Atraumatic posterior dislocation of the sternoclavicular joint. A case report and literature review.

Atraumatic spontaneous posterior dislocation of the sternoclavicular joint (SCJ) is an extremely rare event. Only three recorded cases exist in the literature, and they are poorly documented and without roentgenographic confirmation. Spontaneous posterior dislocation of the SCJ occurred in an active 50-year-old woman without any known underlying pathology. Closed reduction attempted five days later was unsuccessful, and the patient was treated conservatively with short-term modification of activity. The patient is asymptomatic and followed carefully one year postdislocation. A review of the literature discloses a 25% complication rate involving the vital structures of the superior mediastinum after posterior dislocation of the SCJ. Because of this high complication rate, a thoracic or vascular surgeon must be available should closed or open reduction become necessary.