Anatomic total shoulder arthroplasty is a shoulder replacement surgery that maintains the “normal” or “anatomic” relationship of the ball-and-socket joint of the shoulder (glenohumeral joint).

Shoulder arthroplasty is designed to treat glenohumeral osteoarthritis, or arthritis of the ball-and socket-joint in your shoulder. Arthritis occurs when there is loss of cartilage on the ball (humeral head) and socket (glenoid). This causes pain, grinding, and restricted range of motion.

• During the procedure, the arthritic portion of the ball (humeral head) is cut and removed. This is replaced with a new smooth metal hemisphere that is anchored into the arm bone (humerus).

• The socket (glenoid) is gently reamed down to a flatter surface to accept new smooth plastic socket (highly cross linked polyethylene). This is anchored into the bone with pegs that are cemented for fixation.

• In summary, both arthritic surfaces (the ball and the socket) are replaced with metal and plastic, respectively, to create a new joint that has smooth motion.

• The humeral head (ball) is typically made of a cobalt-chromium alloy.

• The glenoid component (socket) is typically made of a highly cross linked polyethylene (plastic).