Failure of arthroscopic decompression by subacromial heterotopic ossification causing recurrent impingement.

Heterotopic ossification is a well-recognized complication of musculoskeletal trauma and elective orthopaedic surgery. A series of 10 cases of arthroscopic subacromial decompressions developed postoperative heterotopic bone. In eight, the ectopic bone caused recurrent shoulder impingement. These are the first reported cases in which heterotopic ossification compromised the results of an arthroscopic procedure. It is recommended that the patient at risk (e.g., with active spondolytic arthropathy or a profile of hypertrophic pulmonary osteoarthropathy--obesity, diabetes with a history of chronic pulmonary disease) be considered for heterotopic ossification prophylaxis.