Heterotopic ossification occurring after the use of commercially available bone morphogenetic proteins has not been widely reported. We describe four cases of heterotopic ossification in patients treated with either recombinant bone morphogenetic protein 2 or recombinant bone morphogenetic protein 7. We found that while some patients were asymptomatic, heterotopic ossification which had occurred around a joint often required operative excision with good results.

We have examined the relief from pain and the functional outcome in 18 patients who underwent resection arthroplasty of the shoulder as a salvage operation between 1988 and 2002. The indications included failed shoulder replacement in 17, with infection in 13, and chronic septic arthritis in one. The mean follow-up was 8.3 years (2.5 to 16.6). Two intra-operative fractures of the humerus occurred, both of which healed.

The level of pain was significantly decreased (t-test, p < 0.001) but five patients continued to have moderate to severe pain. The mean active elevation was 70° (0° to 150°) postoperatively and represented an improvement from 39° (0° to 140°) (t-test, p = 0.003), but internal and external rotation were hardly changed. The mean number of positive answers on the 12-question Simple Shoulder Test was 3.1 (0 to 12) but the shoulder was generally comfortable when the arm was positioned at rest by the side. The mean post-operative American Shoulder and Elbow Surgeon’s score was 36 (8 to 73).

Despite applying this procedure principally to failed shoulder replacements, the results were similar to those reported in the literature for patients after severe fracture-dislocation. Reduction of pain is possible in one half to two-thirds of patients. The outcome of this operation in providing relief from pain cannot be guaranteed, but the shoulder is usually comfortable at rest, albeit with profound functional limitations.