Master Techniques in Podiatric Surgery The Foot and Ankle [1 ed.] 9780781732352, 0781732352, 2004021750

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Editor Thomas J. Chang DPM Clinical Professor and Past Chairman Department of Podiatric Surgery California College of Podiatric Medicine Oakland, California Faculty The Podiatry Institute Tucker, Georgia Chief, Podiatry Section Department of Surgery Sutter Medical Center Santa Rosa, California P.xi

Contributors Heiko B. Adams DPM, AACFAS Commonwealth Foot and Ankle Center P.S.C. Louisville, Kentucky Cameron M. Akbari MD Attending Vascular Surgeon Director, Vascular Diagnostic Laboratory Washington, District of Columbia Remy Ardizzone Armstrong DPM, AACFAS Podiatry Fellow Sports, Oethopedic, and Rehabilitation Associates (S.O.A.R.) Redwood City, California Babak Baravarian DPM, FACFAS Assistant Clinical Professor Dept. of Surgery/Division of Podiatric Surgery UCLA School of Medicine Los Angeles, California Gary R. Bauer DPM Associate Professor of Surgery Department of Surgery Temple University School of Podiatric Medicine Philadelphia, Pennsylvania Edwin L. Blitch DPM, FACFAS LowCountry EHCPOD North Charleston, South Carolina Jeff Boberg DPM Bridgeton, Missouri Richard Bouche DPM Virginia Mason Sports Medicine Center Seattle, Washington Michelle L. Butterworth DPM, FACFAS Pee Dee Foot Center Kingstree, South Carolina

David J. Caldarella DPM Director, Podiatric Medical Education Department of Podiatric Medicine and Surgery Gundersen Lutheran Medical Center La Crosse, Wisconsin Faculty Member, The Podiatry Institute Atlanta, Georgia Craig A. Camasta DPM, FACFAS, FACPS Faculty Podiatry Institute Tucker, Georgia Alan R. Catanzariti DPM Department of Surgery Division of Foot and Ankle Surgery Director, Residency Training Programs The Western Pennsylvania Hospital Pittsburgh, Pennsylvania Thomas J. Chang DPM Northern California Foot and Ankle Center Santa Rosa/San Francisco, California Jeffrey C. Christensen DPM Ankle and Foot Clinic of Everett Everett, Washington Luke D. Cicchinelli DPM, FACFAS Department of Surgery, Podiatry Section University Health Systems of Eastern Carolina Greenville, North Carolina Stephen V. Corey DPM, FACFAS Pee Dee Foot Center Kingstree, South Carolina Mary Elizabeth Crawford DPM, FACFAS Chair, Department of Education Northwest Podiatric Surgical Residency Program Swedish Medical Center Providence Hospital Campus Seattle, Washington Ankle and Foot Clinic of Everett Everett, Washington Lawrence A. DiDomenico DPM, FACFAS Department of Surgery Northside Medical Center, Regional Referral Center Youngstown, Ohio Bruce M. Dobbs DPM Serramonte Podiatry Group Daly City, California P.xii Gary L. Dockery DPM, FACFAS Founder and Director of Scientific Affairs Northwest Podiatric Foundation for Education and Research Seattle, Washington Mark H. Feldman DPM, MS Staff Surgeon Podiatric Surgery Parkway Regional Medical Center North Miami Beach, Florida Joshua Gerbert DPM, FACFAS Professor of Podiatry Surgery California School of Podiatric Medicine at Samuel Merritt College San Francisco, California

Sean Grambart DPM Carle Clinic Association Champaign, Illinois Daniel Greenan DPM Burien Foot Clinic Burien, Washington Jordan P. Grossman DPM Orthopaedic Surgery Akron General Medical Center Northeast Ohio Orthopaedic Associates Akron, Ohio William Hal Hatchett DPM LowCountry EHCPOD North Charleston, South Carolina Mark H. Hofbauer DPM McMurray Ankle and Foot Care McMurray, Pennsylvania Byron L. Hutchinson DPM, FACFAS Board of Directors Northwest Podiatric Foundation Seattle, Washington Clinician Department of Podiatry Franciscan Foot and Ankle Institute Federal Way, Washington William Jenkin DPM Podiatric Surgery CCPM/Parnassus Heights Podiatry Group San Francisco, California Louis A. Jimenez DPM Chief, Podiatric Surgery Eastside Medical Center Private Practice Gwinnett Foot, Ankle, and Leg Center Snellville, Georgia Cherie H. Johnson DPM, FACFAS Northwest Podiatric Surgical Residency Swedish Medical Center Seattle, Washington Gary P. Jolly DPM Clinical Professor College of Podiatric Medical Surgery University of Des Moines Des Moines, Iowa Director, PGY IV Fellowship in Reconstructive Surgery of the Foot New Britain General Hospital New Britain, Connecticut Guido A. LaPorta DPM, MS Professor, Department of Podiatric Surgery New York College of Podiatric Medicine New York, New York Chief, Division of Podiatric Surgery Community Medical Center Scranton, Pennsylvania Kieran T. Mahan MS, DPM Professor, Department of Surgery Associate Dean for Research Temple University School of Podiatric Medicine Philadelphia, Pennsylvania Scot D. Malay DPM, FA, FACFAS Department of Surgery, Podiatric Section Presbyterian Medical Center University of Pennsylvania Health System Philadelphia, Pennsylvania

Dennis E. Martin DPM, FACFAS Chairman Podiatry Institute Tucker, Georgia Podiatry Department Trident Regional Medical Center Charleston, South Carolina Michael C. McGlamry DPM, FACFAS North Florida Foot and Ankle Associates Gainesville, Florida Brian D. McInnes DPM Department of Orthopaedics, Podiatry Section Virginia Mason Medical Center Issaquah, Washington Robert W. Mendicino DPM, FACFAS Foot and Ankle Surgery The Foot and Ankle Institute The Western Pennsylvania Hospital Pittsburgh, Pennsylvania P.xiii Aimee A. Nichols DPM Resident Northlake Medical Center Podiatric Residency Program Tucker, Georgia Lawrence M. Oloff DPM Sports Orthopaedic and Rehabilitation Menlo Park, California Amberly Paradoa DPM Second Year Resident Palmetto General Hospital Hialeah, Florida Adam D. Perler DPM Chief Resident Palmetto General Hospital Hialeah, Florida Ronald G. Ray DPM Foot and Ankle Clinic of Montana Great Falls, Montana Christopher L. Reeves DPM, MS Chief Surgical Resident Department of Surgery/Division of Foot and Ankle Surgery The Western Pennsylvania Hospital Pittsburgh, Pennsylvania Matthew Rockett DPM, FACFAS Bay Area Podiatry Associates Houston, Texas Jason Rockwood DPM First Year Resident Palmetto General Hospital Hialeah, Florida Barry Rosenblum DPM Assistant Clinical Professor of Surgery Department of Surgery Harvard Medical School Director of Residency Training Department of Surgery, Division of Podiatry Beth Israel Deaconess Medical Center Boston, Massachusetts

John A. Ruch DPM, FACFAS DME, The Podiatry Institute Resident Member, Department of Podiatry Northlake Medical Center Tucker, Georgia Robert Salk DPM Northern California Foot and Ankle Center San Francisco, Califoria Amber Shane-Reeves DPM, MS Chief Surgical Resident Department of Podiatric Surgical Residency Florida Hospital East Orlando Orlando, Florida Stacey A. Stefansky DPM, AACFAS Podiatric Surgeon Department of Surgery Wuesthoff Medical Center Rockledge, Florida James Thomas DPM Department of Surgery Division of Orthopaedic Surgery University of Alabama School of Medicine Birmingham, Alabama Brandon Tullis DPM, Sutter Gould Medical Foundation Dale Road Care Center Modesto, California John Vanore DPM Gadsden Foot Clinic Gadsden, Alabama Lowell Scott Weil Jr, DPM, MBA, FACFAS Weil Foot and Ankle Institute Des Plaines, Illinois Lowell Scott Weil Sr, DPM, FACFAS Weil Foot and Ankle Institute Des Plaines, Illinois Robert B. Weinstein DPM Resident Member The Podiatry Institute Third Year Resident Podiatric Surgery Department Northlake Medical Center Tucker, Georgia Gerard V. Yu DPM Fellow, American College of Foot and Ankle Surgeons Diplomate, American Board of Podiatric Surgery Director of Podiatric Residency Training Chief, Section of Podiatry Division of Orthopaedic Surgery, Department of Surgery St. Vincent Charity Hospital/St. Luke's Medical Center Faculty Member, The Podiatry institute Private Practice Cleveland, Ohio

2005 Lippincott Williams & Wilkins Philadelphia 530 Walnut Street, Philadelphia, PA 19106 USA 978-0-7817-3235-2 0-7817-3235-2

Acquisitions Editor: Robert Hurley Developmental Editor: Scott Scheidt Marketing Director: Sharon Zinner Project Manager: Nicole Walz Senior Manufacturing Manager: Ben Rivera Creative Director: Doug Smock Compositor: Maryland Composition, Inc. Printer: Quebecor World-Bogota © 2005 by LIPPINCOTT WILLIAMS & WILKINS 530 Walnut Street Philadelphia, PA 19106 USA LWW.com All rights reserved. This book is protected by copyright. No part of this book may be reproduced in any form or by any means, including photocopying, 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. Printed and bound in Colombia Library of Congress Cataloging-in-Publication Data Master techniques in podiatric surgery : the foot and ankle / editor, Thomas J. Chang. p. ; cm. Includes bibliographical references. ISBN 0-7817-3235-2 1. Foot—Surgery. 2. Ankle—Surgery. 3. podiatry. I. Chang, Thomas J. [DNLM: 1. Ankle—surgery. 2. Foot Diseases—surgery. 3. Podiatry—methods. 4. Postoperative Care—methods. 5. Surgical Procedures, Operative—adverse effects. WE 880 M423 2005] RD563.M366 2005 617.5′85—dc22 2004021750 Care has been taken to confirm the accuracy of the information presented and to describe generally accepted

practices. However, the authors, editors, and publisher are not responsible for errors or omissions or for any consequences from application of the information in this book and make no warranty, expressed or implied, with respect to the currency, completeness, or accuracy of the contents of the publication. Application of this information in a particular situation remains the professional responsibility of the practitioner. The authors, editors, and publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accordance with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any change in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new or infrequently employed drug. Some drugs and medical devices presented in this publication have Food and Drug Administration (FDA) clearance for limited use in restricted research settings. It is the responsibility of the health care provider to ascertain the FDA status of each drug or device planned for use in their clinical practice. 10 9 8 7 6 5 4 3 2 1

Dedication I dedicate this book to the following individuals: My Mom and Dad—for providing me with the opportunities in my life. My wife, Elaine, and my children Jayson, Cobi, and Meghan—for all the love and support that has inspired me to complete this project and many of my life's projects. Dr. Gerard Yu—for being a wonderful role model, his commitment to excellence, and his constant support and friendship. Current and future residents—my primary efforts in this project were made with you in mind.

Acknowledgments Each of the authors has been selected for their recognized expertise in the area of foot and ankle surgery and for being leading educators. Their time and effort given to share their knowledge with us cannot be overlooked. I have derived my inspiration and motivation from many talented individuals. I am grateful to Dr. E. Dalton McGlamry for his influence on my career and his significant contributions in developing both the residency training program and the Podiatry Institute in Tucker, Georgia. I was likewise stimulated by the commitment to surgical excellence by many in my training program, and I am indebted to Drs. John Ruch, Alan Banks, Stan Kalish, Louis Jimenez, Tom Smith, Gordon Patton, Tom Cain, James Bouchard, Steve Corey, and all the members of the residency training program at Emory / Northlake Regional Medical Center. Many of these individuals have dedicated their lives to podiatric education and have made a difference in my life. I am also grateful to my past colleagues at the California College of Podiatric Medicine. They provided a supportive environment for my early development and growth in private practice. Currently, my colleagues in Northern California continue to challenge and stimulate me with the opportunities to learn with them on many cases. Their constant support and friendship is invaluable to my surgical practice and to my educational life. And I am grateful to my wonderful wife Elaine and my children. It is easy to find inspiration in their smiling faces. They remind me daily the importance of balance in my life. I would like to send special thanks to Mr. Robert Hurley and the rest of the editorial staff at Lippincott Williams & Wilkins for their persistence and guidance. I am especially grateful for the assistance of Grace Caputo, Scott Scheidt, and Louise Bierig.

Preface Throughout my career, I have found tremendous satisfaction in podiatric education and reconstructive foot and ankle surgery. These two areas have been the most exciting and rewarding parts of my practice, and I feel fortunate to be able to blend these together in this book. It truly is a privilege to have trained under and worked alongside so many wonderful educators, many of whom have contributed to this book. I have learned so much from each of the contributors, and I know you will, too. Although there are several textbooks currently available on foot and ankle surgery, Master Techniques in Podiatric Surgery offers a unique focus on the technical execution of clinical procedures. Before our patients enter the operating room, there are often many technical questions that arise. These questions include incisional placement, dissection techniques, osteotomy design and execution, fixation constructs, and post-op management. Within each of these areas are important technical segments that blend together in an effort to provide a predictable positive outcome. I encounter these questions continually, and I strive to answer them in this book for the curious students, the developing residents, and even the experienced surgeons. I hope this will be a valuable and practical resource for all foot and ankle surgeons looking for additional guidance in the care of their patients. Thomas J. Chang DPM

1 Nail Surgery: Nail Avulsions and Matrixectomies William M. Jenkin

INDICATIONS/CONTRAINDICATIONS The nail unit consists of the nail plate (NP) and its periungual components, including the terminal phalanx. The main constituent of the nail unit is the translucent NP, which varies in thickness from 0.3-0.65 mm and is thicker at its distal end. When an abnormal interaction develops between the NP and the periungual tissue, various forms of pathology will result that create inflammation (paronychia), callused nail groove (onychophosis), potential for ulceration, infection, pain, and disability. Toenail surgery is performed in the treatment of ingrown (onychocryptotic) or abnormally thick (onychauxic) toenails, which may or may not be associated with a fungus infection (onychomycosis) (1). Avulsion results in the temporary removal of the NP from its attachments to the nail matrix, nail bed, and periungual skin folds. It can be performed in a total or partial fashion either as the primary procedure or as an initial step in the performance of another more involved procedure. Matrixectomy results in the permanent destruction of the matrix cells, thereby ending NP production. The entire matrix can be destroyed (total matrixectomy), resulting in the permanent absence of a NP, or only that portion of the matrix producing the offending nail margin can be destroyed (partial matrixectomy), resulting in a narrower NP. The two main surgical methods of matrix destruction are chemical and excisional. Matrixectomy is an elective procedure and can be performed on surgical candidates who are clear of local infection with good vascular status. Often in the presence of an infective paronychia secondary to onychocryptosis, an initial partial nail avulsion must be performed in order to treat infection prior to performance of the matrixectomy. The definitive matrixectomy may then be performed 3-4 weeks after the infection has cleared. Chemical matrixectomy is the most common method. The chemical solution creates a focused third degree burn of the matrix tissue to which it is applied. The resultant wound heals by secondary intent. It drains a serous exudate for several weeks as the wound rids itself of necrotic tissue. The chemical reaction and tissue destruction is self-limiting due to the layer of necrotic cells created by cellular destruction. The goal is to destroy just enough P.2 matrix to prevent nail regrowth. Excessive tissue destruction is to be avoided, as it will result in prolonged drainage and tissue slough. The degree of tissue destruction is dependent upon the underlying vascularity of the area, concentration of the chemical, amount of chemical applied, area of application, and duration of application. The chemicals utilized to perform chemical matrixectomies are phenol and sodium hydroxide. Phenol (carbolic acid) 89%, is the most commonly utilized chemical (2). It causes denaturation of proteins. It is acidic, fungicidal, bactericidal, a disinfectant, antiseptic, and a topical anesthetic upon mucous membranes. It is extremely toxic, and must be handled with caution. It is soluble in alcohol and insoluble in water. Alcohol dilutes but does not neutralize phenol. Sodium hydroxide (NaOH) 10% is also utilized to destroy matrix tissue. It is alkaline and creates a liquefaction necrosis. It is neutralized when combined with acetic acid 5%. NaOH application must be monitored closely as it requires much less time to cause tissue destruction (3,4). Excisional matrixectomies eliminate the matrix tissue by physically removing it. A partial excisional matrixectomy is accomplished by excising the matrix portion that produces the offending nail margin. The medial, lateral, or both margins of the nail can be involved. A total excisional matrixectomy involves excising the entire matrix tissue.

The above procedures can be combined in some cases with excision of the corresponding nail groove(s). If hypertrophic ungual labium is involved with the problem then a wedge resection or labiomatrixectomy procedure is performed. In addition to a partial excisional matrixectomy a wedge of tissue, including the hypertrophic ungual labial tissue, is excised. Contraindications for nail avulsion include a severe dysvascular situation. Total nail avulsion should never be performed when a partial avulsion would accomplish the same goal. Care should be taken in performing matrixectomies in the presence of infection or any dysvascular situation. Although this is performed occasionally, the chances of complications may ncrese with these underlying conditions. An allergy to the chemical will preclude a chemical matrixectomy.

PREOPERATIVE CONSIDERATIONS Before commencing any invasive procedure adequate vascular status must be documented, relevant medical issues must be addressed, informed consent must be obtained, and finally the appropriate procedure, based upon your evaluation, must be employed. Radiography is indicated in the evaluation of a chronic onychocryptosis in order to rule out osteomyelitis (5), in the pincer shaped nail to rule out a subungual bony growth (Fig. 1-1), and when evaluating for epidermal inclusion cyst to see if the cyst has caused bony erosion.

Figure 1-1. Type IV nail deformity, which may be associated with a subungual bony growth (A). Radiograph showing a subungual osteochondroma (B). P.3

SURGICAL TECHNIQUE The area must be thoroughly scrubbed at least to the base of the digit with an appropriate solution. When performing excisional procedures, it is recommended to prep after the initial avulsion due to the high bacterial count normally found in the nail groove (6). If the procedure in question will expose bone or if extensive soft tissue dissection is anticipated, then the entire foot must be prepped and draped in the usual sterile fashion. At all times, all instruments must be sterilized. A basic instrument tray for a chemical matrixectomy consists of the following: nail nipper, nail splitter, two straight Kelly forceps, curette, cotton tipped applicators, tourniquet, and chemical solution. For total avulsion a broad blunt instrument such as a periosteal elevator is needed. Additional instrumentation for excisional procedures consists of a surgical scalpel, Brown Adson pick-up, skin hook retractors, needle-nosed rongeur, and instruments necessary to avulse the nail and perform suturing as needed. Local anesthesia utilizing a complete digital block is indicated for invasive nail procedures even if only one side

of the nail is involved. In certain situations involving pediatric or allergic patients as well as high anxiety patients, general, regional, or monitored anesthesia care (MAC) may be necessary. For a hallux block up to 1.5 mL on each side of the toe and for lesser toes up to 1.0 mL on each side is usually sufficient. Hemostasis, if necessary, can be obtained by applying a digital tourniquet, such as a quarter-inch penrose drain or a finger cut from a latex glove, circumferentially at the base of the digit and holding it in place with a Kelly forceps. The tourniquet should be wide enough to disperse tourniquet pressure and should not be left on for more that 15 minutes. Prolonged pressure from the tourniquet may cause vascular and or neurological trauma. For prolonged hemostasis, especially in the diabetic candidate, an ankle tourniquet is recommended. When performing excisional matrixectomies, epinephrine in a dilution of 1:200,000 has been used successfully in many situations. It is contraindicated in the patient with peripheral vascular disease. Care should be taken when utilizing epinephrine in the diabetic and the post-lumbar sympathectomy patients.

Total Nail Plate Avulsion Techniques Proximal to Distal Technique of Total Nail Avulsion. In this approach the NP is first freed proximally and flipped distally over onto its dorsal surface. When performed in this manner the epithelium of the nail bed along with any subungual hyperkeratosis is removed with the avulsed NP. This is especially useful in the management of certain forms of toe onychomycosis. 1. Free the proximal nail fold from the NP dorsally and laterally with a blunt elevator in order to expose the root of the NP (Fig. 1-2A). All forces should be directed against the surface of the NP being removed, avoiding matrix trauma. 2. Gently slip the elevator beneath the middle portion of the nail root such that the elevator is now aiming from proximal to distal along the long axis of the digit. 3. Grasp the elevator as if you were prying the nail off. For leverage place the thumb of the operating hand upon the dorsal aspect of the nail while it is avulsed from proximal to distal. The NP will actually be flipped over with the undersurface of the plate now facing dorsally (Fig. 1-2B). 4. Free the nail distally by severing its final attachments to the hyponychium and inspect the nail bed for remaining debris (Fig. 1-2C). 5. Apply a wound cover and a postoperative dressing. P.4

Figure 1-2. A-C: Total nail avulsion: proximal to distal technique. Distal to Proximal Technique of Total Nail Plate Avulsion. In this approach the NP is freed from the nail bed from distal to proximal. Care is taken to separate the nail bed tissue from the undersurface of the NP such that only the NP is removed with the avulsion. This is the preferred approach when the NP is of normal thickness without subungual hyperkeratosis. 1. Free the proximal nail fold from the NP dorsally and laterally with a blunt instrument such as a periosteal elevator in order to expose the root of the NP. 2. Separate the NP from the nail bed all the way to its root by inserting a blunt instrument under the NP from distal to proximal, directing all the force against the ventral surface of the NP. 3. Avulse the NP by inserting a hemostat from distal to proximal. Grasp the instrument on one side while rotating the instrument to the center of the nail. Lower the operating hand in such a fashion that it will allow the most peripheral proximal part of the nail to be presented first. Continue the rotation until at least one half of the nail plate has been avulsed from the nail bed. 4. Loosen the hemostat and reapply it to the opposite side of the NP and complete the avulsion. 5. Apply a wound cover, topical antibiotic medication, and sterile dressing. P.5

Partial Nail Plate Avulsion Technique. 1. Determine the width of the medial and/or lateral nail section to be removed. Always attempt to remove enough NP to reverse the pathology while leaving enough to make it aesthetically pleasing. This amount should also allow for drainage from the root portion. This usually equals about one eighth of the plate (Fig. 1-3).

Figure 1-3. A-J: Standard partial nail avulsion technique. A: Hallux block given with 3-5 mLs of plain local anesthesia circumferentially around the base of the toe. Note the erythema and edema to the tip of the toe. B: Topical antiseptic prep of the nail border. C: A straight elevator is used to free up the proximal eponychium from the nail. The elevator will abut proximally against the extensor ridge at the base of the distal phalanx. D: In the performance of a partial chemical matrixectomy, the NP incision is performed before freeing the undersurface of the NP to prevent unwanted NB destruction once the chemical is applied. Otherwise, the nail is separated from the nail bed and the lateral nail groove prior to splitting of the nail. Note the purulence expressed when the abcess is exposed. P.6

Figure 1-3. Continued. E: Illustration of the English anvil nail splitter. The flat arm is placed under the nail. F: The nail is split distally and this is carried proximally underneath the eponychium to the proximal extent of the nail. G: A No. 61 or No. 62 Beaver blade can also be utilized to complete the nail splitting. Care is taken not to lacerate the eponychium as the tip of the blade slips underneath this delicate area. H: A hemostat is now used to firmly grab the nail for removal. To facilitate removal, the nail is simultaneously rotated centrally and pulled distally. P.7

Figure 1-3. Continued. I: Example of the nail removed, free from the border. J: A curette is used to carefully inspect the extent of the nail groove to make sure all nail spicules have been removed. 2. With a nail nipper divide the distal leading edge of the NP corresponding to the distance determined above. This will serve as a starting site for the future NP incision. 3. Free the corresponding portions of the proximal nail fold (PNF) from the portion of the NP that will eventually be avulsed. 4. Incise the NP longitudinally from distal to proximal with a nail splitter. Avoid cutting into the nail bed or PNF. The instrument is held using negative pressure. 5. Free the ventral portion of the nail to be avulsed from its nail bed, starting distally and proceeding proximally. 6. Insert a straight hemostat from distal, clamping the nail section to be removed as far proximally under the PNF as possible. 7. Avulse the nail by first rotating the hemostat centrally prior to pulling out the sectioned nail distally. Remnants of the nail plate will commonly be left behind if the nail is not rotated centrally before pulling distally. 8. Confirm complete removal by curetting and inspecting for a nail remnant inferior to the PNF. 9. By curettage remove any hyperkeratotic or exuberant granulation tissue (pyogenic granuloma) along the distal nail groove. 10. Apply topical antibiotic medication of choice and the postoperative dressing.

Partial Chemical Matrixectomy. 1. Following partial avulsion of the nail border firmly curette the exposed portions of the inferior and superior portions of matrix under the PNF in order to debulk the matrix tissue. 2. Apply the tourniquet. Once the tourniquet is secured, confirm hemostasis and thoroughly dry the exposed

matrix by sponging with a sterile cotton-tipped applicator. 3. Deliver the chemical to the exposed matrix in separate applications. Away from the patient saturate three cotton-tipped applicators with the chemical solution or utilize P.8 applicators already impregnated with the chemical. Place each applicator beneath the PNF for the appropriate time making sure that the chemical does not spread (Fig 1-4). The following application times are recommended: Phenol 89%, three applications, 30-45 seconds each, and NaOH 10%, three applications, 10 seconds each. NaOH 10% is neutralized immediately with a flushing of dilute acetic acid or white vinegar. Avoid excessive chemical being applied to the area by blotting the applicators as well as utilizing applicators that have been prepared with minimal amounts of cotton on them. An ointment may be placed in such a fashion as to further protect the tissue from spread of the chemical.

Figure 1-4. Chemical matrixectomy with cotton tipped applicator stick. 4. Lightly curette the area of tissue destruction between each chemical application and after the final one. This will allow for adequate destruction of the matrix tissue as well as help eliminate the necrotic tissue created by the chemical destruction of the matrix.

5. Release and remove the tourniquet. Observe for a reactive hyperemia. Bleeding is encouraged so as to assist in stopping any remaining chemical destruction. If none is observed, flush with normal saline or an antiseptic solution. 6. Apply a topical antibiotic of choice, such as silver sulfadiazine 1% cream. 7. Apply a wound dressing consisting of several sterile gauze pads with a compressive wrap applied snugly to help reduce hemorrhage but not so tight as to be constrictive.

Partial Avulsion/Excisional Matrixectomies (Frost Procedure) (7). 1. A partial nail avulsion is performed. 2. A linear incision is placed to bone through the PNF, superior and inferior matrix, and nail bed. It runs parallel and slightly to the side of the remaining NP. This incision P.9 extends 1 cm proximal to the eponychium and runs distally the entire length or the nail bed. If the nail groove is not going to be excised, the incision stops at the distal extent of the matrix (modified Frost). 3. A transverse incision measuring 1 cm is placed at a right angle to the initial incision in the PNF. To avoid a tissue slough, the right angle incision can be modified into a curvilinear incision connecting the two arms (modified Frost) (Fig. 1-5). 4. Utilizing skin hooks, a flap is created as the PNF is further dissected free from the superior matrix peripherally, exposing the extent of the matrix proximally and medially/laterally. 5. A second linear incision is now placed on the periphery of the isolated matrix and distally connects with the most distal part of the initial incision. 6. The inferior matrix is sharply dissected free from the underlying periosteum. The entire matrix corresponding to the avulsed portion of nail is excised and removed. If the groove is to be removed the dissection continues distally and the wedge of tissue containing matrix and nail groove is excised and removed. 7. A further modification employs an “acisional” approach wherein no visible incisions are placed in the PNF, but rather the eponychium is split and the matrix portion to be removed is isolated and “blindly” excised. 8. The matrix area is inspected for remnant tissue and any tissue of a fibrous nature is removed with a needle nosed rongeur. 9. The area is flushed with normal saline. 10. Incision closure consists of simple interrupted sutures. Avoid placing sutures through the NP.

Figure 1-5. Example of a modified Frost with a slightly curved incision from the level of the eponychium, extending over the matrix cells, which will be exposed. A suture or Steri-strip can hold the skin edge together for 2 weeks. P.10

Labiomatrixectomy Procedure (Winograd Technique) (8). 1. A partial nail avulsion is performed. 2. Two semielliptical incisions are created that encompass the hypertrophic ungual labia, the nail groove, and a portion of the nail bed and matrix (Fig. 1-6) 3. The wedge of tissue is then sharply dissected from the underlying periosteium, excised, and removed. 4. The matrix area is inspected for remnant matrix tissue. 5. The skin margins are approximated and closed with simple interrupted sutures, avoiding the NP. 6. Postoperative dressings, including a wound cover and sterile gauze are applied.

Figure 1-6. A-C: Modified Winograd excisional matrixectomy. Elliptical excision is seen to include the nail, matrix, and hypertrophic skin border. P.11

Total Excisional Matrixectomy. 1. The total NP is avulsed. 2. A transverse incision to bone is placed at the distal extent of the matrix. 3. A medial and lateral dorsal linear incision through the PNF to the superior matrix measuring 1 cm is placed along each side of the PNF. 4. The eponychium between these two incisions is also incised or split. A flap is created as the PNF is dissected free from the superior matrix, exposing the proximal, medial, and lateral borders (Zadik procedure) (9). 5. Modifications to the above procedure include the “acisional” technique wherein no visible incision is made in the PNF. Instead, the PNF is split, allowing the matrix to be isolated. 6. The entire matrix envelope is sharply excised and removed. Often the matrix can be removed in two sections after an initial central linear matrix incision has been made.

7. The area is inspected for remaining matrix tissue. 8. The distal nail bed is then undermined and mobilized. 9. Additionally, the nail grooves can be excised with the above techniques. 10. Incisions are approximated and closed using simple interrupted sutures. 11. Postoperative dressings consisting of a wound cover and sterile gauze are applied.

POSTOPERATIVE MANAGEMENT Expect minimal disability with avulsion or partial chemical matrixectomy. Most often the patient is managed in his or her own footgear and requires no time off from work. On the other hand, pain and time off from work and activity can be expected after total matrixectomy. A surgical shoe is required to accommodate the dressing and prevent pressure on the surgical site. Analgesics are needed postoperatively with most excisional matrixectomies. Postoperative instructions for NP avulsion: (a) Keep the dressing dry and in place for 24 hours. (b) Remove the dressing while soaking the foot in warm water for 5 minutes. (c) Apply a topical antibiotic or a hydrogel dressing and adhesive bandage. (d) Repeat steps b and c once a day until the return appointment. (e) For a chemical matrixectomy, continue moist wound management for 2 weeks or until drainage ceases. (f) Return appointment in seven days or have the patient call earlier if anything of concern is noted. (g) Prescribe oral antibiotics as necessary. Postoperative management for excisional matrixectomy: (a) Keep dressing dry and intact. (b) Limit activity, rest, and elevate foot when not using it. (c) Return in 3 days for redress. (d) Return in 7-10 days for suture removal. (e) Foot gear as tolerated.

COMPLICATIONS The various nail avulsion and matrixectomy techniques share general complications and possess specific inherent complications. General complications secondary to avulsion include nail deformity upon regrowth such as onychocryptosis, split NP, or permanent onycholysis. Complications specific to partial avulsion consists of a continual paronychia requiring removal of more nail margin along with ruling out or treating an infection. Complications specific to total avulsion most often occur after NP regrowth and include club (bulbous) toe deformity with or without distal onychocryptosis (distal ingrown nail) and thickened NP (onychauxis). Treatment of the former after ruling out a subungual exostosis consists of debridement of any hyperkeratotic hyponychium, softening agents, and distal retraction of tissue with tape. If this plan fails, or if there is an exostosis, surgical intervention in the form of a transverse surgical ellipse of distal digital pulp with or without resection of the distal aspect of the terminal phalanx is indicated (10). Treatment of the onychauxis consists of simple observation and nail debridement as necessary or a total matrixectomy, depending on the severity of symptoms. P.12 General complications secondary to matrixectomy include regrowth (failure), tourniquet trauma causing a tendonitis or neuritis at the base of the toe, infection, and vascular embarrassment resulting in ulceration and gangrene. Complications specific to chemical matrixectomy include chemical burn resulting in prolonged drainage, tissue slough, and periostitis (11); “pseudo” abscess formation under the PNF; allergic reaction; and chemical spill on intact skin. Treatment of tissue slough consists of debridement of necrotic tissue and wound management. Treatment of a periostitis is injection of a corticosteroid once the presence of an infection has been ruled out. Treatment of abscess formation is incision and drainage followed by increased soaking and possibly instilling a wick or drain. First aid for phenol spills on intact skin consists of immediate dilution and copious flushing with alcohol rather than water. Neutralize NaOH 10% with vinegar (acetic acid 5%). Complications

specific to partial avulsion/chemical matrixectomy include inadequate nail margin removal and nail deformity because the chemical destroyed more of the matrix than anticipated. Treatment consists of surgical revision. Complications specific to total avulsion/chemical matrixectomy include an extensive third degree chemical burn. Treatment consists of debridement and wound management, which could include a split thickness skin graft. Complications specific to excisional matrixectomy include wound dehiscence, nail spicule formation (spiculization), and epidermal inclusion cyst formation (12). Always advise the patient of the potential for an inclusion cyst when performing excisional matrixectomies. Inclusion cysts are excised surgically and removed. The complication specific to partial avulsion/excisional matrixectomy is inadequate nail margin removal. Treatment consists of surgical revision. Complications specific to total avulsion/excisional matrixectomy include bulbous shaped (club) toe, hallux malleus, and mallet toe deformity secondary to laceration of the long extensor tendon attachment to the terminal phalanx. Treatment of the digital deformity is repair of the laceration, if possible, or distal interphalangeal joint fusion.

