the deltoid. The cephalic vein will be of help in locating the groove. Superficial Surgical Dissection Find the deltopectoral groove, with its cephalic vein (Fig. 1-9). The vein may be difficult to visualize. It is often surrounded by some fatty tissue which can act as a guide to identifying it. Retract the pectoralis major medially and the deltoid laterally, splitting the two muscles apart. The vein may be retracted either medially or laterally. Taking a small cuff of deltoid with the vein may reduce the number of bleeding tributaries that require ligation, but it leaves a small amount of denervated muscle. For that reason, it is not recommended as a routine practice. Try to preserve the cephalic vein in order to reduce postoperative upper limb edema. 50 Deep Surgical Dissection The short head of the biceps (which is supplied by the musculocutaneous nerve) and the coracobrachialis (which is supplied by the musculocutaneous nerve) must be displaced medially before access can be gained to the anterior aspect of the shoulder joint. Simple medial retraction after division of the overlying fascia may be enough for procedures such as the Magnuson–Stack subscapularis tendon advancement,6 the Putti–Platt subscapularis5 and capsule imbrication, and open reduction and internal fixation of a proximal humeral fracture but if more exposure is necessary, or if the coracoid process is to be transposed,8 the two muscles can be detached with the tip of the coracoid process. To release them, detach the tip of the coracoid process with an osteotome. The bone can be reattached later either with a screw or with sutures. If a screw is used, the coracoid process must be drilled and tapped before the osteotomy is carried out. Otherwise, the small piece of coracoid may split during drilling, and anatomic reduction can be obtained only with extreme difficulty (Figs. 1- 10 and 1-11). The axillary artery is surrounded by the cords of the brachial plexus, which lie behind the pectoralis minor muscle. Abduction of the arm causes these neurovascular structures to become tight and brings them close to the tip of the coracoid and the operative site. Therefore, the arm should be kept adducted while work is being done around the coracoid process (Fig. 1-12).4 51 Figure 1-10 Retract the pectoralis major medially and the deltoid laterally to expose the conjoined tendon of the short head of the biceps and coracobrachialis muscle. Drill the tip of the coracoid process before cutting it. Incise the fascia on the lateral aspect of the conjoint tendon. Note the leash of vessels at the inferior end of the subscapularis muscle. 52 Figure 1-11 Cut through the predrilled coracoid process. Retract the conjoint tendon medially to give greater exposure to the subscapularis tendon. Figure 1-12 Protect the axillary sheath during coracoid osteotomy by having the arm in the dependent position; abduction of the arm will draw the sheath against the coracoid process. 53 Retract the coracoid (with its attached muscles) medially. Divide the fascia that fans out from the conjoined tendons of the coracobrachialis and the short head of the biceps on the lateral side of the coracobrachialis—the safe side of the muscle, because the musculocutaneous nerve enters the coracobrachialis on its medial side. If a coracoid osteotomy has been used, take care in retracting the coracoid with its attached muscles; overzealous downward retraction can cause a neurapraxia of the musculocutaneous nerve. If the coracoid process is left intact, the attached coracoid muscles protect the nerve from traction injury (Fig. 1-13) but nevertheless do not apply vigorous medial retraction as this can also damage the nerve. Beneath the conjoined tendons of the coracobrachialis and the short head of the biceps lie the transversely running fibers of the subscapularis muscle, which forms the only remaining anterior covering of the shoulder joint capsule (Fig. 1-14).4 As the muscle crosses the glenoid cavity, a bursa separates it from the joint capsule; that bursa may communicate with the shoulder joint. In cases of multiple anterior dislocations, adhesions often exist between the muscle and the joint capsule, making it difficult, if not impossible, to find the layer between the two. If you need to divide or detach the insertion of subscapularis to gain access to the shoulder joint apply external rotation to the arm to stretch the subscapularis, bringing the muscle belly into the wound and making its superior