Rotator cuff tearing and inferior subluxation of the humeral head: report of two cases.

We encountered two patients with atraumatic rotator cuff tears who exhibited inferior subluxation of the humeral head. In both patients shoulder motion was limited by pain. Repair of the rotator cuff tear relieved the pain and restored glenohumeral joint motion. Although the cause of this unusual complication of rotator cuff damage remains unclear, the inferior subluxation was associated with reflex muscle hypotonia, which would have reduced the pressure in the subacromial space and thus would have decreased the pain caused by the cuff lesion. No similar case seems to have been documented in the literature.