CLINICAL TIPS AND PEARLS 1. Always advise of the possibility of a nail deformity with any type of avulsion or partial matrixectomy. 2. Apply a nonadherent wound cover to prevent the dressing from adhering to the nail bed after a total NP avulsion. 3. The NP incision when performing partial avulsion should be performed prior to undermining the NP in order to prevent inadvertent lysis of the remaining “good” NP, preventing any unwanted spread of chemical when performing a matrixectomy. 4. With partial avulsion when grasping the offending nail margin do not pull toward yourself, but rather rotate the nail margin towards the center of the nail while raising the tip of the instrument so the nail matrix tissue flips out from beneath the PNF. This avoids leaving a remnant of nail matrix behind. 5. Curette the area of tissue destruction between chemical applications and after the final application. This will insure adequate destruction of matrix tissue and help to eliminate necrotic tissue. 6. Always utilize a reversible form of hemostasis when performing chemical matrixectomy because, to a large extent, it is blood that inactivates the chemical reaction, lessening the chance of a more severe chemical burn. It is better to have nail regrowth than a severe nonhealing chemical burn or painful periostitis. Therefore, underapply the chemical. Moist wound healing is best for chemical matrixectomy (warm water soaks or hydrogel dressings). 7. A needle nosed rongeur is essential when performing an excisional matrixectomy. P.13

RECOMMENDED READING 1. Shaw AH: Ingrown Toenail-Preferred Practice Guidelines. Park Ridge, Ill: American College of Foot and Ankle Surgeons, 1996. 2. Boll OF: Surgical correction of ingrowing nails. J Natl Assoc Chiropodists 35: 8, 1945. 3. Travers GR, Ammon RG: The sodium hydroxide chemical matricectomy procedure. J Am Podiatry Assoc 71: 388, 1981.

4. Greenwald L, Robbins HM: The chemical matricectomy. JAPA 71: 388, 1981. 5. Cox HA, Jones Maj RO: Direct extension osteomyelitis secondary to chronic onychocryptosis. J Am Pod Med Assoc 85: 321, 1995. 6. Wolf EW, Hodge W, Spielfogel WD: Periungual bacterial flora in the human foot. J Foot Surg 30: 253, 1991. 7. Frost L: Root resection for incurvated nail. J Natl Assoc Chiropodists 40:19, 1950. 8. Winograd AM: A modification in the technic of operation for ingrown toenail. JAMA 91: 229, 1929. 9. Zadik FR: Obliteration of the nail bed of the great toe without shortening the terminal phalanx. J Bone Joint Surg 23; 405, 1972. 10. Bouche RT: Distal skin plasty of the hallux for clubbing deformity after total nail loss. J Am Pod Med Assoc 85: 11, 1995. 11. Gilles GA, Kenrick JD, Harkless LB: Periostitis associated with phenol matricectomies. J Am Pod Med Assoc 76: 469, 1986. 12. Wadhams PS, McDonald JF, Jenkin WM: Epidermal inclusion cysts as a complication of nail surgery. J Am Pod Med Assoc 80: 610, 1990.

2 Syndactyly and Desyndactyly Craig A. Camasta Robert B. Weinstein

DESYNDACTYLIZATION INDICATIONS/CONTRAINDICATIONS Syndactylism is commonly a congenital or developmental defect, although this condition can be iatrogenic or traumatically acquired. This deformity can be isolated with sporadic occurrence or associated with other congenital malformations such as Apert's syndrome (craniostosis, ocular hypertelorism, downslanting palpabral fissures, midface dificiencies, mental deficiency, and symmetrical syndactyly of the hands and feet involving digits 2, 3, and 4) or Poland's anomaly (unilateral synbrachydactyly and ipsilateral aplasia of the sternal head of the pectoralis major muscle). Congenitally fused digits of the hand and foot have been classified based on the degree of fusion by several authors. In 1932, Kanavel first classified syndactylism of the hand by degree based on the severity of fusion (1). In first-degree syndactyly only the skin and subcutaneous tissues are involved, and second degree indicates an element of bony fusion. Both of these types are amenable to surgical correction. Third and fourth degrees indicate severe alteration of anatomy that obviates surgical intervention on the premise that restoration of normal function cannot be expected. Perhaps the most commonly cited classification schemes of syndactyly are those of Temtamy and McKusick and of Davis and German, both of whom describe specific types of isolated osseous and nonosseous syndactylies of the foot (2,3). The indication for surgical separation of digits is usually related to cosmesis, although pain and digital contractures can compel a patient to seek treatment. Nonosseous syndactyly of the toes usually has no functional consequence, although osseous involvement implies shared myotendinous units and therefore functional alteration. Cosmetic concerns may range from the inability to wear certain types of shoe gear to ridicule with psychosocial implications in the child. P.16 Contraindications for desyndactylization are few. Noncompliance may be the only real contraindication, as improper postoperative care can compromise the success of the operation and lead to infection, dehiscence, hypertrophic scarring, slough of skin graft, or recurrence of the deformity.

PREOPERATIVE CONSIDERATIONS The goals of surgical desyndactylization include complete release of the affected digits, adequate soft tissue coverage, acceptable cosmetic appearance, and prevention of contracture and recurrence of the deformity. A complete physical examination should include assessment of the neurovascular supply to each digit. Local skin tension and mobility will become an issue if the surgical plan includes local rotational or advancement flaps. Digital contractures place tension on the skin, which will afford more cutaneous coverage due to digital shortening if concomitant contracture release or arthroplasty is planned. Flexion/extension functions of each toe should also be assessed, as this may indicate absence or weakened myotendinous input to the fused digit. There have been a variety of operations described in the literature in which the separation of digits can be achieved and the resulting cutaneous defect closed. One method is the use of local flaps from dorsal and plantar tissues that are advanced to fill the defect. Kanaval described a “butterfly” flap for use in finger syndactyly in

which a single, full-thickness, skin graft is fashioned to fill the entire defect of the new web (Fig. 2-1). Weinstock et al described a similar procedure in the foot using a full thickness skin graft obtained from redundant skin on the dorsum of the foot (4). Other plastic surgical techniques have been described including variations of skin plasty. For simple soft tissue syndactyly, the authors use a full-thickness sinus tarsi skin graft to cover the cutaneous defect between the separated digits. Local flaps may provide adequate coverage, albeit at the expense of increased tension on the wound. Repair in this fashion also has a tendency toward more contracture than the use P.17 of a skin graft. Grafts to cover this defect are easily obtained from the redundant skin on the dorsum of the foot, take quite readily to the wound bed in this region, and can be bolstered to the wound without significant tension on the local tissues. This is of course at the expense of a separate surgical (donor) site. If the surgical plan is to use a full thickness skin graft, the donor site must also be evaluated for mobility and redundancy of tissue and be free of skin lesions.

Figure 2-1. Preoperative clinical photograph of type I syndactyly of the foot. Radiographic examination should be performed to assess for osseous involvement. Ancillary imaging studies

(magnetic resonance, tenography, arthrography) are generally not indicated for this condition.

SURGICAL TECHNIQUE The procedure is carried out with the patient supine and under intravenous sedation with local anesthesia to the affected digits and graft donor site (if required). A tourniquet is not utilized. The foot is prepped and draped just above the ankle. The syndactylized toes are addressed first to prepare the recipient site. The orientation of the adjacent sulci to the syndactylized webspace is appreciated both dorsally and plantarly, and an arc is formed from these boundaries to define the proximal extent of the incision (Figs. 2-2 and 2-3). The normal commissure between digits is beveled from dorsal proximal to plantar distal and this relationship should be appreciated. A hypodermic needle may be used as a point of reference. A No. 15 blade is used to carry out a linear incision that extends along the convexity from dorsal to plantar and is carried down to the superficial fascial layer (Fig. 2-4). Electrocautery is used for additional hemostasis. The wound is measured along the sagittal and transverse axes, and a moist sponge is then applied in the sulcus. The transverse axis effects two “wings” with each “wing” being oriented on either side of the commissure.

Figure 2-2. The skin incision will be carried out dorsally to a level defined by the adjacent sulci.

Figure 2-3. The skin incision will be carried out plantarly to an appropriate level. This level should account for the normal slope of the webspace and end distal to the level defined by the dorsal incision. P.18

Figure 2-4. The skin is incised and the dissection is carried through to the subcutaneous tissue.

Figure 2-5. The redundant skin over the dorsolateral aspect of the foot is appreciated and two converging semielliptical incisions are marked out along the relaxed skin tension lines. The recipient site is measured and the graft length and width is defined. The actual size of the graft taken is slightly longer than that measured, which will allow for trimming of the apices after the graft is sewn in place. Attention is then directed to the dorsal lateral aspect of the foot in the region of the sinus tarsi. Two converging semi-elliptical incisions are arranged in oblique fashion along the axis of relaxed skin tension (Fig. 2-5). The incision length is slightly greater than double one of the wing measurements and slightly wider than the dorsal plantar measurement. This will allow for apices that can be handled with tissue forceps, as these will later be trimmed and decrease the likelihood of tip necrosis. A No. 15 blade is then used to remove the full thickness skin graft in toto from the underlying subcutaneous tissues (Fig. 2-6). Any adhering subcutaneous tissue is dissected from the graft as this will impede graft acceptance. Care should be taken to reflect the branches of the superficial peroneal nerve if these are encountered during dissection. The graft can be meshed using a No. 15 or a No. 11 blade. A suture is placed at the medial and lateral margins and the fit of the graft in the sulcus is assessed. Suture is then placed at the dorsal and plantar margins of the graft, dividing the graft into quadrants. If needed, a basting stitch is placed in the midsubstance of the graft to hold the graft in place and P.19 diminish the dead space between the graft and the subcutaneous fascia (Fig. 2-7). Each quadrant is then sutured in place. We use a simple running-type stitch extending from each corner, with the final throw exiting from the proximal skin at the adjacent corner. A tag is left in this stitch that is used to tie in to the adjacent running stitch (Fig. 2-8). Any excess skin is removed at the apices. We recommend a small gauge (5-0 or 6-0) absorbable braided or monofilament suture for this procedure.

Figure 2-6. A and B: The full-thickness skin graft is dissected from the underlying subcutaneous tissue.

Figure 2-7. The graft is sewn in place with a suture at the medial and lateral margins and the size and position of the graft is assessed. A basting stitch is placed in the graft midsubstance to hold the central portion of the graft to the wound bed.

Figure 2-8. The edges of the graft are sewn towards the apices using a running-type stitch of small-gauge absorbable suture. The apices are handled and will be trimmed before the two converging suture ends are sewn together. Attention then proceeds to the donor site where the subcutaneous tissue is undermined as needed to mobilize the skin for closure. The foot is also held in a slightly everted position to reduce some tension on the skin margins during closure. Subcutaneous and intradermal closure are achieved with 4-0 and 5-0 absorbable suture respectively (Figs. 2-9 and 2-10). One effective method for reducing the tension on the skin wound is to remove a portion of subcutaneous fat along with the skin graft and perform a subcutaneous fascial closure.

Figure 2-9. The foot is held everted while the subcutaneous and dermal tissues of the donor site are sewn with small-gauge absorbable suture in a running fashion.

Figure 2-10. Final appearance of the graft in the new webspace. P.20 Bismuth-impregnated nonadherent gauze is placed against the graft site. The drying effect of this dressing is especially important during the plasmatic stage when significant serous weeping can become problematic, resulting in maceration of the graft and surrounding skin. Both wounds are then covered with a dry sterile dressing. The dressing over the graft is placed with slight compression to maintain adherence of the skin graft to the recipient site.

POSTOPERATIVE MANAGEMENT Atraumatic handling of the full-thickness skin graft or flap intraoperatively and careful attention to local skin tension postoperatively will contribute to a favorable postoperative outcome. The surgical dressings should apply compression, although they should not be excessively tight as this may place too much pressure on the graft or flap. The skin graft will undergo some contraction as it “takes” to the recipient site. In the immediate postoperative week there may be very little, if any, serous weeping from the new interspace. After this period, the wound will have increasing amounts of transudative fluid; however, this oozing will decrease substantially once the plasmatic stage of graft healing has ceased. The goal of the primary (initial) surgical dressing is to ensure graft “take” to the wound bed, while secondary dressings for the most part wick away excessive fluid. Therefore, the initial surgical dressing should be removed at 5-7 days postoperatively and then converted to daily changes to prevent maceration of the graft when oozing becomes substantial. Additional gauze is placed between the toes at this time to maintain separation and help absorb the serous transudate. Care should be taken to minimize trauma to the graft and prevent excessive movement of the digits during the immediate postoperative period. The patient is placed on minimal to no weightbearing in the first week, then minimal to partial weightbearing until the graft fully takes. The patient should expect to wear a surgical dressing for several weeks and ambulate in a rigid-

soled surgical shoe.

COMPLICATIONS Complications of surgical desyndactylization include those associated with any surgical procedure (infection, allergic reaction, etc.), although there are several specific adverse events related to this procedure that can be divided into early and late complications. When local flaps are used, whether rotational or advancement, excessive tension is placed on fragile digital circulation. Excessive skin tension may lead to early complications such as hypertrophic scar formation, tissue contracture, or wound dehiscence. When using skin grafts, there is always a possibility that the graft may not “take” and slough from the recipient bed. Local wound care should be initiated in this circumstance until the wound is healed, and revision may be considered if the toes syndactylize. Likewise, in these cases, the donor site may undergo dehiscence if not adequately closed, if closed under excessive tension, or if closed in the face of infection. The most common late complication related to desyndactylization, regardless of technique, is recurrence of the deformity, which is minimized through thorough preoperative planning and atraumatic technique.

CLINICAL TIPS AND PEARLS Although simple soft tissue syndactyly of the toes rarely causes functional difficulty, this deformity can be painful or lead to digital contracture. It is in these cases that consideration should be given to surgical desyndactylization. 1. Atraumatic surgical technique is essential to a favorable postoperative course. As with any plastic surgical procedure, excessive tension on the wound must be prevented. This P.21 is the reason that the authors prefer the use of a full thickness skin graft rather than use local flaps for coverage of the cutaneous defect. 2. In these cases, the graft donor site should be assessed for lesions, including scars, which may preclude the use of a graft from the desired area. 3. Proper postoperative bandaging under appropriate compression is essential; too much could lead to graft necrosis and too little will allow digital motion (shear), which could compromise the sutures. The postoperative bandaging is an important component of the operation and should be perceived as an instrument to assist in graft uptake. 4. The surgeon should realize that these grafts will ooze significantly and have a tendency to become macerated if the dressing is not changed daily after the first week following surgery. There appears to be a delay in the vasomotor innervation of the dermis that allows the skin to retain moisture in the subacute phase of healing (24 weeks postoperative). It is during this time that the patient may need to paint the web space with a drying agent, such as topical povidone-iodone solution, in addition to packing a cotton gauze bandage in the web space and holding it in place with a strip of paper or silk tape. 5. Finally, it is important to recognize the early complications of this procedure, including digital contracture or graft slough, and the primary late complication, recurrence of the deformity.

SYNDACTYLIZATION INDICATIONS/CONTRAINDICATIONS One method for dealing with a flail or unstable toes is through surgical syndactylization. The original description of the procedure is attributed to McFarland and has also been described by Scrase and Kelikian (5, 6, 7). This procedure is commonly utilized in cases involving a flail or overriding fifth toe. This procedure may also be

indicated as a treatment for a recurrent or intractable interdigital heloma molle. Excision of an interdigital corn may leave behind a painful scar, or perhaps there was never resolution of the original symptomatology after interphalangeal joint arthroplasty or exostectomy. After exhausting conservative measures, such as splinting and manipulation, there may be an indication for excision of the sulcus and partially or completely joining the adjacent toes. The floppy digit is tethered through skin plasty to a functional toe for stabilization. Often a significant stabilizing portion of a digit is lost secondary to long-term joint luxation, reconstructive procedures (i.e., resection arthroplasty), trauma, or infection. Loss of function of the flexor apparatus at the base of the proximal digital phalanx can result in severe digital contracture. Due to the loss of intrinsic stability, the toe may be flail and require further reconstruction, including osseous or soft tissue balancing procedures. In cases involving central digits a stable adjacent toe can be harnessed through syndactylization to provide function and stability to an otherwise unbalanced toe. Finally, artificial syndactylization has been utilized in cases of a congenital crossed fifth toe where there is no underlying osseous deformity (8). In these cases additional skin may be removed from the plantar sulcus to further plantar flex the toe upon closure. When an adductovarus component is also present, Z-plasty lengthening of the extensor tendon may be necessary as will arthroplasty to release joint contracture. Other compounding factors affecting the fifth toe must be identified and addressed for a successful outcome of syndactylization. An abducted or plantar flexed fifth metatarsal head, medially deviated fifth metatarsal head cartilage, dorsomedial contracture of the skin, metatarsophalangeal joint capsule and extensor tendon, and plantar medial contractures of interphalangeal joints may be present (9,10). P.22

PREOPERATIVE CONSIDERATIONS Syndactylization of toes can be thought of as a “web advancement” procedure. The essentials of this procedure include removal of a skin wedge devoid of subcutaneous tissue, including the heloma if present, and suturing the skin edges on the adjacent digits together. As with desyndactylization, consideration should be given to neurovascular structures and local soft tissue tension. Soft tissue contracture of the digits should be addressed if present. Sequential release of the extensor hood apparatus and interphalangeal and metatarsophalangeal joints are carried out. It is easier and safer to syndactylize after resection of a heloma in the presence of web space maceration than with bone work. Radiologic examination may reveal osseous deformity such as prominent phalangeal condyles, which may be ressected as part of the arthroplasty procedure. If there is osseous deformity that requires correction, this work should be done first and the area covered with an occlusive adherent dressing before the heloma is addressed and syndactylization carried out. Consequently these procedure are performed through separate incisions to prevent the possibility of contamination of a joint or bone.

SURGICAL TECHNIQUE The authors utilize a lesion encircling technique for the deep-seeded heloma molle. The same procedure can be used for syndactylization of any two digits. The patient is placed in the normal supine position and the foot is prepped to the ankle. The digits are infiltrated with local anesthetic containing a dilute epinephrine solution. If digital contracture exists it is addressed in stepwise fashion prior to sketching the incision for the sulcus excision. Any lesion within the web space is circumscribed with the skin marker because this skin will be excised in toto (Fig. 2-11). Often the case is opposing lesions on both digits, most commonly the fourth and fifth toes. In this case the incision is marked out on the fifth toe that is then pressed against the fourth to create the “butterfly” shaped incision. A No. 15 blade is used to excise the skin wedge in toto from the underlying subcutaneous tissue (Fig. 2-12). The

wedge can be handled with tissue forceps, although a skin hook may help tense the local tissues while incising through them. The blade is held perpendicular to the skin while this procedure is carried out to prevent skiving the wound edges. The toes are then held together to assess the position of the digits as they will sit when syndactylized. Small gauge (5-0) absorbable suture is used in an interrupted fashion to reapproximate the skin edges and close the sulcus (Fig. 2-13).

Figures 2-11. A and B: Preoperative photograph of interdigital maceration with deep seeded central lesion (heloma molle). The lesion is completely encircled with a skin marker. P.23

Figures 2-12. A and B: The lesion is completely excised to the level of the superficial fascia. The wound is then painted with betadine and dressings are applied. Sterile 4 × 4 inch gauze squares and gauze wrap should be sufficient to protect the wound and stabilize the toes. Postoperative splinting is carried out for several weeks to prevent disruption of the syndactyly. Excessive local skin tension or premature movement of the toes away from each other postoperatively can lead to hypertrophic scar formation or wound dehiscence. Digital contracture is also a possibility due to scar formation or excessive sulcus tissue excision. Every measure should be taken to ensure atraumatic handling of the delicate digital tissue intraoperatively, and stability is added through proper postoperative bandaging. When excessive tissue is removed from the dorsum of the interdigital space of central digits or the excised skin ellipse is asymmetrical, rotation of one or both of the toes may occur. This is due to a “teardrop” shaped defect that remains dorsally after the toes have been opposed and is then sutured under tension. Position assessment should be made intraoperatively and should be identified as related to skin wedge dimensions or to soft tissue contracture or osseous deformity of the digits. If not properly released prior to syndactylization, residual joint or soft tissue contractures will result in two adjoined contracted digits. Active digital dorsiflexion and plantarflexion

may be lost. This is especially true for cases involving P.24 subluxed or cross-over fifth toes where sacrifice of digital flexors may be required to reposition the toes.

Figures 2-13. A and B: The fifth toe is held in position while small-gauge absorbable suture is run in a horizontal mattress fashion. Care is taken to evert the skin edges during closure. Invagination of the skin while healing can result in recurrence of the original lesion.

COMPLICATIONS Potential complications of this procedure include those related to any surgical procedure (infection, scarring, etc.). Specific to this procedure, disruption of the syndactyly is possible in the immediate postoperative period if proper splinting is not carried out. Wound dehiscence also remains a concern, although this complication can be minimized through atraumatic tissue handling, aseptic technique, and the use of nonreactive suture material.

CLINICAL TIPS AND PEARLS Syndactylization of digits is a relatively simple though extremely effective procedure for dealing with intractable interdigital heloma and web space maceration. The procedure is also very effective for stabilization of “floppy” central or peripheral digits. 1. It is essential that adequate hemostasis is maintained to prevent postoperative hematoma from compromising the surgical site. 2. It is important to aggressively evert the skin edges while suturing the digits together to prevent invagination of the skin edges and recreation of the original lesion. 3. All digital contractures must be released prior to tethering the digits together. If osseous deformity needs to be addressed this should be done first and through a separate incision, with this incision protected while the interspace is addressed. Contamination of the arthroplasty site could result in septic arthritis or osteomyelitis, which will obviously compromise the operation. 4. Finally, digital position and parabola should be assessed before the skin wedge is removed. Removal of excessive skin from the dorsum of the interspace may result in an extensus deformity of the conjoined digits, while removal of excessive plantar skin can result in disproportionate flexion of the digits.

REFERENCECES 1. Kanavel AB: Syndactylism. Arch Surg 25: 282, 1932.

2. Temtamy SA, McKusick VA: Syndactyly as an Isolated Malformation. In: Bergsman D, ed. The Genetics of Hand Malformations. The National Foundation-March of Dimes. Birth Defects: Original Articles Series 14(3). New York: Alan Liss, 1978. 3. Davis JS, German WJ: Syndactylism (coherence of the fingers and toes). Arch Surg 21: 32-75, 1930. 4. Weinstock RE, Bass SJ, Farmer MA: Desyndactylization: A new modification. J Am Podiatr Med Assoc 74: 458-461, 1984. 5. McFarland B: Congenital Deformities of the Spine and Limbs. In: Platt H, ed. Modern Trends in Orthopaedics. London: Butterworth, 1950. 6. Scrase WH: The treatment of dorsal adduction deformities of the fifth toe. J Bone Joint Surg 36B: 146, 1954. 7. Kelikian H, Clayton L, Loseff H: Surgical syndactylia of the toes. Clin Orthop 19: 208-229, 1961. 8. Rao GS, James JH: Artifical syndactilisation for congenital crossed toes. Br J Plast Surg 40: 502-504, 1987. 9. Leonard MH, Rising EH: Syndactylization to maintain correction of an overlapping fifth toe. Clin Orthop 43: 241-243, 1965. 10. Trepal Ml: Surgery of the Fifth Ray. In: McGlamry ED, Banks AS, Downey MS, eds. Comprehensive Textbook of Foot Surgery. 2nd ed. Baltimore: Williams & Wilkins, 1992: 390.

RECOMMENDED READING Blackfield HM, House DP: Syndactylism. Plast Renconstr Surg 16: 37-46, 1955. Cockin J: Butler's operation for overriding fifth toe. J Bone Joint Surg 50B: 78, 1968. Coleman WB, Kissel CG, Sterling HD: Syndactylism and its surgical repair. J Am Podiatry Assoc 71: 545, 1981. Marek L, Giacopelli J, Granoff D: Syndactylization for the treatment of fifth toe deformities. J Am Pod Med Assoc 81: 248-252, 1991.

3 Primary and Revisional Neuroma Excision Bruce M. Dobbs

INDICATIONS/CONTRAINDICATIONS The treatment for interspace neuromas has been a subject of debate for decades. Newer nonsurgical and surgical treatments have recently been found in an attempt to decrease what some believe are high complication and failure rates. This chapter will deal with several surgical techniques for excision of intermetatarsal neuromas; the effectiveness of conservative treatments (e.g., sclerosing solutions such as 4% alcohol) and new surgical approaches (e.g., external neurolysis, laser modalities) will not be debated. This chapter will focus on the most effective approaches to interspace neuroma excision and revisional neuroma excision. The third interspace will be used to describe the surgical technique, but the procedure can be performed on the second and fourth interspaces as well. Surgical treatment of intermetatarsal neuroma is indicated when pain is not adequately relieved by nonsurgical methods. It is my personal experience, reinforced by the literature, that nonsurgical treatment adequately reduces the pain in a great percentage of patients. Neuroma pain can be difficult for patients to describe but often presents as a burning sensation, a numbing or knife-like pain, or an electric shock. The pain may radiate into the toes or proximally into the foot. Classically, tight shoes exacerbate the symptoms and their removal brings almost instant relief. Conservative care can be judged successful if the reduction of pain allows the patient to return to activities of daily living even if some symptoms persist. The length of time required to treat the patient conservatively will vary and an absolute timetable should be avoided. Treatment should be tailored to the patient's needs. There are no true contraindications to the procedure, assuming that the surgeon has made the correct diagnosis and inflammatory diseases and nerve irritations that may mimic neuroma symptoms have been ruled out. More proximal pathology such as lumbar radiculopathy or discogenic disease may cause distal pain as can tarsal tunnel syndrome. Neuroma surgery, with or without digital surgery, is contraindicated when circulation to the digit would be compromised. Operating on adjacent interspaces may increase the chance P.26 of circulatory embarrassment to the toe. An “interspacectomy” should be avoided and meticulous dissection with magnifying loops should be considered. They are relatively inexpensive and greatly enhance the surgeon's ability to dissect tissue and discriminate between nerves, vessels, and intrinsic tendons.

PREOPERATIVE CONSIDERATIONS The assumption is that all other etiologies have been ruled out and that appropriate radiographs and scans have been taken. Later in this chapter we will discuss adjacent interspace procedures. Diagnostic blocks are helpful when considering multiple interspace procedures. The pain from one interspace can cause the patient to feel similar sensations in adjacent interspaces. Diagnostic blocks of only 1-1.5 mL should always be given when this occurs. The interspace that is most symptomatic should be injected first; once anesthesia has been established the second interspace should be examined. Often the pain in the adjacent interspace is gone. Finally, the diagnostic block should produce complete relief of pain in the interspace injected. If all of the pain is not relieved, it is important to rethink the diagnosis as the cause may be more proximal. There is much debate about the proper approach for removal of a third interspace (Morton's) neuroma. The nerve can be approached from the top or the bottom. Classically, surgeons have used a dorsal linear incision

extending from the web space proximally between the third and fourth metatarsals to approximately midmetatarsal shaft. This incision affords adequate exposure to dissect through the foot into the plantar neuroma. In 1982, Burns and Stewart offered an alternative approach by using a plantar transverse incision on the nonweightbearing portion of the foot between the metatarsal heads and interdigital folds of the toes. In my experience, the advantages of this approach far outweigh the disadvantages. The plantar transverse approach is the superior incision for an isolated neuroma excision and the preferred approach if neuromas are being removed from adjacent interspaces. The dorsal approach requires an incision of the intermetatarsal ligament, increasing the chance of compromise to the dorsal vascular supply and injury to the digital nerves. There is also greater potential for hematoma formation with the dorsal technique due to increased dissection. The dorsal approach allows for immediate weightbearing and obviously a plantar scar is avoided. The plantar transverse incision has several additional advantages. The incision is on a nonweightbearing aspect of the foot; thus, weightbearing can begin immediately after the procedure. The resultant scar is almost always minimal and obviously there are no cosmetic issues as there are with a dorsal scar on the foot. There is a learning curve to the procedure and at first the surgeon may be frustrated in his or her attempt to find the nerve. It is not difficult to dissect the nerve trunk proximal to the metatarsal heads with this exposure, although that is a common criticism. Once the neuroma is identified it can be gently pulled distally and dissected proximally beyond the metatarsal heads. Finally the use of a plantar longitudinal incision for primary neuroma excision should be avoided. This technique will create a plantar weightbearing scar with all the resultant potential complications. This incision should be saved for revisional surgery when removing a “stump” neuroma. The patient must also be kept nonweightbearing for a period of time with the use of this incision. Finally, when planning to remove neuromas in adjacent interspaces the plantar transverse incision is superior to all the others. The use of one central dorsal incision or two separate and essentially parallel dorsal incisions has the potential to cause necrosis to the skin between the incisions. With a single central incision, traction problems when pulling the skin from one side to the other can interfere with healing. The potential for deep space hematomas and complications are also increased with these dorsal approaches. Conversely, a plantar transverse incision is merely extended medially and laterally and adjacent interspaces can be easily identified and entered. When planning this incision, the rule of thumb is to extend the incision from the adjacent interspaces P.27 medially and laterally to the involved interspace(s). For example, if the third interspace is to be entered, the incision would extend from the second to the fourth interspace. If the second and third interspaces are to be exposed, the incision would extend from the first to the fourth interspace.

SURGICAL TECHNIQUE The successful removal of an interspace neuroma requires meticulous dissection, hemostasis, and closure. This is performed under MAC (monitored anesthesia care) or general anesthesia in a fully equipped operating room. The use of a tourniquet is imperative to meticulous dissection. When the nerve is severed, the patient may feel acute pain and become highly anxious. For this reason, unless the patient is deeply sedated, the surgeon should consider depositing a small amount of local anesthesia directly upon the proximal nerve trunk before the actual cut.

Plantar Transverse Incisional Approach As stated earlier, this approach provides excellent visualization of the neuroma, but it may take the surgeon several procedures to become confident and proficient in this technique. The most common frustration encountered when first learning this approach is finding the nerve, which is deeper into the vault of the foot than one might suspect. Usually the nerve is tucked in between the metatarsal heads. The use of loop magnification

greatly enhances the success of the procedure and the surgeon's ability to perform the accurate and meticulous dissection needed to avoid accidentally transecting vessels and intrinsic tendon structures. Use of a skin scribe to mark the incision with several perpendicular hash marks is also recommended to insure the skin will align correctly at closure. The incision is placed halfway between the metatarsal phalangeal joints and the web space. The skin at this level is thicker than on the dorsal surface so slightly firmer pressure should be applied to the scalpel with the initial perpendicular skin incision. The incision is deepened to expose a layer of adipose tissue. This tissue is carefully separated transversely along the incision line exposing the fascia. An enlarged intermetatarsal bursa is frequently encountered next and P.28 should be excised. With careful dorsal dissection, the neuroma will be found between the sheaths of the long flexor tendons (Fig. 3-1). Palpation of the plantar condyles should be a reference point in finding the neuroma. The neuroma is then separated from surrounding tissues via blunt dissection. A dissecting scissors should be used at this point. Once the surgeon can visualize the common proper branch and two digital branches, the nerve is ready to be severed.

Figure 3-1. Standard incision at the dorsal interspace for neuroma excision. Dissection is carried through the deep transverse intermetatarsal ligament for exposure of the nerve trunk. The branches are dissected out to the digits and then the nerve is cleanly resected at the most proximal level possible. The first of the three cuts should be to the common proper branch. If the patient experiences pain with this first cut, transection of the two digital branches should be without pain. The neuroma should be gently grasped and lightly pulled distally. The dissecting scissor is then slid down the nerve as far as possible, proximal to the metatarsal heads and one clean cut is made across the nerve. Each proper digital branch is then severed and the specimen sent to pathology. It is not necessary to suture the proximal nerve stump into an adjacent intrinsic muscle for primary neuroma excision as long as the nerve has retracted into essentially normal tissue. The most important step is to sever the nerve trunk as proximally as possible so that it will now be located in the deep vault of the foot, free of the surgical scar. There should be little, if any, dead space with this technique; however, if

dead space is visible, it should be closed with absorbable suture. Superficial fascia is then closed with absorbable suture and skin with 4-0 nonabsorbable suture in a simple interrupted manner. A compression bandage is applied and the patient is allowed to walk immediately in a postoperative shoe.

