The Impact of Gunshot Injury on the Development of Heterotopic Ossification after Periarticular Elbow Trauma

OBJECTIVES: – To evaluate whether ballistic (gunshot) injuries increase the rate of severity of heterotopic ossification (HO) compared to blunt trauma in patients with peri-articular elbow fractures.METHODS: – Design: Retrospective CohortSetting: – Single Level 1 Trauma CenterPatient Selection Criteria: – Study inclusion required; patients of mature skeletal age diagnosed with a peri-articular elbow fracture (OTA/AO 13A-C) with a minimum of 6-weeks radiographic follow-up between 2018-2024.Outcome Measures and Comparisons: – Data on demographics, injury characteristics, and surgical management were collected for the ballistic trauma cohort and blunt trauma cohort. HO was assessed using the Hastings/Brooker Classification. Secondary outcomes included post-injury stiffness defined as a flexion/extension arc of motion < 100°, revision surgery, and complications. Descriptive statistics were used to compare frequencies of categorical outcome variables between blunt and ballistic cohorts, and multivariable logistic regressions were used to identify risk factors for elbow HO occurrence and severity as well as all secondary outcomes.RESULTS: – A total of 171 patients met inclusion criteria including 65 GSW-related fractures (38%). GSW patients were younger (29.2 [Range: 18-62] vs. 43.8 years [Range: 18-93]) and more often male (84.6% vs 51.9%). Overall HO occurrence was 61.4%. GSW was not significantly associated with HO (63.1% vs. 60.4%, p=0.607). Distal humerus fractures were associated with increased HO risk (OR 2.15) and severity (OR 2.63) compared to proximal radius/ulna injuries. Stiffness occurred in 73.7% of patients and was more common in distal humerus injuries than proximal radius/ulna fractures (OR 2.50; p = 0.030). No significant differences were found in stiffness, revision surgery, or complication rates between GSW and non-GSW groups (OR 1.36; 95% CI: 0.537-3.455; p =0.51).CONCLUSIONS: – Ballistic injury did not significantly increase heterotopic ossification risk or stiffness compared to blunt trauma in a civilian population. Consistent with prior literature, fracture location, specifically distal humerus fractures compared to proximal radius/ulna injuries, appears to be an important driver for heterotopic ossification prevalence and severity. Identifying heterotopic ossification risk factors after peri-articular elbow trauma can help clinicians stratify patient risk and guide preventive strategies for managing these complex injuries.LEVEL