A prospective evaluation of the timing of postoperative radiotherapy for preventing heterotopic ossification following traumatic acetabular fractures

Purpose: Preoperative and immediate postoperative irradiation of traumatic acetabular fractures (TAF), although known to reduce heterotopic ossificati on (HO), can cause significant organizational and logistic difficulties. We sought to determine an acceptable time interval between surgery and radiat ion without compromising control, as well as to update our large experience and to further validate our treatment philosophy. Methods and Materials: Beginning in June 1995, we began a prospective study , irradiating 152 patients on postoperative days 1, 2, or 3. There were als o 17 patients delayed further secondary to medical difficulties. Results: A ll patients treated since June 1995 received 700 cGy/1 fx. Fifty-eight pati ents received radiation within 24 hours of surgery, 41 within 2 days, 53 wi thin 3 days, 13 within 4 days, and 4 were delayed further. Delaying irradia tion for up to 4 days postoperatively caused no statistical increase in HO (p = 0.625). Of 263 patients in our retrospective cohort, HO occurred in 5. 3% of patients who received irradiation versus 60% of patients who did not. Conclusion: In our prospective study, we noted no perceptible increase in H O with up to a 3-day interval between surgery and radiotherapy. This allows a more structured treatment schedule and allows the patient more time to h eal and recover. Updated results from our overall series continue to demons trate that adjuvant radiation decreases the incidence and severity of HO af ter TAF. (C) 2000 Elsevier Science Inc.