ABSTRACT
Heterotopic ossification is a well-recognized complication of spinal cord injury, closed head injury, total hip arthroplasty, burns, and other trauma and has been observed in various tissues such as muscles, tendons, ligaments, and menisci. Complications of arthroscopic acromioplasty are relatively uncommon and include hematoma, traction neuropathy, infection, acromial fracture, reflex sympathetic dystrophy, and instrument breakage. However, little has been reported on heterotopic ossification of the shoulder, particularly after arthroscopic surgery. Recurrent rotator cuff impingement symptoms caused by small amounts of heterotopic ossification after arthroscopic acromioplasty have been described. We report a case of severe heterotopic ossification about the shoulder after arthroscopic acromioplasty.