Even though orthopedic surgeons like to do surgery, they still prefer that patients get better without an operation. In the case of an unstable shoulder without a traumatic injury, physical therapy works about 80 percent of the time. Up to 20 percent of patients still need surgery after trying therapy.
In this study doctors looked at the 20 percent who didn’t get better without surgery. They used arthroscopic surgery to look inside the shoulder joint and find out what was wrong. Most often damage or tears of the joint capsule and labrum were found. The joint capsule is a fibrous envelope of tissue that goes around the shoulder joint. The labrum is a rim of cartilage on the joint itself.
This study shows that shoulder instability involving the capsule and labrum can occur without a traumatic injury. Doctors should suspect a problem in the joint when patients don’t get better with physical therapy. Another sign is that the shoulder dislocates but goes back in by itself, and there’s little or no pain when this happens.