Radiation Therapy for Prophylaxis of Heterotopic Ossification at the Elbow: A Single-Institution Retrospective Study

Purpose/Objective(s): Radiation therapy (RT) for prevention of heterotopic ossification (HO) around the joints has been used for decades. While there is ample evidence to support its use at the hip, data on non-hip joints such as the elbow are scant, with recent studies raising concern over toxicities. We conducted an IRB-approved single-institution retrospective review of our experience delivering radiation to the elbow to evaluate outcomes and complications related to RT. Materials/Methods: From 2003 to 2012, 31 patients received perioperative RT for HO prophylaxis at the elbow. Patients with postoperative films (n Z 20) were included in our study. Data on patient characteristics, treatment details, and clinical status at each encounter were reviewed. Radiological studies were reviewed using 5 classification schemes. Patients were contacted for interview on current status using the Mayo Elbow Performance Score (MEPS). Results: Median patient age was 42.5 years, median body mass index (BMI) was 29, and 85% were male. Mean follow-up was 9.2 months. All patients received a single fraction of 600-700 cGy, preoperatively within 24 hours (n Z 8), postoperatively within 24 hours (n Z 11), or postoperatively in 3 days (n Z 1). Five patients underwent primary prophylaxis while 15 patients received RT for secondary prophylaxis. Two patients developed new HO and 1 patient had progression of disease at the time of follow-up, but all 3 reported a fair MEPS and denied severe functional limitations. Three patients required surgical re-excision of HO. Conclusions: NSAID treatment, whether newly prescribed or prior use, variations in field size, differences in technique, whether open-field AP/PA or 3D conformal with multi-leaf collimation, did not appear to make a difference in risk of recurrence, mal-union, non-union, or functional outcome. Furthermore, all of the subjects available for phone interview, including those with evidence of severe HO, reported fair or better functionality. Timing of RT seems optimal within 24 hours preoperatively or postoperatively. Patients with high-risk indications should undergo primary prophylaxis against HO. Author Disclosure: S.K. Yoo: None. C. Miyamoto: None.