Dorsal Approach As stated above, this surgery should be performed under loop magnification. The incision begins at the web space and extends proximally between the third and fourth metatarsals to the midshaft area. The incision is deepened and the dorsal nerves and vessels should be identified, retracted, and protected (Fig. 3-2). As the incision is deepened, the dorsal fascia is incised and deeper dissection will identify the transverse intermetatarsal ligament. If enlarged, an intermetatarsal bursa will be present. The ligament is incised along its entire length. Care should be taken not to injure the intrinsic tendons in the area. An assistant should retract the interspace with Senn retractors or any spreaders that the surgeon feels comfortable using for this task. If needed, the assistant may gently press the plantar structures dorsally if the neuroma is not readily identifiable. This maneuver should push the neuroma dorsally, making it easier to identify. Once found, the assistant should discontinue this maneuver if it is no P.29 longer needed as tissue planes will be distorted. Using dissecting scissors the nerve is now followed proximally and distally, as previously described in the section on the plantar transverse approach, and resected. If an area of dead space has been created, it must be closed with deep suture. The fascia and skin are then closed as previously described. Sutures can be removed sooner than in the plantar transverse incision, and the postoperative course can proceed.

Figure 3-2. Plantar incision placement for third interspace neuroma. Note that incision extends from the second to the fourth interspace, and hash marks are used to insure proper alignment of the skin for closure. The incision is distal to the metatarsal heads and can allow for immediate postoperative weightbearing. The neuroma is easily visualized and resection can still be carried out proximal to the metatarsal heads to help minimize stump formation.

Revisional Neuroma Excision Through a Plantar Incision Once the decision has been made to perform revisional surgery for an amputation or stump neuroma, the plantar incisional approach is the simplest, offering the best exposure to find the entrapped proximal nerve trunk (Fig. 33). The obvious problem with this incision is a scar on the weightbearing portion of the foot and the potential for it to be painful. In order to reduce this problem, the incision must be placed between the metatarsals, extending from between the metatarsal heads to the midshaft area. Once the skin is incised, the proximal nerve trunk is remarkably superficial, located just under the adipose tissue (Figs. 3-4, 3-5, 3-6, 3-7, 3-8, 3-9, 3-10, 3-11 and 312). The nerve is then traced distally and proximally and severed proximal to the weightbearing portion of the foot, where the intrinsic musculature resides. This proximal portion of the nerve should then be anchored into an adjacent muscle belly to prevent further regeneration. Minimal deep sutures are then used and the skin is closed carefully to insure as pleasing a scar as possible.

Figure 3-3. Plantar exposure with visualization of the medial and plantar nerves coming into the third interspace. The curvilinear incision provides a broader perspective for a thorough evaluation.

Figure 3-4. Revisional surgical approach for a stump neuroma secondary to a previous second interspace resection. The incision is curvilinear to allow for oblique alignment with the relaxed skin tension lines (RSTL), as well as allowing better medial and lateral exposure. This incision does not need to extend to the level of the metatarsal heads and avoiding this area will result in less scarring. P.30

Figure 3-5. Full thickness skin flaps are maintained to preserve all the vascularity to the skin edges. The target tissue is the deep fascia, which is the plantar fascia in this approach.

Figure 3-6. At this level of the foot, the separate slips of the fascia can be seen as they extend towards each metatarsophalangeal joint. Depending on the interspace involved, this is a natural plane to follow to deeper exposure. A Metzenbaum scissors is used here to split the fascia above the entrapped nerve and facilitate exposure.

Figure 3-7. The entrapped nerve is usually found within the superficial layers directly underneath the fascia. There may be a moderate amount of scar tissue surrounding the nerve. At this time, the exposure is evaluated to decide at what level the nerve will be resected and where the nerve will be anchored into an adjacent muscle under minimal tension.

Figure 3-8. With distal tension on the nerve, an epineurial cuff is formed by gently scraping the nerve free of the epineurium from a distal level to proximal. This cuff is important for anchoring two 6-0 monofilament nonabsorbable sutures. P.31

Figure 3-9. Two simple interrupted stitches are placed on opposite sides of the nerve within the delicate epineurial cuff and the nerve is cleanly resected at this time. The distal nerve is now dissected to the distal extent of the incision and removed from the wound. It is not necessary to dissect the branches distal to the metatarsal heads as long as a section is removed from the interspace.

Figure 3-10. A tunnel is now made into an adjacent muscle with an attempt to place the nerve under minimal tension. It is helpful to dorsiflex the foot to 90 degrees and evaluate the actual position of the nerve and muscle in stance before deciding on where the nerve should be placed.

Figure 3-11. The needles are now brought through to the far side of the tunnel to bring the nerve deep into the muscle and the knot is tied on the far side of the muscle. This serves to anchor the nerve into skeletal muscle tissue and inhibits the need for the nerve to regenerate.

Figure 3-12. Closure of the plantar fascial separation is done using 4-0 absorbable suture. This will maintain integrity of the fascial attachments distally into the metatarsophalangeal joints. P.32

POSTOPERATIVE MANAGEMENT As stated above, the patient should return in about 1 week for dressing change. If the wound looks well coapted and the patient is willing to change the dressing, the foot can get wet in a brief shower. The patient must then redress the wound in an appropriate manner. The patient should wear a postoperative shoe until the sutures are removed. Again, the sutures should remain in longer for the plantar incision—up to 3 weeks. Butterfly closures and compression are then used for an additional 2 weeks or until no longer needed. The return to normal shoes and activities can progress as tolerated from the time the sutures are removed. Some patients are eager to return to some form of normal shoes while others want to protect their foot for an additional length of time, and these patients are treated on an individual basis. Once the area is no longer overtly symptomatic, they are not required to return to the office on a regular basis. With the plantar incision, the foot needs to remain nonweightbearing with the patient on crutches until the first postoperative dressing change (Fig. 3-13). The patient may then progress to protective, limited weightbearing by

off weighting the incision for an additional 2 weeks. The most important part of the postoperative management is to stress the need for off weighting of the incision for the first 3-4 weeks. The sutures are removed 2-3 weeks after the procedure, and the incision protected as described above. The patient is progressed to full weightbearing as tolerated. Physical therapy may also be helpful to assist in rehabilitation.

Figure 3-13. Patient evaluated 5 days postoperatively. A spring-loaded pain pump can be useful for a slow hourly infusion (0.5 mL/h) of local anesthesia to the end of the resected nerve. This will provide early anesthesia and minimize the need for oral pain management within the first week. The erythema present is of no concern. P.33

MANAGEMENT OF COMPLICATIONS The complication that occurs most often, besides those associated with surgery in general, is scarring and fibrosis around the remaining proximal nerve trunk. In the case of a dorsal incision, the dorsal nerves may be trapped within the scar. My experience has shown the problem of scarring around the proximal nerve trunk occurs more often with poor surgical technique and dissection. The proximal nerve trunk needs to be cut cleanly, and if it is severed with multiple knife or scissor strokes, the likelihood of complications increase. As stated earlier, the nerve needs to be pulled distally and severed proximally to allow it to retract into the proximal aspect

of the foot. If the proximal nerve trunk is left within the surgical scar, a resultant amputation or stump neuroma will usually develop. The severed nerve will attempt to regenerate, causing these pain scenarios. With the plantar transverse approach the resultant scar is aesthetically pleasing, and although there is inevitable scar fibrosis, it is minor and usually resolves within the first year. A repository steroid may be injected into the area to decrease fibrosis. It is preferable to wait until the 1-year anniversary of the procedure to inject cortisone, but the scar can be injected at 6 months if it is particularly bothersome to the patient. The first line of treatment for scar tissue or secondary nerve entrapment is repository steroid. Several injections spaced at least 1 month apart will significantly decrease fibrosis or free the nerve from the fibrosis. In general, cortisone injections should not be instituted for at least a few months after the operation, unless the surgeon feels strongly that the body is not going to break down the fibrosis or scar. If cortisone fails to obtain the desired results or if its use is not desired, 4% alcohol injections can be employed. These injections are given just proximal to the entrapped nerve. Repository steroids may cause depigmentation of the skin, which can be avoided with alcohol injections. The use of a metatarsal bar on a functional orthotic can be of benefit if the problem is not too severe. It can also be used as an adjunct to the injections. If these conservative measures fail to adequately relieve the pain, and an appropriate time interval has taken place between the primary neuroma excision and conservative care, it may be appropriate to consider revisional surgery. A plantar incision should be used for revision, assuming it is the plantar proximal nerve trunk that is involved. Lastly, vascular embarrassment of a digit following neuroma excision could lead to loss of the digit. Obviously patients with preexisting vascular pathology are at a higher risk for this complication, yet this problem can occur in any age group if the vascular supply to the toe is sufficiently damaged during the operation. The loss of a digit is highly unlikely with dissection into a single web space, but if dorsal incisions are used in adjacent interspaces, the toe between the incisions is a greater risk for vascular embarrassment.

CLINICAL TIPS AND PEARLS 1. The use of a plantar transverse incision for single or adjacent interspaces offers excellent exposure of the neuroma(s) and, in my opinion, is the preferred incisional approach. 2. Regardless of the incisional approach used, the nerve should be gently pulled distally and cut as far proximally as possible with a single clean stroke of a scissors or scalpel. 3. For a revisional neuroma, to assist in incision planning, a needle can be placed at the proximal level of the dorsal incision. Push the needle through the interspace and see where it exits plantarly. The plantar incision can then be centered in this general area. 4. When revisional neuroma surgery is performed, a plantar curvilinear incision is simple and effective in exposing the stump neuroma. The proximal nerve trunk should then be buried in an intrinsic muscle belly to minimize the regeneration of the nerve trunk. 5. Nonweightbearing for 3-4 weeks is essential to insure a soft supple plantar incision (Fig. 3-14). P.34

Figure 3-14. Short (2 months, left foot) and longer term (2 years, right foot) follow-up illustrating the excellent appearance of this curvilinear plantar incision. Three to four weeks of nonweightbearing is necessary to allow adequate skin healing prior to loading the foot.

RECOMMENDED READING 1. Dellon AL, Mackinnon SE: Treatment of the painful neuroma formation by neuroma resection and musce implantation. Plast Reconst Surg 77: 427-436, 1986. 2. Morton TG: A peculiar and painful affection of the fourth metatarsa-phalangeal articulation. Am J Med Sci 71: 37-45, 1876. 3. Jones JR, Klenerman L: A study of the communicating branch between the medial and lateral plantar nerves. Foot Ankle 4: 313-315, 1984. 4. Gauthier G: Thomas Morton's disease: a nerve entrapment syndrome-a new surgical technique. Clin Orthop 142: 90-107, 1979. 5. Miller SJ : Surgical technique for resection of Morton's Neuroma. J Am Podiatry Med 71: 181-188, 1981. 6. Mulder JD: The causative mechanism in Morton's metatarsalgia. J Bone J Surg Br 33: 94-95, 1951. 7. Banks AS, Vito GR, Giorgini TL: Recurrent intermetatarsal neuroma: a follow-up study. J Am Podiatr Med Assoc 86: 299-306, 1996.

4 Lesser Digital Surgery: Arthroplasty, Arthrodesis, and Flexor Tendon Transfer Mark H. Hofbauer Amber M. Shane-Reeves

INDICATIONS/CONTRAINDICATIONS Lesser digital deformities are one of the most common problems of the foot and ankle. They may exist as an isolated deformity or in conjunction with hallux deformities. Digital deformities occur in the frontal, transverse, or sagittal planes or in a combination of planes. The interphalangeal and metatarsophalangeal joints (MTPJ) along with the tendinous and ligamentous structures surrounding them encompass these deformities, creating a complex deformity. Digital deformities include, but are not limited to, mallet toe, claw toe, curly toe, adductovarus, congenital overlapping fifth toe, and, most commonly, hammertoes. Successful surgical treatment depends on developing an understanding of the etiology. Biomechanical etiologies are the number one contributing factor to digital deformities. A pes cavus or pes planus foot type can produce abnormal weightbearing patterns that can lead to excess pressure, eventually leading to deformities of the digits or dislocation of the MTPJ. Examine the foot in both weightbearing and nonweightbearing positions to determine the flexibility and the reducibility of the deformity. Examine each digit for hyperkeratotic lesions on the joints as well as the tip of the digit. Also, apparent swelling and possible erythema of the digit can be visualized. Inspect the skin thoroughly, checking for any resulting ulcers. Carefully evaluate the neurological status of the digits. Impaired sensory status may be from underlying diabetes or other metabolic disorders. Since digital surgery can diminish sensation postoperatively, preoperative assessment is essential. Generally in digital deformities the malalignment of the digits may be easily visualized. Evaluation of the MTPJ alignment is also important. MTPJ instability can be found by easily palpating dorsally a prominent base of the proximal phalanx. A positive Thompson and Hamilton sign—pain with pure vertical force across the MTPJ—may be elicited. This pain needs to be addressed because often it is the source of recurrent pain. P.36 When considering surgery the overall medical condition of the patient must be assessed. The risks of surgery versus the benefits need to be considered. Contraindications to digital surgery can be, but are not limited to, active skin infection, impaired neurovascular status, and comorbid medical conditions.

PREOPERATIVE CONSIDERATIONS Radiographic evaluation is used as a confirmatory measure and to assess the severity of the deformity before performing surgery. AP (anteroposterior) and lateral radiographs are helpful in confirming the location and specific type of deformity. The MTPJ may also be evaluated for decreased joint space and joint dislocation/subluxation (Figs. 4-1 and 4-2). When choosing the appropriate surgical procedure the physician must be aware of the lifestyle and activity level of the patient. Arthroplasty is recommended in older, nonambulatory patients and patients with minimal activity levels because arthroplasty can decrease toe purchase and propulsion of the digit. Patients with painful lesions or ulcerations around the digit are also candidates for arthroplasty. Arthroplasty is the procedure of choice for fifth digit deformities as arthrodesis of the fifth digit causes problems with shoe gear.

In an active young patient, digital arthrodesis is recommended because it stabilizes the flexor and extensor musculature, while arthroplasty may lead to recurrence of the deformity because of excessive flexibility. When performing procedures on multiple digits, arthrodesis should be chosen due to the lack of stability that occurs with arthroplasty. It is important to educate the patient so that he or she can make an informed decision about the surgery as well as understand the surgical and healing processes. Arthrodesis is the procedure of choice for fixed digital deformities lacking MTPJ stability and decreased intrinsic muscle function of the digits. Both the end-to-end and peg-in-hole P.37 are common arthrodesis procedures. The peg-in-hole creates a larger amount of shortening than the end-to-end procedure; therefore, it is typically used in patients with long digits. Due to the nature of bone remodeling the peg-in-hole procedure should only be used in patients with good bone stock. Due to the time required to fashion the peg as well as increased technical difficulty, many surgeons prefer the end-to-end procedure to the peg-inhole.

Figure 4-1. Lateral radiograph of a hammertoe with dorsiflexion at the MTPJ and plantarflexion at the interphalangeal joints.

Figure 4-2. AP radiograph showing the second digit dislocation deformity. Joint narrowing or subluxation is noted with sagittal plane contractures. Flexor tendon transfer is commonly used to augment arthroplasty or arthrodesis of the central digits. Flexor tendon transfer is indicated in patients with a floating digit and metatarsalgia. These patients may also have a dorsally contracted MTPJ, which can be reduced. The literature is controversial; many reports of the digit becoming stiff after the procedure have been published. It is the senior author's opinion that this stiffness is actually a key to the procedure's success. By fusing the proximal interphalangeal joint and stiffening the MTPJ, there is less chance of recurrence at the MTPJ level. If there is any question about the vascular status of the patient or if there is a history of vascular insufficiency, obtain noninvasive vascular studies before surgery. The vascular supply should be adequate for healing of the digits before surgery is considered. Digital surgery in a patient with vascular insufficiency should only be considered when trying to off-load chronic ulceration sites, commonly the distal tufts of the digits in the diabetic patient.

SURGICAL TECHNIQUE Digital surgery can be approached systematically by utilizing a “sequential” release popularized by McGlamry. Besides the obvious bone deformity, one needs to recognize the significant soft tissue contributions to the digital deformity. As each component of the repair is performed, the digit is evaluated to assess the level of reduction and/or need for further release. The Kelikian “push-up” test will assist in this sequential evaluation and is performed by loading the ball of the foot to assess the digital position. If a dorsal or transverse contracture still exists at each step, then the next component of release is performed. The sequential approach is described as the following: Interphalangeal joint tenotomy/capsulotomy Removal of bone from the interphalangeal joint Extensor hood (wing/sling) release (Fig. 4-3)

MTPJ release (can also involve medial and lateral MTPJ capsule) (Fig. 4-4) Flexor plate release (Fig. 4-5) P.38

Figure 4-3. Diagram illustrating release of the extensor hood apparatus from the MTPJ capsule.

Figure 4-4. Diagram illustrating transverse capsulotomy of the MTPJ.

Figure 4-5. Diagram illustrating release of the plantar plate utilizing a McGlamry elevator. P.39

Figure 4-6. Example of several common skin incisions. The most common is the linear incision shown on the second toe. Elliptical linear or transverse incisions are also used for removal of keratotic tissue. A fifth derotational ellipse runs proximal lateral to distal medial, centered over the head of the proximal phalanx.

Figure 4-7. Incision through the skin onto the extensor tendon. This is the deep fascial layer and the target tissue for dissection. The subcutaneous tissue is preserved with the skin.

Arthroplasty Place the patient supine on the operating table with an ankle tourniquet for hemostasis. Make a 3-cm linear incision at the proximal interphalangeal joint (Fig. 4-6). Deepen the incision to the level of the extensor tendons, preserving the subcutaneous tissue with the skin edge (Fig. 4-7). The proximal interphalangeal joint can be easily identified by plantar flexing the joint and identifying the delve between the middle and proximal phalanges (Fig. 4-8). Incise the extensor tendon transversely at the highest point, which will correspond to the head of the proximal phalanx (Fig. 4-9). This will provide a nice tag of distal extensor tendon to repair during closure. Grab this distal slip of tendon and apply gentle distal tension while freeing up the dorsal capsule. You will now see the joint space clearly (Fig. 4-10). Release the medial and lateral collateral ligaments along the head of the proximal phalanx by flexing the digit and then inserting the No. 15 blade into the proximal interphalangeal joint along the plantar aspect of the head (Fig. 4-11). Stroke the blade from plantar to dorsal along the medial side of the head, keeping the blade in close contact to the bone and P.40 parallel to the long axis of the phalanx. This will serve to protect the flexor tendons as well as the neurovascular bundles (Fig. 4-12). Repeat the similar release of the lateral side. Free the extensor tendon from dorsal soft tissue attachments at the head of the proximal phalanx. Isolate and grasp the head of the proximal phalanx, using a pickup to steady and isolate the head. Using either an oscillating saw or bone cutting forceps, resect the head of the proximal phalanx (Fig. 4-13A and B). The amount resected depends on the length of the digit and the amount needed to reduce the deformity. Generally, resect just proximal to the flare of the phalangeal head. Be sure to remove an adequate amount of bone with the initial cut because rongeuring and rasping is not recommended due to spicule development.

Figure 4-8. Flexion of the interphalangeal joint showing the head of the phalanx. All the superficial tissues are retracted away from the deep tendon.

Figure 4-9. Transverse tenotomy of the extensor at the head of the phalanx. This will provide a nice portion of distal extensor tendon for closure after joint resection.

Figure 4-10. Complete exposure to the interphalangeal joint with release of the dorsal joint capsule.

Figure 4-11. Initial approach to medial/lateral collateral ligament release. The scalpel is inserted parallel to the long axis of the phalanx and brought from under the head outward. Care is taken to stay plantar to the head of the proximal phalanx against the bone. Now load the forefoot (Kelikian test) to see if there is acceptable reduction to the digit. If dorsal contracture still

exists, then the extensor hood mechanism will need to be released from the MTPJ and the proximal phalanx. Pull distally on the proximal stump of the extensor tendon and incise the extensor hood both medially and laterally just below the extensor tendon. Keep tension on the tendon and run the scalpel blade parallel to the long axis of the tendon (Fig. 4-14). The extensor tendon and the MTPJ are distinct layers of tissue at the level of the MTPJ, and the extensor tendon can be released proximal to the P.41 MTPJ (Fig. 4-15). The Kelikian test is performed again. If contracture is still observed, the next step is MTPJ release. This is facilitated by distal traction on the remaining stump of the proximal phalanx. Once the puckering is observed, perform a distal transverse capsulotomy along the base of the proximal phalanx (Fig. 4-16). Care is taken to avoid damage to the cartilage of the metatarsal head. The medial and lateral capsule can also be released at this time, depending on transverse plane alignment. The Kelikian test is performed again. If this is still contracted, then a McGlamry elevator is used to release the flexor plate contracture. It is very important to place the elevator in carefully as iatrogenic damage to the metatarsal head is possible with aggressive placement. With distal traction on the digit, initially P.42 insert the elevator in the plantar distal direction and then allow the concavity of the elevator to follow the convexity of the metatarsal (Fig. 4-17). Once the elevator has cleared the plantar condyles of the metatarsal, the release of the flexor plate contracture will be felt with a steady proximal pressure. This step should adequately conclude release of the soft tissue contributions to digital malalignment.

Figure 4-12. Release of the medial/lateral collateral ligament. Take care to stroke the blade from plantar to medial/lateral maintaining close contact with the bone. As this motion is made, the blade will make a 90-degree turn from under the phalanx onto the side of the bone.

Figure 4-13. Two approaches shown for removal of cartilage and bone resection. Use of an oscillating saw (A) as well as bone cutting forceps (B) are commonly seen. For an interphalangeal joint arthroplasty, the bone is resected behind the flare of the phalangeal head.

Figure 4-14. With distal tension on the tendon, the medial and lateral arms of the extensor hood are released. Again, the scalpel is held parallel to the long axis of the tendon.

Figure 4-15. After proper release of the extensor hood above the MTPJ, the dorsal MTPJ capsule is visible and noted to be intact. At the level of the MTPJ, the tendon and the capsule are two distinct layers.

Figure 4-16. With distal tension on the phalanx, the MTPJ capsule will pucker and guide the transverse capsulotomy for the MTPJ release. Care is taken to avoid damage to the cartilage deeper in the joint. To help provide postoperative stability during healing, a K-wire can be utilized to pin the toe. Make a guide hole

in the center of the distal aspect of the proximal phalanx (Fig. 4-18). Now introduce a K-wire distally through the base of the middle phalanx out through the distal tip of the distal phalanx, keeping the wire slightly dorsal in the bone. Pay attention to the location of the wire in order to keep from damaging the nail bed or plate (Fig. 4-19). In a P.43 retrograde fashion, drive the K-wire through the predrilled hole in the proximal phalanx to the base of the digit. If the MTPJ release was not performed, the tip of the pin will seat nicely within the subchondral bone of the phalanx, without violation into the joint. If the MTPJ release was performed, the pin should also cross the MTPJ to allow positional stability to the MTPJ for a 4-6 week period (Fig. 4-20).

Figure 4-17. Use of a McGlamry elevator to release the contracture of the flexor plate. Care is taken to avoid injury to the cartilage and the plantar condyles. This can be a dangerous instrument if used incorrectly or too aggressively.

Figure 4-18. Manual introduction of a K-wire into the medullary canal of the proximal phalanx to prepare a guide hole and facilitate future placement.

Figure 4-19. The pin is now driven through the base of the intermediate and distal phalanges to exit out the distal tip of the toe. Care is taken to avoid exiting too low into plantar pulp or too high into the nail region. Suture the extensor tendons ends together with a 3-0 or 4-0 absorbable suture (Fig. 4-21). Close the skin with a

horizontal mattress or simple interrupted technique (Fig. 4-22). Place a sterile compressive bandage on the digit. The senior author prefers utilizing betadine soaked T or L bandaging around the digit for added support. Please note that when performing an arthroplasty of the fifth digit, correction of the adductovarus rotation may need to be addressed. This can be accomplished by utilizing a derotational skin procedure to the arthroplasty. Make the initial incision as two semicon-verging elliptical incisions oriented distal medial to proximal lateral, centered over the neck of the proximal phalanx. The incision should be large enough to remove all of the hyperkeratotic tissue on the digit. This will increase the likelihood of success of the derotation. Take care not to compromise the vascular status of the digit. The toe will then be derotated upon closure of the skin.

Figure 4-20. Rectus alignment of the digit after pin placement. The tip is bent 90 degrees, then cut and capped for protection. Antibiotic ointment is placed at the exit hole of the pin.

Figure 4-21. Deep fascial closure of the extensor tendon with 3-0 absorbable suture. If the tendon is under too much tension, a Z type of tendon lengthening is necessary for closure. P.44

Figure 4-22. Skin closure with steri-strips for added support. Note the pin exiting the tip of the toe.

Figure 4-23. Use the oscillating saw to resect the medial, lateral, and plantar condyles for fashioning of the peg. Care is taken to avoid fracturing the peg or removing excessive bone.

Arthrodesis End-to-End Arthrodesis. The same approach to the proximal interphalangeal joint has been described above. In the same fashion as the arthroplasty, detach the collateral ligaments both medially and laterally, paying close attention to the neurovasculature. Resect the cartilage on the head of the proximal phalanx and the base of the middle phalanx utilizing an oscillating saw or hand instrumentation. These cuts are made slightly proximal to the articular cartilage in the subchondral bone. The proximal cut is more distal on the proximal phalanx than the arthroplasty technique, allowing the preservation of adequate digital length. The K-wire is introduced into the toe as described in the prior section. Again, for a MTPJ release, the wire will be extended across the MTPJ into the metatarsal head. Reapproximate the extensor tendon in a corrected position using absorbable suture. Close the skin with nonabsorbable horizontal mattress or simple sutures. After skin closure, bend the distal end of the K-wire leaving a half inch of exposed wire to allow for swelling. Bandage the forefoot with the toe protected and in anatomic alignment. Peg-in-hole Arthrodesis. Detach the collateral ligaments both medially and laterally while avoiding the neurovasculature. Fashion the peg by resecting the plantar, medial, and lateral condyles of the proximal phalanx with an oscillating saw (Fig. 4-23). It is very important to be sure not to fracture the peg or cause excess shortening. Resect the distal cartilage while taking care to maintain the dorsal cortex. Using a K-wire predrill a hole in the medullary canal of the peg. Keep the wire dorsal in cortical bone. Drill a hole into the base of the middle phalanx with the Shannon burr corresponding to the size of the peg. Make sure to check the fit of the peg into the hole before inserting the K-wire. The K-wire is inserted in a retrograde fashion. Make sure the peg sits securely before closing. Bandage the forefoot with the toe protected and in anatomic alignment. Check anatomic alignment of the K-wires with a postoperative radiograph (Fig. 4-24). Flexor Tendon Transfer. The senior author does not perform this as an isolated procedure but in conjunction

with an arthrodesis. As a result, a dorsal approach to the flexor tendon transfer allows easy access and eliminates an additional incision. Once bony resection of the phalanx has taken place, the flexor tendon can be easily accessed. Plantarflex the ankle to relieve the tension on the flexor tendons. Identify and pull the flexor digitorum longus tendon proximally with a hemostat through the dorsal incision, attempting to leave the split brevis tendons on either side of it intact (Fig. 4-25). Spilt the flexor digitorum longus longitudinally approximately 2 cm proximally using the shallow groove on the plantar surface of the tendon as a guide (Fig. 4-26). Position one half of the tendon on each side P.45 of the digit so that there are tendon halves on either side of the head of the proximal phalanx. Bring both the medial and lateral slips of the flexor digitorum longus dorsally over the shaft (Fig. 4-27). While loading the forefoot to assess proper tension, suture the two halves together with absorbable suture (Fig. 4-28). The extensor tendon should be placed through the loop created by the flexor tendons. Reapproximate the extensor tendon utilizing absorbable suture. After skin closure, bandage the forefoot, maintaining the toe in proper anatomic alignment.

Figure 4-24. Postoperative radiograph showing proper alignment of the K-wire across a peg-in-hole fusion site. Note the tip of the pin in place at the subchondral bone of the phalanx. Care is taken not to extend into the MTPJ.

Figure 4-25. The flexor digitorum longus is identified immediately under the plantar interphalangeal joint capsule and isolated with a hemostat.

Figure 4-26. The flexor is split longitudinally with a No. 15 blade while maintaining gentle medial and lateral tension on the tendon edges. P.46

Figure 4-27. Shows the two tendon halves positioned on opposite sides of the proximal phalanx.

Figure 4-28. The two halves of the flexor tendon have been securely sutured together on the dorsal aspect of the phalanx. It is helpful to load the forefoot when determining the amount of tension needed for physiologic transfer of the tendon. The transfer is supported with a 3-0 absorbable repair.

POSTOPERATIVE MANAGEMENT

After an arthroplasty without K-wire stabilization, bandage the toe in a corrected position, and utilize betadine soaked T- or L-shaped bandages to maintain alignment and reduce edema. A mild analgesic is prescribed for pain. The patient can ambulate in a rigid postoperative shoe immediately following surgery. The patient is seen 2 weeks postoperatively when the bandage is changed and the sutures are removed. Corrective valgus positioned bandaging is especially important in the derotational fifth toe arthroplasty in order to maintain the corrected alignment. With arthrodesis, flexor tendon transfer, or arthroplasty with a K-wire, postoperative care varies slightly to that of the nonfixated arthroplasty. The toes are bandaged in a corrected position with only mild analgesics needed for pain. The patient is instructed to decrease the amount of weight applied to the foot and partially bear weight by heel walking in a rigid surgical shoe with crutches. The patient is seen 2 weeks postoperatively. The K-wire P.47 is left in place for 4-6 weeks postoperatively until evidence of healing across the arthrodesis site is observed or if the pin is loose. Removal of the pin is performed in the office without need for local anesthesia. When a wire is introduced across the MTPJ, a ¼-½inch felt pad needs to be placed up to the digital sulcus to protect the pin from upward pressure (Fig. 4-29). It is important to remain in the rigid surgical shoe throughout this period of time. The wires should be kept dry and protected in order to avoid pin tract infections. If an infection is suspected, the wire should be removed and the toe splinted with the patient placed on antibiotics. In the end-toend arthrodesis, there may not be radiographic confirmation of complete healing for up to 1 year.

Figure 4-29. Example of a postoperative shoe padded from the heel to the digital sulcus to protect upward forces on the K-wire and toe. This will greatly decrease the chances of wire irritation, bending, and breakage.

COMPLICATIONS As with any surgery, there are associated risks and complications. Common complications with digital surgeries include swelling, recurrence, apposition, vascular compromise, floppy toe, nonunion, pain, hardware failure, infection, and erythema.

The most common of these is swelling. Maintaining the toe in a compressive elastic bandage (coban) for at least 1 month postoperatively can minimize swelling. According to Burns, the most common complication seen is an “enlarged fibrotic sausage” digit with excessive scar tissue. This can be treated similar to a keloid with steroid injections and by wrapping the digit with a coban dressing to decrease the swelling. Oral nonsteroidal antiinflammatory medication is also helpful. The authors feel that swelling can be initially minimized by maintaining the practice of minimal dissection during the surgery. The floppy toe can be created by resecting too much of the proximal phalanx. Initially this problem can be prevented by taking care not to resect too much of the proximal phalanx and by ensuring preservation of the flexor tendons. The floppy toe can be corrected by syndactylization with the adjacent digit or conversion to an arthrodesis. Wire irritation or breakage is a not uncommon postoperative concern. Studies report a large number of broken wires when 0.045-inch K wires are used. Recommendation for a 0.062-inch wire will minimize the potential for breaking. Patients must be made aware of the postoperative course of the surgery and given realistic expectations. The patient needs to be aware that the goal of surgery is reduction of pain and not necessarily cosmesis and understand that there will be a minimum of 5-6 weeks before the patient will return to regular shoes. It may take months after the surgery before the patient will fit into a dressy shoe.

CLINICAL TIPS AND PEARLS 1. Safe dissection is essential to avoid vascular compromise. Minimal dissection is essential to avoid postoperative swelling. 2. Make the initial cut a good one; excessive debridement can increase regrowth. 3. When inserting wire fixation, be sure to keep the K-wire dorsal in thebone. A 0.062-inch K-wire provides much more stability than a smaller one. 4. When inserting a pin across the MTPJ, leave the pin in for an average of 4-6 weeks to encourage adequate soft tissue stability. 5. All wires placed across the MTPJ should be protected by padding the postoperative shoe from the heel to the digital sulcus to avoid bending of the pin during ambulation.

