Proximal Implant Breakage After Cephalomedullary Nailing of Extracapsular Proximal Femur Fractures: A Multicenter Retrospective Comparative Analysis

OBJECTIVE: To compare rates of nail breakage of 3 common cephalomedullary nails for the treatment of AO/OTA 31A1-3 femur fractures. DESIGN: Multicenter retrospective study. SETTING: Thirteen level I trauma centers. PATIENT SELECTION CRITERIA: Adult patients with AO/OTA 31A1-3 femur fractures treated between 2014 and 2021 with the trochanteric fixation nail-advanced (TFNA), Gamma3, or Trigen InterTAN were included. OUTCOME MEASUREMENTS AND COMPARISONS: The primary outcome was implant (nail or head element) breakage. The secondary outcomes included nonunion, cut-out/cut-through, and overall reoperation rate. Univariate and multivariable analyses were performed to compare breakage rates between implants while controlling for age, sex, AO/OTA 31A1-2 versus 31A3 fracture patterns, low- versus high-energy mechanisms, and postoperative neck shaft angle (NSA). RESULTS: In total, 2130 patients were included: 770 (36.2%) TFNA, 1073 (50.4%) Gamma3, and 287 (13.5%) InterTAN. The InterTAN group had younger patients (median age: InterTan: 74, TFNA: 77, Gamma3: 80, P < 0.001), more high-energy mechanisms (InterTan: 23%, TFNA: 14%, Gamma3: 10%, P = 0.001), and more varus malreductions (NSA < 128.5: InterTan: 46%, Gamma3: 39%, TFNA: 34%, P = 0.001). The TFNA group was more likely to have an AO/OTA 31A3 fracture pattern than the Gamma3 (TFNA: 17.3%, InterTAN: 14.3%, Gamma3: 12.1%, P = 0.002). The overall rate of implant breakage was 1.4% in the InterTAN group, 1.2% in the TFNA group, and 0% in the Gamma3 group. All breakages occurred in the presence of a nonunion or delayed union. Only two of the 31A3 fracture patterns resulted in breakage, both in the TFNA group, while the remainder occurred in 31A1-2 fracture patterns ( P = 1.0). After controlling for confounding factors listed above, the TFNA and InterTAN groups were associated with a marginally increased odds of implant breakage compared with the Gamma3 (TFNA vs. Gamma3: OR: 0.04, 95% CI: