Is surgeon technique a modifiable risk factor for heterotopic ossification after posterior acetabular fracture fixation? A multi-surgeon study

Heterotopic ossification (HO) is a well-recognized complication following operative fixation of acetabular fractures through a posterior approach. Established risk factors largely reflect nonmodifiable patient and injury characteristics. Whether surgeon-controlled aspects of operative technique influence HO remains poorly defined. The purpose of this study was to determine if the individual surgeon and specific technique variables are associated with HO after accounting for established patient and injury factors.

We retrospectively reviewed 1292 patients who underwent acetabular fracture fixation through a Kocher-Langenbeck approach at two Level 1 trauma centers between 2010 and 2025 by 14 fellowship-trained orthopaedic traumatologists. Patients receiving any form of HO prophylaxis were excluded. Four surgeon-controlled variables were examined: aggressiveness of gluteus minimus debridement, trochanteric osteotomy, thrombin gel use, and closed suction drainage. HO was graded on final radiographs by two independent reviewers using the Brooker classification, with third-reader adjudication for disagreements, and categorized as little-to-no (grade 0-I), moderate (grade II), or severe (grade III-IV). Mixed-effects logistic regression models with surgeon as a random effect were used to assess the associations between patient, injury, and surgeon-controlled technique variables, as well as the individual surgeon, with severe and moderate HO formation.

Little-to-no HO occurred in 1132 patients (87.6%), moderate HO in 96 (7.4%), and severe HO in 64 (5.0%). Aggressive gluteus minimus debridement was not associated with HO severity. For severe HO, the surgeon did not contribute meaningfully to model performance, and no surgeon-controlled technique variables were significant; severe head injury, mechanical ventilation beyond 72 h, African-American race, and dual surgical approaches were associated with severe HO. For moderate HO, the surgeon contributed moderately, and both trochanteric osteotomy (odds ratio [OR] 3.7, 95% confidence interval [CI] 1.1-12) and closed suction drainage (OR 1.8, 95% CI 1.0-3.1) were associated with increased odds of moderate HO.

Severe HO following posterior acetabular fracture fixation is predominantly driven by patient and injury characteristics rather than surgeon technique. Aggressive gluteus minimus debridement does not appear to reduce HO risk, and prevention efforts should prioritize patient-level risk stratification.