Posterior Sterno-clavicular Dislocation

R Posterior Sternoclavicular Joint Dislocation with venous impingement

A 25 year old motorcyclist is hit by a car at approximately 50kmph, impacting on the windscreen of the car with his chest. The motorcyclist was wearing full protective clothing, and denied striking his head, complaining of only mild pain to his chest. He was able to ambulate after the accident, and an ambulance was not called, and instead he self presented to his local emergency department a few hours later, as the pain in his chest became worse. 

He was immediately placed in a cervical collar, and assessed. His primary survey was unremarkable, with a negative FAST, and normal appearance of chest on a plain film. His secondary survey demonstrated only some mild bruising to his sternum, which was tender on palpation. Given the mechanism of injury, and pain, the decision was made to CT his thorax....

Posterior Sternoclavicular Joint Dislocation Facts

- Rare. Anterior dislocations are more common by a ratio of approximately 20:1

- Important, due to close proximity to important anatomic mediastinal structures - major vessels, trachea, oesophagus

- Injury suggests significant blunt force trauma to chest, and associated head, spine, & abdominal injuries should be actively sought out and excluded / managed. 

- Diagnosis is difficult, based on high index of suspicion clinically. 

- Chest X-rays are often non-diagnostic given the presence of superimposed lungs and bony ribs. CT (plus contrast) is the imaging modality of choice

- Definitive management involves prompt, closed reduction under orthopaedic surgeons with cardiothoracic surgeons standing by in case of mediastinal injury.