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AC Joint Separation


The Injury
The Acromioclavicular (AC) joint is the junction of the clavicle (collar bone) and the shoulder. Separation of the AC joint occurs with a fall onto the shoulder which tears the ligaments that stabilize the clavicle. This results in elevation of the clavicle, creating a prominent bump on the top of the shoulder. Complete tearing of the ligaments is called a type three injury.

The great majority of AC separations can be treated with a sling for a few weeks to control pain and allow healing. The clavicle will always remain elevated, but function will return to normal in 90+% of cases. In very severe cases of separation, or occasionally for a professional athlete we recommend surgical repair. For the majority of these injuries, however, conservative treatment is recommended.

AC Arthritis
Degeneration of the acromioclavicular joint is common in weight lifters and in laborers, and can be quite painful. Because of the proximity of the AC joint to the rotator cuff, patients will often be misdiagnosed as having rotator cuff problems. There will be tenderness directly over the AC joint and pain with movement of the arm across the chest to touch the opposite shoulder. Often the joint will be prominent with an overlying spur.

Treatment Options
Treatment involves the injection of cortisone, use of ice, activity modification and occasionally surgery. Surgical treatment involves removing the arthritic portion of the clavicle, which currently is being done arthroscopically.

Surgery is performed as an outpatient and takes one hour. The post surgical sling and bandages are removed the day after surgery. Range of motion excercises and physical therapy are begun immediately.

85-90% of patients will obtain excellent range of motion and be able to return to weight lifting and over shoulder lifting activities. Complete recovery often takes several months.


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San Francisco, CA 94115
Phone: 415-923-0944
Fax: 415-923-5896

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