and inferior borders easier to define. External rotation of the humerus also increases the distance between the subscapularis and the axillary nerve as it disappears below the lower border of the muscle (see Fig. 1-14). The most easily identified landmarks on the inferior border of the subscapularis are a series of small vessels that run transversely and often require ligation or cauterization. The vessels run as a triad: A small artery with its two surrounding venae comitantes, one above and one below the artery (Fig. 1-15). The superior border of the subscapularis muscle is indistinct and blends in with the fibers of the supraspinatus muscle. Pass a blunt instrument between the capsule and the subscapularis, moving upward (see Fig. 1-15). Tag the muscle belly with stay sutures to prevent it from disappearing medially when it is cut and to allow easy reattachment of the muscle to its new insertion onto the humerus. Then divide the subscapularis 2 to 3 cm from its insertion onto the lesser tuberosity of the humerus (Fig. 1-16). Note that some of its muscle fibers insert onto the joint capsule itself; the capsule frequently may be opened inadvertently when the muscle is divided, because the two layers cannot always be defined. 54 Alternatively, rotate the shoulder internally and identify the insertion of the tendon of the subscapularis onto the humerus. Detach this insertion with a small flake of bone using a fine osteotome. This will allow more lateral reattachment of the muscle in a prepared channel in the bone, using staples. Incise the capsule longitudinally to enter the joint wherever the selected repair must be performed. Each type of repair has its own specific location for incision (Fig. 1-17). If the approach is used for treatment of fractures, the deep surgical dissection has often been performed by the trauma. Fractures of the greater and lesser tuberosities usually have their musculotendinous insertions preserved and the unopposed pull of the muscles causes displacement and rotation of the bony fragments. Attachment of sutures to the tendons allows manipulation and reduction of the tuberosities. Try to preserve any remaining blood supply to the head fragment if possible to reduce the risk of avascular necrosis. The biceps tendon, which runs in the groove between the greater and lesser tuberosities, is usually preserved and can act as a key surgical landmark for bony reconstruction. 55 Figure 1-13 Vigorous retraction of the conjoint tendon distally can injure the musculocutaneous nerve, causing neurapraxia or avulsion. 56 Figure 1-14 A: The subscapularis muscle lies in the deep part of the wound. It is to be incised perpendicular to its fibers, close to its tendon. The axillary nerve passes anteroposteriorly through the quadrangular space. B: External rotation of the arm during incision into the subscapularis tendon will draw the point of incision away from the axillary nerve. Figure 1-15 Insert a curved artery clamp under the subscapularis muscle. A leash of vessels at the caudal end of the wound marks the lower border of the subscapularis. 57 Figure 1-16 Incise the end of the subscapularis. Tag and place stay sutures into the muscle to prevent it from retracting medially. Some of the subscapularis fibers insert directly into the joint capsule. 58 Figure 1-17 Incise the joint capsule longitudinally to expose the humeral head and the glenoid cavity. Dangers Nerves The musculocutaneous nerve enters the body of the coracobrachialis about 5 to 8 cm distal to the muscle’s origin at the coracoid process. Because the nerve enters the muscle from its medial side, all dissection must remain on the lateral side of the muscle. Great care should be taken not to retract the muscle inferiorly, to avoid stretching the nerve and causing paralysis of the elbow flexors (see Fig. 1-13). Also take care to avoid overzealous medial retraction if a coracoid osteotomy is not performed. 