Point-of-care ultrasound facilitates diagnosing a posterior shoulder dislocation

Posterior shoulder dislocation is an uncommon disruption of the glenohumeral joint. Risk factors include seizure, electric shock, and underlying instabilities of the shoulder joint.

A 27-year-old man with a history of recurrent posterior shoulder dislocation presented to the Emergency Department with sudden shoulder pain and reduced range of motion about the shoulder after abducting and internally rotating his arm. Radiographs did not show fracture or dislocation. The treating physician suspected an occult posterior shoulder dislocation, but wanted to avoid performing a computed tomography scan of the shoulder, as the patient had undergone numerous scans during the evaluation of similar complaints. Instead, a point-of-care ultrasound was performed, demonstrating posterior displacement of the humeral head relative to the glenoid rim, confirming the presence of a posterior shoulder dislocation. The patient received procedural sedation, and the shoulder was reduced with real-time ultrasound visualization. The patient tolerated the procedure well, and had decreased pain and improved range of motion. He was discharged with a sling, swathe, and orthopedic follow-up.

Point-of-care ultrasound of the shoulder may be used to demonstrate posterior shoulder dislocation. This may have particular utility in the setting of non-diagnostic radiographs.