A dislocation occurs when the ball and socket of the shoulder joint become separated. The shoulder is the most commonly dislocated joint in the body. The most common cause is traumatic twisting injuries, falls, and sports related injuries. Most cases of dislocation require emergency treatment to put the shoulder joint back in place. Once the joint has been reduced (put back in place) the arm is placed in a sling to prevent motion and re-dislocation.
With regard to shoulder dislocations, there are several issues that help guide treatment. These include whether or not the patient has a history of dislocation or injury to the shoulder, the mechanism of injury, age of the patient and the x-ray appearance of the shoulder. Many patients will have a traumatic rupture of the supporting ligaments in the shoulder at the time of dislocation. If there is evidence of ruptured ligaments, an MRI fairly early in the clinical course will fully evaluate the tendons and ligaments in the shoulder. Most patients have an injury to the capsule of the shoulder joint but do not have ligament rupture. In these cases treatment centers on therapy to rehabilitate the joint and strengthen the muscles around the joint. Patients who have had a dislocation are more likely to have recurrent dislocations in the future.