RECOMMENDED READING 1. Burns AE: Digital arthroplasty. Clin Podiatric Med Surg 3: 20-21, 1986. 2. Coughlin MJ, Dorris J, Polk E: Operative repair of the fixed hammertoe deformity. Foot Ankle Int 21: 94103, 2000. 3. Gould N, Schneider W, Ashikaga T: Epidemiological survey of foot problems in the continental United States. Foot Ankle 1: 8-10, 1980. P.48 4. Gerbert J: Digital arthrodesis. Clin Podiatric Med Surg 3: 77-93, 1986. 5. McGlamry ED, Jimenez AL, Green DR: Lesser Ray Deformities. In: Banks AS, Downey MS, Martin DE, Miller SJ: Comprehensive Textbook of Foot and Ankle Disease. 3rd ed. Philadelphia: Lippincott Williams &

Wilkins, 2001: 253-304. 6. Sokoloff HM: Soft tissue digital procedures. Clin Podiatr Med Surg 3: 23-5, 1986. 7. Trepal MJ, Harkless LB: Preferred practice guidelines: hammer toe syndrome. J Foot Ankle Surg 38: 166176, 1999.

5 Hallux Interphalangeal Joint Fusion Luke D. Cicchinelli John Ruch

INDICATIONS/CONTRAINDICATIONS The hallucal interphalangeal joint is primarily fused to eliminate pain or deformity of the great toe. Intra-articular pain is often the result of previous trauma to the joint with an intraarticular fracture or related to systemic arthritides such as rhuematoid or psoriatic arthritis. This is a fairly common occurrence in football players and wrestlers whose toes are subjected to the extremes of ranges of motion and impact forces. Pure positional deformity at this joint level is also a reason to consider fusing the joint to ameliorate the resultant biomechanical abnormalities. Rigid hallux malleus often causes a retrograde buckling force on the first metatarsal head and can cause plantar callouses as well as dorsal interphalangeal keratomas and ulcerations. This condition is most commonly observed in individuals with cavus feet and neurological deformity, and it is among the myriad of forefoot pathologies that patients with diabetes mellitus seek treatment. Iatrogenic deformity from failed bunion surgery and hallux varus frequently cause functional instability at the interpahalangeal and metatatarsophalangeal joints. Effective arthrodesis at this level will halt further progression of the deformity and eliminate symptoms. Contraindications to fusion of the interphalangeal joint are inadequate vascularity and active infection. Clinical acumen is required to ensure that fusion for the stabilizing effect at the first metatatarsophalangeal joint and reduction of metatatarsal declination will indeed be the desired result. A dropfoot with paralysis of the extensor hallucis longus tendon is a relative contraindication to this procedure unless this deficit is addressed simultaneously to provide for adequate toe clearance during the swing phase of gait. P.50

PREOPERATIVE CONSIDERATIONS Pertinent anatomic concerns are the location of the neurovascular bundles in each quadrant of the toe. Normal, plain film, weightbearing x-rays are sufficient for preoperative evaluation. Give consideration to a raised lateral hallux view to better visualize the joint and the presence or absence of an interphalangeal sesamoid. If a sesamoid is present it will need to be removed so the surgeon will be able to create a flush fit at the site of the arthrodesis. Attention is given to the quality of bone stock in elderly patients to determine whether fixation is best achieved via screw or pin fixation.

SURGICAL TECHNIQUE The procedure is readily performed under local anesthetic (Figs. 5-1, 5-2, 5-3, 5-4, 5-5, 5-6, 5-7, 5-8, 5-9, 5-10, 5-11, 5-12, 5-13, 5-14, 5-15, 5-16, 5-17, 5-18, 5-19, 5-20, 5-21, 5-22, 5-23, 5-24, 5-25, 5-26, 5-27, 5-28, 5-29, 530 and 5-31). Tourniquet control is the surgeon's choice. A variety of incisional approaches are available including straight longitudinal, lazy S, and transverse. The author typically employs a transverse incision to allow for the removal of redundant tissue at closure.

POSTOPERATIVE MANAGEMENT Patients are managed with protected weightbearing in a surgical shoe for 6 weeks or until radiographic evidence of fusion. Patients are told that clinical rigidity may be present prior to 6 weeks, and if they are doing well, then

early return to soft shoe gear may be possible on a case by case basis. They may also expect that on occasion the hallux will not be able to completely make contact with the ground. This is dependant on contracture or pathology at the metatarsal phalangeal joint.

COMPLICATIONS The most likely complication is delayed union or migration of internal fixation devices. This is usually caused by inattention to detail during the procedure, particularly in not obtaining a flush fit of both surfaces while inserting internal fixation. These healing complications routinely strengthen or consolidate when given time and more aggressive immobilization such as placing the patient in a Cam walker or a walking cast.

Figure 5-1. Two transverse semi-elliptical incisions are made over the hallux interphalangeal joint. This should be centered just slightly closer to the base of the distal phalanx to improve visualization of the articular cartilage borders. P.51

Figure 5-2. Dissection is carried out at the dermal-subcutaneous interface and the wedge of skin is removed completely. Care is taken not to deviate too far medially or laterally for risk of injuring the neurovascular bundles. The short end of Ragnell retractors is ideally suited for protecting these structures. Senn retractors are too large and double skin hooks are too small.

Figure 5-3. The thin deep fascia overlying the extensor hallucis longus tendon is reflected.

Figure 5-4. A transverse tenotomy of the extensor tendon is performed, exposing the head of the proximal phalanx and the base of the distal phalanx.

Figure 5-5. The collateral ligaments on each side are released, allowing the head of the phalanx to be delivered

into the wound more completely. A small amount of dissection around the periphery of the base of the distal phalanx is performed to facilitate the removal of the articular cartilage. P.52

Figure 5-6. Any angular deformity that requires correction within the joint resection is now evaluated.

Figure 5-7. Resection of the head of the proximal phalanx is performed with a power saw. This allows for a planar resection and is particularly appropriate when angular correction is desired. Hand instrumentation may also be used.

Figure 5-8. The resection of the base of the distal phalanx is performed with hand instrumentation as the concave shape of the base is more difficult to access with a saw. Take care to inspect the periphery of the base of the phalanx to ensure that all the edges are removed and will allow a flush fit of the two surfaces. It is easy to

“scoop” out the base of the phalanx inadvertently because of its concavity and this prevents a nice contiguous fusion site. P.53

Figure 5-9. Prepared fusion site with contiguous subchondral bone exposed. The site is now ready for fixation.

Figure 5-10. A fully threaded cancellous screw allows maximal thread purchase into the denser subchondral bone of the proximal phalanx.

Figure 5-11. A potential pitfall of a partially threaded screw is poor purchase in the soft intramedullary canal of the proximal phalanx. The screw may spin freely without providing compression at the joint. This is due to the not infrequent cavitation of the medullary canal in the phalanx.

Figure 5-12. The sequence for screw fixation follows standard AO technique starting with a 2.5-mm thread hole, a 3.5-mm overdrill, and a 3.5-mm cancellous tap. The thread hole in the distal phalanx with the 2.5-mm drill is centered in all planes. P.54

Figure 5-13. Entrance of the 2.5-mm drill centrally into the base of the distal phalanx from within the joint.

Figure 5-14. A small linear incision is made distally to allow exit of the drill. It is enlarged to allow entry of the screw.

Figure 5-15. Completion of the thread hole in the distal phalanx as the tip of the drill exits out the distal portion of the toe.

Figure 5-16. The thread hole is then advanced into the proximal phalanx.

P.55

Figure 5-17. While the bone surfaces are held in a flush fitting position, the 2.5-mm drill bit is threaded from distal to proximal. This guarantees a linear track for the future screw to follow.

Figure 5-18. A and B: When the proximal phalanx is drilled separately, there is a much higher chance of a malalignment or gap at the fusion site. The joint must be opposed in its desired final position prior to introduction of the drill into the proximal phalanx.

Figure 5-19. The solution to the potential gap at the interphalangeal joint is to complete the thread hole into the proximal phalanx while the joint is opposed. A perfectly linear or central orientation of the screw into the proximal phalanx is not necessary. The goal is a flush fit at the joint interface and maximal thread purchase in solid bone. P.56

Figure 5-20. Countersinking is now performed with great care to avoid deviation from the central canal of the drill hole. A distal tuft fracture of the distal phalanx could occur.

Figure 5-21. Countersinking of the distal phalanx.

Figure 5-22. The depth gauge is also used while the joint is flushed and fully opposed. It is a good idea to also measure the expected screw length on preoperative x-rays.

Figure 5-23. Overdrilling is performed on the distal phalanx to achieve a lag effect with a fully threaded screw. This is most easily performed from proximal to distal exiting the pulp of the hallux. A 3.5-mm drill is used as a 4.0mm drill does not exist. P.57

Figure 5-24. The proximal phalanx is tapped with a 3.5-mm × 1.75-mm tap. The distal phalanx does not require tapping as the lag effect will obviate the need for thread purchase in the distal phalanx.

Figure 5-25. A 4.0-mm fully threaded cancellous screw is now held against the skin to make sure the length appears adequate for purchase into the proximal phalanx.

Figure 5-26. The thread pattern of the distal phalanx must be stripped to allow for interfragmentary compression via the lag technique. This is because the overdrill is 3.5 mm and the screw thread pattern is 4.0 mm. Therefore the 0.5 mm differential must be stripped to create an effective gliding hole in the distal phalanx.

Figure 5-27. The insertion of a fully threaded screw into the distal phalanx with subsequent stripping of the 3.5mm thread pattern. P.58

Figure 5-28. Insertion of the screw into the proximal phalanx and tightening.

Figure 5-29. The apposition and fit is confirmed at the interphalangeal fusion site.

Figure 5-30. A 4.0-mm fully threaded cancellous screw inserted in the lag technique with overdrilling of the distal phalanx.

Figure 5-31. Long-term follow-up radiograph with successful fusion of the hallux interphalangeal joint. P.59

CLINICAL TIPS AND PEARLS 1. A fully threaded screw affords more opportunity for quality thread purchase in the proximal phalanx. 2. Be sure all threads are stripped in the distal phalanx so that the lag effect with screw insertion occurs. 3. Do not drill the proximal phalanx separately. To ensure accurate alignment and a flush fit, the proximal phalanx should be drilled while the joint is flush and with the drill entering from the distal phalanx and then into the proximal phalanx. 4. Always have K-wires available as alternative fixation in case of failure or poor bone stock.

RECOMMENDED READING 1. Adams JC: Standard Orthopedic Operations: A Guide for the Junior Surgeon. New York: Longman, 1976: 359. 2. Asivatham R, Rooney RJ, Watts HG: Stabilization of the interphalangeal joint of the big toe: comparison of three methods. Foot Ankle 13(4): 181-187, 1992. 3. Cicchinelli LD, Ruch JR: Hallux Interphalangeal Joint Arthrodesis: A Clinically Illustrated Technique. Reconstructive Surgery of the Foot and Leg, Update′93. Tucker, Ga: The Podiatry Institute, 1993: 109-115.

4. Gerbert J: Digital arthrodesis. Clin Podiatr Med Surg 2: 81-94, 1985. 5. Langford JH, Fenton CF: Hallux interphalangeal arthrodesis. J Am Podiatry Assoc 72: 155-157, 1982. 6. Schives TC, Johnson KA: Arthrodesis of the interpahalangeal joint of the great toe-an improved technique. Foot Ankle 1: 26-29, 1980. 7. Sharon SM, McClain J: An alternative fixation technique when performing interphalangeal fusion. J Foot Surgery 24: 132-135, 1985. 8. Yu GV, Vargo FE: Hallux Interphalangeal Arthrodesis: A Simple Technical Pearl. Reconstructive Surgery of the Foot and Leg, Update 98. Tucker, Ga: The Podiatry Institute, 1998: 129-134.

6 Phalangeal Osteotomies John Vanore

INDICATIONS/CONTRAINDICATIONS Phalangeal osteotomies of the hallux have traditionally been utilized for the treatment of hallux valgus and hallux valgus interphalangeus. For these deformities, the primary goal is reduction of the abduction of the great toe through a wedge osteotomy. Akin (1) performed a simple cuneiform wedge resection within the basal portion of the hallucal proximal phalanx combined with medial bump resection. Variations of this procedure are still performed daily for hallux valgus deformities with a low intermetatarsal angle (Fig. 6-1). Traditionally, surgeons have viewed the hallux osteotomy or Akin type osteotomy as an adjunctive procedure to improve the cosmetic alignment of the great toe. This procedure has also been used with some frequency in as an adjunctive procedure in combination with metatarsal osteotomy for treatment of more severe deformities (2, 3, 4). Hallux valgus interphalangeus is a deformity occurring within the great toe (5) itself and a more distal type of Akin procedure has been advocated for this variation of the deformity (6,7). With the advent of screw fixation of pedal osteotomies, an oblique wedge osteotomy was performed to allow rigid interfragmentary compression screw fixation. An Akin type bunionectomy as the sole procedure has had its critics (8,9). Careful clinical examination correlated with weightbearing foot radiographs are generally adequate for the surgeon to appraise the deformity and plan the corrective surgical intervention (10). Another well accepted phanlangeal procedure was described by Regnauld (11). The Regnauld procedure may be applied to a variety of clinical pathologies of the first metatarsal phalangeal joint (MTPJ) including hallux rigidus and hallux valgus. Patients may present with a hybrid deformity involving both abduction of the great toe with first MTPJ osteoarthrosis (hallux valgus rigidus). The Regnauld type procedure is useful for decompressing the first MTPJ through linear reduction of the phalanx. Reduction of the first MTPJ deformity is enhanced through the joint relaxation inherent to this procedure. The most striking examples of joint relaxation accomplished through bone resection are with variations of the Keller resection arthroplasty or first MTPJ fusion. P.62

Figure 6-1. The Akin osteotomy has been performed with several variations, most notably the proximal Akin (A), distal Akin (B), and as an oblique osteotomy (C), wedge distal, is illustrated. Regnauld described the procedure as an osteocartilaginous graft with three variants (a) a hat-shaped graft, (b) a cork-shaped graft, and (c) an inverted graft. Of these three types, the hat graft has gained the most popularity (Fig. 6-2). All three begin with osteotomy within the midsubstance of the proximal phalanx. The basal portion is extirpated and remodeled, then reinserted as an osteocartilaginous graft. The amount and process of bone removal is probably an important determinant in accomplishing the desired joint decompression or relaxation. To maintain this relaxation, the amount of bone reinserted must be less than that removed.

PREOPERATIVE CONSIDERATIONS The Akin is most appropriate for deformity within the osseous segments of the hallux itself. The typical situation is one of hallux valgus with an elevated DASA (distal articular set angle) deformity. The Akin was originally practiced as a cuneiform osteotomy with the P.63 base medial performed at the proximal metaphysis of the proximal phalanx to adduct the toe distal to the osteotomy (1). A similar distal procedure has been advocated for hallux valgus interphalangeus (7). With the application of AO techniques of rigid internal fixation, the Akin was modified and the osteotomy performed in an oblique manner, usually with the base distal.

Figure 6-2. The Regnauld “hat graft” is illustrated with removal of the phalangeal base followed by its remodeling into a “hemi-implant” shape with subsequent reinsertion. Long-standing hallux valgus often presents with significant soft tissue contractures in and around the first MTPJ. Joint decompression procedures allow for reduction of significant proportions of transverse or frontal plane deformity. Radiographically, surgeons like to quantitate deformity and devise a surgical plan on the basis of osseous relationships, for example radiographic angles, such as the intermetatarsal or DASA (12). Determining the corrective potential of joint decompression procedures is more difficult. The bone resection of a decompression osteotomy provides soft tissue and joint relaxation that allows for not only positional or soft tissue components of deformity but also indirect reduction of structural components. Joint relaxation plays an important role in reduction of deformity and improvement of mobility. This is most clearly evident in cases of severe deformity and a rigid foot type. The Regnauld enclavement procedure provides much greater potential but preoperative assessment must identify the problems and the surgeon then plan corrective maneuvers. The objectives of the Regnauld procedure are reduction of deformity, be it abduction of the great toe, valgus rotation, restoration of normal sagittal plane position of the great toe at the first MTPJ, and nonpainful movement of the great toe joint. This is accomplished through (a) joint decompression through shortening of the phalanx and soft tissue dissection, (b) cheilectomy (clean up all adjacent joint margins), (c) rigid internal fixation (Herbert bone screw), and (d) early mobilization. The Regnauld procedure is a joint preservation type of reconstruction versus the joint destructive nature of a resection arthroplasty such as a Keller. A younger more active patient is a candidate for this type of reconstruction. The therapeutic nature of the Regnauld enclavement procedure is one of a decompression osteotomy with joint relaxation. Some degree of decompression does occur with linear shortening of the proximal phalanx but in order to accomplish maximal relaxation, the soft tissue attachments to the basal fragment must be completely dissected free. One of the most valuable aspects of the Regnauld procedure is the exposure it affords

to the metatarsal upon removal of the phalangeal base from the wound. Medial bunion resection or cheilectomy of both the metatarsal head and the phalanx are easily accomplished. Access to the sesamoids, including potential sesamoidectomy, is also allowed from an intracapsular approach.

SURGICAL TECHNIQUE Oblique Akin The operation may be performed through either a dorsal or medial incisional approach. Dissection usually involves first MTPJ exposure if done as part of a bunionectomy. The exposure to the bone is made from a deep fascial/periosteal incision medial to the extensor hallucis longus tendon. Subperiosteal dissection of the proximal phalanx is performed, keeping in mind performance of the osteotomy and subsequent anticipated fixation. The osteotomy will be described as an oblique variant of the traditional transverse Akin with the base medial and distal and the apex proximal and lateral in the basal metaphysis. The apex is located at least 0.5 cm from the joint to avoid extension of the osteotomy into the joint space. Generally, a long oblique osteotomy is performed with a narrow medial section removed. The osteotomy is “feathered” and reduced. Correction is assessed with a reduction forceps prior to definitive fixation. Rigid internal fixation with a lag screw technique is the norm with either a single 2.7-mm or two 2.0-mm screws. A single screw is generally placed from medial and proximal perpendicular to the osteotomy to provide optimal interfragmentary compression. Two smaller diameter screws may also be placed in a medial to lateral orientation. P.64 The fixation sequence for the two-screw technique will be described in detail. Usually preliminary reduction will be performed with a serrated bone forceps placed distally to allow room for the initial proximal screw. The pilot hole is created equivalent to the core diameter of the selected screw. For a 2.0-mm screw, a drill bit 1.5 mm in diameter is utilized. With this oblique osteotomy, the orientation of screw insertion is determined. Generally, a direct medial to lateral placement is selected. In order to begin the drill hole at a precise location, a drill guide is useful. The drill guide has a serrated edge that allows secure placement of the guide to prevent “skipping” of the drill bit. The 1.5-mm hole is drilled from medial to lateral completely through both the near and far cortices. Alternatively, the initial screw hole may be performed with a 0.045-inch K-wire and enlarged with a 1.5-mm drill by hand. The pilot hole is enlarged to the diameter of the selected screw. A 2.0-mm drill bit in a hand chuck is inserted and rotated alternatively in a clockwise and counter-clockwise direction. This is an atraumatic method to increase the diameter of the near cortex with limited chance of damaging the core diameter hole in the far cortex. The 1.5-mm core diameter hole is contoured to the undersurface of the screw head with a countersink. This not only reduces the prominence of the screw head but also increases the surface contact of the screw head with the opposing bone and thus disperses the pressures of interfragmentary compression. A mini fragment depth gauge is extended and the tip inserted through the medial drill hole. This is placed completely through both cortices and then retracted after the tip is caught on external surface of the far cortex. The outer barrel of the instrument (depth gauge) is slid down toward the surface of bone and the measurement read directly from the ruler on the barrel of the depth gauge. As screws generally come in 2.0-mm increments, the surgeon must never err to the shorter size. The correct screw length should possess threads that completely engage and perforate the far cortex. The entire depth of the pilot hole is tapped with the 2.0-mm tap that cuts the exact thread profile as found on the 2.0-mm screw. Use of a tap sleeve is recommended to avoid soft tissue entanglement with the flutes of the tap. The screw is inserted until it obtains complete contact with the countersunk bone surface. A 16.0- or 18.0-mm screw is most commonly used so that the leading thread can completely engage the opposite (lateral) cortex for solid purchase of bone. The reduction forceps is removed and a second screw is inserted distal to the initial

screw in precisely the same sequence as described above. Wound irrigation is recommended prior to closure; capsular and skin closure is performed according to the surgeon's preference. Immediate weightbearing in a surgical shoe is allowed. The procedure may be performed bilaterally on an outpatient basis. Immediate range of motion is allowed with stable fixation. The radiographs that follow illustrate an Akin type osteotomy in a female with hallux valgus who experienced joint pain with prominent degenerative changes.

Regnauld Procedure The Regnauld procedure has many permutations; the author has eliminated the various complexities of the hat graft technique, which was the mainstay technique for many years. Simplification with a double transverse osteotomy (Fig. 6-3), usually in a trapezoidal manner, is the preferred technique. The surgeon still has the option of complete removal of the proximal phalangeal base or performance as an “in-situ” or cylindrical Akin technique. The operation may be performed through either a dorsal (Fig. 6-4A) or medial (Fig. 6-4B) incision; the approach use reflects the surgeon's preference rather than a requirement of the procedure. Joint exposure is similar to that of an implant arthroplasty procedure with subperiosteal dissection of the base of the proximal phalanx and distal first metatarsal. Osteotomy at the level of the proximal metaphysis (Fig. 6-5A) of the proximal phalanx is preformed, usually as a trapezoidal osteotomy (Fig. 6-5B) with the medial section being wider. This will result in an overall shortening of the proximal phalanx proportional to the overall length of the phalanx, great toe, and degree of correction required. P.65

Figure 6-3. Preoperative AP radiograph (A) of planned osteotomy as illustrated in a line diagram (B) with intraoperative view (C).

Figure 6-4. Intraoperative views of dorsal (A) versus medial (B) exposures of the first MTPJ. The exposures are similar and use is determined by the surgeon's preference.

Figure 6-5. Line diagram (A) and intraoperative view (B) of phalangeal osteotomy utilized for the Regnauld “autograft.” P.66

Figure 6-6. Intraoperative view of placement of the “rudder pin.” A K-wire is placed dorsally in the “autograft” with a power wire driver (A). The lateral view (B) illustrates the reference position of the pin.

Prior to removal of the phalangeal base, a 0.045-inch K-wire is placed directly from dorsal to plantar (Fig. 6-6A) just distal enough to avoid placing the wire through or damaging the articular surface; remember, that the phalangeal articular surface is concave. This wire, the “rudder pin” will remain until the base is reinserted later in the procedure (Fig. 6-6B). It provides a reference point so that articular congruency will be maintained as well as providing a point for handling of the bone fragment. The basal fragment is then extirpated from the wound with care to minimize damage to its structure (Fig. 6-7). The bone may be soft and this often means avoidance of the points of bone forceps to grasp the base during excision. A 6-inch Brown forceps may be useful. Following its removal from the wound, the resected portion of proximal phalanx is wrapped in a damp sponge for later use. The surgeon may now address the proliferative bone or osteophytosis of the first metatarsal. If the operative pathology is one of hallux valgus, only limited dissection of the first metatarsal is necessary. In cases of severe deformity or first MTPJ arthrosis, additional dissection is required to fully free all soft tissue attachments to the distal third of the P.67 metatarsal. This is performed so that a peripheral cheilectomy may also be adequately performed. This should also accomplish a sesamoid release and allow inspection of all surfaces of the metatarsal head and its sesamoids (Fig. 6-8). Cheilectomy, or removal of peripheral lipping of the sesamoids, is possible and complete removal of a sesamoid, if necessary, is quite easy from an intracapsular approach with the base removed from the wound.

Figure 6-7. The base of the proximal phalanx is completely detached (A) and removed from the wound (B).

Figure 6-8. Intraoperative illustration of the McGlamry elevator for performing sesamoidolysis and detaching adhesions that restrict joint motion. Even if the base is not excised, complete subperiosteal dissection along the medial aspect of the base of the proximal phalanx is necessary for both internal fixation and to provide some degree of joint relaxation. Subchondral drilling, or abrasion chondroplasty, of areas of chondromalacia or articular erosions may be easily performed. Up to 50% of the articular surface of the metatarsal head or phalangeal base has been abraded as part of this joint preservation arthroplasty (Fig. 6-9). With the phalangeal base removed from the wound, tethering of the flexor tendons to each other may be accomplished to aid in hallucal purchase and help avoid later interphalangeal joint instability. A hallux malleus was identified in some of the early cases postoperatively and tethering is now a routine maneuver to avoid this complication in all cases where the base is completely excised.

Figure 6-9. Intraoperative views of the first metatarsal head pre- (A) and post cheilectomy (B) are visualized. All remodeling is easily facilitated by removing the base of the phalanx.

P.68

Figure 6-10. Following cheilectomy of the metatarsal, similar remodeling of the “autograft” is performed with remodeling of the basal fragment with a roungeur (A). The peripheral cortex is “thinned” and “decorticated” with a rotary burr (B).

Figure 6-11. Fenestration of the “autograft” cortex is felt to be an important determinant of revascularization. This is performed with a 0.028-inch K-wire perforating the circumference thirty or more times.

Figure 6-12. Fixation of the “autograft” with a Herbert bone screw is illustrated. Note the orientation of the rudder pin that helps to re-align the phalanx in proper anatomic position. Following preliminary fixation, the pilot hole is initially predrilled with a 0.062-inch K-wire. P.69 The excised portion of the phalangeal base is remodeled. All soft tissue attachments to the base should be removed. Usually, this is begun with a rongeur followed by decortication of the periphery of the base performed with a rotary drill and side-cutting oval or round burr (5 mm) (Fig. 6-10). The hand rongeur is also helpful in resecting the periarticular lipping or osteophytosis that may be present. Following remodeling, a small K-wire is used to perforate the entire remaining cortical surface (Fig. 6-11) to aid in revascularization and avoidance of avascular necrosis. These holes are similar to those placed in any bone graft to encourage revascularization. A 0.028-inch K-wire is utilized to drill 25-35 holes around the entire osseous circumference of the phalangeal base. Care must be taken to avoid drilling into the articular surface due to the concave geometry of the articular surface. The wound is copiously irrigated and the graft is reinserted using the “rudder pin” as a reference or guide to its placement. A 0.045-inch K-wire is used for preliminary fixation from the medial aspect of the reinserted base placed in a distal-lateral direction to perforate the lateral cortex of the phalangeal shaft (Fig. 6-12). Definitive fixation with a compression screw is accomplished from the plantar medial aspect of the base into the distal lateral aspect of the head of the proximal phalanx. Numerous other techniques, including absorbable screws, compression staples, bilos pin, and multiple K-wires, have been utilized but the author prefers the Herbert or Bold screw. The fixation sequence for the Herbert Bone Screw (Zimmer Corporation, Warsaw, IN) will be described as it has been utilized with the greatest frequency, although the Bold screw offers simplicity of insertion. An AO type triple drill guide is useful as a guide to drill the 2.0-mm pilot or core diameter hole. The drill guide has

a pointed edge that allows placement of the drill hole on the edge of the osseous/articular surface along the plantar medial aspect of the base of the proximal phalanx. The hole is drilled from plantar medial in a dorsal lateral and distal direction. Actually, the preferred technique is to form the initial screw hole with a 0.062-inch Kwire, and then enlarge it with a 2.0-mm drill by hand. The 2.0-mm hole in the base is enlarged with the 2.4-mm Herbert drill with stop, a hand instrument that allows for overdrill of only a short segment of the phalangeal base (Fig. 6-13A). A small fragment depth gauge can then be used to measure the correct length screw necessary. Alternatively, a reliable and accurate technique is to insert a 0.045-inch K-wire by hand and clamp it with a hemostat. The inserted wire is then measured with a ruler and a screw the exact length of it is inserted. Note that no countersinking is performed. The entire depth of the pilot hole is tapped with the 3.0-mm Herbert tap equivalent to the thread of the leading 3.0-mm thread of the Herbert screw. It is important to cut the thread through the entire portion of phalanx to avoid later difficulties with screw insertion. The screw is inserted and using axial pressure it is advanced until it lies completely within the substance of bone. A 28.0- or 30.0-mm screw is most commonly used so that the leading thread may just perforate the opposite (lateral) cortex for solid purchase of bone (Figs. 6-13B-D). The K-wire used as preliminary fixation as well as the “rudder pin” can then be removed and any overhang between the base and shaft remodeled (Fig. 6-14A). A second point of fixation has been found useful both for increasing the rigidity of the osteosynthesis as well as for stabilization of the hallucal interphalangeal joint. A 0.062-inch K-wire is driven from the tip of the toe in a proximal manner, crossing the interphalangeal joint as well as the osteotomy (Fig. 6-14B). Irrigation is again performed followed by capsular and skin closure according to the surgeon's preference. Immediate weightbearing in a surgical shoe is allowed. The procedure may be performed bilaterally on an outpatient basis. Immediate range of motion is encouraged as this is a joint salvage procedure in patients who usually have evidence of joint disease or preoperative limitation of joint movement. The radiographs that follow illustrate the preoperative deformity of a 53-year-old female with hallux valgus who experienced joint pain with prominent degenerative changes (Fig. 6-15A). An enclavement procedure with cheilectomy of both the proximal phalanx and first metatarsal was performed with complete removal and reinsertion of the “autograft.” Excellent correction of the transverse plane deformity was obtained as well as complete elimination of her joint pain (Fig. 6-15B). P.70

Figure 6-13. A short 2.4-mm drill with stop enlarges the area for the trailing thread (A). Optimal position of the screw is from the plantar medial aspect of the phalangeal base proximal and inserted in a distal and lateral direction with axial pressure maintained on the screw. Note that through the entire fixation sequence the hallux is stabilized with the opposite hand against the metatarsal head. Intraoperative dorsoplantar view of the great toe showing the position of insertion of the Herbert screw (B), final placement of the screw (C), and a postoperative AP radiograph (D). The screw just exits the lateral cortex. P.71

Figure 6-14. The preliminary fixation as well as the “rudder pin” is removed. The phalangeal base is further remodeled (A) and a 0.062-inch Kwire is inserted in an axial manner from the tip or distal medial aspect of the toe across the interphalangeal joint as well as the osteotomy (B).

POSTOPERATIVE CARE Postoperative care is similar for the various phalangeal osteotomies. Generally, a Darco or Reese type surgical shoe is utilized postoperatively for 3-4 weeks. Thereafter, a gym shoe or soft leather shoe is allowed. Avoidance of extension of the MTPJ and coming up on the toes is recommended until the surgeon is confident that bony union of the osteotomy has occurred, but early range of motion is possible due to the stability imparted by the internal fixation.

Figure 6-15. Pre- (A) and postoperative (B) radiographs of a patient with hallux valgus deformity as well as degenerative arthrosis successfully reconstructed with the Regnauld “autograft.” P.72 With the Regnauld procedure, when the base is completely excised, my preference is to continue to splint the hallux for a period of time—usually with a bunion splint for 6 weeks. Very predictable bone healing and almost complete absence of avascular necrosis can be expected with this technique. Complete bony union within 3 months is the rule. Less than ideal fixation may be associated with low-grade swelling at the base of the hallux.

COMPLICATIONS Complications occur as with any surgical procedure but certain points deserve mention. Recurrence of transverse plane deformity may occur with hallux osteotomies, be it the Akin or Regnaud type, and attention to the metatarsal deformity is recommended. These procedures may be combined with metatarsal osteotomy if the

degree of deformity dictates it. The Regnauld procedure, particularily the “autograft” procedure with complete removal of the base of the proximal phalanx, often reduces toe purchase, although the procedure is generally performed in cases of significant pathology so it is usually not too prominent. In many ways, the “autograft” is like a Keller with a hemi implant. As a result of the arthroplasty, some flexor function is lost. Tethering of the long and short flexor tendons just distal to the sesamoids has proven effective. Overzealous soft tissue repair plantarly at the first MTPJ may be associated with limitation of motion, although it is worthwhile to exchange some loss of toe purchase for improved joint motion. Bone healing has shown little impairment when the procedure is performed as described. Rigid internal fixation may be performed by a variety of techniques, but after almost twenty years of use, the intraosseous screw technique with a Herbert or Bold screw is preferred and avascular necrosis will rarely occur. There has been a problem with healing or fracture of the phalangeal base when the “autograft” has been cut too thin (Fig. 6-16).

CLINICAL TIPS AND PEARLS 1. The Akin osteotomies have limited usefulness as a solitary procedure and generally are utilized with deformity in the presence of a low intermetatarsal angle. The distal Akin osteotomy P.73 is utilized in cases of deformity adjacent to the interphalangeal joint. In more severe deformities, a combination of hallux and metatarsal osteotomies may prove useful.

Figure 6-16. Dorsoplantar radiographs illustrating Herbert screw fixation with ancillary K-wire (A) that subsequently yielded fracture of the “autograft” (B) because it was made a little too narrow.