59 The axillary nerve runs on the deep surface of the deltoid muscle running from posterior to anterior. Retraction of the deltoid muscle posteriorly cannot therefore damage the nerve but instruments placed around the lateral side of the proximal humerus to facilitate retraction of the deltoid may press directly on the nerve causing a neurapraxia. The nerve is also in danger when dividing the subscapularis muscle tendon. The nerve lies just inferior to the inferior border of the muscle. The danger can be reduced by externally rotating the arm before dividing the tendon (see Fig. 1-14A,B). If the dissection is not carried out inferior to the triad of vessels marking the lower border of the muscle the nerve will be safe. Vessels The cephalic vein should be preserved, if possible to reduce the risk of postoperative upper limb edema. However a traumatized cephalic vein should be ligated to prevent the slight danger of thromboembolism. There are no valves between the cephalic vein and the superior vena cava. Figure 1-18 Remove the origins of the deltoid from the anterior portion of the 60 clavicle to expose the joint further proximally. Identify the coracoacromial ligament. How to Enlarge the Approach Local Measures The exposure can be enlarged in the following five ways: 1. Extend the skin incision superiorly by curving it laterally along the lower border of the clavicle. Detach the deltoid from its origin on the outer surface of the clavicle for 2 to 4 cm to permit better lateral retraction of the muscle (Fig. 1-18). Unfortunately, because reattaching the deltoid securely is very difficult, this maneuver is not recommended for routine use. If further deltoid retraction is required, it may be best to detach part of the muscle’s insertion onto the humerus. 2. Lengthen the skin incision inferiorly along the deltopectoral groove to separate the pectoralis major from the deltoid further inferiorly and to improve the exposure without having to detach the deltoid origin. 3. Partially detach the insertion of the pectoralis major tendon into the humerus. 4. Use a suitable retractor (such as the Bankart skid) for the humeral head. A humeral head retractor is the key to excellent exposure of the inside of the glenoid fossa once the joint has been opened (Fig. 1-19). 5. Rotate the shoulder internally and externally to bring different elements of the anterior shoulder coverings into view. Extensile Measures Proximal Extension. To expose the brachial plexus and axillary artery, and to gain control of arterial bleeding from the axillary artery, extend the skin incision superomedially, crossing the middle third of the clavicle. Next, dissect the middle third of the clavicle subperiosteally and perform a double osteotomy of the bone, removing the middle third. Cut the subclavius muscle, which runs transversely under the clavicle. Retract the trapezius superiorly and the pectoralis major and pectoralis minor inferiorly to reveal the underlying axillary artery and the surrounding brachial plexus (Fig. 1-20). Take care not to damage the musculocutaneous nerve, which is the most superficial nerve in the brachial plexus. Distal Extension. The approach can be extended into an anterolateral 61 approach to the humerus. Extend the skin incision down the deltopectoral groove, then curve it inferiorly, following the lateral border of the biceps. Deep dissection consists of retracting the biceps brachii medially to reveal the underlying brachialis, which then can be split along the line of its fibers to provide access to the humerus. For details of this approach, see Anterior Approach to the Humerus in Chapter 2, page 74–80, 4th edition. 62 Figure 1-19 A Bankart skid is used to retract the humeral head to expose the glenoid cavity and its labrum. 63 Figure 1-20 A, B: Extend the incision superomedially. Expose and resect the 64 middle third of the clavicle subperiosteally. C: Expose the brachial plexus and axillary artery. Applied Surgical Anatomy of the Anterior Approach to the Shoulder Joint Overview All approaches to the shoulder involve penetrating the two muscular coverings, or sleeves that cover the joint. The outer sleeve is the deltoid muscle. The inner sleeve is the rotator cuff, which consists of four muscles: The supraspinatus, infraspinatus, teres minor, and subscapularis (Fig. 1-21). Anteriorly, gaining access to the shoulder joint involves reflecting the outer sleeve (deltoid) laterally and incising the inner sleeve, specifically the subscapularis. The deltoid, together with the pectoralis major and the latissimus dorsi (the two great muscles of the axillary fold), supplies most of the power that is required for shoulder movement. The muscles of the inner sleeve can act as prime movers of the humerus, but their most important action is to control the humeral head within the glenoid cavity while the other muscles are carrying out major movements. The supraspinatus also has a key role as a prime mover of the humerus in initiating abduction. The teres minor and infraspinatus muscles are