Distal clavicle or "AC" (acromioclavicular) arthritis results in pain over the shoulder, especially right on top of the shoulder with overhead and cross body maneuvers. Sometimes pain from AC arthritis can be present in addition to rotator cuff pain or a completely separate issue. Pain from the AC joint is usually quite distinct from rotator cuff pain but they can be confused. Arthritis of the AC joint is initially treated with physical therapy, NSAIDs, and cortisone injections. When these measures fail to help, a limited distal clavicle resection surgery can be performed to open up the space between the clavicle and acromion. This can be performed arthroscopically and requires only a few days of immobilization afterwards.
Arthroscopic images before and after distal clavicle resection, demonstrating an increased space between the distal arthritic clavicle and the acromion.
Shoulder radiographs demonstrating "AC" arthritis