Trochanteric fracture pattern is associated with increased risk for nonunion independent of open or closed reduction technique

PURPOSE: Soft tissue injury and soft tissue injury as risk factors for nonunion following trochanteric femur fractures (TFF) are marginally investigated. The aim of this study was to identify risk factors for impaired fracture healing in geriatric trauma patients with TFF following surgical treatment with a femoral nail. METHODS: This retrospective cohort study included geriatric trauma patients (aged > 70 years) with TFF who were treated with femoral nailing. Fractures were classified according to AO/OTA. Nonunion was defined as lack of callus-formation after 6 months, material breakage, and requirement of revision surgery. Risk factors for nonunion included variables of clinical interest (injury pattern, demographics, comorbidities), as well as type of approach (open versus closed) and were assessed with uni- and multivariate regression analyses. RESULTS: This study included 225 geriatric trauma patients. Nonunion was significantly more frequently following AO/OTA 31A3 fractures (N = 10, 23.3%) compared with AO/OTA type 31A2 (N = 6, 6.9%) or AO/OTA 31A1 (N = 3, 3.2%, p < 0.001). Type 31A3 fractures had an increased risk for nonunion compared with type 31A1 (OR 10.3 95%CI 2.2 to 48.9, p = 0.003). Open reduction was not associated with increased risk for nonunion (OR 0.9, 95%CI 0.1 to 6.1. p = 0.942) as was not the use of cerclage (OR 1.0, 95%CI 0.2 to 6.5, p = 0.995). Factors such as osteoporosis, polytrauma or diabetes were not associated with delayed union or nonunion. CONCLUSION: The fracture morphology of TFF is an independent risk factor for nonunion in geriatric patients. The reduction technique is not associated with increased risk for nonunion, despite increased soft tissue damage following open reduction.