Is a common injury to the acromioclavicular joint. It occurs as a result of a downward force being applied to the superior part of the acromion, either by something striking the top of the acromion or by falling directly on it. The injury is more likely to occur if the shoulder is struck with the hand outstretched. Despite the scapula pulling on the clavicle during impact, the clavicle remains in its general fixed position because of the sternoclavicular joint ligaments. The separation is classified into 6 types, with 1 through 3 increasing in severity, and 4 through 6 being the most severe.
Diagnosis is based on physical examination and an x-ray. A separated shoulder occurs because of a direct blow to the AC joint or a fall on the elbow that forces the head of the humerus into the AC joint. Furthermore, AC separation can be identified point tenderness, pain at the AC joint with cross-arm adduction, and pain relief with an injection of a local anesthetic. The cross-arm adduction will produce pain specifically at the AC joint and will be done by elevating the arm to a 90° angle, flexing the elbow to a 90° angle, and adducting the arm across the chest. The pain in the shoulder is hard to pinpoint of the innervation of the AC joint and the glenohumeral joint. An injury to the AC joint will result in pain over the AC joint, in the anterolateral neck and in the region in the anterolateral deltoid.
Generally a X-RAY is good enough to confirm the diagnosis and quantify the severity . sometimes MRI is also required.
When beginning treatment some of the things one should do first, is control the inflammation, rest the joint, and ice the joint. Take an anti-inflammatory to help minimize the pain and inflammation. Rest the joint which will also help minimize painful symptoms and allow the healing to begin. When icing, it should be done every four hours for 15 minutes at a time. One can wear a sling until the pain subsides; then some simple exercises can be started.
Type I and type II shoulder separation are the most common types of separated and rarely need surgery. However, the risk of arthritis with type II separations is greatly increased.
Most non-surgical treatment options include physical therapy to build up the muscles and help stabilize the joint. Literature regarding long-term follow-up after surgical repair of type III injuries is scarce, and those treated nonoperatively generally do quite well. There may also be the potential that surgical repair may be less painful in the long run.
Once the pain has eased, range-of-motion exercises can be started followed by a strength training program. The strength training will include strengthening of the rotator cuff, and shoulder blade muscles. With most cases the pain goes away after three weeks. Although full recovery can take up to six weeks for type II and up to twelve weeks for type III.
Those who do have a separated shoulder will most often return to having full function, although some may have continued pain in the area of the AC joint. With the continued pain there are some things that maybe causing it. It may be due to an abnormal contact between the bone ends when the joint is in motion, the development of arthritis, or an injury to a piece of the cushioning cartilage that is found between the bone ends of this joint.
Type IV, V, and VI shoulder separations are very uncommon but always require surgery.