Effectiveness of Radiotherapy in Preventing Heterotopic Ossification: A Meta-analysis of Randomized Controlled Trials Beyond Total Hip Arthroplasty.

Heterotopic ossification (HO) frequently occurs after procedures such as hip replacements, acetabular fractures, and elbow fractures. While radiotherapy (RT) has been a longstanding preventive measure against HO, its efficacy remains controversial, with some studies questioning its effectiveness and noting potential side effects. Previous research has predominantly focused on total hip arthroplasty (THA), leading to a gap in comprehensive evaluation of RT's efficacy and safety across other conditions. This systematic review and meta-analysis were conducted strictly adhering to PRISMA guidelines, utilizing the PICO framework to critically assess randomized clinical trials. A thorough literature search was executed across PubMed, Embase, Cochrane Library, and Web of Science). Methodological integrity was ensured through structured data extraction and quality assessment using validated criteria. The protocol was prospectively registered with INPLASY, ensuring full methodological transparency. A total of seven studies with 933 patients were included in the analysis, comprising 594 patients receiving RT and 339 patients in the control condition. Subgroup analyses included 784 patients undergoing THA and 149 patients receiving other surgical interventions. Overall findings supported RT's efficacy in significantly reducing severe HO formation. Notably, subgroup analysis of patients who underwent non-THA procedures indicated no statistically meaningful reduction in the incidence of mild-to-moderate HO (Brooker I-II) after RT treatment compared to controls. Conversely, an increased risk of nonunion was specifically noted among patients receiving elbow RT. Our meta-analysis strongly supports the preventive effect of RT on HO, especially for high-risk patients and in cases that other treatments, like NSAIDs, are contraindicated or avoided. However, the risk of nonunion in elbow treatments warrants caution. Further prospective randomized controlled trials, particularly focusing on non-hip joints, are necessary to validate these findings.