the only important external rotators of the shoulder. Pathology of this joint most often occurs in this inner group of muscles. Degenerative lesions of the rotator cuff are extremely common with increasing age. Their function is critical not only to the coordination of joint movement, but also to the stability of the shoulder joint itself. Fracture patterns and bone displacement are dictated not only by the forces causing the injury but also by the soft tissue attachments of elements of the rotator cuff to the greater and lesser tuberosities. A third group of muscles intervenes between the two muscular sleeves when the joint is approached from the front. These muscles (the short head of the biceps, the coracobrachialis, and the pectoralis minor) require medial retraction for exposure of the inner sleeve. They all are attached to the coracoid process (see Fig. 1-21). 65 Figure 1-21 Anatomy of the anterior portion of the shoulder. Landmarks and Incision Landmarks The coracoid process of the scapula is a palpable bony protuberance that lies at the upper end of the deltopectoral groove and is the landmark for incisions based on that groove. It is also a critical landmark for injections and arthroscopic examinations of the shoulder joint. Hook shaped, the coracoid process sometimes is described as resembling a crow’s beak, as is implied by its name, corax. The tip of the coracoid process projects forward, laterally, and inferiorly toward the glenoid cavity. Therefore, it is palpated best by posterior and medial pressure. Be aware that palpation of the coracoid process often is painful; therefore, tenderness over this site is not diagnostic of local pathology. Attached to the coracoid process are the 66 six clinically important structures described below (Fig. 1-22). Coracoacromial Ligament. The tough, fibrous coracoacromial ligament is variable. It is classically described as being triangular connecting the horizontal portion of the coracoid process to the tip of the acromion. Other authors describe it as trapezoidal.17 It is one of the few ligaments that connects two parts of the same bone. The coracoid process, the acromion, and the coracoacromial ligament form the coracoacromial arch. This structure may be implicated in the pathology of the impingement syndrome. The function of the coracoacromial ligament is unclear. It may act as a dynamic brace between the two portions of the scapular.18 Resection of the coracoacromial ligament, which is frequently carried out in subacromial decompression, does not appear to be associated with significant long-term clinical problems. Conoid and Trapezoid Ligaments. The conoid and trapezoid ligaments are extremely strong. The conoid ligament, which resembles an inverted cone, extends upward from the upper surface of the coracoid to insert into the conoid tubercle on the underside of the clavicle. The trapezoid ligament runs from the upper surface of the coracoid process and extends superiorly and laterally to the trapezoid ridge on the undersurface of the clavicle. These two structures are the main accessory ligaments of the acromioclavicular joint. They are extremely difficult to repair in cases of acromioclavicular dislocation and, once they are torn, are difficult to identify as individual structures. Coracohumeral Ligament. This ligament arises from the undersurface of the coracoid process and runs laterally over the shoulder to blend in with the shoulder joint capsule. It is the most important and most constant thickening of the fibrous capsule of the shoulder but probably of little clinical significance.19 Conjoined Tendons of the Coracobrachialis and Biceps Brachii. See Figure 1-25. Pectoralis Minor Muscle. See Applied Surgical Anatomy of the Anterior Approach in this chapter. Incision Because a skin incision that runs down the deltopectoral groove cuts 67 almost transversely across the relaxed skin tension lines (cleavage lines of the skin), it often leaves a broad scar, even if a subcuticular skin closure is used. An incision in the axilla runs with the relaxed skin tension lines and leaves a much narrower scar. The latter scar is almost invisible, because it is hidden in the axillary fold and is covered by hair. Figure 1-22 Five clinically important structures are attached to the coracoid process. 