Acromioclavicular Joint Separation
A 30-year-old man visited the emergency department after a fall that had resulted from a loss of balance while he was walking that day. The patient recalled that he had sustained the impact of the fall on his left shoulder. On examination, his vital signs were normal, but a palpable posterior fullness with swelling was seen over his left shoulder (Panels A and B). Active abduction of the shoulder was limited and painful. Findings from a neurovascular examination of the ipsilateral arm and hand were normal. No tenderness over the sternoclavicular joint was noted. A left anteroposterior radiograph of the shoulder revealed complete separation of the acromioclavicular joint (Panel C). The injury was classified as a type IV acromioclavicular joint separation according to Rockwood’s classification (acromioclavicular joint separation and rupture of the joint capsule and acromioclavicular and coracoclavicular ligaments, with the distal portion of the clavicle displaced posteriorly through the trapezius muscle). The patient underwent a closed reduction of the acromioclavicular joint. At the 6-month follow-up visit, he had full range of motion around his shoulder and reported no pain.
