Naproxen in the prevention of heterotopic ossification after total hip replacement

The effectiveness of naproxen, indomethacin, and a placebo were compared fo r the prevention of heterotopic ossification after total hip arthroplasty, Eighty-four men at high risk of experiencing heterotopic ossification recei ved randomly either naproxen 750 mg per day, indomethacin 75 mg per day, or a placebo for 6 consecutive weeks after surgery. Efficacy analysis showed that in 70% of patients treated with naproxen, in 34.8% of those treated wi th indomethacin, and in 15% of those treated with a placebo, no heterotopic ossification appeared on radiographs taken at 6 months. Naproxen was signi ficantly more effective than the placebo or indomethacin in preventing the development of heterotopic ossification. Stratification into five categorie s, according to Brooker's classification at 6 months, showed that both drug s were equally superior to the placebo. Class III heterotopic ossification occurred only in patients who were given the placebo. The improvement in cl inical criteria was comparable in the three groups, although at 6 months th ere was an improvement in abduction in patients treated with indomethacin c ompared with those treated with naproxen and the placebo. The overall toler ance was rated good by 87% of patients and 86% of physicians, with no diffe rence between the groups. The results show that naproxen, given daily for 6 weeks, is an effective and safe medication for the prevention of heterotop ic ossification after total hip replacement.