68 Figure 1-23 The superficial anatomy of the anterior shoulder, revealing the deltopectoral groove and the neurovascular bundle. Superficial Surgical Dissection Three major structures are involved in the superficial surgical dissection of the anterior approach to the shoulder joint: The deltoid muscle laterally, the pectoralis major muscle medially, and the cephalic vein, which lies between them in the deltopectoral groove (Fig. 1-23). Deltoid Muscle The anterior fibers of the deltoid muscle run parallel to each other, without fibrous septa between them. Because sutures placed in this kind of muscle fiber tend to tear out, it is difficult to reattach the deltoid to the clavicle. Sutures must be placed through the full thickness of the muscle, including its fascial coverings, to effect a strong reattachment. Transosseous sutures are also frequently required. The attachment should be protected from active stress for 4 to 6 weeks to allow for adequate healing. For these 69 reasons routine detachment of the muscle from the clavicle is not advised. The axillary nerve is the nerve supply of the muscle and runs on its undersurface from posterior to anterior. The anterior portion of the deltoid can be denervated only if the entire anterior part of the muscle is stripped and retracted vigorously in a lateral direction (Fig. 1-24) or if a retractor is placed under the muscle directly over the nerve. Pectoralis Major Muscle The two nerve supplies of the pectoralis major allow the muscle to be split without the loss of innervation to either part. The attachment of the pectoralis tendon to the humerus may need to be partially detached especially if the approach is used for fixation of a proximal humeral fracture (see Fig. 1-24).20 Cephalic Vein The cephalic vein drains into the axillary vein after passing through the clavipectoral fascia. On occasion, it may be absent. Few complications result from its ligation (see Fig. 1-23) but routine ligation is not advised because of the slight risk of postoperative upper limb edema. Deep Surgical Dissection The coracobrachialis and the short head of the biceps brachii share a common origin from the tip of the coracoid process. They also share a common nerve supply, the musculocutaneous nerve. These muscles form an intermediate layer during the surgical approach (Fig. 1-25). Coracobrachialis Muscle The coracobrachialis muscle is largely vestigial and has little function. It acts as a weak flexor and abductor of the arm and may help to stabilize the shoulder. Extremely variable in size, it is the counterpart in the arm of the adductors in the thigh. 70 Figure 1-24 The anterior portion of the deltoid has been resected from its origin, revealing the insertion of the pectoralis major muscle and the subscapularis tendon, supraspinatus tendon, and coracoacromial ligament. The coracobrachialis used to have three heads of origin. The musculocutaneous nerve passes between two of the original heads, which now are fused during development. Its course represents one of the few instances in which a nerve appears to pass through a muscle. When a nerve does this, it always is passing between two heads of origin (see Fig. 1-25). Biceps Brachii Muscle The tendon of the long head of the biceps is an anatomic curiosity; it is one of only two tendons to pass through a synovial cavity. The joint capsule of the shoulder is incomplete inferiorly, so the tendon can escape under the transverse ligament. From there, it runs in the bicipital groove of the humerus. It is easy to palpate the tendon in the groove as long as the arm is rotated externally (see Fig. 1-27). The biceps tendon is a common site of 71 inflammatory changes, partly because it is capable of tremendous excursion, moving some 6 cm between full abduction and full adduction of the shoulder. This continual movement may produce attrition between the tendon and the bicipital groove. The tendon also may rupture, producing a characteristic change in the contour of the muscle. Surgeons have speculated whether the anatomic shape of the bicipital groove may be a factor in predisposing to inflammatory/degenerative changes but recent MRI studies suggest that this is not the case.21 The biceps can slip medially out of the bicipital groove. This dislocation usually is painful,22 although it sometimes is found during postmortem examinations of individuals who have had no known shoulder symptomatology.23 Considerable variability exists in the depth of the bicipital groove and in the angle that its medial wall makes with its floor.24 Shallow grooves with flat medial walls may be predisposed to such tendon dislocation. Nevertheless, the transverse humeral ligament (retinaculum), which is the chief stabilizer for the tendon, must be ruptured before the tendon can be displaced. The tendon is a useful surgical landmark in the reconstruction of complex proximal humeral fractures. Pectoralis Minor Muscle The only surgical importance of the pectoralis minor muscle lies in its neurovascular relations. The second part of the axillary artery and the cords of the brachial plexus lie directly behind the muscle and below the coracoid process (see Fig. 1-25). 