Articular impingement in malunited fracture of the humeral head.

We report on the case of a fracture of the humeral metaepiphysis, surgical neck, and greater tuberosity treated conservatively. Malunion of a fracture of the greater tuberosity developed an impingement on the glenoid surface, causing an articular locking in internal rotation that resolved with slight pressure and a painful "click." The impinging bone was removed arthroscopically. Its extreme posterior position required opening a second, novel portal close to the posterior edge of the acromion for instrument access. Complete removal of the impinging bone restored free internal rotation without signs of impingement on the glenoid surface. Passive motion was initiated immediately postoperatively, and active motion in a water pool was initiated after 2 weeks. After 1 year, the patient has no pain, has maintained complete range of motion, and experiences no limitations in daily or sports activities. The peculiar features of this case are the absence of soft tissue scar stiffness and deficiency of the rotator cuff, because malunion of the bone fragment to the posterior edge of the humeral head produced a mechanical block of internal rotation, and the arthroscopic treatment of the impingement through an atypical superoposterior portal, which has not been described in the literature before.