By Jerome Barton, M.D.
Injuries to the acromioclavicular joint are also known as shoulder separation injuries. They are distinct from shoulder dislocations, which take place at the shoulder joint itself, the gleno-humeral joint. Shoulder separations occur at the small joint at the top of the shoulder where the outer end of the clavicle ( collar bone ) meets the acromion, the superior outermost portion of the scapula.
Injury to the acromioclavicular joint (AC joint) usually occurs from a fall on to the outer portion of the shoulder and usually with the arm at the side. It is characterized by varying degrees of pain and swelling dependent upon the extent of the injury to the supporting ligaments. The patient will point directly to the top of the shoulder as the painful injured area.
The extent of injury to the AC joint is determined by the degree of trauma sustained and is measured by the extent of injury to the shoulder ligaments. Treatment of these injuries varies, of course, with the extent of injury.
Some injuries are treated with ice for swelling, possibly anti-inflammatory medication and analgesics as needed and a sling for support. As the acute symptoms subside a self-administered or formal therapy program is used to help regain motion and function and when appropriate the shoulder is guided back to a full activity schedule. The results are almost always good.
More severe injuries are frequently considered for surgical repair. Surgical repair involves operative fixation and repair of both the CC ligaments and the AC joint and the other injured soft tissue structures. Results are usually good but both the extent of injury and surgery lead to a more prolonged recovery and rehabilitation period.
Rehabilitation is an important part of the recovery process and becomes more important and prolonged with more severe injuries. The patient must be guided through a program designed to recover range of motion, strength and neuromuscular control of the shoulder.
Results of treatment for AC injuries are generally quite good for the less extensive injuries but results may be compromised to some degree in the more extensive injury. Patient perception of outcomes will vary with age and functional demands of the shoulder.