72 Figure 1-25 The pectoralis major and deltoid muscles have been removed completely, revealing the two heads of the biceps tendon, the rotator cuff, the coracoacromial ligament, and the neurovascular bundle. 73 Figure 1-26 The neurovascular bundle lying on the subscapularis is revealed. The axillary nerve exits through the quadrangular space, and the radial nerve exits through the triangular interval. Deltoid. Origin. Anterior border of lateral third of clavicle. Outer border of acromion and inferior lip of crest of scapular spine. Insertion. Deltoid tubercle of humerus. Action. Abduction of shoulder. Anterior fibers act as flexors of shoulder; posterior fibers act as extensors of shoulder. Nerve supply. Axillary nerve. Pectoralis Major. Origin. From two heads. Clavicular head: from medial half of clavicle. Sternocostal head: from manubrium and body of sternum, upper six costal cartilages, and aponeurosis of external oblique. Insertion. Lateral lip of bicipital groove of humerus. Action. Adduction of arm. Nerve supply. Medial and lateral pectoral nerves. (A separate branch of the lateral pectoral nerve supplies the clavicular fibers.) Coracobrachialis. Origin. Tip of coracoid process. Insertion. Middle of medial border of humerus. Action. Weak flexor of arm and weak adductor of arm. Nerve supply. Musculocutaneous nerve. Biceps Brachii. Origin. Short head from tip of coracoid process. Long head from 74 supraglenoid tubercle of scapula. Insertion. Bicipital tuberosity of radius. Action. Flexor of elbow. Supinator of forearm. Weak flexor of shoulder. Nerve supply. Musculocutaneous nerve. Pectoralis Minor. Origin. Outer borders of third, fourth, fifth, and sixth ribs. Insertion. Coracoid process of scapula. Action. Lowers lateral angle of scapula. Protracts scapula. Nerve supply. Medial pectoral nerve. Subscapularis Muscle The deep layer of the dissection is formed by the subscapularis muscle, which covers the shoulder joint capsule (Fig. 1-26). The subscapularis, which is the anterior portion of the rotator cuff, inserts partly into the capsule of the joint. The muscle tendon undergoes degeneration in the same way as do other muscles of the rotator cuff, but to a lesser extent. The problem rarely is severe or symptomatic, because there are other internal rotators of the shoulder and the loss of subscapularis action is not functionally disabling. The subscapularis may be stretched in cases of anterior dislocations of the shoulder or it may be contracted as a result of previous surgery.24 Traumatic rupture of the tendon due to trauma has also been described.25 75 Figure 1-27 The fibrous joint capsule inserts into the humerus around the articular margin of the neck, except inferiorly where it inserts below that articular margin. The capsule bridges the gap across the bicipital groove, forming a structure known as the transverse ligament. Subscapularis. Origin. Medial four-fifths of anterior surface of scapula. Insertion. Lesser tuberosity of humerus. Action. Internal rotator of humerus. Nerve supply. Upper and lower subscapularis nerves. The subscapularis limits external rotation, helping to prevent anterior dislocations; it also may block anterior dislocation physically because of its size and its position in front of the shoulder joint. Because the two subscapular nerves enter the subscapularis medially, incising it 2.5 cm from its insertion does not denervate the muscle (Fig. 1-27). Superiorly, the muscle is connected intimately to the supraspinatus. The plane of cleavage between the two muscles, which represents a true internervous plane between the suprascapular and subscapular nerves, may be impossible to define, especially near the insertions of the muscles. The tendon of the long head of the biceps corresponds to the interval between the muscles and can be used as a surgical guideline to that interval. Shoulder Joint Capsule The shoulder joint has an enormous range of motion. The capsule is loose and redundant, particularly