Acromioclavicular and sternoclavicular injuries and clavicular, glenoid, and scapular fractures.

Injuries to the acromioclavicular joint and the sternoclavicular joint and fractures of the clavicle, glenoid, and scapula vary widely in incidence, treatment, and prognosis. The treatment for acromioclavicular joint and clavicle injuries, which are relatively common, has significantly evolved. Controversy exists regarding the ideal treatment of type III acromioclavicular separations, whereas significant research has shown many potential benefits for surgically treating significantly displaced midshaft clavicle fractures that had traditionally been treated nonsurgically. Sternoclavicular injuries and scapula fractures are less common but are associated with high-energy mechanisms of injury and are potentially life threatening. Most of these injuries can be treated conservatively, although some injuries will benefit from surgical fixation. Identifying floating shoulders or unstable glenoid neck fractures without bony or ligamentous stabilization requires an understanding of the multiple anatomic stabilizers of the glenoid. Floating shoulders, glenoid neck fractures with 1 cm or 40 degrees or more of displacement, and intra-articular glenoid fractures with associated glenohumeral instability or intra-articular displacement of 5 mm or more may require surgical repair.