Acute and chronic traumatic injuries of the sternoclavicular joint require accurate diagnosis and management if complications are to be avoided. Sternoclavicular subluxation or dislocation, medial clavicle physeal injuries, and degenerative arthritis are the most frequently diagnosed of these relatively uncommon injuries. The medial clavicular epiphysis does not ossify until the 18th to 20th year. Knowledge of its developmental anatomy is essential because most physeal injuries will heal with time without surgical intervention. In contrast, posterior dislocation of the sternoclavicular joint requires prompt closed or open reduction, as posterior displacement of the medial clavicle has been associated with numerous complications, including respiratory distress, venous congestion or arterial insufficiency, brachial plexus compression, and myocardial conduction abnormalities. A myriad of procedures have been recommended for repair or reconstruction of the sternoclavicular joint. On the basis of the authors' experience and review of the literature, they advocate surgical resection of the medial clavicle, with maintenance, repair, or reconstruction of the costoclavicular ligaments, when surgery is indicated. Metallic-pin fixation of the joint should be avoided, as Steinmann pins, Kirschner wires, threaded pins with bent ends, and Hagie pins have all been reported to migrate and cause serious complications, including death.