A rare cause of chest/shoulder pain following trauma, but one that can be associated with serious vascular injuries.
Anterior dislocations of the Sternoclavicular(SC) Joint are much more common than posterior and usually resulting from blow to the anterior shoulder that rotates the shoulder backward and transmits the stress to the medial clavicle and SC joint.
A blow to the posteior shoulder that drives the shoulder forward or a direct blow to the medial clavicle can cause a posterior dislocation.
Anterior SC dislocations
Generally not associated with any underlying injury and can be safely reduced in the ED.
Ligaments and joint capsule entrapment can make it difficult to reduce the joint, and often it is difficult to maintain the reduction.
It is not uncommon for these to require open reducation and internal fixation.
Can be reducted by abducting, extending, and applying traction to the ipsilateral arm/shoulder while applying posterior and inferior pressure on the medial clavicle.
Posterior SC dislocations
Associated with injuries to the underlying vasculature, dyspnea due to tracheal compression, and parasthesias.
Often missed on plain films (CXR, Shoulder Series or Clavicular Series)
Best visualized with enhanced CT Scan of the Chest. IV enhancement recommended to ensure that their is no associated vascular injury.
Can be reducted by abducting, extending, and applying traction to the ipsilateral arm/shoulder while pulling the clavicle forward. Several references recommend using a towel clip to grasp the clavicle if you are unable to grab it effectively with your fingers.