Shoulder and humerus trauma.

Three bones and two joints comprise the pectoral girdle. These are the clavicle, scapula, proximal humerus, acromioclavicular joint, and shoulder joint. The pectoral girdle binds the upper extremity to the torso. Thus, injury to any of the pectoral girdle's components can impact the function of the entire extremity. The spectrum of pectoral girdle injuries ranges from a simple acromioclavicular joint sprain to scapulothoracic dissociation. Whereas the former is a painful but self-limiting injury with minimal sequelae, the latter is life threatening. However, the severity of most pectoral girdle injuries lies between these two extremes. Fractures and dislocations are common in this region throughout life, and a clear understanding of the patterns of injury and their radiographic spectrum is essential for all radiologists who deal with trauma.