Variants of the shoulder side impact syndrome: the posterior sternoclavicular dislocation.

Side impact syndrome of the shoulder is rare and usually associated with concomitant mid-shaft clavicle, rib and scapular fractures. Visceral complications involve pleural cavity and/or lung injuries. The authors report two rare instances of posterior sternoclavicular dislocations with this entity. This association is rare and diagnosis can be overlooked in multi-trauma patients especially when blunt thoracic lesions can be life threatening. The absence of a fracture of the clavicle after a high-energy side impact to the shoulder should suggest this diagnosis, which can be facilitated by systematic total body CT scan with 3D reconstruction. Management is surgical.