The third edition of the Essentials of Orthopedic Surgery provides a concise overview of orthopedic surgery directed toward third- and four- year medical students. In this edition, physical diagnosis is a subsection in each chapter, which we believe gives better continuity. Additionally, at the end of each chapter we have created a number of multiple-choice questions considered appropriate for medical students to be able to answer. Each chapter has been revised to re?ect updated material and, as in previous editions, we have kept to a standardized format as much as p- sible. The topics are presented from a straightforward practical point— view, with the material being condensed to its most salient features. Algorithms are at the heart of each chapter, with the decision points being based on practice standards and guidelines. This format allows the student, when confronted with a speci? c clinical problem, to formulate both a diagnostic plan and a treatment plan. Also, we have enjoyed working with our new publisher—Springer—and with Robert Albano as well as Sadie Forrester, who have guided this text to publication. Finally, and most importantly, it has been again a very exciting and stimulating experience to work with all the members of the Department of Orthopaedics of Georgetown University Medical Center. Since the last edition we have welcomed seven new members to the faculty, each a s- specialist. Everyone has given very generously of their time. We are most appreciative of each contribution and are proud of the ?nal text.