UC Irvine

INTRODUCTION: The purpose of this study was to describe the outcomes after operative repair of ballistic femoral neck fractures. To better highlight the devastating nature of these injuries, we compared a cohort of ballistic femoral neck fractures to a cohort of young, closed, blunt-injury femoral neck fractures treated with open reduction and internal fixation (ORIF). METHODS: Retrospective chart review identified all patients presenting with ballistic femoral neck fractures treated at three academic trauma centers between January 2016 and December 2021, as well as patients aged ≤50 with closed, blunt-injury femoral neck fractures who received ORIF. The primary outcome was failure of ORIF, which includes the diagnosis of non-union, avascular necrosis, conversion to total hip arthroplasty, and conversion to Girdlestone procedure. Additional outcomes included deep infection, postoperative osteoarthritis, and ambulatory status at last follow-up. RESULTS: Fourteen ballistic femoral neck fractures and 29 closed blunt injury fractures were identified. Of the ballistic fractures, 7 (50%) patients had a minimum of 1-year follow-up or met the failure criteria. Of the closed fractures, 16 (55%) patients had a minimum of 1-year follow-up or met the failure criteria. Median follow-up was 21 months. 58% of patients with ballistic fractures were active tobacco users. Five of 7 (71%) ballistic fractures failed, all of which involved non-union, whereas 8 of 16 (50%) closed fractures failed (p=0.340). No outcomes were significantly different between cohorts. CONCLUSION: Our results demonstrate that ballistic femoral neck fractures are associated with high rates of non-union. Large-scale multicenter studies are necessary to better determine optimal treatment techniques for these fractures. LEVEL OF EVIDENCE: Level III. Retrospective cohort study.