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Shoulder News

Shoulder Separation: Results Ten Years Later

What happens to athletes who injure their shoulder and end up with a shoulder separation? Acromioclavicular (AC) joint separation occurs in almost 10 per cent of athletes who suffer some type of shoulder injury. The most common mechanism for an AC separation is a hard fall directly on the shoulder with the arm next to the body.

The AC joint is part of the shoulder complex. The shoulder is made up of three bones: the scapula (shoulder blade), the humerus (upper arm bone), and the clavicle (collarbone). The connection between the scapula and the clavicle is the AC joint.

To be a little more specific, the part of the scapula that makes up the top of the shoulder is called the acromion. The AC joint is where the acromion and the clavicle meet. Ligaments hold these two bones together.

AC joint separations are graded from mild to severe, depending on which ligaments are sprained or torn. The mildest type of injury is a simple sprain of the AC ligaments. Doctors call this a grade I injury. A grade II AC separation involves a tear of the AC ligaments and a sprain of the coracoclavicular ligaments. A complete tear of the AC ligaments and the coracoclavicular ligaments is a grade III AC separation. This injury results in the obvious bump on the shoulder.

Only patients with Type I or II were included in this study. These represent the more mild cases of AC disruption. More severe cases are more likely to have surgical care. Twenty-three (23) patients treated with conservative (nonoperative) care were followed for 10 years to see how they fared. There's always been a question about how these shoulders hold up over the years without surgery to repair the ligamentous and joint damage that occurs.

Conservative care included resting the arm in a sling, using ice, taking oral antiinflammatory drugs, and exercising. A specific rehab program under the direction of a physical therapist was prescribed. Patients were seen four to six weeks after the injury. Sessions were conducted for the next two to three weeks.

Most of the patients in this study were men. Everyone was tested using the Constant score, University of California-Los Angeles Shoulder Scale (UCLA), and the Simple Shoulder Test (SST). Both shoulders (involved side and uninjured side) were measured and compared. Ultrasound studies were used to measure the width of the joint separation. Joint displacement (distance from clavicle to acromion) was also measured.

Half the patients reported ongoing mild but persistent symptoms of pain and/or clicking of the AC joint. The symptoms were enough to interfere with functional activities but not enough to seek the services of a physician or therapist for follow-up treatment. The actual width of the separation did not seem to be linked with loss of shoulder function.

The authors sum up their findings by saying that what seem like minor shoulder injuries may not be as innocent as they first appear. The incidence of residual symptoms is fairly high. More than one-third of the patients with a Type I injury have ongoing symptoms years later. And patients with type II AC separation are twice as likely to have long-term symptoms as those with type I injuries.

One surprising finding was the comparison of the AC joint space from side-to-side. They expected to find that the injured joint would have a wider distance between the two joint surfaces. What they actually found was the two sides (injured and uninjured) were very similar. And that was surprising because the AC joint usually narrows with aging and degeneration. It's possible the group just wasn’t old enough to register this type of change yet. Another 10 years might be more telling.

Martin Mikek, MD. Long-Term Shoulder Function After Type I and II Acromioclavicular Joint Disruption. In The American Journal of Sports Medicine. November 2008. Vol. 36. No. 11. Pp. 2147-2150.


*Disclaimer:* The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.
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