2. Primary joint reconstruction via cheilectomy and enclavement osteotomy is still a relatively underutilized technique. Long-term results are yet to be appreciated. Due to the complete removal of the phalangeal base, many of the negative aspects of resection arthroplasty are encountered such as disruption of the glenosesamoidal joint and its distal attachments. The surgeon must address this problem to avoid a potential hallux malleus deformity. Various techniques include tethering of the long flexor tendon to the phalangeal base, tethering of the plantar aponeurotic medial and lateral heads of the short flexor to the base, or simply anastomotic suture between the long and short flexor. Any of these variations are useful adjuncts to improve hallucal purchase, avoid sesamoidal retraction, and improve joint stability. 3. In addition, the demands of bone healing must be considered. Avascular necrosis probably occurs in a good number of nonfixated procedures. Primary vascular bone union implies an early restoration of the osseous blood supply. Rigid internal fixation is an aid to this revascularization process. A technique utilizing solid screw compression achieves rigid internal fixation and allows for reincorporation of the autograft with primary bone healing in a good proportion of the cases. Rigid fixation allows for the immediate joint movement with rapid rehabilitation and weightbearing. 4. This procedure also does not address metatarsus primus elevatus or a long first metatarsal as observed in many cases of hallux rigidus. Careful preoperative assessment is mandatory for successful results. Our experience with this procedure has been very gratifying particularly in cases of stages II and III hallux rigidus or hallux valgus rigidus with a long proximal phalanx and short first metatarsal. The procedure is useful in obese patients wherein first metatarsal osteotomy is difficult to protect.

REFERENCECES 1. Akin OF: The treatment of hallux valgus—an operative procedure and its results. Med Sentinel 33: 678679, 1925. 2. Lidge RT: Hallux valgus—surgical correction by three-in-one technique. In: Bateman JE. Foot Science. Philadelphia: W.B. Saunders. 1976: 188-210. 3. McDonald KC, Durrant MN, et al: Retrospective analysis of Akin-Austin bunionectomies on patients over fifty years of age. J Foot Surg 27: 545-555, 1988. 4. Mitchell LA, Baxter DE: A Chevron-Akin double osteotomy for correction of hallux valgus. Foot Ankle 12: 714, 1991. 5. Sorto LA, Balding MG, et al: Hallux abductus interphalangeus: etiology, x-ray evaluation and treatment. J Am Podiatry Assoc 66: 384-396, 1976. 6. Gerbert J, Spector E, et al: Osteotomy procedures on the proximal phalanx for correction of a hallux deformity. J Am Podiatry Assoc 64: 617-629, 1974. 7. Boberg JS, Menn JJ, et al: The distal akin osteotomy: a new approach. J Foot Surg 30: 431-436, 1991. 8. Goldberg I, Bahar A, et al: Late results after correction of hallux valgus deformity by basilar phalangeal osteotomy. J Bone Joint Surg Am 69: 64-67, 1987.

9. Frey C, Jahss M, et al: The Akin procedure: an analysis of results. Foot Ankle 12: 1-6, 1991. 10. Vanore JV, Christensen JC, et al: First metatarsophalangeal joint disorders: Section 1: Hallux valgus. A Clinical Practice Guideline. J Foot Ankle Surg 42: 112-123, 2003. 11. Regnauld B: Disorders of the Great Toe. In: Regnauld B. The Foot. Berlin: Springer-Verlag, 1986: 249290. 12. Goel AR, Vogel BI: The off-set V osteotomy with screw fixation for correction of hallux valgus: a retrospective study. J Foot Ankle Surg 32: 305-310, 1993.

RECOMMENDED READING Burutanan JM: Correción quirurgica para el valgo del hallux y del 5 metatarsiano. Congrès du collège international de podologie. Turin. Hanft JR, Feiertag MA, et al: Preliminary report: modifications of the Regnauld osteochondral autogenous graft. J Foot Surg 29: 577-580, 1990. Hanft JR, Kashuk KB, et al: Rigid internal fixation of the Austin/Chevron osteotomy with Herbert screw fixation: a retrospective study. J Foot Surg 31: 512-518, 1992.

7 Second Metatarsophalangeal Joint Instability Gary Jolly

INDICATIONS/CONTRAINDICATIONS Afflictions of the second toe, such as crossover deformity and predislocation syndrome, are commonly seen in clinical practice. Although common, there does not exist a clearly defined terminology, an understanding of the pathology, or appropriate methods of treatment. This lack of a systematic approach, due in large part to an unwillingness to confront the actual focus of pathology, has led to a random and largely ineffective collection of operations for treatment of these disorders. The second metatarsophalangeal joint (MTPJ) is exposed to weightbearing stresses during virtually all activities in which the forefoot is under load. In addition, the flexor tendon sheath and the plantar plate are located directly under the second metatarsal head, rather than offset medially as they are in the other rays (Fig. 7-1). As a result of these functional and anatomic features, the second MTPJ plantar restraints can fail, leading to instability of this MTPJ more often than with the other joints. The surgical treatment of instability of any joint begins with the recognition of the disorder. The presence of pain and swelling beneath the second MTPJ and deformity of the second toe, appreciated in either the transverse or sagittal plane, should alert the surgeon to the fact that the normal restraints of the MTPJ have been compromised. Generally, the presence of a crossover toe suggests a lesion of the lateral collateral and suspensory ligaments, whereas a dorsal contracture of the toe is usually associated with a disruption of the plantar plate (Fig. 7-2). The suspensory ligament in the metacarpophalangeal (MCPJ) of the hand is called the accessory collateral ligament, because it is smaller in size than the collateral ligament. However, in the MTPJ, it is significantly larger than the collateral ligament. This difference reflects the fact that in the hand, the MCPJ's position of function is in flexion (grasp), while in the foot the functional position of the MTPJ is in hyperextension (push-off) (Fig. 7-3). Conservative treatment for second MTPJ instability generally focuses on symptomatic relief. Unfortunately, attenuation of ligaments and disruptions of the plantar plate do not lend themselves to self-repair. Resectional arthroplasties or fusions of the proximal interphalangeal joint, with or without releases of the MTPJ, have no real place in treating this P.76 condition, unless there is a rigid ankylosis of the proximal interphalangeal joint. The location of the problem is plantar, therefore a plantar approach is required to adequately assess the extent of the problem and to repair the damaged plantar structures.

Figure 7-1. A cross-sectional view through the MTPJs showing the plantar plates and flexor tendon sheaths and their relationship to the overlying metatarsal heads. (Reprinted from Saraffian: Anatomy of the Foot and Ankle. 2nd ed. Philadelphia: JB Lippincott, 1993 with permission of the publisher.) There is a general reluctance among foot surgeons to make plantar incisions. However, no outcome studies support that reluctance. Numerous papers describe plantar incisions for treatment of Morton's neuroma, without production of dysfunctional plantar scars. The only absolute contraindication against reconstruction of the second MTPJ is the presence of a frank dislocation of the toe.

Figure 7-2. Clinical example of the triplanar changes that accompany a crossover toe deformity. The AP (A) and frontal plane (B) views are shown. Note the medial deviation suggestive of collateral and suspensory injury. P.77

Figure 7-3. An anatomic photo showing the collateral (1) and suspensory ligament (2) of the lesser MTPJs. (Reprinted from Saraffian: Anatomy of the Foot and Ankle. 2nd ed. Philadelphia: JB Lippincott, 1993 with permission of the publisher.)

PREOPERATIVE CONSIDERATIONS The diagnosis of instability of the second toe is made by history and physical examination. Pain and effusion about the second MTPJ and a dorsal or dorsomedial drawer sign are the sine qua non for instability of the second toe. The second MTPJ is surrounded by a soft tissue envelope that provides a platform on which the metatarsal rests and supports movement of the metatarsal around the toe during load. The metatarsal head rests in a glenoid made up of the articular surface of the phalanx and the deep surface of the plantar plate. The proximal edge of the plantar plate is attached to the plantar surface of the metatarsal neck by a synovial redundancy, which allows for hyperextension of the joint during push-off. The nonarticular, superficial surface of the plate provides a pulley for the flexor tendons and is held beneath the metatarsal head by the suspensory and collateral ligaments. These ligaments attach the plantar plate to both the metatarsal and the phalanx on both sides of the joint, maintaining the flexor tendons in a central position (see Fig. 7-3). Instability of the second MTPJ may develop as the result of a disruption or attenuation of the plantar plate or the suspensory ligaments. In cases where there is a full thickness defect in the plantar plate, a communication develops between the MTPJ and the flexor tendon sheath. Arthrography, in these cases, will demonstrate egress of the contrast medium into the flexor tendon sheath or into the adjacent soft tissues (Fig. 7-4).

SURGICAL TECHNIQUE The surgical approach for repair of an unstable second MTPJ is through a plantar incision in the first intermetatarsal space. If necessary, the incision may be extended distally onto the plantar surface of the toe in a zigzag fashion (Fig. 7-5A). The dissection is to the deep fascia, and the preflexor fat pad is reflected with the skin, exposing the flexor tendon sheath. A careful inspection of the sheath is made for evidence of fibrosis or synovial herniation (Fig. 7-5B). The tendon sheath is then opened, and if the short flexor's mesotenon is fibrosed, a complete tenosynovectomy is performed. The tendons are then mobilized and the floor of the tendon

groove is inspected for disruption or attenuation. P.78

Figure 7-4. An arthrogram of the second MTPJ, demonstrating leakage of radiopaque dye through the plantar plate and into the flexor tendon sheath. This confirms plantar plate and capsular distruption.

Repair of Central Lesions (Plantar Plate Disruption) Although midsubstance ruptures of the plantar plate do occur, the most common site of plantar plate disruption is at the plate's attachment to the phalanx. This is also the weakest anatomic part of the plate. All fibrillated fibrocartilage should be sharply excised, converting the lesion to a transverse defect (Fig. 7-6). A mini-anchor is then inserted into the intercondylar notch of the proximal phalanx, and angled distally to avoid inadvertently placing it in the joint. The needles from the anchor, containing 2-0 polyester suture, are then passed into the distal edge of the plantar plate to avoid the deep articular surface. The needle tips should emerge centrally in the plate, and the sutures are pulled through and tightened so that the distal P.79 edge of the plate is brought into contact with the plantar rim of the phalanx. Before tying down the knot, the position of the toe is checked with the foot loaded. If the defect in the plate is closed and the toe is adequately reduced, the knot is tied (Fig. 7-7A). At this point, the position of the toe at the MTPJ should be at or below the level of the other joints (Fig. 7-7B).

Figure 7-5. A: The surgical approach to the second MTPJ through the plantar surface. Note the incision is centralized in the first intermetatarsal space to avoid scarring under the metatarsal. B: Reflection of the plantar skin and preflexor fat pad and exposure of the flexor tendon sheath. This is a full thickness soft tissue flap with the subcutaneous tissues maintained within the skin edges. Note the herniation of synovitis.

Figure 7-6. With the flexor tendons retracted, a well defined defect in the midsubstance of the plantar plate is observed. At times, the plantar plate may be compromised by attenuation of its fibrocartilage into a membranous structure rather than by rupturing. In that instance, the repair may be P.80 augmented by placing the long flexor tendon under distal traction and passing the suture through it. When the suture ends are tied, the long flexor's pull will apply a plantarflexory moment directly to the proximal phalanx (Fig. 7-8). Additionally, the medial and lateral labra of the flexor tendon sheath may be folded down and sutured into the plantar plate to provide an additional layer of tissue to this structure. If the plantar plate is severely attenuated, the use of a cruciate free tendon graft may prove useful in restoring plantar stability.

Figure 7-7. A: A single stitch repair utilizing 2-0 nonabsorbable suture. B: The appearance of the second toe after repair of the plantar plate. The sagittal plane position is now acceptable and usually at the level of the adjacent toes or slightly below.

Figure 7-8. With a bone anchor imbedded in the phalanx and the plantar plate advanced onto the phalanx, the

anchor sutures are passed through the flexor digitorum longus tendon, transferring the pull of the tendon to the base of the toe. A free tendon graft may be harvested from the extensor tendon to the fifth toe, the peroneal tendons, or the gastrocnemius fascia. Micro-anchors are then inserted into the medial and lateral condyles of the base of the proximal phalanx. The tendon graft is then split and one end of each piece of tendon is sutured to the phalangeal condyle by the sutures of the mini-anchor. The tendon grafts are then crisscrossed over the plantar plate and sutured to the most proximal edge of the plantar plate (Fig. 7-9). Care should be taken in not attaching the tendon graft to the metatarsal shaft as this will have the effect of producing a checkrein and limiting extension of the MTPJ.

Repair of a Lateral Defect (Lateral Suspensory and Collateral Ligaments) Instability of the second MTPJ, which produces a crossover deformity, will also require repair of the lateral restraints of the joint. The surgical approach is the same as it would be for a central lesion. The flexor tendons should be first inspected, and the central portion of the plate within the tendon groove should be examined for defects. If there is a central defect it should be repaired. In a crossover toe deformity, the plantar plate and the flexor tendons will be seen as medially displaced beneath the metatarsal head (see Fig. 7-2A). This can only occur if the lateral suspensory ligament is attenuated. To return the plate and the pull of the flexor tendons to a centralized position and restore the stability to the joint, the lateral ligaments must be P.81 repaired. There are two ligaments on either side of the joint that maintain normal stability and a complete repair must involve both ligaments. The lateral collateral ligament extends from the metatarsal condyle distally and plantarly to the lateral condyle of the phalanx. The suspensory ligament, which is much larger than the collateral ligament, takes off from the lateral condyle of the metatarsal head and fans plantarly, investing the lateral edge of the plantar plate (see Fig. 7-3).

Figure 7-9. A free tendon graft applied in cruciate fashion to reinforce a severely attenuated plantar plate. This graft can come from the extensor tendon to the fifth toe, the peroneal tendons, or the gastrocnemius fascia. Mini suture anchors in the base of the proximal phalanx are also utilized for this repair technique. The medial collateral and medial suspensory ligaments may adaptively shorten and should be released prior to lateral repair, as necessary. The lateral collateral ligament is reconstructed by inserting a micro-anchor into the lateral condyle of the phalanx and tying the sutures to the end of a strip of merseline ribbon (5 mm). A second strip of merseline is then sutured to the plantar plate, just lateral to flexor tendon groove. Four to six sutures of 40 polyester are used for this. The merseline strip is positioned so that its long axis is perpendicular to the course of the flexor tendons (Fig. 7-10).

Figure 7-10. One end of a strip of merseline is being sutured to the plantar plate. This is placed slightly lateral to the flexor groove. The other end is passed up along the side of the joint to be attached to the metatarsal head and replace the lateral suspensory ligament. Another strip is attached to the lateral condyle of the phalanx for repair of the collateral ligaments. Both strips will be attached to the lateral metatarsal head. P.82

Figure 7-11. A dorsal incision is made in the second interspace and the two strips of mersilene are passed through from plantar to dorsal. With the foot loaded, the strips are grasped and the position of the toe is manipulated into an anatomic position. These are attached by a soft tissue anchor placed into the lateral metatarsal head. An incision is then made dorsally in the second interspace. Dissection proceeds along the hood ligament and connects to the plantar incision. The two strips of merseline are then passed up along the hood ligament and out though the dorsal incision (Fig. 7-11). The foot is loaded and tension is placed on each of the merseline strips until the proper balance is obtained and the second toe is found to be in the correct position in all planes. A minianchor is inserted into the lateral condyle of the metatarsal head. With the foot loaded and the toe corrected, the sutures from the metatarsal head anchor are then passed through the two strips of merseline and tied. The dorsal and plantar incisions are closed. Only skin sutures should be used plantarly to minimize inflammation with deeper sutures.

POSTOPERATIVE MANAGEMENT A dynamic flexor splint is made by inserting one or two 0.045 K wires into the toe, but these wires do not pass through the MTPJ. The wires are then bent into hooks and attached to the bottom of the dressing by a rubber band that is wound around the pins and attached to a safety pin. Sufficient tension is applied to the rubber band to maintain the toe in a slightly plantarflexed position. The splint prevents the patient from inadvertently extending the joint. If the lateral ligaments were repaired, the safety pin is placed in a position to produce a lateral pull as well (Fig. 7-12). The patient is kept nonweightbearing for the first 3 weeks, and is then permitted to bear weight in a walking heel for an additional 3 weeks. Active motion of the toes is encouraged after the third week.

COMPLICATIONS Complications of surgery of the plantar plate and suspensory ligaments include suture failure or pullout with recurrence of the deformity.

CLINICAL TIPS AND PEARLS

1. Because the plantar plate is made of fibrocartilage, nonabsorbable sutures are preferable to materials whose tensile strength will decrease with time. Furthermore, attempts to primarily repair collateral and suspensory ligaments by direct suturing are likely to fail P.83 if the holding strength of the ligament has been compromised. The use of a material like merseline mesh imparts a significant increase in the tensile strength of the ligament, as well as permitting biological ingrowth into the construct.

Figure 7-12. Postoperatively, the foot is placed in a compression dressing and a dynamic flexor splint is applied. Stabilization of this position is maintained for at least three weeks prior to weightbearing. 2. The surgeon should be aware of the presence of a short first metatarsal or a long second metatarsal before surgery, and if the length differential is great enough, the second metatarsal can be shortened at the time of surgery. However, in an unpublished series of twenty-four patients who underwent repair of the second MTPJ, only eight had clinically significant length discrepancies. 3. Although hallux valgus has been characterized as a cause of this clinical disorder, in the same series of patients, only eleven had clinically significant deformities of the first ray and required concomitant correction of their bunion deformities. 4. Longstanding instability of the second MTPJ may present with a fixed contracture of the proximal interphalangeal joint. In this event, the proximal interphalangeal joint may be fused or simply released plantarly through an extension of the plantar incision (see Fig. 7-3A).

RECOMMENDED READING 1. Bhatia D, Myerson MS, Curtis MJ, et al.: Anatomic respraints to dislocation of the second metatarsophalangel joint and assessment of a repair technique. J Bone Joint Surg 76A: 1371-5, 1994. 2. Ford LA, Collins KB, Christensen JC: Stabilization of the subluxed second metatarsophalangeal joint: flexor tendon transfer versus primary repair of the plantar plate. J Foot Ankle Surg 37: 217-22, 1998. 3. Bojsen-Moller F: Anatomy of the forefoot, normal and pathologic. Clin Orthop 142: 10-18, 1979. 4. Branch HE: Pathologic dislocation of the second toe. J Bone Joint Surg 19: 978-984, 1937. 5. Bruner JM: The zig-zag volar-digital incision for flexor-tendon surgery. Plast Reconstr Surg 40: 571-574, 1967. 6. Coughlin MJ: Crossover second toe deformity. Foot Ankle Int 8: 29-39, 1987. 7. Coughlin MJ: Lesser Toe Abnormalities. In: Chapman M, ed. Operative Orthopedics. Philadelphia: JB Lippincott, 1988: 1765-1776. 8. Coughlin MJ: Lesser toe abnormalities. Orthopedics 10: 63-75, 1987 9. Coughlin MJ: When to suspect crossover second toe deformity. J Musculoskel Med 4: 39-48, 1987. 10. Coughlin MJ: Subluxation and dislocation of the second metatarsophalangeal joint. Orthop Clin North Am 20: 535-551, 1989. 11. Deland JT, Kyung-Tai L, Sobel M, DiCarlo EF: Anatomy of the plantar plate and its attachments in the lesser metatarsal phalangeal joints. Foot Ankle Int 16: 480-486, 1995. 12. Fortin PT, Myerson MS: Second metatarsophalangeal joint instability. Foot Ankle Int 16: 306-313, 1995. 13. Johnston RB, Smith J, Daniels T: The plantar plate of the lesser toes: an anatomical study in human cadavers. Foot Ankle Int 15: 276-282, 1994. 14. Karpman RR, MacCollum MS: Arthrography of the metatarsophalangeal joint. Foot Ankle Int 9: 125-129, 1988.

8 Lesser Metatarsal Osteotomy Babak Baravarian

INDICATIONS/CONTRAINDICATIONS Lesser metatarsal osteotomy techniques have presented with mixed results to date. Often, there is a lack of true reasoning behind the osteotomy, resulting in poor outcomes. The Weil osteotomy shows promise because it is easy to perform and offers many correctional options with predictable positioning (Fig. 8-1). The general work-up of the patient is begun with a complete foot and ankle examination. In many cases, a lesser metatarsal osteotomy is performed on the second metatarsal. This is often due to a crossover second toe, a long second metatarsal, or a rear foot valgus with or without associated forefoot varus and an underlying equinus deformity (Fig. 8-2). The result of such a deformity is overloading of the medial arch and forefoot. An underlying hypermobility of the first metatarsal will allow increased loading of the second metatarsophalangeal joint (MTPJ) and subsequent pain. Examination of the specific metatarsal consists of palpation of the plantar surface of the metatarsal and a dorsal drawer examination in order to check for a possible torn plantar plate. The interspace(s) is also checked for a possible intermetatarsal neuroma. Deformity of the associated toe with possible hammertoe or crossover toe position will also cause pain and may need correction in conjunction with the metatarsal osteotomy. Further diagnostic testing may consist of intra-articular local anesthesia injection and magnetic resonance imaging of the region. One point of special note is that local intra-articular cortisone injections should be avoided as they will weaken the tissue and cause further damage to the underlying ligament and tendon structures. If antiinflammatory treatment is deemed necessary, phonophoresis may be used locally or a short course of steroid therapy orally may be considered. The indications for lesser metatarsal osteotomy include a relatively long metatarsal, a relatively plantarflexed metatarsal, a contracted digit that cannot be reduced without decrease in metatarsal length with or without associated dislocation of the MTPJ, and angular deformity of the metatarsal. Contraindications to lesser metatarsal osteotomy include plantar callus formation, pain of unknown etiology, parabola correction without underlying pain or symptoms, and prophylactic surgery. P.86

Figure 8-1. Positioning of the osteotomy.

PREOPERATIVE CONSIDERATIONS Radiographic examination will aide in examination of parabola and metatarsal position. Standard AP (anteroposterior), oblique, and lateral films with the foot in the rectus position and fully loaded are taken. If a possible plantar flexed metatarsal is suspected, a plantar axial film is taken. Although there have been advances in the procedure and new uses for it are being considered, currently the indications for a metatarsal osteotomy are limited. In most cases, I use the osteotomy in conjunction with digital correction. There is often a contracture at the P.87 MTPJ that is difficult to reduce without shortening of the metatarsal. Furthermore, plantar plate disruptions and crossover toe correction is greatly improved with metatarsal shortening in cases of a long metatarsal or a severely contracted MTPJ and digit.

Figure 8-2. Clinical picture of a typical patient in whom a metatarsal osteotomy may be considered. This crossover second toe deformity may be secondary to a long second metatarsal in the forefoot as well as contributions from the rear foot, such as a rear foot valgus with an underlying equinus deformity.

SURGICAL TECHNIQUE The patient is placed on the operating room table in the supine position. The foot is prepped and draped with the ankle exposed. This is done in order to load the foot during intra-operative fluoroscopy without drapes preventing proper positioning. The procedure may or may not be combined with hammertoe correction of the associated digit. If concurrent hammertoe correction is being performed, a dorsal linear incision is made over the toe with a slight serpentine rotation across the MTPJ. If the metatarsal osteotomy is performed without hammertoe correction, a 2.0-3.0 cm dorsal linear incision is made over the MTPJ (Fig. 8-3). In order to minimize contracture of the digit, the incision should stop at the base of the proximal phalanx unless hammertoe correction is also planned. Blunt dissection is performed to the level of the long extensor tendon and joint capsule edges. The extensor tendon and wing apparatus are released and the tendon is shifted either medially or laterally in order to access the joint. If a combined toe and metatarsal correction are being done, the extensor digitorum longus tendon is

transversely released at the proximal interphalangeal joint of the associated toe and the extensor tendon is released proximally to the level of the proximal metatarsal head region. In most cases, there is a dorsal contracture of the digit at the MTPJ that requires a dorsal MTPJ release. This is done through a T incision into the capsule (Fig. 8-4). The horizontal incision is done at the level of the distal MPTJ while the vertical incision is placed from the level of the MTPJ proximally 3.0 cm. A release of the collateral ligaments and plantar metatarsal should only be performed in cases of severe contracture in order to prevent plantar scar formation (Fig. 8-5). Ligament contracture P.88 should be decreased with the shortening osteotomy. If contracture is still present after the shortening osteotomy, a release of the plantar contraction may then be performed.

Figure 8-3. Typical incision for a second metatarsal osteotomy with hammertoe correction. If the metatarsal osteotomy is performed without hammertoe correction, a 2-3 cm dorsal linear incision is made over the MTPJ.

Figure 8-4. Intraoperative photo showing exposure to the digit and metatarsal. In most cases, there is a dorsal contracture of the digit at the MTPJ that requires a release. This is done through a transverse incision into the capsule at the joint level. Care is taken to distract the joint and perform the capsulotomy distally to avoid injury to the cartilage of the metatarsal head.

Figure 8-5. After the horizontal incision is made, the vertical incision is performed from the level of the MTPJ proximally 3 cm. This resembles a “T”. A release of the collateral ligaments and plantar metatarsal should only be performed in cases of severe contracture in order to prevent plantar scar formation. The osteotomy is performed from a slight intra-articular position with the initial position of the saw blade on the dorsal articular cartilage of the metatarsal head (Fig. 8-6A). In order to achieve a proximal shift without plantarflexion, the osteotomy is started 2.0-3.0 mm plantar to the most dorsal articular surface of the metatarsal head (Fig. 8-6B). This position allows for direct proximal shift of the metatarsal capital fragment. If plantarflexion is necessary, the osteotomy is made from a more dorsal position with a greater amount of plantar angulation. If dorsiflexion is necessary, the saw blade is passed several times though the osteotomy site prior to completing the osteotomy. With each pass of the saw blade, a small amount of bone is removed at the osteotomy site, allowing for dorsal displacement of the capital fragment at the time of fixation. However, the Weil osteotmy is not ideal for dorsiflexion procedures. Some dorsiflexion is achieved with shortening, yet if pure dorsiflexion is required, a transverse osteotomy of the metatarsal may be a better choice. Following completion of the osteotomy, the capital fragment slides into a proximal position. If necessary, the capital fragment may be rotated medially or laterally to assist with slight correction of any angular deformity of the toe. Two techniques may be used in order to assess the ideal position of the capital fragment. A rough estimate may be done by palpation of the adjacent metatarsal heads. The osteotomized metatarsal is then shifted into position P.89 and temporarily fixated with a small K-wire (Fig. 8-7). The adjacent metatarsals are again palpated until ideal position is achieved. A more reliable method of positioning the metatarsal osteotomy is with the use of intraoperative fluoroscopy. An AP picture with the foot loaded is used to position the metatarsal. Once ideal position is achieved, the metatarsal is compressed with direct plantar pressure and temporarily held with a small

K-wire. It is essential to place the osteotomized metatarsal at the level of or slightly longer than the next shortest adjacent metatarsal. If overshortening is performed, adjacent transfer lesion or pain is more likely to occur.

Figure 8-6. A and B: In order to achieve a proximal shift (shortening) without plantar flexion, the osteotomy is started 2-3 mm plantar to the most dorsal articular surface of the metatarsal head. A dorsal and oblique view is illustrated.

Figure 8-7. A and B: The osteotomized metatarsal is then shifted into position and temporarily fixated with either a smooth or threaded K-wire. Note the slight distal orientation of the fixation that engages the largest area of the metatarsal head. Care is taken not to leave a pin prominent within the joint space. Fixation may be performed by a variety of options. In general, fixation is usually done either by a pin or a screw. A simple and economical choice is a 0.062-inch threaded K-wire. The wire is placed in the desired fixation location without penetration of the plantar metatarsal head cortex. If there is concern about the plantar position of the wire, a freer elevator is used to palpate the plantar metatarsal head. If the wire is palpated, it is reversed proximally until it is proximal to the plantar cortex. The wire is cut leaving 4-5 cm of dorsally exposed wire. A small metal suction tip is placed over the exposed dorsal wire and the wire is bent as far distally and then as far proximally against the metatarsal head as possible. This will cut the wire flush with the dorsal cortex of the metatarsal. Although this form of fixation is simple, it is very difficult to remove the wire and there is limited compression at the osteotomy site after the wire is cut flush with the bone. A better form of fixation is through the use of a small screw (Figs. 8-8 and 8-9). In general, a 2-mm screw is ideal. Either a cannulated or noncannulated, cancellous or noncancellous screw may be used. Standard AO technique is used for screw placement. Screw placement should be from dorsal to proximal with slight distal angulation. The distal cortex should be purchased without plantar penetration of the metatarsal head. If there is concern about metatarsal head rotation, a second screw or pin may be used for two points of fixation. Adjunct procedures such as

hammertoe correction and flexor to extensor transfer are then completed. In the case of MTPJ contracture requiring pinning across the MTPJ, a pin can be placed into the osteotomized head with caution (Fig. 8-10). The extensor tendon is then reattached. It is helpful to attach the tendon to the flexor digitorum longus at the site of transfer instead of its original site in order to prevent further contracture. Closure is performed with the surgeon's choice of capsular and skin sutures; however, the transverse capsular incision is not approximated again in order to avoid further contracture at the MTPJ. Standard dressings are applied and the patient is placed in a surgical shoe or below the knee walker boot. Alternatively, the patient may be placed in a below the knee walking cast. P.90

Figure 8-8. A better form of fixation is through the use of a small screw. A 2.0-mm screw works very well for this technique.

POSTOPERATIVE MANAGEMENT During the initial 5 postoperative days, the patient is instructed to limit ambulation to essential activity within the house. The patient is seen in 5 days for a wound check and dressing change. Standard radiographic examination of the foot is also done at this time. Increase in activity is then begun in the postoperative boot or shoe with elevation of the foot as much as possible for the subsequent 2 weeks. The patient is then seen at 3 weeks postoperatively for suture removal. Two more weeks of guarded ambulation is instructed and at about the 5 week postoperative period, and if no concurrent surgeries require further care, the patient is allowed to progress into a tennis shoe and begins physical therapy.

Figure 8-9. A and B: Pre- and postoperative radiograph of Weil xstoeotomy with screw fixation. Note the shortening achieved, yet this is still slightly longer than the adjacent metatarsal, minimizing the potential of transfer lesions. The digit has also been stabilized. P.91

Figure 8-10. In the case of MTPJ contracture requiring pinning across the MTPJ, a pin can gently be placed into the osteotomized head with caution. The main point of physical therapy is to increase toe purchase and limit dorsal migration of the toe at the MTPJ. This is a common problem with any shortening osteotomy of the lesser metatarsals and seems to be helped by

physical therapy. Total return to activity is begun at the 7-8 week period. Commonly, there is minimal pain with such a procedure. The patient should be comfortable ambulating at the 1 week postoperative period. Total recovery is very patient dependant and may range from 4-12 weeks. In most cases, by the 6-7 week period, the patient is in regular shoes and beginning regular activity with progression to high impact sports activity in the following 1-2 weeks.

COMPLICATIONS A multitude of complications exist for metatarsal osteotomy procedures. These include stiffness, persistent deformity, poor toe purchase, nonhealing of the wound, nonunion, malunion, or avascular necrosis of the osteotomy, and possible transfer lesion formation. Stiffness is common with any joint procedure and is exacerbated with involvement of toe procedures. In most cases, stiffness is the result of adjunctive procedures such as flexor to extensor transfer, resulting in decreased motion at the MTPJ, or a K-wire placed across the MTPJ for a prolonged period of time, resulting in scarring. However, a delayed dorsal tenotomy and capsulotomy of the MTPJ or scar tissue breakup with joint mobilization under anesthesia may help decrease stiffness. Persistent deformity may be present as a result of poor length reduction and limited correction of deformity plantar to the metatarsal. It is essential to plan properly in the preoperative period and check position intraoperatively to avoid such a complication. With decrease in the length of the metatarsal there is an increased chance of dorsal toe contracture, leading to poor toe purchase. This complication may be avoided with placement of a pin across the MTPJ for 3-4 weeks following surgery or flexor tendon transfer. It is essential to place the flexor tendon transfer under physiologic tension in order to hold the toe position without causing stiffness of the MTPJ. P.92 Nonhealing wounds are rare in the region of the metatarsal head as long as proper vascular work-up has been done. In cases of diabetic or rheumatoid patients, it is essential to warn the patient of possible wound problems and diagnose any vascular insufficiency issues with proper vascular testing. Healing of the osteotomy site is critical to proper outcome. Healing rates have been increased with the use of internal fixation and stable osteotomy position. Malunion or nonunion rate can also be decreased with internal fixation use. If there is motion after one point of fixation, a second screw or pin can be placed. This will decrease the chance of motion at the osteotomy, resulting in better healing rates. Avascular necrosis is rare. It is possible with degloving of the metatarsal head and may be avoided with meticulous dissection and attention to the vascular structures. The most common complication of metatarsal procedures is transfer lesions. This is mainly due to poor use of the procedure for treatment of underlying keratoma formation without attention to toe deformities, hypermobility, and equinus issues. Once this complication occurs, it is very difficult to deal with. Therefore, it is essential to choose the proper patient for such procedures and incorporate adjunct procedures in order to avoid a poor outcome. In cases of transfer lesion formation, orthotics may be considered to allow better weight distribution across the metatarsal head region. Further metatarsal surgery should be avoided, if possible, due to the possibility of other transfer lesions.

