I had a shoulder that just wouldn’t stop popping out of the socket. I finally had it operated on and its fine but now there’s a new problem: arthritis. Is that from the dislocations or from the surgery?

Many studies have been done in gaining understanding of shoulder dislocations. For example, surgeons have asked the question: if surgery is done, will arthritis set in sooner than if there never had been an injury? Another area of investigation has been the role of surgery as the cause of arthritis after repeated anterior (forward) shoulder dislocation.

A group of Japanese orthopedic surgeons recently reported on a long-term study of arthritis that was present after surgery for recurrent shoulder dislocations. They discovered that one-forth of the patients actually had arthritic changes before surgery was ever done.

An analysis of all the factors present preoperatively (e.g. patient age, total number of dislocations, and side affected) was done. It showed that the severity of the damage present as a result of the repeated dislocations was the real deciding factor.

On a more positive note, after following these patients for five to 20 years, they saw that the arthritis progressed slowly over time. Many of the patients were asymptomatic — in other words, if the X-ray or CT scan hadn’t shown the arthritic changes, they would never have even known that had a problem.

Apparently, the arthritis progresses very slowly and may not be a problem for some patients. CT scans may be helpful in the diagnosis of osteoarthritis in recurrent anterior shoulder dislocations.

The more often the shoulder dislocates, the more likely postoperative arthritic changes will develop. These preoperative dislocations cause repeated trauma to the shoulder and worsening instability. Instability of this type should be treated operatively to avoid the worsening of arthritic changes.