Prevention of heterotopic ossification after total hip replacement. A prospective, randomised study using acetylsalicylic acid, indomethacin and fractional or single-dose irradiation

J Bone Joint Surg Br. 1997 Jul;79(4):596-602. doi: 10.1302/0301-620x.79b4.6829.


We have carried out a prospective, randomised study of prophylaxis for heterotopic ossification (HO) comparing indomethacin for 7 and 14 days, acetylsalicylic acid, and fractional (4 x 3 Gy) or single exposure of 5 or 7 Gy irradiation after operation. We initially had 723 patients (733 hip replacements), but after withdrawals there were 685 hips of which 18.4% developed HO; 14% were grade I, 2.9% grade II and 1.5% grade III of the Brooker classification. We compared the results between these groups with those of a matched control series and found that indomethacin, 2 x 50 mg for 7 and 14 days, and postoperative irradiation of 4 x 3 Gy or 1 x 7 Gy, significantly reduced the development of HO compared with the control group. Patients in the acetylsalicylic acid group and those with a single irradiation of 5 Gy after operation developed significantly more ossification than those in the indomethacin and other irradiation groups. We suggest the use of 2 x 50 mg of indomethacin with mucoprotection for seven days as prophylaxis against HO after total hip replacement for all patients. A single irradiation of 7 Gy is recommended for patients who have developed HO after previous operations or to whom administration of indomethacin is contraindicated.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use*
  • Aspirin / therapeutic use*
  • Female
  • Hip Prosthesis*
  • Humans
  • Indomethacin / therapeutic use*
  • Male
  • Middle Aged
  • Ossification, Heterotopic / drug therapy
  • Ossification, Heterotopic / prevention & control*
  • Ossification, Heterotopic / radiotherapy
  • Postoperative Complications / prevention & control*
  • Postoperative Period
  • Prospective Studies
  • Radiotherapy Dosage


  • Anti-Inflammatory Agents, Non-Steroidal
  • Aspirin
  • Indomethacin