CLINICAL TIPS AND PEARLS 1. It is essential to select the proper patient for metatarsal osteotomy procedures. Metatarsal osteotomy is not ideal for all cases and should be limited to severe cases that cannot be treated by other measures. 2. Perform the osteotomy with minimal soft tissue degloving of the metatarsal head. There will be a relative

relaxation of the soft tissue structures about the metatarsal head following the osteotomy and bone shortening. 3. Perform the osteotomy slightly plantar to the dorsal articular cartilage of the metatarsal head in order to get direct proximal migration with minimal plantar flexion. 4. Pay a great deal of attention to adjunct procedures such as hammertoe correction, tendon balancing, instability of the first ray, and equinus deformity. 5. One point of great importance is to consider a flexor tendon transfer to the associated toe as an adjunctive procedure with metatarsal osteotomy as this will greatly reduce the possibility of a floating toe that does not purchase the ground.

RECOMMENDED READING 1. Trnka HJ, Gebhard C, Muhlbauer M, et al.: The Weil osteotomy for treatment of dislocated lesser metatarsophalangeal joints: good outcome in 21 patients with 42 osteotomies. Acta Orthop Scand 73: 190194, 2002. 2. OKane C, Kilmartin TE: The surgical management of central metatarsalgia. Foot Ankle Int 23: 415-419, 2002. 3. Melamed EA, Schon LC, Myerson MS, et al.: Two modifications of the Weil osteotomy: analysis on sawbone models. Foot Ankle Int 23: 400-405, 2002. 4. Trnka HJ, Nyska M, Parks BG, et al.: Dorsiflexion contracture after the Weil osteotomy: results of cadaver study and three-dimensional analysis. Foot Ankle Int 22: 47-50, 2001. 5. Vandeputte G, Dereymaeker G, Steenwerckx A, et al.: The Weil osteotomy of the lesser metatarsals: a clinical and pedorarographic follow-up study. Foot Ankle Int 21: 370-374, 2000. 6. Trnka HJ, Muhlbauer M, Zettl R, et al.: Comparison of the results of the Weil and Helal osteotomies for the treatment of metatarsalgia secondary to dislocation of the lesser metatarsophalangeal joints. Foot Ankle Int 20: 72-79, 1999.

9 Surgical Considerations of the Fifth Metatarsal Bunionette Condition Mary E. Crawford

INDICATIONS/CONTRAINDICATIONS The bunionette condition manifests itself as a protruding bony prominence on the lateral side of the foot over the fifth metatarsal head (Fig. 9-1). The deformity can be present for many years with minimal symptoms experienced by the patient until pain, redness, or swelling develops, sometimes suddenly. It is frequently seen in conjunction with a splayfoot condition that results in widening of the forefoot and a prominent bunion and bunionette deformity (Fig. 9-2). As both of these progress, shoe wear accommodation becomes difficult, resulting in additional pressure being placed over the bony enlargements both medially and laterally with increased symptomatology experienced by the patient. Conservative measures include change of shoe style to accommodate the bony enlargements, padding to prevent direct shoe contact, debridement of any hyperkeratotic lesions associated with the condition, and injection of cortisone or other anti-inflammatory measures such as physical therapy modalities to resolve any concomitant adventitial bursitis formation. These measures are frequently unsuccessful in resolving complaints of pain or discomfort, especially in the female patient where chronic irritation is likely. When conservative care fails, surgical intervention is commonly employed, usually with very successful outcomes.

PREOPERATIVE CONSIDERATIONS Proper evaluation of the deformity involves both a thorough physical evaluation as well as radiographic review. It is not normally necessary to perform any additional advanced imaging studies. On physical examination, the location of the patient's complaints of discomfort as well as any corresponding conditions should be carefully evaluated. In some cases, a painful hyperkeratotic lesion either plantar or plantar lateral to the fifth metatarsal head (Fig. 9-3) or a painful inflammatory bursa will be present (Fig. 9-4). The fifth digit is P.94 rarely rectus in the bunionette deformity and is often painful due to an adductovarus position of the digit, resulting in pressure between the fourth and fifth toes or on the lateral side of the fifth toe. This toe problem may need to be surgically addressed along with the bunionette condition (Fig. 9-5). The bony protuberance of the fifth metatarsal head may be the culprit, and there may be some degree of excessive ligamentous laxity of the lateral column, which allows for the increased splaying of the metatarsal. Commonly, a posterior equinus condition is seen with this foot type, especially when splaying and increased laxity of both the medial and lateral column is noted. The need for concurrent treatment of posterior equinus, if present, should be carefully evaluated.

Figure 9-1. Clinical presentation of bunionette deformity of the right foot.

Figure 9-2. Clinical presentation of splayfoot deformity with concomitant bunion and bunionette condition.

Figure 9-3. Preoperative appearance of bunionette condition with overlying hyperkeratotic lesion. P.95

Figure 9-4. Clinical appearance of bunionette condition with overlying inflamed adventitial bursa.

Figure 9-5. Severe overlapping adductovarus fifth digit with concurrent bunionette condition. Once the physical attributes of the deformity are recognized, the radiographic evaluation will add information necessary to the decision making process. Required radiographs for proper assessment include anterior/posterior (AP), medial oblique (MO), and lateral (Lat) views of the foot in normal weightbearing base and angle of gait. The AP view provides the greatest degree of information with the width of the metatarsal and metatarsal head visualized as well as the degree of increased intermetatarsal angle and lateral deviation angle present. The width of the metatarsal and metatarsal head is a relative evaluation to determine if enough reduction of the deformity can be obtained by a distal metatarsal procedure or if a more proximal procedure may be necessary. This must be taken into consideration along with the increased intermetatarsal and lateral deviation angles. For example, if the patient had a very narrow neck region of the fifth metatarsal, or already had a previous lateral eminence resection performed with recurrence, adequate reduction of the deformity would be difficult with a distal metaphyseal osteotomy (Fig. 9-6). The measured angles can be helpful in determining the appropriate procedure to perform but can be misleading if not placed in context with your physical examination. This is especially true in the presence of hypermobility of the lateral column and a concurrent equinus condition. Normal intermetatarsal angle measurements vary depending on the author of the paper but averages between 6.5-8 degrees with increased values as the deformity advances. The intermetatarsal angle is measured from the longitudinal bisection of the fourth metatarsal and the medial cortex of the base of the fifth metatarsal. Lateral deviation angles have even wider variability and can range between 2.6-4.8 degrees with measurements up to 8 degrees in the bunionette condition. The intersection of the medial cortex of the base of the fifth metatarsal and the longitudinal bisection of the distal metaphyseal area of the fifth metatarsal are used to calculate this angle (Fig. 9-7). Because of this inconsistency, it is difficult to base the surgical procedure selection solely on

radiographic calculations. The lateral radiograph helps to determine if a plantar flexed fifth metatarsal or prominent plantar condyle is present, resulting P.96 in the formation of an intractable plantar keratosis that may need to be addressed in addition to the transverse plane deformity.

Figure 9-6. Radiographic presentation of splayfoot with high intermetatarsal angle and narrow fifth metatarsal neck and distal metaphysis.

Figure 9-7. AP radiograph of right foot with measured intermetatarsal angle (angle A) and lateral deviation angle (angle B). Once all aspects of the physical examination and radiographic evaluation are complete, the surgical procedure can be selected. Generally, in cases of a mild to moderately elevated intermetatarsal angle with normal fifth metatarsal width, a distal metaphyseal osteotomy provides a consistently reproducible successful result. However, in cases of high intermetatarsal deviation with ligamentous laxity present and possibly narrow metatarsal width, P.97 a proximal procedure may lead to greater favorable outcomes with less recurrence (Fig. 9-8). Other deformities, such as an adductovarus fifth digit, bunion condition, and equinus, should be addressed with selection of the procedure individualized for each patient.

Figure 9-8. Radiographic appearance of foot with highly elevated intermetatarsal angle and previous surgical lateral eminence resection and the postoperative correction obtained with a proximal base osteotomy.

SURGICAL TECHNIQUE The surgical procedure preferred by the author is a distal L-configured metaphyseal osteotomy to correct a moderately increased intermetatarsal angle with an average metatarsal width (Fig. 9-9). The osteotomy is performed with a long plantar arm and short dorsal arm. This procedure lends itself to inherent stability due to the manner in which the osteotomy is created and ease of internal rigid fixation that provides good transverse plane correction. The osteotomy can also be biplanar or triplanar to correct multiple planes of deformity and realignment of the adductovarus digit. The shortcomings of the procedure usually involve poor patient selection due to failure to appreciate significant laxity in the lateral column, resulting in a recurrence of the deformity. A narrow metatarsal head and neck will also limit adequate reduction, and lead to continued deformity postoperatively. Positioning the patient properly on the operating room table may facilitate performance of the procedure. Most patients are supine for surgery, and they will frequently externally rotate the lower extremity while under anesthesia. This external leg position often hampers good visualization of the lateral aspect of the fifth metatarsal. A bump or sandbag placed under the patient's hip will provide internal rotation of the entire leg, allowing better visualization of the surgical area. A tilt of the surgical table toward the opposite extremity may also be extremely helpful. Be certain the patient has appropriate placement of a safety belt and that during surgery the opposite leg does not inadvertently fall from the operating room table. Once positioned, a local anesthetic mixture of 1:1 ratio of 0.5% bupivacaine plain is mixed with 0.5% bupivacaine with epinephrine 1:200,000, making a 1:400,000 epinephrine concentration. This combined solution is injected proximally in a fifth ray block fashion. This provides both postoperative analgesia and intraoperative hemostasis to the area.

Attention is now directed to the fifth ray where a skin incision is planned from the proximal phalanx base to approximately the midshaft of the fifth metatarsal. The skin incision is fabricated to avoid the neurovascular bundle on the dorsolateral side of the fifth metatarsal and curved over the fifth metatarsophalangeal joint (MTPJ) to avoid postoperative skin contracture (Fig. 9-10). Once the skin incision is made, dissection is carried into the superficial subcutaneous level where transversing venous branches are identified and cauterized. The neurovascular bundle laterally may possibly be seen at this point and safely retracted laterally to avoid damage. The extensor digitorum longus tendon is now seen entering from the medial direction and can be retracted medially allowing unobstructed access to the underlying fifth metatarsal. The incision is carried down onto the periosteum and through the fifth MTPJ capsule to identify the underlying osseous structures. The fifth MTPJ is examined for any articular cartilage damage or adaptation that may require repair. The soft tissue is now freed from the lateral aspect of the fifth metatarsal head and distal P.98 metaphyseal region. Care should be taken at this point to be certain there is good visualization of the plantar aspect of the distal fifth metatarsal. There is frequently an increased plantar concavity to the fifth metatarsal that if not well visualized could result in poor implementation of the osteotomy. Slight release of the dorsal capsular structure is now performed to allow completion of the osteotomy. Excessive dissection should be avoided in order to prevent violation of the vascularity to the metatarsal head.

Figure 9-9. Line drawing representing lateral view of the location and orientation of the fifth metatarsal L long plantar arm osteotomy.

Figure 9-10. Planned incisional approach dorsolateral left foot. The neurovascular bundle is retracted laterally within the soft tissue envelope.

Figure 9-11. Minimal resection of lateral eminence of fifth metatarsal.

Figure 9-12. Insertion of K-wire guide from lateral to medial with sagittal plane deviation as well. Predicatable triplanar correction can be achieved with utilization of an axis guide.

Figure 9-13. Long plantar osteotomy in line with guide pin with visualization of proximal extent. This is performed first to secure adequate bone stock for dorsal to plantar screw fixation. P.99 Once all soft tissue is safely retracted and visualization is optimal, the hypertrophic lateral eminence of the metatarsal head is resected sparingly, just enough to provide a flat surface at the lateral head to perform the osteotomy (Fig. 9-11). A guide pin, usually a 0.035-mm K-wire, is then inserted from lateral to medial and adjusted in the other planes to allow for possible shortening or lengthening and elevation or plantar flexion if needed (Fig. 9-12). The long plantar arm of the osteotomy is first, taking care to visualize the exit point proximally to prevent tracking down the metatarsal shaft. It is also important to avoid exiting the shaft too early, making the osteotomy less stable and not amenable to internal rigid fixation (Fig. 9-13). The dorsal arm of the osteotomy is now performed perpendicular to the plantar osteotomy and parallel to the guide pin (Fig. 9-14). If there is adaptation of the articular cartilage requiring transverse plane correction, this is now addressed with a laterally based wedge removed from the distal portion of the osteotomy parallel to the deviated articular cartilage of the fifth metatarsal head (Fig. 9-15). The osteotomy is then transposed medially approximately one half the width of the distal metatarsal to reduce the intermetatarsal angle and deformity (Fig. 9-16). The osteotomy is then impacted on the proximal metatarsal segment and stabilized with temporary fixation. I have noticed from previous experience that an attempt to provide temporary fixation with a standard bone clamp proved to be too large and frequently fragmented the plantar arm of the osteotomy (Fig. 9-17). K-wires provide adequate temporary fixation while the rigid internal fixation is implanted and is the preferred method (Fig. 9-18). My preferred fixation device is the 2.0-mm Synthes cortical screw due to its good overall fixation, low screw head profile, and low cost. Twoscrew fixation is preferred if the plantar osteotomy length is able to accommodate this. It may be noted that the 2.0-mm cortical screw does have some peculiarities when applied to this osteotomy. First, the osteotomy must be well stabilized with K-wires prior to drilling or else the bone fragments may shift. Second, the angle for drilling should be from proximal dorsal lateral to distal plantar medial and not from straight dorsal to plantar. This is because the plantar arm is shifted medially in relation to the dorsal cortex and tapers at the proximal aspect that could lead to missing the plantar aspect completely or possibly breaking the thin plantar proximal wing with the

drill bit if the angle is incorrect. Third, caution as to the length of the screws is advised; if they are too long, they may protrude onto the weightbearing aspect of the fifth metatarsal head, causing pain during gait. And lastly, I no longer tap the 2.0-mm cortical screw because there is better compression and less stripping and the screw inserts without difficulty or displacement of the osteotomy (Fig. 9-19). Once the osteotomy is fixated and stable, the overhanging lateral portion of the fifth metatarsal shaft is removed and made flush with the transposed portion (Fig. 9-20). Intraoperative imaging is utilized when available to confirm correction obtained and screw placement prior to closing the incision (Fig. 9-21). Closure is then performed in a layered fashion with closure of the periosteum and capsular layer by simple interrupted sutures, followed by closure of the subcutaneous and subcuticular layer in a running horizontal mattress configuration with absorbable or nonabsorbable suture as desired (Fig. 9-22).

Figure 9-14. Dorsal osteotomy perpendicular to plantar osteotomy and parallel to guide pin. P.100

Figure 9-15. A: Deviated articular cartilage of fifth metatarsal head. B and C: Line drawings of dorsal lateral based wedge osteotomy to correct deviated cartilage.

Figure 9-16. Transposition of fifth metatarsal distal head, neck, and shaft up to one half the width of the fifth metatarsal. Impaction of the capital fragment after transposition will secure a tight apposition of the osteotomy.

Figure 9-17. Utilization of the bone clamp to stabilize the osteotomy and proper angle of drilling. Beware of iatrogenic trauma to the fragile plantar arm with standard bone clamps. Use of a small towel clamp may be of benefit. P.101

Figure 9-18. Utilization of a K-wire for temporary fixation to stabilize the osteotomy and proper angle for drilling for rigid internal fixation.

Figure 9-19. Insertion of 2-0mm screws with no tapping required.

Figure 9-20. Resection of overhanging lateral aspect of fifth metatarsal. P.102

Figure 9-21. Intraoperative imaging showing correction achieved and placement of hardware.

Figure 9-22. Closure with nonabsorbable subcuticular running suture technique.

POSTOPERATIVE MANAGEMENT The patient is initially placed into a compression cast for 1 week nonweightbearing or a compressive wrap and postoperative shoe with partial weightbearing. At the first dressing change 1 week postoperatively, the incision is examined and radiographs performed to confirm osseous correction and screw placement. A sterile dressing and a compressive wrap are applied and the patient is given a postoperative shoe and allowed to begin weightbearing to tolerance. At 2 weeks postoperatively, the patient is seen for suture removal; weightbearing in the postoperative shoe with compressive wrap is continued for an additional 2 weeks. The patient is next seen at 4 weeks postoperatively and if no complicating factors such as excessively swelling or pain are noted, the patient is allowed to begin wearing a stiff-soled shoe or sandal as tolerated. At 6 weeks postoperatively, radiographs are again taken to confirm osseous healing and the patient may begin nonimpact physical activity such as biking, walking, or swimming. At 10 weeks postoperatively most patients are able to begin some low impact exercises in regular shoe gear and can realistically resume high impact activities by 12 weeks. Some patients may initially experience increased swelling or induration with increased exercise. This improves as the soft tissues and bone continues to heal.

P.103

COMPLICATIONS This has been my procedure of choice for painful bunionette conditions for over 12 years due to the stability of the osteotomy, the ability to correct deformity in multiple planes, the long-term success in correction with decreased recurrence, and the ability to allow early weightbearing during the postoperative course. There are few complications seen as a direct result of this surgical procedure compared to other osseous corrections for a painful bunionette condition. Besides the typical complications of any surgery, such as infection or chronic swelling, probably the most frequently encountered problem is irritation from the implanted hardware. Many patients have minimal subcutaneous fat tissue on the lateral aspect of the forefoot, resulting in prominence of the screw heads. This is not a problem initially because of localized swelling in the area from the surgery. As the swelling decreases and activities increase, the head of the screws may become irritating in certain shoe gear. To resolve this problem, I have been utilizing the smaller, low profile, 2.0-mm cortical screw instead of larger core diameter screws that have inherently more compression strength but a larger screw head. I have also considered some of the other low-profile screws available on the market; however, they are more costly and do not seem to offer a significant advantage. An absorbable screw may be an alternative in this situation but I have no direct experience with them. I always inform my patients prior to surgery that the hardware implanted may eventually require removal. There is minimal morbidity and the patient is frequently able to return to regular shoe gear immediately afterwards. Another less frequent complication is neuritis due to damage of the nearby lateral neurovascular bundle. With common knowledge of the location of this nerve, damage should easily be avoidable. Only in revision surgery with a prior bunionette correction can this nerve be difficult to discern and inadvertently injured during dissection. If the nerve is encountered intraoperatively and damaged beyond repair, the nerve should be resected proximally out of the surgical incision area to avoid continued entrapment postoperatively. The incidence of nonunion or malunion in this surgical procedure is rarer even yet. With the inherent stability of the osteotomy due to the long plantar arm on the weightbearing aspect of the metatarsal and the two-point rigid compression fixation, the osteotomy is contrived to heal in the position placed intraoperatively without displacement and without secondary bone callous formation. This allows for a low malunion rate and an even lower nonunion rate. If there is delayed healing due to loosening of the screws or excessive early impact activity, then a short period of immobilization should resolve this complication, allowing for complete bony union (Fig. 923). I have not had to surgically address any delayed unions and no nonunions have been seen postoperatively.

Figure 9-23. A: Radiograph of loss of hardware purchase of distal screw. B: Delayed union and eventual healing of osteotomy with no loss of correction.

P.104 Probably the most frustrating postoperative complication is recurrence of the deformity. The recurrence is often directly related to an incomplete evaluation of the degree of deformity and concurrent conditions such as ligamentous laxity, equinus, and splayfoot deformity. In all cases of recurrence, the extent of deformity was too large for this procedure and a more proximal procedure should have been selected. This is especially true in treating a previously corrected bunionette condition that has recurred or one that presents with a narrow head and neck of the metatarsal. Minimal correction can be obtained distally if the osteotomy cannot be transposed medially enough to reduce the intermetatarsal angle due to instability of the osteotomy. It is much more difficult, however, to perform the proximal base osteotomies accurately and a much longer recovery period for the patient can be expected with nonweightbearing—up to 8 or more weeks. Still, this should be something in every surgeon's armamentarium for the correction of the bunionette deformity when faced with such complicating factors.

CLINICAL TIPS AND PEARLS As stated above, the success of this surgical procedure is firmly rooted in its inherent stability and ease of execution. The final outcome should be consistently favorable for both surgeon and patient with excellent longterm results. Nevertheless, some difficulties may be encountered with this procedure, although they can often be avoided by taking certain precautions. We will review some of them now. 1. Proper patient selection is vital. If the metatarsal is too narrow distally or there is a high intermetatarsal angle with ligamentous laxity, this is not the procedure of choice. Instead correction with a proximal osteotomy is indicated and if an entire splayfoot deformity involving the first ray and equinus condition is present it may have to be corrected. 2. Proper patient positioning with internal rotation of the leg and tilting of the operating room table will facilitate execution of the procedure. 3. The osteotomy must be made in the appropriate orientation, which is facilitated by the use of a guide pin prior to fabricating the osteotomy. All three planes of deformity should be addressed if needed. Be certain there is good visualization of the plantar aspect of the fifth metatarsal prior to performing the osteotomy in order to get adequate length of the osteotomy for fixation. 4. Get good temporary fixation prior to attempting rigid internal fixation. This will decrease the chance of rotation during fixation and increase the likelihood of adequate compression with the 2.0-mm cortical screw. 5. Avoid using the bone clamp for temporary fixation because it may cause fracture of the fragile plantar wing of the osteotomy. 6. Caution should be taken to prevent stripping of the screw or inserting too long of a screw in the weightbearing area of the metatarsal head. The 2.0-mm Synthes cortical screws are preferred and no tapping is necessary in order to minimize stripping.

RECOMMENDED READINGS 1. Catanzariti AR, Frieman D, Distazio J: Oblique osteotomy of the fifth metatarsal: a five year review. J Foot Surg 27: 316-320, 1988. 2. Crawford ME: Fifth metatarsal bunionette deformity: aetiology and correction. Br J Podiatr Med Surg 5: 79, 1993.

3. Crawford ME: Deformities of the Fifth Metatarsal. In: Banks AS, Downey MS, Martin DE, Miller SJ, eds. McGlamry's Comprehensive Textbook of Foot and Ankle Surgery. 3rd ed. Philadelphia: Lippincott Williams & Wilkins, 2001: 339-353. 4. Dockery GL: A plantar “L” distal osteotomy bunionectomy procedure. Br J Podiatr Med Surg 5: 10-13, 1993. 5. Fallat LM, Buckholz J: Analysis of the tailor's bunions by radiographic and anatomical display. J Am Podiatry Assoc 70: 597-603, 1980. 6. Gerbert J, Sgarlato TE, Subotnick SI: Preliminary study of a closing wedge osteotomy of the fifth metatarsal for correction of a tailor's bunion deformity. J Am Podiatry Assoc 62: 212-218, 1972. 7. Schoenhaus H, Rotman S, Meshon AL: A review of normal intermetatarsal angles. J Am Podiatry Assoc 70: 597-603, 1980.

10 Double Stem Silicone Implantation for First Metatarsal Phalangeal Joint Arthroplasty Joshua Gerbert

INDICATIONS/CONTRAINDICATIONS Since the 1960s, first metatarsal phalangeal joint (MTPJ) implants in one form or another have been utilized for nonsalvageable joints. The literature has revealed successes and failures with every type of implant that has been used. The 1960s introduced the hemi design implants, the late 1970s introduced modifications of the hemi design, the 1980s introduced the double stem constrained designs along with the use of titanium grommets, and the early 1990s introduced the two component metallic nonconstrained designs. After looking critically at all the implants available, the double stem silicone design implant has proven to be the most effective in relieving pain, restoring first MTPJ motion, and withstanding years of usage. Of the various double stem designs available, the LaPorta total implant (Fig. 10-1) provides the most flexibility and can be used regardless of the condition of the hallucal sesamoids. The LaPorta total implant is constructed of UltraSil, a high performance medical-grade silicone elastomer. The design features include a broad collar on either side of the hinge and a 10-degree transverse angulation of the proximal stem. It comes in a neutral or regular design. The neutral design can be used for either the right or left foot and its stems have no sagittal plane angulation, whereas the regular design has a 15-degree sagittal plane angulation in the proximal stem. The neutral design is utilized in patients with an abnormally low first metatarsal declination angle while the regular design is used those with a more normal metatarsal declination angle. P.106

Figure 10-1. Photograph showing the four sizers (20, 30, 40, and 50) for the regular LaPorta implant. The Neutral design has no planar angulation while the regular design incorporates 15 degrees of sagittal plane angulation.

PREOPERATIVE CONSIDERATIONS No implants are impervious to failure; however, the surgeon can control certain variables that decrease the incidence of implant failure. In order to achieve the best long-term outcome when using a first MTPJ implant, the following preoperative criteria should be considered. It is imperative that the surgeon rely upon information

gained from good quality weightbearing AP (anterio/posterior), lateral, and plantar axial radiographs. 1. Patient awareness of implant degradation over time and the need for possible replacement, arthrodesis, or removal without replacement. 2. Adequate bone stock to withstand stress of implant material. 3. Normal first metatarsal alignment on both the transverse and sagittal planes unless corrected by an osteotomy procedure at the time of implant insertion. A first metatarsal elevatus seen on a lateral x-ray not secondary to a previous osteotomy will most likely reduce itself with decompression of the first MTPJ and shortening of the first metatarsal. 4. Normal to short length of the second metatarsal unless corrected by a shortening osteotomy of the second metatarsal. 5. No history of prior first MTPJ infection unless treatment was well documented, organism had been identified, and the event occurred at least 6 months earlier. 6. No history of patient allergy to silicone. 7. Patient has a strong desire to maintain some first MTPJ motion following the joint destructive procedure.

SURGICAL TECHNIQUE Consider the use of antibiotic prophylaxis and an ankle tourniquet in the perioperative period. Flush the wound often during surgery in order to maintain tissue hydration and to maintain a low concentration of contaminants. A dorsal medial, slightly curved incision (Fig. 10-2) is made medial to the extensor hallucis longus tendon, approximately half way between the most medial border of the foot and the extensor tendon. Make the incision in this manner in order to avoid any potential scarring and/or adhesions with the extensor tendon. Curving the incision will minimize a dorsal contracture of the first MTPJ if the incision line abnormally contracts. Dissection is carried down to the area of the extensor tendon, which in most cases can be kept intact within its tendon sheath. It is very rare this tendon needs to be lengthened. The dissection is kept to a minimum. A dorsal incision is then made though the remainder of P.107 the subcutaneous tissue and first MTPJ capsule. The length of this deep fascial incision is the same length as the skin incision, in order to maximize exposure. This will provide adequate exposure to the base of the proximal phalanx and the metatarsal head without any tension on the surrounding soft tissues.

Figure 10-2. The proposed skin incision typically used for insertion of the LaPorta implant remains medial to the extensor hallucis longus tendon. Note that the incision is long enough to allow good tissue exposure without undue tension on the skin.

Figure 10-3. Exposure of the dorsal aspect of the base of the proximal phalanx and the metatarsal head using a dorsal linear approach through the subcutaneous tissue and capsular structure. Notice the full thickness flaps of subcutaneous tissue and deep fascia. This approach minimizes soft tissue dissection and postoperative adhesions. Care is taken to develop a single flap of subcutaneous tissue and capsule as it is dissected from the base of the proximal phalanx and the metatarsal head. The entire base is carefully exposed as well as the metatarsal head (Fig. 10-3). If there are significant osseous proliferations at the dorsal aspect of the base of the phalanx and/or on the dorsal aspect of the metatarsal head, they are removed at this time in order to have a better visualization of the first MTPJ; however, one should not be too aggressive with bone removal. Depending on the preoperative plantar axial radiograph (Fig. 10-4), make a decision whether or not to purposely detach the sesamoid attachments from the base of the phalanx, allowing the sesamoids to retract proximally. Depending on the preoperative symptoms of the patient and the information gained from the plantar axial radiograph, one might elect to remove one or both of the hallucal sesamoids. If the sesamoids are to be removed, it occurs following removal of the base of the proximal phalanx and the distal portion of the metatarsal head. The bone cut on the base of the proximal phalanx should be perpendicular to its long axis and the weightbearing surface of the foot. The use of an overlay acetate sheet that contains the actual sizes of the LaPorta implants

may be helpful preoperatively to determine the amount of bone to be removed (Fig. 10-5). The usual amount of bone removed from the base is approximately 10.0 mm (Fig. 10-6). Care is taken to remove the bone perpendicular to the long axis of the phalanx and not parallel to its articular surface. This is important as the plantar aspect of the base slants and protrudes more proximal then its dorsal aspect (Fig. 10-7). Be careful when cutting through the base to only sever the plantar cortex and not extend into the plantar soft tissues and risk injury to the flexor hallucis longus (FHL) tendon. The base can then be removed using a sharp towel clamp. Once again, be careful P.108 to preserve the capsular flap and the plantar soft tissue structures, especially the FHL tendon. In the majority of cases, the base can be removed without detaching any of the attachments of the flexor hallucis brevis and much less the FHL (Fig. 10-8). In cases when all soft tissue is removed, thereby exposing the FHL tendon, create several drill holes into the plantar aspect of the phalanx after creating the medullary hole for the stem of the implant. Using these drill holes, reattach the FHL to the proximal phalanx prior to the insertion of the implant (Fig. 10-9). This maneuver will assist in maintaining hallux toe purchase postoperatively.

Figure 10-4. A preoperative plantar axial view in which the hallucal sesamoids are enlarged and arthritic. This view can assist in deciding whether to remove or leave in the sesamoids. The next step is to fashion a hole within the proximal phalanx to receive the distal stem of the implant (Fig. 10-

10). Perform this prior to removing the metatarsal head to determine if the bone stock of the phalanx is strong enough to withstand the implant. If the bone stock at the base cannot withstand an implant, complete the procedure as a Keller arthroplasty or possibly an arthrodesis, depending on the consent obtained. In creating the hole in the phalanx one needs to keep in mind the normal plantar concavity of the phalanx and make certain that the initial drill hole is dorsal enough to prevent exiting out the plantar cortex. The drill hole is made along the long axis of the phalanx using a 4-mm burr. The depth of the hole is dependent upon the length of the distal stem of the implant. The LaPorta design implant has a relatively short distal stem. The use of broaches to complete the hole or the use of the 4-mm burr is surgeon's preference. A rotary burr is often adequate to create a rectangular stem hole. The periodic use of the implant sizer will guide the surgeon as to whether the hole is acceptable. The distal stem of the sizer should easily fit into the phalangeal hole without any force and it should fully insert to allow the broad collar of the implant to rest evenly on the cortical margins of the phalanx (Fig. 10-11). The distal portion of the metatarsal head is removed next. The amount of bone removed should be kept to a minimum (usually 3-4 mm) in order to preserve as much of the weightbearing portion of the metatarsal head. Again the use of the overlay acetate sheet containing the actual implant sizes may be useful to determine the amount of bone to be removed (see Fig. 10-5). Make this cut perpendicular to the weightbearing surface to assist in maintaining as much of the plantar weightbearing portion of the metatarsal head as possible (Fig. 1012). At this time, inspect the hallucal sesamoids and compare to the preoperative axial radiographs. If the sesamoids are arthritic, make certain that they are free of their distal attachments and can retract proximally. At times, the use of a McGlamary elevator will assist in freeing of the sesamoids for proximal retraction. If the sesamoids will not retract proximally or if a particular sesamoid is hypertrophic, excise one or both of them. P.109

Figure 10-5. By using this overlay acetate sheet preoperatively, one can determine which implant size will probably be correct for the specific patient and how much bone will need to be removed. P.110

Figure 10-6. Demonstrating the use of calipers intraoperatively to mark off the amount of bone to be removed from the base of the proximal phalanx. The usual amount of resection is 1.0 cm.

Figure 10-7. The photograph shows the use of a sagittal saw used to remove the base of the proximal phalanx. Make sure the saw is perpendicular to the long axis of the phalanx for proper alignment of the implant. The drawing demonstrates the need to make the cut through the base perpendicular to the weightbearing surface and not parallel to the joint surface. Note the proximity of the FHL tendon to the plantar cortex of the proximal phalanx.

