Mariano Rivera's injury has a quick fix

New York Daily News—February 16, 2009

By Dr. Josh Dines and Dr. Rock Positano

Shoulder problems in pitchers are usually related to the rotator cuff muscles or the labrum. These are soft tissue structures that help stabilize the shoulder during the throwing motion. Luckily for Mariano Rivera, the shoulder pain that he had during last season was related to his acromioclavicular joint (or AC joint).

The AC joint is located on top of the shoulder, where the distal end of the clavicle (or collarbone) meets the acromion. Like other joints, the ends of each bone are covered with cartilage, which allows the bones to smoothly glide over each other with movement. Ligaments surround the joint to help keep it stable.

When one talks about shoulder separations in football or hockey, it is often these ligaments that tear. More often, however, overuse leads to a degeneration of the cartilage in the joint known as AC joint arthritis. Calcifications, or deposits of calcium, can also form.

Patients with AC joint arthritis typically have pain on top of their shoulder right above the joint, and the pain is exacerbated when the arm is brought in front of the chest. In baseball players this motion would occur right after the ball is released during the throwing motion.

Treatment options for AC joint arthritis range from anti-inflammatory medication usage to injections to surgery.

This story originally appeared at  nydailynews.com.

Drs. Dines and Positano write a new weekly column on sports injuries called X-Ray Vision in the New York Daily News and practice sports medicine at Hospital for Special Surgery.