Radiotherapy vs. nonsteroidal anti-inflammatory drugs for the prevention of heterotopic ossification after major hip procedures: A meta-analysis of randomized trials

Abstract

Purpose To evaluate the efficacy of radiotherapy (RT) vs. nonsteroidal anti-inflammatory drugs (NSAIDs) in the prevention of heterotopic ossification (HO) after major hip procedures. Methods and materials We conducted a meta-analysis of 7 randomized studies ( n = 1143) comparing RT with NSAIDs. Data were combined across studies using fixed and random effects models. We conducted separate analyses for clinically significant HO (Brooker Grade 3 and 4) and for any HO (any Brooker grade). Results Overall RT tended to be more effective than NSAIDs in preventing Brooker 3 or 4 HO (risk ratio, 0.42; 95% confidence interval [CI], 0.18–0.97) or any HO (risk ratio, 0.75; 95% CI, 0.37–1.71), but with significant between-study heterogeneity for the second analysis. The overall absolute risk difference for Brooker 3 or 4 HO was small (−1.18%; 95% CI, −2.45% to 0.09%). Subgroup analyses showed that early preoperative RT (16–20 hours before surgery) and acetylsalicylic acid were less effective. For postoperative RT, there was a significant dose–response relationship ( p = 0.008): 6 Gy of RT was equally effective as NSAIDs, whereas increasing radiation doses were more effective. Conclusions Although absolute differences may be small, postoperative RT is on average more effective than NSAIDs in preventing HO after major hip procedures, and its efficacy is dose dependent.