PROPHYLACTIC INDOMETHACIN FOR THE PREVENTION OF HETEROTOPIC OSSIFICATION AFTER ACETABULAR FRACTURE SURGERY IN HIGH-RISK PATIENTS

Thirty-seven male patients with acetabular fractures requiring an exte nsile surgical approach were treated using a uniform protocol that was begun in July 1984. In 1987, prophylactic indomethacin was added to t he protocol to study its effects on the prevention of heterotopic ossi fication. Nineteen patients with at least 12 months' follow-up were op erated on prior to, and 16 after the initiation of the indomethacin tr eatment program. Two patients were lost to follow-up. The severity of heterotopic ossification was evaluated for each of these two patient g roups using the Brooker classification and was correlated with hip joi nt mobility. Statistical analysis revealed that indomethacin was effec tive in decreasing the overall incidence of heterotopic ossification ( p < 0.01). The occurrence of severe heterotopic ossification (Brooker class III and class IV) was also significantly reduced (p < 0.01) and functional results thereby improved. The maximal extent of heterotopic ossification was evident by 6 weeks postoperatively in all patients. In the patients receiving indomethacin, heterotopic ossification did n ot progress after the drug was discontinued.