inferiorly and anteriorly. The area of the fibrous capsule itself is about twice the surface area of the humeral head (Fig. 1-28). Anteriorly, the capsule is attached to the scapula via the border of the glenoid labrum and the bone next to it. The anterior part of the capsule usually has a small gap that allows the synovial lining of the joint to communicate with the bursa underlying the subscapularis.26,27 This bursa extends across the front of the neck of the scapula toward the coracoid process (see Fig. 1-27). Posteriorly and inferiorly, the capsule is attached to the border of the labrum. A second gap may exist at this point to allow communication between the synovial lining of the joint and the infraspinatus bursa. The fibrous capsule inserts into the humerus around the articular margins of the neck, except inferiorly, where the insertion is 1 cm below the articular margin. The capsule bridges the gap across the bicipital groove, forming a structure known as the transverse ligament. The long head of the biceps enters the joint beneath this ligament (see Fig. 1-27). The shoulder joint capsule receives reinforcement from all four muscles of the rotator cuff. Further reinforcement is provided by the three glenohumeral ligaments, which appear as thickenings in the capsule. These 76 ligaments are extremely difficult to identify during open surgery, but are usually obvious in arthroscopic procedures. They appear to be of no clinical relevance (see Figs. 1-83A and 1-85A). Figure 1-28 Cross section of the joint. The joint capsule is redundant inferiorly to allow abduction. The long head of the biceps tendon traverses the joint. The tendon is surrounded by synovium and, therefore, is anatomically intracapsular but extrasynovial. Synovial Lining of the Shoulder Joint The synovial membrane, which is attached around the glenoid labrum, lines the capsule of the joint. The membrane usually communicates with the subscapularis bursa and, occasionally, with the infraspinatus bursa (see Figs. 1-27 and 1-54). It envelopes the tendon of the long head of the biceps within the shoulder joint. The synovium forms a tubular sleeve that permits the tendon to glide back and forth during abduction and adduction of the arm. Therefore, the tendon is anatomically intracapsular, but extrasynovial (see Figs. 1-28 and 1-54). Glenoid Labrum The glenoid labrum is a triangular, fibrocartilaginous structure that rings 77 the glenoid cavity (see Fig. 1-28). The joint capsule attaches to it superiorly, inferiorly, and posteriorly. Anteriorly, the attachment depends on the presence or absence of the synovial recess running across the scapular neck (subscapularis bursa; see Fig. 1-54); the presence of the synovial recess leaves a gap in the attachment of the glenoid to the scapula (see Fig. 1-27). It is the detachment of the glenoid labrum anteriorly with or without a bone fragment that creates the Bankart lesion in cases of recurrent anterior dislocation of the shoulder (Fig. 1-29). Dangers Nerves The musculocutaneous nerve is a branch of the lateral cord of the brachial plexus. It supplies the coracobrachialis, biceps brachii, and brachialis muscles, and terminates as the upper lateral cutaneous nerve of the forearm (see Figs. 1-13 and 1-25). The nerve passes through the coracobrachialis, entering the muscle from its medial side about 8 cm below the tip of the coracoid process. The nerve rarely is cut during surgery, but a neurapraxia resulting from excessive retraction can occur. If the coracoid process is detached then a traction lesion may occur if downward retraction is applied to the coracoid process with its attached muscles. If the coracoid process is not detached vigorous medial retraction of the muscles may cause a neurapraxia. When the arm is abducted, the musculocutaneous nerve becomes the most superficial nerve structure in the axillary bundle. Therefore, it is the most common nerve structure to be injured in types of trauma, such as fractures of the clavicle. Care should be taken not to overpenetrate the inferior cortex when using a drill on the superior surface of the clavicle in its middle or lateral thirds. Vessels The second part of the axillary artery lies inferior to the coracoid process under cover of the pectoralis minor muscle. It may be damaged if the arm is not kept adducted while work is being performed on the coracoid process (see Figs. 1-12 and 1-26). 78 Figure

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