Figure 10-8. A and B: Demonstrating the removal of the base of the proximal phalanx using a sharp towel clamp and scalpel. The surgeon must use great care when dissecting the base from the soft tissue attachments in order not to accidentally sever the FHL tendon. P.111

Figure 10-9. Drawing demonstrating the use of nonabsorbable sutures placed through a plantar drill hole into the proximal stump of the flexor tendon. The tendon is usually not transected prior to reattachment back to the phalangeal base. The sutures are tightened to create physiological tension of the long flexor tendon into the base of the phalanx, assisting in hallux purchase.

Figure 10-10. The fashioning of the medullary stem hole into the base of the proximal phalanx. The rotary burr, rasps, or broaches can all be utilized to create a rectangular hole.

Figure 10-11. This photograph shows the use of an implant sizer to check the fit of the stem hole and the overall fit of the implant to the base of the phalanx. Ideally, the collar of the implant should extend just beyond the cortices of the phalanx. Note the sagittal plane angulation of the metatarsal stem in this regular design. P.112

Figure 10-12. Dorsal (A) and medial (B) views show the amount of bone to be removed from the metatarsal head. It is important to remove this portion perpendicular to the weightbearing surface of the foot in order to preserve as much of the plantar aspect of the metatarsal head as possible. C: Photograph showing the actual amount of bone that was removed from the base of the phalanx as well as the metatarsal head. Note the minimal resection from the metatarsal head. The next step is to fashion the hole within the metatarsal head to receive the proximal stem of the implant. Use the plantar surface of the metatarsal head and the crista as guidelines for centering the hole (Fig. 10-13). Fashion the hole as plantar as possible into the metatarsal in order to assist in maintaining hallux toe purchase postoperatively. The hallux position on the sagittal plane is directly dictated by the stem hole, which is created in the metatarsal (Fig. 10-14). The hole is drilled once again using the 4-mm burr and is then fashioned into a rectangular receptacle, using either the 4-mm burr or the broaches. Care should be taken to fashion the hole into the metatarsal, keeping in mind whether the implant being used has a sagittal plane angulation. A sizer is used periodically to check the width and depth of the hole. When the hole is properly completed, the proximal stem should seat within the hole easily and the broad collar should rest evenly against the cortical margins of the metatarsal head (Fig. 10-15). The actual size implant selected for the patient can usually be determined preoperatively by using the overlay acetate sheets shown (see Fig. 10-5). The size of the proximal phalanx may dictate the size of implant that can be used. In fashioning the stem holes in the phalanx

P.113 one can only create a hole of a certain size without compromising the integrity of the phalanx itself. Therefore a smaller implant may need to be used compared to the size that could be used to seat within the metatarsal head. Use an implant size that provides the best collar coverage of the cut bone surfaces on the phalanx as well as the metatarsal head. Once the sizer implant is fully inserted and the first MTPJ range of motion tested, the surgeon should make certain that there is a slight 1.0-2.0 mm of pistoning of the implant from proximal to distal. This will increase the life span of the implant by dispersing stresses from the implant hinge itself. This implant should never be inserted under pressure with an absolute tight fit. That technique will only lead to pain and osseous reabsorption at the implant/bone interface.

Figure 10-13. A-C: demonstrate the selection of the site for fashioning the medullary stem hole into the metatarsal using the crista as a guide. One attempts to start the hole as plantar as possible and then fashion it from an oval to a rectangle that more closely resembles the shape of the stem of the implant. One can use broaches as a final step in creating this rectangular hole or one can just use the 4-mm egg burr to accomplish this task. If the lateral portion of the capsule and/or any remnants of the lateral collateral ligament appear to be tight, perform a vertical lateral capsulotomy. This will prevent undue lateral stress on the implant. Once the correct implant sizer is in place, take a skin marker and outline any bone that extends beyond the margins of the collar of the implant on both the phalanx and the metatarsal (Fig. 10-16). The sizer is then removed and the redundant bone is removed and smoothed prior to insertion of the actual implant (Fig. 10-17). When inserting the actual implant, care should be taken to keep the implant from coming in contact with the skin as it is being inserted. Prior to insertion, place the implant in saline or antibiotic solution to eliminate static charge on the implant (Fig. 10-18). The proximal stem is inserted, using smooth Adson forceps; the hallux is then plantarfexed and the

P.114 distal stem is inserted (Fig. 10-19). If a shaft/base osteotomyneeds to be performed in order to realign the first metatarsal on the transverse and/or sagittal planes, perform and fixate that procedure after the sizer implant had been inserted but prior to the insertion of the actual implant.

Figure 10-14. This drawing depicts the metatarsal stem of the implant inserted in a more dorsal position in the metatarsal with the resultant dorsal position of the hallux. This will produce a lack of hallux toe purchase postoperatively.

Figure 10-15. A sizer being tested in the metatarsal head. The ideal fit is to have the collar of the implant sit beyond the cortices of the metatarsal head, which may not always be possible due to the size implant that could be inserted into the proximal phalanx.

Figure 10-16. The sizer is shown in place in the metatarsal head and the surgeon using a skin scribe to mark the amount of bone that extends beyond the collar of the implant. This excess bone will be removed after the sizer is removed.

Figure 10-17. The implant sizer in place following the circumferential removal of the excess bone from the metatarsal head. The implant should be able to piston within the joint several millimeters. A tight fit for the implant is not desirable and will shorten the life of the implant. P.115

Figure 10-18. Placement of the actual implant in the antibiotic solution in order to reduce the static charge on the device prior to implantation. The capsule is then closed using 4-0 absorbable suture. The subcutaneous tissue is reapproximated using several 5-0 absorbable buried knot stitches. The skin is reapproximated using 5-0 nonabsorbable simple or horizontal mattress stitches. Since the patient begins first MTPJ range of motion as soon as possible following the surgery, I have seen an increase P.116 incidence of wound dehiscence when the running subcuticular stitch is used. If the second metatarsal was abnormally elongated preoperatively, it should be shortened to decreased the possibility of second MTPJ stress syndrome and lesser metatarsalgia.

Figure 10-19. A: The metatarsal stem is inserted first and then the phalangeal stem follows. An atraumatic pickup is used to gently rotate the distal stem into the phalanx while the joint is manually distracted. B: The implant is carefully evaluated after insertion. There should be an even alignment of the implant to the edges of the bone. Compression type bandages are used with a small amount of full strength betadine solution on the gauze directly over the incision site. This technique assists in reducing the edema at the incisional site and the formation of a hypertrophic scar.

POSTOPERATIVE MANAGEMENT If no osteotomy was needed, the patient is allowed to begin propulsive ambulation as soon as he or she has recovered from the anesthetic. If an osteotomy was used, the patient will be managed based on the osteotomy procedure performed; however encourage the patient to begin early first MTPJ motion. Postoperative radiographs should be taken within the first week to serve as a baseline for future reference (Fig. 10-20). It is not uncommon for these early radiographs to show increased separation of the stems of the implant from the phalanx and/or the metatarsal due to immediate postoperative bleeding and hematoma formation. The use of a small drain system for several hours after surgery can greatly reduce the hematoma formation. I will definitely use the drain system if I remove both sesamoids. The stitches are removed at 2-3 weeks depending upon the healing process. Have the patient use an elastic type self-adherent bandage around the forefoot for several P.117 additional weeks in order to minimize edema. If no osteotomy procedure was performed, the patient is allowed to return to a regular type shoe as soon as the stitches are removed. A radiograph is usually taken at 6 weeks to check the implant position.

Figure 10-20. A and B: Postoperative AP and lateral radiographs showing the proper placement of the implant. Note the rectus alignment of the hallux in both views. The utilization of physical therapy is dependent upon the degree of postoperative edema at 4-6 weeks after surgery. The use of an orthotic device is based on several factors. If the patient demonstrated a functional hallux limitus preoperatively secondary to abnormal foot mechanics, then a functional orthotic device should be used postoperatively in order to decrease the stresses on the implant. If the patient begins to develop transfer lesser metatarsalgia, an orthotic device of some type with a Morton's extension should be utilized.

COMPLICATIONS The complications can be related to one or more of the following categorizes: infection, failure of the implant, reaction to the implant, failure to comply with preoperative indications for implant usage, failure due to poor surgical technique, and/or abnormal foot mechanics. My personal experiences regarding complications with at least 400 LaPorta total implants are as follows: 1. Wound infection that required removal of the implant very rare. 2. Implant destruction and fracturing that required removal due to symptoms secondary to reactive synovitis. This complication is seen more frequently in the younger active patient population in which daily stresses on the first MTPJ are greater than in the elderly patient population. The problem appears to surface at 6-7 years following implantation. 3. Implant destruction and/or fracturing as a radiographic finding without symptoms. This is one of the more frequent complications following patients over a 10-20 year period. 4. Ectopic bone formation around the margins of the implant. Some patients developed significant symptoms that necessitated surgical debridement of the bone and replacement of the implant. At other times, it was a noted radiographic finding, although there were no symptoms and no treatment was required. This problem seems to be the result of having bone at either the phalangeal base or the metatarsal head extend beyond the collar of

the implant at the time of insertion. 5. Osseous reabsorption of the proximal phalanx and/or metatarsal head at the implant collar interface with the bone. This is usually the result of an abnormally tight implant fit at the time of implant insertion. In patients evaluated many years following insertion of the implant, this may be the result of chronic synovitis and a reactive hyperemia of the involved bone. At times symptoms were present, necessitating removal of the implant. 6. Chronic edema secondary to either tissue reaction to the implant and/or reactive synovitis. If the edema is secondary to tissue reaction from the surgery and the implant, usually physical therapy and tincture of time will resolve the issue. If the edema is secondary to reactive synovitis due to implant degradation, then removal of the implant is necessary. 7. Lack of hallux toe purchase is a common postoperative finding, especially in the elderly patient population. This may be due to the hallucal sesamoids retracting proximally or being excised due to their pathology. This can also be the result of fashioning the stem hole in the metatarsal too dorsally. The use of an orthotic device with a Morton's extension will usually prevent or eliminate symptoms associated with this complication. 8. Transfer metatarsalgia and second MTPJ stress syndrome is one of the more common complications 6-12 months following the implant procedure. Certain etiologies include lack of hallux toe purchase, removing too much bone from the metatarsal head, and not identifying an elevated first metatarsal or an abnormally elongated second metatarsal at the time of the implant procedure. The etiology for this complication will dictate what form of treatment will be most effective. This may require a simple orthotic device with a Morton's extension or it may necessitate another surgical procedure. P.118

CLINICAL TIPS AND PEARLS First MTPJ implantation is not a procedure that should be performed on every patient who has a nonsalvageable first MTPJ. It is certainly a viable alternative to a Keller arthroplasty and in women a viable alternative to a joint fusion. The patients must be aware of the potential complications associated with the implant. The surgeon needs to be realistic regarding the risk/benefit ratio for the specific patient. The following are a few important points for the surgeon to consider in order to give the patient the best chance for a successful longterm outcome following first MTPJ implantation using the LaPorta silastic double stem device. 1. The first metatarsal must be in good transverse and/or sagittal plane alignment at the time of implant insertion. 2. The bone stock must be adequate to withstand the stresses of the implant. 3. Preserve as much of the weightbearing surface of the metatarsal head as possible (see Fig. 10-11). Shorten an abnormally long second metatarsal even when asymptomatic. 4. The stem hole in the metatarsal must be as plantar as possible. Remove redundant bone from the phalanx and metatarsal only after the correct implant sizer has been inserted. 5. Maintain FHL attachment to the proximal phalanx. 6. Allow the implant to piston several millimeters distal to proximal after insertion.

RECOMENDED READING 1. Bonet J, Taylor DT, Lam AT, et al.: Retrospective analysis of Silastic implant arthroplasty of the first metatarsophalangeal joint. J Foot Ankle Surg 37: 128, 1998.

2. Burns A: Implant Procedures. In: Gerbert J, ed. Textbook of Bunion Surgery. 3rd ed. Philadelphia: WB Saunders, 2001: 319-346. 3. Burns A: Implant Complications. In: Gerbert J, ed. Textbook of Bunion Surgery. 3rd ed. Philadelphia: WB Saunders, 2001: 448-461. 4. Cracchiolo A, Swanson A, Swanson GD: The arthritic great toe metatarsophalangeal joint: a review of flexible silicone implant arthroplasty from two medical centers, Clin Orthop 157: 64, 1981. 5. Dobbs B: LaPorta great toe implant: long term study of its efficacy.J Am Podiatr Med Assoc 80: 379, 1990. 6. Farnworth C, Haggard S, Nahmias MC, et al.: The LaPorta great toe implant: a preliminary study of its efficacy. J Am Podiatr Med Assoc 76: 625, 1986. 7. Futura Biomedical: The Futura hinged great toe metatarsophalangeal joint implant (LaPorta design) [commercial prospectus]. San Diego, Calif: Futura Biomedical, 1996. 8. Gerbert J, Chang T: Clinical experience with two-component first metatarsophlangeal joint implants. Clin Podiatr Med Surg 12: 403, 1995. 9. Granberry W, Noble PC, Bishop JO, et al.: Use of a hinged silicone prosthesis for replacement arthroplasty of the first metatarsophalangeal joint. J Bone Joint Surg 73A: 1453, 1991. 10. Hanyu T, Yamazaki H, Ishikawa H, et al.: Flexbile hinge toe implant arthroplasty for rheumatoid arthritis of the first metatarsophalangeal joint: long term results. J Orthop Sci 6: 141, 2001. 11. Laird L: Silastic joint arthroplasty of the great toe: a review of 228 implants using the double stemmed implant. Clin Orthop 255: 268, 1990. 12. LaPorta GA, Piloa P, Rickter KP: Keller implant procedure. JAPA 66: 126, 1976. 13. Lemon B, Pupp GR: Long term efficacy of total silastic implants: a subjective analysis. J Foot Ankle Surg 36: 341, 1997. 14. McNearney T, Haque A, Wen J, et al.: Inguinal lymph node foreign body granulomas after placement of a silicone (Silflex) implant of the first metatarsophalangeal joint. J Rheumatol 23: 1449, 1996. 15. Shankar NS, Asaad SS, Craxford AS. Hinged silastic implants of the great toe. Clin Orthop 272: 227, 1991. 16. Vanore J, O'Keefe R, Pikscher I: Silastic implant arthroplasty-complications and their classification. J Am Podiatry Assoc 74: 423, 1984. 17. Vanore J, O'Keefe R, Pikscher I: Complications of silicone implants in foot surgery. Clin Podiatry 1: 175, 1984.

11 First Metatarsophalangeal Joint Arthrodesis Lowell Scott Weil Jr.

INDICATIONS/CONTRAINDICATIONS Arthrodesis of the first metatarsophalangeal joint (MTPJ) has been the gold standard for treating late stages of hallux rigidus and arthritic hallux valgus and destructive joint changes from inflammatory arthropathies such as rheumatoid arthritis. It may also be used as a salvage procedure in cases of failed “decompression osteotomies”, cheilectomies, and implants for hallux rigidus as well as failed revision of hallux varus. Arthrodesis of the first MTPJ is most commonly used for late stage hallux rigidus. The etiology of hallux rigidus is controversial. Thus, many foot and ankle surgeons, uncertain of how to interpret the varied reports of the results of procedures for this condition choose arthrodesis as the primary procedure for painful hallux rigidus. Painful, clinical crepitus of the first MTPJ combined with significant joint space narrowing will often lead to the decision to perform a joint destruction or arthrodesis procedure. Rarely, is the decision made intraoperatively based on the percentage of “good cartilage”. Special consideration should be given to the patient who has hallux rigidus with severe osteophytosis and only a few degrees of first MTPJ range of motion. Shoe pressure may be the only entrance complaint and based on the above criteria, the surgeon may be tempted to perform an extensive cheilectomy, only to discover postoperatively that the patient has painful joint crepitus along with the increased range of motion.

PREOPERATIVE CONSIDERATIONS Many factors must be considered when choosing the best surgical option for each patient. Age, activity level, gender, and type of employment are important criteria in the decision making process. Often, a thorough history and careful examination will reveal the patient's complaints to be limited to shoe pressure rather than joint motion pain. This can be determined P.120 by finding out if the patient has pain when ambulating without shoes. If the patient is comfortable when ambulating without shoes, a joint sparing procedure may be a better choice. If the patient does have pain ambulating with shoes, one must assess the severity of the disease within the joint to determine if a joint preserving procedure can be considered or if a joint destructive procedure (arthrodesis or arthroplasty) will be necessary. Joint destructive alternatives to arthrodesis include arthroplasty with or without implant. Patients with painful hallux rigidus who are less than 45 years old should cautiously be considered for silicone implant arthroplasty. Metallic, hemi-joint, implant arthroplasty may have a role in the treatment of this age group. Based on poor results following thirty years of experience in the author's group, total joint replacement using a metatarsal head and phalangeal base component is not recommended for the treatment of hallux rigidus. Prior to surgery, one should assess bone quality and determine if the patient is an appropriate candidate for arthrodesis. The patient should have adequate circulation. Osteopenic bone and smoking can lead to difficulties with fixation and potential nonunion. Because arthrodesis requires some time for immobilization and altered weightbearing, there may an increased risk of deep vein thrombosis. Appropriate perioperative medical prophylaxis may be considered in the “at risk” patient. Typically, weightbearing AP (anteroposterior) and lateral projections of both the symptomatic and contralateral foot will help assess the overall structure of the joint (Figs. 11-1 and 11-2). Often, oblique and axial sesamoid

views will add additional information regarding the extent of the disease. Careful assessment of the first MTPJ space should be undertaken. Narrowing of the joint space, periarticular osteophytosis, length of the hallux and first metatarsal, loose bodies and fracture fragments of the proximal phalangeal base should all be assessed. First metatarsal declination angle, hallux abductus angle, hallux asymmetry, hallux interphalangeal angle, and sagittal position of the first MTPJ of both the symptomatic and contralateral foot should be evaluated in order to attempt to provide symmetry in the final result. The presence of hyperextension of the interphalangeal joint and lesser toe position in the transverse plane is evaluated.

Figure 11-1. Preoperative AP radiograph of end stage arthrosis of the first MTPJ. P.121

Figure 11-2. Lateral radiograph with mild elevation of the first metatarsal noted. This will be reduced after successful arthrodesis. Evaluation of the midfoot, hindfoot, and ankle must also be undertaken to assess the potential functional influence of structural abnormalities. Magnetic resonance imaging may be beneficial in assessing revision cases for possible avascular necrosis and medullary bone destruction secondary to silicone synovitis. Mini-fluoroscopy can evaluate the function of the sesamoids. Bone scintography rarely provides any useful information in the decision making of this condition. Gait analysis and computerized footprint analysis is often used in the complex revision cases involving significant foot and ankle dysfunction.

SURGICAL TECHNIQUE Arthrodesis is typically performed under intravenous sedation and local anesthesia. The patient is placed in a supine position and prepped and draped in a standard sterile fashion. An incision is made on the dorsal medial aspect of the first MTPJ of the foot (Fig. 11-3). The incision is deepened down to the joint capsule (Fig. 11-4), which is incised, exposing the joint. The capsular structures are commonly found to be hypertrophied and wedging into the dorsal P.122 aspect of the joint. A loose body is often noted dorsally at the base of the proximal phalanx and this is excised. The articular cartilage and subchondral bone is assessed and often noted to be severely eroded with corresponding osteophytosis throughout the metatarsal head and phalangeal base. Utilizing a combination of osteotomes and a bone saw, the first metatarsal head and phalangeal base is then remodeled to a more anatomic size.

Figure 11-3. Dorsal medial incision for exposure of the first MTPJ. The standard neurovascular structures will be visualized and retracted plantarly within the subcutaneous soft tissue envelope.

Figure 11-4. Exposure of the first MTPJ after deep fascial/periosteal incision. Adequate soft tissue release is needed for exposure of the dorsal lateral and plantar medial aspects of the joint. The main points to a successful fusion include proper preparation of the bone surfaces and positioning. Actual techniques include end-to-end fusion, curettage, and reamer systems. The fusion site can be prepared with a variety of methods, but removal of the subchondral bone is preferred to facilitate fusion. Our preferred method is with conical reamers (Fig. 11-5), which minimizes bony resection, maintains length, and allows for positional adjustments just prior to fixation. Utilizing conical reamers, the remaining cartilage and top layer of the subchondral bone of the metatarsal head and phalangeal base is removed (Figs. 11-6 and 11-7). Utilizing a 2.0-mm osteotome and mallet, the entirety of the articulating subchondral plates are microfractured multiple times to create a scalloped surface (Fig. 11-8). For proper positioning, a flat surface to load the foot and simulate weightbearing is useful (Fig. 11-9). The toe is now placed in the appropriate position in relationship to the weightbearing surface (5-15 degrees of dorsiflexion), 1020 degrees of abductus (in rheumatoid arthritis or when used for arthritic hallux valgus, the abductus position may be greater), and neutral rotation in the frontal plane. An axial pin or bone clamp is applied and a scout minifluoroscopy is performed to verify position. A surgical assistant is valuable at this juncture to assist in carefully evaluating the joint position. Next, utilizing appropriate technique for a cannulated screw, a guide pin is

placed in the medial aspect of the base of the proximal phalanx, beginning 1.0-1.5 cm distal to the articulation and driven at a lateral angle of approximately 30 degrees through the first metatarsal head. A secondary guide pin is placed at the medial plantar aspect of the first metatarsal head and driven distally through the lateral phalangeal base (Fig. 11-10). It is helpful to keep the pin entering the phalanx on the dorsal half of the joint and the second pin within the plantar half. This will assure they do not contact each other during insertion and also provide more extensive compression of the joint surface.

Figure 11-5. The first metatarsal is now prepared with the conical reamer system; it can also be prepared by manual techniques. All cartilage and the top layer of the subchondral bone plate is removed during joint preparation. These curettage techniques will maintain the “ball and socket” architecture of the joint and also preserve length to the first ray.

Figure 11-6. Illustration of the “cup” reamer system for the base of the phalanx. Manual techniques with curettes, osteotomes, and burrs will also work fine for joint preparation. P.123

Figure 11-7. The concave architecture of the phalangeal base is maintained during joint preparation.

Figure 11-8. Final joint preparation is performed prior to fixation. It is helpful to essentially pulverize the subchondral bone plate. Drill holes and microfractures to both sides of the joint will allow for faster radiographic and clinical union.

Figure 11-9. To assist in joint positioning, the forefoot is fully loaded with the use of a flat tray. All three planes are properly evaluated and addressed.

Figure 11-10. Temporary fixation is now placed and evaluated prior to permanent fixation. When two cannulated crossing screws are utilized, it is helpful to place the screws in a “stacking” technique, with one pin staying in the dorsal half of the joint and the other within the plantar. This will help avoid contact of the fixation devices within the joint and provide more uniform compression across the MTPJ. P.124

Figure 11-11. Intraoperative imaging is extremely helpful for evaluation of joint alignment and the position of fixation. Both the AP and lateral views should be evaluated. A second scout fluoroscopy is performed and the final position is assessed from all angles (Fig. 11-11). When satisfactory, two 4.0-mm self cutting, self tapping, and partially threaded screws are then inserted over the guide pins. Alternate tightening is performed to accomplish uniform tightening and compression of the arthrodesis site (Fig. 11-12). Intraoperative fluoroscopy is used to verify position and fixation placement. It is ideal to have all screw threads across the arthrodesis site for maximum compression (Fig. 11-13). In situations where a single interfragmentary screw and dorsal plate are the preferred method of fixation, the interfragmentary screw is placed initially as described above and P.125 then a four to five hole bone plate is placed on the dorsal surface of the first MTPJ and fixated with two or three transcortical screws (dorsal to plantar) in the metatarsal and two screws distal in the proximal phalanx. Low profile plates such as the New Deal first MTPJ fusion plate are preferable to prevent postoperative prominence (Fig. 11-14). Intraoperative fluoroscopy is used to verify position and fixation placement (Figs. 11-15 and 11-16).

Figure 11-12. Compression screws are now placed across the fusion site. It is important to select a screw configuration where all the threads will cross the fusion site for optimal compression and stability. The distal threads should also purchase the far cortices laterally.

Figure 11-13. A and B: Three month postoperative radiographs shown here with solid union. Note the lateral cortical purchase on the AP view (A) and the “stacked” placement of the screws on the lateral view (B).

Figure 11-14. Plate fixation is another viable option for arthrodesis. A lower profile plate is ideal to reduce prominence and minimize soft tissue irritation. This may also be augmented with an oblique interfragmental compression screw.

Figure 11-15. AP imaging to assess the position of screw and plate fixation. Note the cortical purchase of the compression screw for maximum stability. Good position of the hallux is noted on the transverse plane. P.126

Figure 11-16. Excellent alignment of the first MTPJ and medial column noted. All the screws within the plate also

purchase the plantar cortex for maximum stability. In revisional cases involving failed implants, avascular necrosis, or significant shortening of the first metatarsal (Fig. 11-17), a humeral head allograft or iliac crest autograft is used to span the gap. A mini laminar spreader is used sequentially to gain length to the soft tissues of the first ray. The spreader is left in place while the bone graft is being prepared. The design of the graft must assure the same angular position as performed in the standard fusion. Fixation is performed with either threaded Steinman pins or a bone plate. All rough edges of bone are smoothed and the area thoroughly irrigated. Absorbable sutures are used for deep closure and skin closure. Steri-strips are applied to reinforce the wound (Fig. 11-18). A bulky compressive dressing is applied.

POSTOPERATIVE MANAGEMENT The patient's age, physical condition, bone quality, lifestyle needs, and reliability determine the postoperative immobilization regimen. Non- or partial weightbearing in a standard postoperative shoe, a wedged postoperative shoe, removable walking boot, or fiberglass cast immobilization are all appropriate depending on the procedure used. The patient P.127 is instructed to ambulate with the weight lateral and on the heel and not attempt to push off the first metatarsal. In cases where an interpositional bone graft is used, strict nonweightbearing is advised. Once radiographic fusion is verified (8-16 weeks) the patient is allowed to return to all activities without restrictions (Figs. 11-19 and 1120).

Figure 11-17. Example of a painful MTPJ with a short first metatarsal segment. Interpositional autograft or allograft can help restore length and optimize function of the first ray.

Figure 11-18. Closure of the wound supported by Steristrips. These patients will also be casted and immobilized for a period of 6-8 weeks.

Figure 11-19. AP radiograph of interpositional bone grafting with plate and screw fixation. Length is maintained to the first ray. Bone grafting will increase the postoperative healing period and these patients will often require an additional month to achieve solid union of both interfaces.

Figure 11-20. Lateral radiograph showing good healing and alignment of interpostional bone grafting.

COMPLICATIONS The most common complications are nonunion, and malalignment of the great toe in the three body planes. Nonunions are most commonly caused by inadequate bone preparation, inadequate fixation, and patient noncompliance. Smoking is a prohibition during the preand postoperative course and patients who will not agree to smoking cessation cannot undergo the procedure. It is beneficial to penetrate the subchondral bone on both sides of the joint to ensure fusion. Choosing the appropriate fixation (3.5-4.0 screws, plates, or threaded pins) and placing them appropriately is a key to success. Malalignment of the arthrodesis can cause problems for a patient. Despite solid union of the arthrodesis, a great toe in the wrong position can be worse than the presenting preoperative complaints. The toe should be fused in the transverse plane so that there is just a bit of space between the great toe and the second toe. Careful consideration of preoperative digital adductus must also be assessed so that the great toe is not fused in varus. Sagittal plane position is a key to a successful arthrodesis and varies depending on the gender and needs of the patient. The most common malalignment is the toe fused in excessive dorsiflexion. Patients will develop a flexion deformity at the interphalangeal joint leading to contracture of the joint with shoe pressure pain. A toe fused in too little dorsiflexion can result in plantar and interphalangeal pain and arthrosis. Care must also be taken for the position of the toe in the frontal plane. Positioning the great toe so that the toenail is directed straight dorsally will ensure that the pulp of the toe is receiving the forces it is intended to take. P.128 Excessive shortening of the first ray can lead to both cosmetic and functional problems. An excessively short first toe will lead to inadequate loading at push off and a resultant overload of the lesser metatarsals, possibly leading to lesser metatarsalgia. In addition, hammertoe deformity of the second toe will often result from this malalignment. Patient satisfaction may be compromised when the great toe is appreciably shorter than the lesser toes. First MTPJ arthrodesis is a valuable salvage procedure that is best used in the painful arthritic first metatarsal joint of an active patient or in patients with rheumatoid arthritis.

Careful preoperative planning, close attention to the technical performance of the procedure, proper postoperative care, and appropriate patient compliance will lead to a reasonably predictable outcome.

CLINICAL TIPS AND PEARLS 1. Removal of articular surface to healthy bleeding subchondral bone is vital. Be sure to penetrate the subchondral plate. Pascal Rippstein calls it the “smash technique” and states the surfaces should appear as if an “explosion” of the joint occurred. 2. Verify position of fusion site and fixation intraoperatively using x-ray and simulated weightbearing surface. View the position from all angles prior to insertion of guide pins and screws. 3. Use the appropriate and well-placed fixation. Smooth pins less than 2.0-mm in diameter are usually not sufficient to adequately immobilize the joint for several weeks. 4. Good positioning of the toe in the sagittal, frontal, and transverse planes. The most functional position of the hallux in the sagittal plane is to place the toe on the ground or in slight dorsiflexion. The hallux should parallel the lesser toes in the transverse plane and lie neutral in the frontal plane. 5. Be sure that the patient's expectations are understood prior to surgery. Be sure to communicate the length of time for healing and complete return to activities. Be sure the patient understands that the toe will be fused and stiff but also pain free following surgery.

RECOMMENDED READING 1. Brodsky JW, Ptaszek AJ, Morris SG: Salvage first MTP arthrodesis utilizing ICBG: clinical evaluation and outcome. Foot Ankle Int 21: 290, 2000. 2. Coughlin MJ, Mann RA: Arthrodesis of the first metatarsophalangeal joint as salvage for the failed Keller procedure. J Bone Joint Surg 69-A: 68, 1987. 3. Mann RA, Oates JC: Arthrodesis of the first metatarsophalangeal joint. Foot Ankle 1: 159, 1980. 4. McKeever DC: Arthrodesis of the first metatarsophalangeal joint for hallux valgus, hallux rigidus, and metatarsus primus varus. J Bone Joint Surg Am 34: 129, 1952. 5. Myerson MS, Miller SD, Henderson MR, et al: Staged arthrodesis for salvage of the septic hallux metatarsophalangeal joint. Clin Orthop 307: 174, 1994. 6. Myerson MS, Schon LC, McGuigan FX, et al: Result of arthrodesis of the hallux metatarsophalangeal joint using bone graft for restoration of length. Foot Ankle Int 21: 297, 2000. 7. Rochwerger A, Lecoq C, Curvale G, et al: Salvage arthrodesis of the first metatarsophalangeal joint using bone grafts. Rev Chir Orthop Reparatrice Appar Mot 88: 501, 2002. 8. Shim GS, Pikshcer I, Frankel N. First metatarsophalangeal joint arthrodesis with the truncated cone reamer system. J Foot Surg 31: 342, 1992. 9. Wilson JN: Cone arthrodesis of the first metatarsophalangeal joint. J Bone Joint Surg Br 49: 98, 1967.

12 Distal Metatarsal Osteotomies for Hallux Valgus and Hallux Limitus Scot D. Malay

INDICATIONS/CONTRAINDICATIONS Distal first metatarsal osteotomies are useful for the correction of a wide range of hallux abductovalgus (HAV) deformities, as well for cases of hallux limitus (HL), and hallux rigidus1 (HR). These deformities are usually accompanied by some degree of first metatarsophalangeal joint (MTPJ) prominence, the degree of which worsens as the proximal phalanx subluxates further into valgus and abduction and the articular surfaces degenerate secondary to progressive wear and tear. In the case of HAV and HL/HR correction, these osteotomies are usually considered inherently stable and allow early weightbearing versus their proximal counterparts. The positional and structural deformities that they address are usually in the mild to moderate range and require a salvageable joint space. In HAV, the standard recommendations for a distal osteotomy are for intermetatarsal angles upwards to 15 degrees. When the degree of positional or soft tissue contributions to the deformity is increased, distal osteotomies may be adequate to correct much larger deformities provided the soft tissues are properly released and balanced. Patients with endstage arthrosis often require a joint arthroplasty or arthrodesis. Although “bump pain” can often be alleviated with padding and alteration of shoe gear, joint pain secondary to synovial capsulitis and cartilage degeneration usually requires the addition of anti-inflammatory medication, biomechanical foot orthoses, and, depending upon the patient's response to therapy, physical measures that enhance intrinsic muscle strength and metatarsophalangeal range of motion and proprioceptive function. Keep in mind, however, that certain patients may respond best by initiating therapy with appropriate surgical measures. Such patients usually suffer significant pain and dysfunction and typically display a prominent bunion with alteration of joint motion. The surgical management of HAV hinges on re-establishment of the soft tissue balance about the first MTPJ, usually in conjunction with first metatarsal osteotomy for structural realignment of the first P.130 ray; while operative treatment of HL/HR is founded upon adequate chielectomy in conjunction with reconstructive osteotomy or joint salvage by means of arthrodesis or replacement with endoprosthesis.

