Primary Versus Secondary Radiotherapy for Heterotopic Ossification Prevention About the Elbow

OBJECTIVES To examine the efficacy and safety of radiotherapy for the prevention of heterotopic ossification (HO) about the elbow. DESIGN Retrospective chart review. SETTING Level 1 Trauma Center. PATIENTS/PARTICIPANTS Two hundred and twenty-nine patients who received prophylactic radiotherapy (XRT) over a 15 year period were identified. Patients were included if they received XRT to the elbow joint and had at least 12 weeks of follow up after XRT. Fifty-four patients were ultimately included. INTERVENTION All patients were treated with a single dose of 7 Gy. 98% of patients received XRT within 24 hours after surgery, and all patients received XRT within 72 hours after surgery. MAIN OUTCOMES MEASUREMENTS The primary study measures evaluated were the presence or absence of clinically symptomatic HO and the presence of radiographic HO after XRT to the elbow joint. RESULTS Eighteen patients were treated with XRT after a traumatic injury requiring surgery (primary prophylaxis), and 36 were treated with XRT after excision surgery to remove HO which had already formed (secondary prophylaxis). In the primary cohort, 16.7% developed symptomatic HO after XRT, and 11.1% required surgery to resect heterotopic bone. In the secondary cohort, 11.1% developed symptomatic HO after surgery and XRT, and 5.5% required resection surgery. No secondary malignancies were identified. CONCLUSIONS Our findings suggest that XRT for elbow HO may be safe and effective for both primary and secondary HO. XRT for HO was not shown to be associated with radiation-induced sarcoma in this series, at least in the short term. Further study in a large patient population with extended follow up is required to better characterize populations at high risk for development of HO and secondary malignancy. [ZERO WIDTH SPACE]. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.