The effect of indomethacin on heterotopic ossification following acetabular fracture surgery.

Sixty-six patients with acetabular fractures requiring a posterior or extensile surgical approach were treated using a uniform protocol that was begun in July 1984. In 1987, prophylactic Indomethacin was added to the protocol to study its effects on the prevention of heterotopic ossification. Forty-six patients were operated on prior to and 20 after the initiation of the Indomethacin treatment program. Patients were observed for at least 6 months and the incidence in severity of heterotopic ossification between groups was compared using the Brooker classification. Patients' were also evaluated for associated risk factors. Statistical analysis revealed that the male sex and the extensile approach were the significant risk factors (p < 0.01). Evaluation of drug treatment revealed that while Indomethacin was not effective in completely eliminating heterotopic ossification, the occurrence of severe heterotopic ossification (Brooker Class III and Class IV) was significantly reduced (p < 0.05).