Joint dislocations as a result of trauma are fairly common injuries. Dislocations can occur in virtually any joint in the body, but the shoulder represents the most common joint dislocation.
The shoulder is made up of the glenohumeral, acromioclavicular, scapulothoracic and sternoclavicular joints. The shoulder joint proper is the glenohumeral joint, a ball and socket articulation. The glenohumeral joint has the greatest range of motion of any joint in the body and, along with the scapulothoracic joint, allows us to position and use our upper extremities in space. The glenohumeral joint is composed of the glenoid (socket) which is part of the scapula (shoulder blade) and the humerus (ball). The glenohumeral joint is stabilized by the capsular ligaments. The shoulder labrum is a fibrocartilage ring around the glenoid that functions to deepen the glenoid and provide an attachment site for the capsular ligaments.
The shoulder can dislocate anteriorly (out the front), posteriorly (back) or inferiorly (bottom). The shoulder most commonly dislocates anteriorly. A shoulder dislocation can be a result of trauma or atraumatic. A dislocation may spontaneously reduce or require reduction by a physician. Shoulder dislocations result in either a tear or stretching of the labrum-ligament complex or a combination of the two. A careful history, physical examination and radiographs are useful in making the diagnosis of a shoulder dislocation.
Initial treatment of a shoulder dislocation is a closed reduction which often requires sedation. Further treatment for shoulder dislocations depends on several factors including cause of the dislocation, age of the patient and any associated injuries. Dislocations may be associated with fractures of the tuberosities or glenoid. In older patients, dislocations may result in tears of the rotator cuff. In patients with atraumatic shoulder instability, a physical therapy program for muscular strengthening may be helpful. Older patients with a shoulder dislocation usually do not experience recurrent dislocations, but may require surgery to repair a rotator cuff tear or tuberosity fracture. Young patients usually experience recurrent dislocations and require early surgery to repair the injured labrum and capsule. In order to properly diagnose and treat shoulder dislocations, an evaluation by an orthopedic surgeon is recommended.
