The Use of External Beam Radiation Therapy for Heterotopic Ossification Prophylaxis After Surgical Fixation of Acetabular Fractures: A Randomized Controlled Trial.

OBJECTIVES

To determine the effect of external beam radiation (XRT) on preventing severe heterotopic ossification (HO) after acetabular surgery.

DESIGN

Randomized controlled trial.

SETTING

Two level I academic trauma centers.

PATIENT SELECTION CRITERIA

Patients with an acetabular fracture (OTA/AO type 62) surgically treated through a posterior or combined anterior and posterior approach.

OUTCOME MEASURES AND COMPARISONS

Radiographic HO was determined using Brooker Classification at the last follow-up. The primary outcome was severe HO (Brooker classes III-IV). The secondary outcome was any HO (Brooker classes I-IV). The incidence of radiographic HO was compared between patients who did and did not undergo postoperative XRT. The results were analyzed in both an intention-to-treat (randomized to XRT) and as-treated (received XRT) basis.

RESULTS

Severe HO occurred in 3 of 54 (6%) patients randomized to XRT and 9 of 50 (18%) patients randomized to no XRT (odds ratio 0.24, 95% confidence interval, 0.05 to 0.94; P = 0.05). Any HO occurred in 10 (19%) patients assigned to XRT and 17 (34%) patients in the no XRT control group (odds ratio 0.39; 95% confidence interval, 0.13 to 1.05; P = 0.07).

CONCLUSIONS

The findings of this dual-center randomized controlled trial suggest that XRT after acetabular surgery significantly reduced the odds of severe HO compared with patients who did not receive XRT. These results can help guide shared decision making between surgeons and patients regarding the use of XRT for HO prophylaxis.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.