Dislocations of the shoulder are one of the most common injuries to the shoulder, especially in younger athletes and those who participate in contact sports.
The shoulder is a ball and socket joint, but the anatomy of the shoulder allows for an amazing amount of flexibility. The humeral head or ball, sits on the glenoid, a very shallow socket. Since the socket is shallow, the shoulder relies on the soft tissue around the shoulder for stability. The labrum, a thickened cartilage layer around the glenoid, ligaments and capsule, provide most of the stability to the shoulder. The muscles of the rotator cuff and scapula also provide stability.
The shoulder is most commonly dislocated when the arm is abducted and externally rotated, in a position as if you were throwing a baseball. When there is a strong force with the arm in this position, the humeral head can dislocate out the front of the glenoid. When this occurs, it can either come partially out, which is termed a shoulder subluxation, or come entirely out, which is termed a shoulder dislocation. Although some people are able to reduce their shoulder (put it back into joint), many others need to have their shoulder reduced in an emergency room.
When a shoulder dislocates, there is most often an injury to the front of the labrum, termed a Bankart Lesion. There is also an injury to the humeral head termed a Hill-Sachs Lesion. The Bankart lesion is what is repaired during surgery for a unstable shoulder.
The natural history of athletes with a shoulder dislocation depends on the age of the athlete. In younger athletes (less than 20 years old), there is a very high risk of re-dislocating the shoulder. However, as we get old, the risk decreases. In people over the age of 50, there is a chance that the shoulder dislocation occurs along with a rotator cuff tear.
Our Approach to Shoulder Dislocation
The immediate treatment for a dislocated shoulder is for a doctor to put the upper arm bone back in the shoulder socket, which significantly relieves pain right away. Simple therapies such as ice packs, pain medication and an arm sling can further reduce pain and swelling after the injury. In many cases, this is all the treatment needed. But for patients who've had multiple dislocations, or who play sports that make another dislocation more likely, surgery may be an option.
Should you need surgery, our team includes orthopedic surgeons who specialize in the shoulder, as well as physical therapists who focus on working with orthopedic and sports medicine patients. We work together to relieve pain and restore mobility, so patients can return to their normal lives and the activities they enjoy.
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UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.