This condition, also called AC joint arthrosis, is a degeneration of the joint at the top of the shoulder where the acromion meets the clavicle.
This condition, which most often affects middle-aged people, is caused by overuse of the shoulder. Occupations such as painting or construction, which require repetitive overhead motions, are common culprits. Degeneration may also result from injury to the shoulder joint.
Symptoms can include pain in the front of the shoulder or over the joint, limited range of motion, and clicking or popping sounds when the arm is moved.
Treatment options include cortisone injections, non-steroidal anti-inflammatory medications, use of a splint or brace, exercise, and modification of daily activities. In severe cases, surgery may be necessary to remove damaged portions of the joint.