Total shoulder replacement, also known as total shoulder arthroplasty (TSA), is a tremendously successful procedure for treating the severe pain and stiffness that often result at the end stage of various forms of arthritis or degenerative joint disease of the shoulder joint. The primary goal of shoulder replacement surgery is pain relief, with a secondary benefit of restoring motion, strength, function, and assisting with returning patients to an activity level as near to normal as possible. Many patients return to the sports they love like tennis, golf, and swimming, while also pursuing personal health initiatives such as individual training, yoga and pilates. The actual surgery involves replacing the damaged humeral head (or joint "ball") with a metal ball, and putting a new smooth plastic surface on the glenoid (called the "socket"). Metal on plastic surfaces (rather than metal on metal) are the hallmark of virtually all shoulder replacement implant systems. Partial shoulder replacement (or hemi-replacement) may also be indicated with certain severe shoulder fractures of the humeral head. This technique requires the replacement of the ball component only.