Gluteus Minimus Debridement During Acetabular Fracture Surgery Does Not Prevent Heterotopic Ossification-A Comparative Study.

Objectives: To compare rates of heterotopic ossification (HO) after acetabular fracture surgery, through a posterior approach, with and without gluteus minimus muscle (GMM) debridement.

Design: Retrospective comparative study.

Setting: Single academic Level I trauma center.

Patients: Ninety-four patients in the GMM preserved group and 42 patients in the GMM debrided group met inclusion criteria.

Intervention: GMM preservation or debridement during acetabular fracture surgery through a single-posterior approach.

Main Outcome Measurements: Primary outcomes were incidence and severity of HO. Reoperation for HO excision was assessed. Other risk factors for severe HO (Brooker class III-IV) were secondarily assessed using multivariable logistic regression analyses. Odds ratios (ORs) with 95% confidence intervals were calculated. The significance was set at P-value ≤ 0.05.

Results: There was no difference in the incidence or severity of HO between the debrided and preserved groups. Rates of reoperation for HO excision were comparable. American Society of Anesthesiologists physical status class (OR = 3.3), head injury (OR = 4.6), and abdominal injury (OR = 4.5) were associated with severe HO.

Conclusion: GMM debridement was not associated with a decreased incidence of HO after acetabular fracture surgery. American Society of Anesthesiologists class is a novel risk factor associated with severe HO formation.

Level Of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.