Rotator cuff tendon tear plain radiograph

This radiograph is from a 74-year-old woman with a 25-year history of "shoulder bursitis." She is unable to raise her arm overhead, cannot comb her hair, and cannot reach up to higher shelves to remove dishes. She cannot abduct her right shoulder without using her left arm for assistance and is unable to externally rotate her right shoulder against the slightest resistance. The plain radiograph above provides indirect evidence of a rotator cuff tendon tear, including cephalad migration of the humerus (high-riding humeral head), indicated by the arrows, and substantial loss of the subacromial space (which normally contains the 7 mm thick rotator cuff tendon and 1 mm thick subacromial bursas), indicated by the dashed arrow.