In Vivo Determination of the Dynamics of Normal, Rotator Cuff-Deficient, Total, and Reverse Replacement Shoulders

Patients with osteoarthritis of the shoulder experience pain and decreased range of motion, which compel them to seek care. The vast majority of osteoarthritic shoulders have an intact rotator cuff. However, the rotator cuff may function poorly because of osseous deformity and soft-tissue contracture. Total shoulder arthroplasty has proved to be a reliable procedure for pain relief and improved function1-5. The ultimate functionality of the arthroplasty depends on multiple factors, including alignment of the prosthetic implant, rotator cuff muscle belly health, soft-tissue balance achieved at the time of surgery, and patient compliance with rehabilitation3-6.