Total shoulder arthroplasty is indicated in the treatment of locked posterior fracture-dislocations of the shoulder where there is extensive damage to the articular surfaces of the humerus and glenoid. This report reviews the surgical technique, postoperative rehabilitation program, and functional results of seven shoulders in five patients who had locked posterior dislocations of the shoulder. Activities involving overhead positioning of the arm and heavy lifting continued to be challenging for this group of patients. The American Shoulder and Elbow Surgeons' Shoulder Score improved from 20.1 before surgery to 55.6 after surgery (p = 0.018). The extrication of the posteriorly dislocated humeral head may be difficult from an anterior deltopectoral approach. The authors describe the use of a secondary posterior incision facilitating the extrication of the humeral head. In this series total shoulder arthroplasty reliably decreased the patients' level of pain, improved their range of motion, and significantly improved their level of function.