AC Joint Arthritis
The AC joint is the acromioclavicular joint. It is the joint where the collarbone (clavicle) connects to the shoulder blade (scapula). Over time, this joint can become inflamed or arthritic.
Symptoms of AC joint arthritis include anterior shoulder pain that is worse when bringing the arm across the body. It is commonly seen in weightlifters and heavy laborers. Initial treatment consists of activity modification, anti-inflammatory medications, or an injection of steroid (cortisone) into the AC joint. If these measures fail, the end of the collarbone can be removed arthroscopically, eliminating the source of the pain.