PREOPERATIVE CONSIDERATIONS Specific procedures for bunionectomy vary a great deal, and it is the surgeon's responsibility to select the best procedure for the patient in question. Procedure selection varies with patient expectations, bone stock, local and systemic factors, and the degree of deformity relative to the above noted anatomic relationships. First metatarsal anatomy pertinent to HAV, HL, and HR includes the proximal distal physeal plate, which closes at about 15-18 years of age; the primary nutrient artery situated in the first intermetatarsal space about 2.0 cm proximal to the articular surface; and the periarticular soft tissue sleeve and sesamoid apparatus. It is important to take weightbearing radiographs to include a DP (dorsal plantar), lateral, and sesamoid axial views. Radiographic angular and anatomic relationships include the following.

Hallux Abductus Angle The angle formed by the intersection of the bisection of the shaft of proximal phalanx and the bisection of the shaft of first metatarsal, normally 15 degrees, is representative of the relative position of the hallux to the first

metatarsal.

Distal Articular Set Angle (DASA) The angle formed by the intersection of a line perpendicular to the effective cartilage of the base of the proximal phalanx and the bisection of the shaft of the proximal phalanx, normally 7.5 degrees, is representative of the relative plane of the effective cartilage to the shaft of the proximal phalanx. An increase in DASA may indicate a lateral deviation in the shaft of the proximal phalanx.

Proximal Articular Set Angle (PASA) The angle formed by the intersection of a line perpendicular to the effective articular cartilage of the metatarsal head and the bisection of the shaft of the first metatarsal, normally 7.5 degrees, is representative of the relative plane of the effective cartilage to the shaft of the metatarsal. An increase in PASA indicates lateral deviation (adaptation) of the metatarsal's cartilage surface.

First Intermetatarsal Angle (First IMA) The angle formed by the intersection of the bisection of the shaft of the first metatarsal and the bisection of the shaft of the second metatarsal, normally 8 degrees, is representative of the angular relationship between the first and second metatarsals. An increase in the first IMA makes the head of the first metatarsal more prominent medially and predisposed to HAV.

Hallux Interphalangeus Angle The angle formed by the intersection of the bisection of the shaft of the proximal phalanx and the bisection of the distal phalanx, normally 10 degrees, is representative of hallux P.131 interphalangeal joint (HIPJ) or phalangeal deformity. This angle will typically increase slightly following surgical correction of HAV.

Metatarsal Protrusion Distance The distance between two arcs, which represents the length of the first and second metatarsals, is the metatarsal protrusion distance. A line representing the bisection of the first metatarsal is extended to intersect with a line representing the bisection of the second metatarsal. A compass is placed at the point of intersection and an arc is drawn from the distal portion of the first metatarsal and another from the distal portion of the second metatarsal. A positive millimeter distance indicates that the first metatarsal is longer than the second metatarsal. A negative distance is used to indicate that the second metatarsal is longer than the first metatarsal. Normal is ± 2 mm and represents the relative length between the first and second metatarsals. A longer first metatarsal may be associated with HL/HR while a shorter one may correlate with lesser metatarsalgia.

Metatarsus Adductus Angle (MAA) The angle formed by the intersection of the bisection of the lesser tarsus and the bisection of the second metatarsal is the MAA. The lesser tarsus is bisected by obtaining the median point between the anteromedial corner of the first cuneiform and the posteromedial corner of the navicular, and the median point between the anterolateral corner of the cuboid and the posterolateral corner of the cuboid. These points are then connected and a perpendicular is drawn to this line. The MAA is normally 10-20 degrees and represents the degree of adduction of the metatarsus. As the MAA increases, the foot becomes more adducted and there is greater chance for development of HAV. Moreover, the first IMA becomes pathologically significant at a lower degree in the presence of an increased MAA (“true” IMA).

Tibial Sesamoid Position The position of the tibial sesamoid is compared to the bisection of the first metatarsal shaft and designated a position in the range of 1-7; positions in the range of 1-3 traditionally indicate the need to remove the fibular sesamoid when performing a true McBride bunionectomy. Tibial sesamoid position 4 indicates erosion of the tibial sesamoid against the plantar central crista of the metatarsal head and relative deviation of the metatarsal head medially so that the fibular sesamoid is positioned in the first intermetatarsal space. When the first metatarsal plantarflexes, a portion of the sesamoid relatively distal to the metatarsal head may appear, whereas dorsiflexion affects the portion relatively proximal to the metatarsal head.

Shape of the First Metatarsal Head The intrinsic stability of the MTPJ varies with the shape of the metatarsal head. A round head is theoretically the least stable and likely to deviate into HAV; a square head is considered stable, and a square head with a central ridge is considered the most stable arrangement of the joint and is often seen in cases of hallux rigidus without HAV.

First MTPJ Position (Congruous, Deviated, or Subluxated) The congruous joint displays a parallel relationship between the effective articular cartilage of the metatarsal head and the phalangeal base; the deviated joint displays extra-articular intersection of the lines representing the effective articular surfaces of the metatarsal head and phalangeal base; and the subluxated (subluxed) joint displays intraarticular P.132 intersection of the lines representing the effective articular surfaces of the metatarsal head and phalangeal base.

Structural, Positional, and Combined HAV Deformities HAV can be classified as to whether or not the MTPJ deformity is a structural, positional, or combined deformity (Table 12-1). A range of motion exam is also important to determine the amount of flexibility within the medial column and the first MTPJ. Sagittal plane first MTPJ range of motion may be a good indicator of the amount of potential transverse plane flexibility within the deformity. Sagittal plane motion of greater than 50 degrees may equate with positional IMA correction after a proper lateral interspace release. If the sagittal plane mobility is less than 50 degrees, there is often a greater structural/rigid component to the IMA. Radiographic signs of advanced HL/HR include subchondral sclerosis, joint space narrowing, flattening of the metatarsal head, and metatarsal head dorsal flag (osteophytosis) formation and trumpeting of the proximal phalangeal base. As with HAV, it is also important to ascertain the status and function of the sesamoids by loading the plantar aspect of the joint while dorsiflexing the hallux. Hallux limitus and HR entail limitation of first MTPJ motion to less than 65-75 degrees of dorsiflexion, with excessive compressive load of the proximal phalangeal base upon the dorsal aspect of the first metatarsal head as the end range of motion is approached. It should be noted, however, that basic walking ambulation uses only about 35 degrees of dorsiflexion range of motion (1). Signs and symptoms include pain and swelling, stiffness, and crepitus, dorsal bony prominence, and HIPJ overload with plantar hyperkeratosis, and lateral metatarsalgia due to antalgic guarding of the painful first ray, apropulsive gait, and even fifth toe heloma durum formation due to lateral shift of weightbearing forces. As with any musculoskeletal deformity, it is incumbent upon the surgeon to ascertain whether underlying systemic arthritic disease is present. Conditions such as rheumatoid arthritis, systemic lupus erythematosus, psoriatic arthritis, and gout can predispose the patient to recurrent inflammation and deformity, even after

treatment. Moreover, the surgeon must determine that the blood supply to the involved extremity is adequate for surgical wound healing. Arthrodesis is indicated in the presence of progressive neuromuscular disease, either spastic or flaccid in nature. Lastly, tobacco use, in particular cigarette smoking, has been shown to have a detrimental influence on bone healing, and this matter should be discussed with the patient and a cessation program undertaken if the patient desires.

SURGICAL TECHNIQUE The standard approach to HAV and HL/HR entails placing the patient in a supine position on the operating table and use of intravenous sedation in combination with local infiltration of local anesthetic to effect first ray anesthesia. A Mayo block performed at the base of the first metatarsal is usually sufficient for isolated first MTPJ procedures. Ankle block local anesthetic infiltration is an effective technique for multiple forefoot (and hindfoot) procedures, and requires careful infiltration of a small amount of local anesthetic agent about each individual nerve traversing the ankle. Care must be taken not to exceed the toxic P.133 dose of local anesthetic. Hemostasis can be achieved with anatomic dissection, infiltration of dilute epinephrine (1:200,000 or less), or a well-padded ankle or midcalf tourniquet, or a combination of these methods. Care must be taken to follow appropriate guidelines for tourniquet pressure and duration of application. Here again, the choice of anesthetic and hemostatic methodology varies depending on the individual patient's needs, both systemic and local, as well as surgeon's preference.

Table 12-1. HAV: structural vs. positional vs. combination deformity Type of deformity

Angle formula

PASA and DASA

First MTPJ alignment

structural deformity

PASA + DASA = HAA

PASA or DASA abnormal

congruent

positional deformity

PASA + DASA < HAA

PASA & DASA normal

deviated/subluxed

combined deformity

PASA + DASA < HAA

PASA or DASA abnormal

deviated/subluxed

Figure 12-1. Standard incision for exposure to the first MTPJ in HV/HL repair. This dorsomedial incision is medial to the extensor hallucis longus tendon and allows access to both the medial and lateral sides of the joint. Sharp dissection is shown here separating the subcutaneous layer from the deep fascia, keeping all the neurovascular tissues within this full thickness flap.

General Dissection and Exposure of the First MTPJ Anatomic dissection for the correction of first MTPJ deformities, specifically HAV and HL/HR, entails placement of a dorsomedial, curvilinear skin incision that extends from approximately midshaft of the first metatarsal to approximately midshaft of the proximal phalanx and follows the contour of the underlying joint malalignment. The general position of the skin incision is between the tendon of extensor hallucis longus and the proper digital branch of the medial dorsal cutaneous nerve (Fig. 12-1). The incision is deepened through the skin into the subcutaneous fat and superficial fascia layer, where vessels and nerves are identified and manipulated accordingly. Vessels that impede exposure of the underlying target tissues (MTPJ) and display visible lumens are ligated, whereas smaller vessels are electrocoagulated. The subcutaneous layer is reflected from the deep fascia that contains the first MTPJ and the periarticular tendons and ligaments (Fig. 12-2).

Figure 12-2. The extent of medial exposure along the first metatarsal is shown. The integrity of the deep fascia covering the first MTPJ is intact. P.134

Figure 12-3. Blunt dissection into the plantar aspect of the first interspace assisted with a moist saline sponge. The superficial fascia is gently peeled away from the deep fascia along the lateral capsule.

Attention is then directed into the first intermetatarsal space, where dissection is carried to the level of the deep transverse intermetatarsal ligament and the fibers of the dorsal hood expansion that are extending laterally from the first MTPJ (Fig. 12-3). The dorsal fibers of the hood expansion, which become confluent with the deep transverse intermetatarsal ligament, are transected, after which the conjoined tendon of adductor hallucis is isolated and freed from its attachment to the plantar lateral aspect of the MTPJ and sesamoid apparatus (Figs. 12-4, 12-5, and 12-6). At this point, the tendon is usually tagged for later transfer; however, not all surgeons feel it necessary to transfer the adductor in order to achieve adequate joint balance and prevention of recurrent deformity. It is, however, the author's routine to transfer this tendon in an effort to enhance articular balance and to avoid recurrent HAV P.135 over time. In fact, gradual improvement in the balance of the phalanx on the metatarsal head has commonly been observed in the postoperative phase following adductor tendon transfer. It should also be noted that transfer of the adductor tendon may, over time, promote the development of hallux varus, and attention must be directed at avoiding this complication. Hallux varus is not likely when care is taken to avoid overly aggressive tension on the transferred tendon, and when attention is directed at establishing an accurate anatomic realignment during the systematic reapproximation of the soft tissues. After release of the conjoined adductor tendon, a stab incision is made parallel and dorsal to the fibular sesamoid, between the sesamoid and the metatarsal head, and the fibular sesamoid suspensory ligament is sectioned (Figs. 12-7 and 12-8).

Figure 12-4. A and B: Visualization is assisted with a self-retaining retractor and a distal Senn retractor. The target structure within this interspace is the adductor tendon, usually covered by the superficial expansions of the intermetatarsal ligament. Once this is transected, the adductor tendon is visible. Diagram of this step is illustrated here (B).

Figure 12-5. Identification of the adductor tendon coursing along the plantar lateral portion of the joint space, inserting into the lateral base of the proximal phalanx. At this point, the phalanx is repositioned on the metatarsal to assess the adequacy of the soft tissue release. The intraoperative reference that indicates achievement of a satisfactory degree of soft tissue release is placement of the medial rim of the base of the proximal phalanx in the tibial sesamoidal sagittal groove (Fig. 12-9). Subsequent exostectomy of the first metatarsal head will be performed in a manner that preserves this anatomic landmark, which, in turn, will serve as the foundation for establishment of an accurate and balanced realignment of the joint. If the surgeon is unable to readily reestablish articular balance due to persistent plantar lateral resistance, then the lateral most fibers of the lateral head of the P.136 short flexor tendon along the proximal and distal margins of the fibular sesamoid are sectioned. Thereafter, realignment is again attempted. If it is unsuccessful, consideration is given to fibular sesamoidectomy (2, 3).

Figure 12-6. A and B: The adductor tendon is grasped by a hemostat and dissected free from the base of the phalanx as well as the lateral sesamoid. Diagram showing the “ J” stroke utilized to free the tendon, with care to avoid the neurovascular structures deeper within the interspace (B). Distal traction is applied to the tendon and

the No. 15 blade is kept parallel to the long axis of the tendon.

Figure 12-7. The next step in the interspace release is transaction of the fibular sesamoidal ligament. This will allow relaxation of the lateral contractures holding the sesamoid in the frontal plane.

Figure 12-8. Intra-articular view of the dorsal aspect of the lateral sesamoid after ligament release.

After achieving satisfactory plantar lateral soft tissue release, attention is directed to the dorsomedial aspect of the first MTPJ where capsulotomy is performed using a modified T incision. The capsulotomy includes a longitudinal component that follows the contour and direction of the overlying skin incision, and a vertical component that runs from the apex of the first metatarsal head just distal the attachment of the medial collateral ligament to the dorsomedial aspect of the tibial sesamoid (Figs. 12-10, 12-11 and 12-12). The capsule is then reflected just enough to expose the articular surfaces of the metatarsal, phalanx, and sesamoids, and to allow subsequent osteotomy, while preserving lateral, plantar, and dorsal attachments to the metatarsal head (Fig. 1213). Particular attention should be directed at preserving the dorsal and plantar synovial folds that attach immediately proximal to the P.137 articular cartilage of the metatarsal head (Fig. 12-14). Preservation of these soft tissues greatly decreases the risk of subsequent bone healing difficulties, in particular, avascular necrosis (4, 5) of the metatarsal head.

Figure 12-9. Manipulation of the first MTPJ to evaluate the efficacy of the lateral release. If the lateral contracture is reduced, then attention is directed towards the medial capsulotomy. If there is still significant pull from the lateral aspect of the joint, the next structure for release is the lateral head of the flexor hallucis brevis, running from the sesamoid to the lateral phalangeal base. If the lateral joint is still contracted after release of this

structure, then excision of the sesamoid is the final option. It is extremely rare to require sesamoid excision.

Figure 12-10. Linear capsulotomy over the medial MTPJ, medial to the extensor tendon. Slight dorsiflexion of the joint is recommended during the incision to avoid injury to the dorsal cartilage.

Figure 12-11. Exposure and dissection of the first MTPJ in preparation for the osteotomy. Preservation of the

dorsal synovial fold will ensure maintenance of vascular supply to the metatarsal head. Prior to reconstructive osteotomy of the distal metaphysis of the first metatarsal, medial exostectomy of the metatarsal head is usually necessary. It is particularly important that this be performed in a fashion that preserve the medial sagittal groove of the metatarsal head and that resection (“staking”) of the medial eminence is not overly aggressive (Fig. 12-15). Preservation of the groove enables anatomic realignment with both the phalangeal base and the tibial sesamoid and serves as a guide to accurate and balanced reconstruction. Once again the key maneuver for balanced realignment of the phalanx on the metatarsal is placement and maintenance, without excessive soft tissue tension, of the medial rim of the base of the proximal phalanx in the preserved tibial sesamoidal sagittal groove. In essence, the metatarsal head is resected primarily at its dorsomedial aspect. After achieving satisfactory soft tissue release and exposure of the articular components, attention is directed to structural repair of the deformity. This usually entails application of P.138 some form of distal first metatarsal osteotomy, the selection of which depends upon specific characteristics of the deformity in question. In some cases, proximal osteotomy or even metatarsocuneiform arthrodesis (Lapidus procedure) may be indicated.

Figure 12-12. Vertical arm of the capsulotomy being performed proximal to the joint space. This will provide additional exposure as well as allow a medial capsulorrhaphy during closure.

Figure 12-13. The distal portion of the vertical capsulotomy is extended to the medial phalanx and this is the view of the medial capsule along with the medial collateral ligaments that will be resected off the medial eminence. Care is taken to avoid “buttonholing” the medial capsule during dissection of this. The freer elevator is currently placed within the “resident's pocket”.

Figure 12-14. Exposure of the metatarsal head after capsular release. Note the preservation of both the dorsal and plantar synovial folds to the metatarsal head. It is helpful to preserve these during dissection and respect these areas when executing the osteotomy.

McBride Bunionectomy This is a versatile and powerful component of almost all bunion repairs and focuses reestablishment of muscletendon balance about the joint. The soft tissue manipulations of the McBride procedure serve as the foundation upon which successful bunionectomy is performed and thoroughly addresses the underlying pathological influences that lead to the development of HAV. Specific surgical maneuvers used in the “true McBride” bunionectomy include medial exostectomy, excision of the fibular sesamoid, medial capsulorraphy, and transfer of the adductor hallucis tendon to the deep surface of the medial capsular flap of the MTPJ. The “modified McBride” procedure involves preservation of the fibular sesamoid, with adductor tendon transfer following complete plantar lateral soft tissue release. P.139 Once again, the modified McBride procedure serves as the foundation for many bunionectomies and is usually combined with first metatarsal osteotomy for the correction of a wide range of HAV deformities.

Figure 12-15. Frontal view of the metatarsal head with execution of the medial exostectomy. It is recommended to preserve the plantar sagittal groove and resect only the dorsomedial portion of the metatarsal head. This sagittal groove will allow for re-alignment of the medial edge of the proximal phalanx back to the metatarsal and also act as a buttress to minimize the incidence of HV. If the sagittal groove is violated, the surgeon runs the risk of “staking” the metatarsal head and significantly compromising the transverse plane stability of the first MTPJ.

Reverdin Osteotomy This is a useful technique for the correction of a high PASA when used in conjunction with appropriate muscletendon balancing of the first MTPJ. The osteotomy is an intraarticular closing adductory wedge osteotomy at the

level of the sesamoids that preserves an intact lateral cortical hinge. The distal cut is made proximal and parallel to the residual articular cartilage of the metatarsal head, and the proximal cut is made perpendicular to the long axis of the first metatarsal (Fig. 12-16). The osteotomy is oriented perpendicular to the weightbearing surface. The Reverdin osteotomy enables first reduction via reverse buckling1 (6, 7) when the hallux applies an abductory force on the head of the flexible first metatarsal when the realigned joint is bandaged in slight overcorrection. The Green modification of the classical Reverdin osteotomy is the plantar osteotomy through the metatarsal head dorsal to the sesamoids so that the Reverdin cuts do not penetrate plantar cortex and violate the sesamoidal articular surfaces. Advantages include decreased likelihood of sesamoiditis and enhanced stability of the osteotomy. Absorbable fixation pins are ideally suited for stabilization of this osteotomy. The Laird modification removes the lateral cortical hinge and allows lateral translocation of the capital fragment.

Austin Osteotomy Other described osteotomies in literature include the Peabody, Wilson, Mitchell, and Austin osteotomies. The Austin is the single most commonly used osteotomy for correction of moderate HAV (8) when the first IMA is usually no more than 16 degrees and the joint is not degenerated. The procedure consists of a through-andthrough sagittal plane V-osteotomy (Chevron) with base proximal and apex distal, situated at the first metatarsal. The osteotomy allows triplanar correction, and is suitable for a wide range of HAV deformities. As with most distal first metatarsal osteotomies an apical axis guide and absorbable fixation can be employed (Figs. 12-17 and 1218). The Youngswick modification makes the Austin procedure very effective for correction of varying combinations of HAV and HL/HR. The apex of the Austin osteotomy is positioned at the center of the imaginary circle of the metatarsal head, and application of a smooth K-wire as an apical axis guide enhances control of the saw and predetermines the direction of displacement of the capital fragment. The arms of the V-cut usually intersect to form a 60-degree angle; however, an offset V (Kalish modification) with the dorsal arm extending proximally into the distal portion of the diaphysis can be used to achieve even greater intermetatarsal reduction when interfragmental screw fixation is employed (Figs. 12-19 and 12-20). (A true offset V positioned through the shaft with the dorsal arm exiting near the proximal metaphysis [Vogler's shaft osteotomy] can also be used to correct HAV, and is usually combined with a significant amount of transverse plane swivel of the dorsal fragment to reduce PASA and increase cortical bone stability.) The degree of displacement of the capital fragment in the Austin procedure is dependent upon the width of the metatarsal and orientation of the osteotomy. Crucial to the widespread application of the Austin bunionectomy is the plantar arm of the osteotomy, which creates a shelf that resists weightbearing forces that can disrupt less secure osteotomy designs. The combination of the WB plantar arm of the osteotomy and proper soft tissue preservation enhances osteotomy stability and reduces the risk of complications related to bone healing. Fixation of the Austin osteotomy is via absorbable pins, buried or percutaneous K-wires, or lag screws (Figs. 12-21, 12-22 and 12-23). Although originally described as an unfixated osteotomy, the addition of fixation decreases the likelihood of delayed union, loss of correction, and avascular necrosis of the capital fragment.

Figure 12-16. Reverdin osteotomy, a transverse plane wedge osteotomy with the apex at the lateral cortical hinge with a medial base. Removal of the wedge of bone allows realignment of the articular surface to correct PASA. The standard Reverdin is performed from dorsal to plantar, with risk of injuring the underlying sesamoid bones. The Green modification describes a plantar arm similar to the plantar arm of an Austin. P.140

Figure 12-17. A K-wire serves as an axis guide for triplanar manipulation of the capital fragment as well as assisting in execution of the osteotomy. By keeping the saw blade parallel to the axis guide during all the cuts of the osteotomy, there will be a predictable flush fit to the osteotomy during transposition.

Figure 12-18. Example of the ability to manipulate the movement of the capital fragment during lateral

translocation. In the frontal plane (A), the direction of the axis guide will dictate the sagittal plane position of the metatarsal head. A neutral to plantar orientation is most common for HAV and HL repair. Example of slight shortening in the transverse plane, by angulating the axis guide proximal to the long axis of the second metatarsal (B). P.141

Figure 12-19. Diagram of a Kalish modification to the traditional design. The apex is more acute at roughly 55 degrees with a resultant longer dorsal arm to facilitate cortical screw fixation.

Procedures Used Primarily to Correct HL/HR First MTPJ Cheilectomy. This involves removal of osteophytic proliferation via a dorsomedial, longitudinal capsulotomy and serves as the foundation procedure upon which all remaining joint preservation procedures for the repair of HL/HR are built. Chielectomy P.142 is necessary to remove osteophytes and spur formation from the dorsal, medial, and lateral aspects of the joint, including the metatarsal head and the phalangeal base. The McGlamry metatarsal elevator should be used to release capsular and sesamoidal adhesion plantarly at the proximal margin of the flexor plate. Loose or degenerated cartilage should be debrided and sculpted to an intact and smooth surface, and exposed subchondral cortical bone should be perforated with multiple 1.5-mm or 0.045-inch″ K-wire holes or perforations of a similar size. Cheilectomy is usually used in conjunction with metatarsal osteotomy and muscletendon balancing and serves as the foundation upon which almost all repairs of HL/HR are based.

Figure 12-20. A and B: Pre and postoperative radiograph 1 year after a Kalish Austin procedure. A sequential lateral release coupled with an aggressive osteotomy and capsule-tendon balancing is paramount to establishing a rectus MTPJ with longterm results.

Figure 12-21. Temporary fixation of the capital fragment after lateral translocation. The head should be manually impacted upon the shaft to provide some initial stability to the construct. A flush fit should be observed at both arms of the osteotomy site. Watermann Osteotomy. This widely used procedure employs a dorsally-based trapezoidal wedge resection of bone at the surgical neck of the metatarsal, designed to rotate plantar cartilage dorsally and to decrease first MTPJ cubic content. This procedure can be used as the primary structural correction, or in combination with a

more proximal first metatarsal osteotomy in cases involving significant metatarsus primus elevatus.

Figure 12-22. A and B: Example of a 0.062″-inch K-wire used for fixation of the Austin procedure. This wire has been rotated from a position medial to the metatarsal to the dorsal position in an attempt to “lock” the wire to the bone for added stability. P.143

Figure 12-23. A and B: Screw fixation is also common in an attempt to provide added stability through compression. A short thread pattern on the partially threaded screws is ideal to secure the threads on the distal side of the osteotomy. A modified Green-Watermann osteotomy involves cheilectomy and osteotomy of the metatarsal neck wherein a

rectangular section of bone is excised from the dorsal aspect of the surgical neck, while a plantar arm (much like that used for the Austin osteotomy) exits the joint parallel to the substrate posterior to the articular surface. This will allow for joint decompression and relaxation of soft tissue contractures. Austin Osteotomy and its Modifications. The Austin procedure has been described above, and variations of the design can be applicable for correction of certain cases of HL/HR. For correction of metatarsus primus elevatus and HL/HR, the apical axis guide is oriented to effect primarily plantar declination of the capital fragment, which limits reduction of the first IMA. In the presence of concomitant HAV and HL/HR, the GreenWatermann and Youngswick-Austin (9,10) osteotomies enable simultaneous reduction of the first IMA, although the Green-Watermann osteotomy generally enables greater plantar declination without excessive shortening. The Youngswick modification of the Austin involves the same sagittal plane chevron orientation with the addition of a dorsal, proximal cut that is parallel to the original dorsal arm (Fig. 12-24). In this way the capital fragment can move down and in, as well as proximally to decompress the joint.

Figure 12-24. A and B: Preoperative radiograph and clinical example of the plantarflexion noted with a decompressional “Youngswick-Austin” procedure for HL. This combination is commonly utilized in HL. P.144

Figure 12-25. A and B: Example of an adductor tendon transfer from the lateral interspace under the extensor tendon and sutured under some tension to the medial capsule. This will theorectically help “derotate” the sesamoids in the frontal plane, but the metatarsal head is really the structure moving back over the sesamoids. After completion of the structural repair of the first MTPJ, copious wound lavage is performed followed by final inspection of the confines of the MTPJ. Thereafter, systematic repair of the various tissue layers proceeds. First, when desired, the previously tagged adductor hallucis tendon is transferred in a subcapsular fashion and anchored to the deep surface of the medial capsular flap, using a 2-0 nonabsorbable suture (Fig. 12-25). Throughout the closure, the hallux is maintained in the corrected alignment, with the medial rim of the base of the proximal phalanx seated in the preserved medial sagittal groove of the first metatarsal head and in slight

plantarflexion. The slight plantarflexion attitude assures avoidance of over tightening dorsal capsular structures, which can lead to reduction of plantar purchase power in the great toe. Following adductor transfer, any redundant medial capsular tissue is excised, with care being taken to resect in the shape of an inverted triangle with base plantar and apex dorsal, here again, trying to assure good plantar purchase of the hallux. Medial capsulorraphy can be readily achieved with 2-0 nonabsorbable sutures placed on a bias, oriented from proximaldorsal to distal-plantar, in an effort to further de-rotate the hallux out of valgus (Fig. 12-26). As a general rule, capsular and deep fascia, subcutaneous fat-superficial fascia, and skin are then closed with 3-0, 4-0, and 5-0 absorbable sutures, respectively.

Figure 12-26. A medial capsulorrhaphy for final transverse plane positioning of the hallux onto the metatarsal head. The hallux should be held in a rectus position by an assistant during capsule preparation and suturing. P.145 The wound is then dressed with a saline moistened dressing sponge, taking care to splint the hallux in the corrected alignment using dry sterile gauze and an elastic compression wrap. A removable surgical shoe with Velcro closure or, when indicated, a fixed castwalker is dispensed. The patient is given written and oral postoperative instructions and an appointment for follow-up in a timely fashion.

POSTOPERATIVE MANAGEMENT Following distal metatarsal and phalangeal osteotomy, postoperative care involves weightbearing in a surgical shoe and early return (3-4 weeks) to a soft shoe or sneaker. Similarly, passive, and then active, ankle and first MTPJ range of motion can be helpful as soon as the patient feels up to it. Professional physical therapy is reserved for those patients not progressing in a satisfactory fashion based on the patient's or surgeon's impressions. The use of postoperative digital splinting and compression, by means of a first web separator and an elastic sleeve about the metatarsus, is used after removal of the surgical bandage and is generally continued until about 8 weeks postoperative. Radiographs are routinely obtained immediately after the surgery and again 6 weeks postoperatively, and at any

other time that the clinical situation indicates the need to inspect the bone. The determination as to when a patient can return to regular duties, as with every step of the postoperative process, is based primarily upon clinical inspection and discussion with the patient, supplemented by radiographic inspection. It is important to remember that clinical decisions are based primarily upon clinical findings, and that the surgeon treats patients and not x-ray images. Patients can be told to expect some degree of residual swelling to persist about the first MTPJ until about 4-6 months into the postoperative phase, and that scar remodeling proceeds in a subtle fashion for up to about one year from the date of the operation (Fig. 12-27).

Complications of Distal First Metatarsal Osteotomies Along with the standard risks related to wound healing and intraoperative systemic complications, it is especially important for the surgeon taking care of patients undergoing first MTPJ surgery to be on the lookout for several potential complications. These include the development of complications of bone healing, avascular necrosis of the first metatarsal head, and the development of hallux varus.

Figure 12-27. Clinical photo of a patient 2 years after correction of her right bunion with a distal osteotomy. Her right bunion was larger clinically than her left one prior to surgery and therefore she decided to fix the right one first. P.146

Delayed Union, Malunion, or Nonunion of Bone Once again, it is not too likely that a complication of bone healing will be encountered when an osteotomy is placed in the distal metaphysis of the first metatarsal. Nonetheless, it is incumbent upon the surgeon to preserve as much of the dorsal, lateral, and plantar soft tissue attachments to the first metatarsal head as possible without inhibiting adequate realignment of the distal component of the metatarsal on the proximal segment. In addition to preservation of soft tissue attachments, use of an osteotomy technique, such as the Austin design or similar techniques that employ a WB plantar shelf, will enhance stability of the osteotomy and minimize the risk of

delayed union, malunion, or nonunion of bone. It is also important to assure that the interface between the distal and proximal segments of bone is congruous and maximizes trabecular bone-to-bone apposition. Lastly, in an effort to reduce the risk of delayed union, malunion, or nonunion of bone, the surgeon should employ some form of fixation across the osteotomy interface. The combination of preserved soft tissue attachments to the capital fragment, a congruous osteotomy interface, and stable fixation across the osteotomy, greatly reduces the risk of bone healing complications following distal first metatarsal osteotomy.

Avascular Necrosis of the First Metatarsal Head Avascular necrosis of the first metatarsal head is not likely to occur following distal first metatarsal osteotomy as long as care is taken to preserve the soft tissue attachments to the capital fragment and the osteotomy is not made too distal in the bone, thereby creating a very narrow (thin) distal segment of bone. The same recommendations mentioned above for prevention of bone healing complications obviously apply to the prevention of avascular necrosis as well. One other point should be made about bone healing in the first metatarsal, and it pertains to a double osteotomy technique (proximal and distal). In this situation, the intervening diaphyseal bone can be vulnerable to avascular necrosis if the lateral periosteal attachments, hence the nutrient artery, have been striped from the cortex. Here, again, it is best to preserve soft tissue attachments as much as possible without inhibiting osseous correction.

Hallux Varus Although this complication is unlikely to be caused by any one contributing factor, it can occur following any intervention to repair HAV. Avoidance of three conditions will minimize the risk of the development of hallux varus. First, preservation of the medial sagittal groove (tibial sesamoidal articular facet) of the metatarsal head enables the surgeon to assess intraoperatively the balance achieved between the base of the proximal phalanx, the sesamoids, and the first metatarsal head. “Staking” the metatarsal head predisposes to articular imbalance in the direction of hallux varus and should be avoided. Second, it is important for the surgeon to avoid overly aggressive adductor tendon transfer, specifically with respect to the degree of tension placed on the tendon when it is transferred into the deep surface of the medial capsular flap. Too much tension tends to pull the tibial sesamoid in a medial direction and, particularly if it is combined with overly aggressive medial eminence resection, coaxes the phalanx to deviate in a medial direction relative to the metatarsal head, thereby establishing hallux varus. The third condition to avoid is the creation of a negative IMA (first IMA