Traumatic bilateral posterior dislocation of the shoulder: a case report

Introduction. Bilateral posterior dislocation of the shoulder is a rare injury, accounted for about 2–5% of all shoulder dislocations. Main courses are electrical shock, epilepsy or extreme trauma with uncontrolled muscle forces. We report about a case of bilateral posterior shoulder dislocation without additional fractures but with a concomitant acromioclavicular joint dislocation. Case presentation. A 46-year-old Caucasian motorcyclist presented to our facility after a fall on slippery ground. He claimed pain in both shoulders with limited range of motion. The initial X-rays were inconclusive, clinical examination showed typical findings of a Rockwood injury with an additional limited external rotation so that a posterior shoulder dislocation was suspected. The CT scan confirmed the clinical suspicion. A closed reduction was performed followed by immobilization in a shoulder abduction pillow for 4 weeks and continuous physiotherapy. Upon follow up normal function with full range of motion was observed. Conclusion. A bilateral posterior shoulder dislocation can be caused by trauma and results in a limited range of motion with often additional injuries. Due to the unusually presentation the risk of missing the injury is increased. Therefore it is most important to consider this rare diagnosis and in case of clinical suspicion perform a careful algorithm of diagnostic.