Heterotopic bone in hip arthroplasties. Cemented versus noncemented.

Sixty-six hip arthroplasties in 55 patients were reviewed to specifically study cemented versus noncemented procedures, as related to heterotopic bone formation (HBF). Other factors considered included the type of arthroplasty, surgical approaches, preoperative and postoperative medicines, preoperative predisposing diagnoses, range of motion, and pain. The overall percentage of heterotopic ossification was 64%. There was no significant difference between cemented (67%) and noncemented (55%) procedures. Except for an increased percentage (80%) of ossification after a trochanteric osteotomy, there were no significant differences between the three reviewed surgical approaches. Male osteoarthritics had the highest overall HBF. Eighty percent of patients who previously had developed HBF also did so with a contralateral hip surgery. Surprisingly, all patients with gout (100%) developed HBF. Acetylsalicylic acid used prophylactically for anticoagulation had no significant effect. Resurfacing arthroplasty procedures accounted for half of the severe grades of HBF. A decreased range of motion occurred with more severe grades of HBF.