Over the past four years, our authors have exhaustively reviewed a multitude of new techniques, new equipment, and new information in the world literature to produce a comprehensive update of our textbook. This edition reflects the growing numbers of less-invasive surgical techniques and devices that are being described, with promising results reported, and many arthroscopic and endoscopic techniques that continue to expand their indications. Over the last several years, ambulatory surgery centers have become an important part of orthopaedic surgery—from ligament repair to total joint arthroplasty—and outpatient orthopaedic surgery is now more frequently performed than standard hospital-based surgery in many centers. With knowledge and technology expanding and evolving at an ever-increasing speed, we have attempted to include the latest orthopaedic procedures while retaining as a foundation many of the classic techniques. As always, the Campbell Foundation staff—Kay Daugherty and Linda Jones, editors; Shawn Maxey, graphics; and Tonya Priggel, librarian—were essential in the production of this edition. Thanks to Kay and Linda for taking sometimes illegible notes on a napkin and translating them into eloquent English, to Shawn for keeping track of the hundreds of illustrations, and to Tonya for always locating the latest information on any topic. As many of our orthopaedic colleagues who have visited our institution can affirm, the piles of references, rough drafts, and jammed-full file folders that occupy the office floor are a testament to this monstrous undertaking. Our thanks, too, to Taylor Ball, Content Development Editor; Dolores Meloni, Executive Content Strategist; and John Casey, Senior Project Manager, at Elsevier publishing, who provided much guidance, encouragement, and assistance and who, while they may have doubted that we would get material in on time, never expressed anxiety. We also are most appreciative of the worldwide community of orthopaedic surgeons for their expertise and innovation without which our book would not be possible.