Compression brachial plexopathy caused by chronic posterior dislocation of the sternoclavicular joint.

Thoracic outlet syndrome developed in a patient due to chronic posterior dislocation of the sternoclavicular joint, following an all-terrain vehicle accident. Decompression of the thoracic outlet was accomplished by surgical reduction of the clavicle, excision of the medial clavicle and reconstruction of the costoclavicular ligament. The patient's symptomatology was relieved by the surgical procedure performed.