Prevention of heterotopic bone formation after acetabular fracture fixation by single-dose radiation therapy: a preliminary report.

A common complication after acetabular fracture fixation is formation of heterotopic ossification (HO) in the soft tissues about the hip. We are reporting on the use of a single, low-dose radiation therapy regimen to prevent HO in the population of postoperative acetabular fracture patients. Thirty acetabular fracture patients who were at risk for HO after surgery were reviewed with an average follow-up of 12 months. Twenty-one of these patients received radiation therapy in the postoperative period according to a single dose protocol. Nine patients did not receive any prophylactic treatment for the prevention of HO during the same period. One patient from each of these categories was lost to follow-up. Of the 20 treated and followed patients, none developed HO higher than grade 2, and nine had no HO at all. None of the treated patients had any functional deficit due to HO, and none had any complications related to radiation treatment. Of the untreated patients, all had grade 2 HO or above. Three developed grade 4 HO and have undergone reoperation for resection of HO. Study weakness include the fact that the non-treated patients were significantly different from the treated patients in several ways; including the incidence of multiple trauma, head injury, and delay to surgery. No attempt was made to randomize patients prospectively, nor to directly compare the two groups. However, we can conclude, based on comparison with reported rates of HO formation, that single, low-dose radiation therapy is a safe and effective method for prevention of HO in the postoperative acetabular fracture patient. It is as effective as previously reported multidose regimens.