The indications and use of shoulder arthroplasty has dramatically increased over the last decade, and this trend will continue in the future. The average age of our population is increasing, yet there is a strong desire to remain active and viable. The majority of people will not accept limitation of a joint function that compromises their life styles if a reasonable surgical solution is available. Our knowledge of disease processes has broadened and improved our understanding about how best to manage these problem¿s cli- cally. Technology and innovation have provided us with options that were not possible before. However, a successful shoulder arthroplasty depends not only on knowledge and modern technology but also on sound clinical judgment, accurate surgical technique, and appropriate postoperative rehabilitation. This book provides a comprehensive approach to dealing with the most common indications for shoulder arthroplasty. In addition, it p- vides insight into some of the more complex problems. Detailed inf- mation concerning preoperative evaluation, approaches, technology, surgical technique, and postoperative therapy will allow the surgeon to make decisions that will help his patient remain active. We thank the contributing authors for their work and commitment to this project. We appreciate the time they took from their practices and more importantly their families to complete this volume and provide an extraordinary text.