Radiotherapy for the prophylaxis of heterotopic ossification: A systematic review and meta-analysis of randomized controlled trials

Introduction: Heterotopic ossification (HO) involves the formation of lamellar bone in nonosseous tissue. For HO, radiotherapy has been shown to be an effective prophylactic modality.

Objective: To compare HO outcomes following radiotherapy and to investigate the comparative efficacy of preoperative versus postoperative radiotherapy.

Methods: A systematic search was conducted on Ovid MEDLINE, EMBASE and Cochrane CENTRAL. Studies were included if they were randomized controlled trials (RCTs) that included patients who were prescribed prophylactic radiation for whom relevant HO progression outcomes were reported.

Results: From a literature search of 528 articles, 12 RCTs were included. There was a statistically significant reduction in HO prevalence with multiple as opposed to single fraction radiotherapy (p=0.04), however there was no statistically significant difference when examining HO progression (p=0.34). There was no statistically significant difference in HO progression when comparing a biologically effective radiation dose (BED) of >2500cGy versus ⩽2500cGy (p=0.28). As well, no statistically significant difference existed in HO progression between postoperative versus preoperative radiation (p=0.43).

Conclusion: There was no difference between postoperative or preoperative radiotherapy in preventing HO progression. There seems to be no relationship between BED greater or less than 2500cGy and the efficacy of HO prophylaxis. Multiple fractions seem to be more effective than single fraction radiotherapy in preventing HO progression.