Closed reduction and intramedullary nailing of atypical femur fractures results in high rates of fracture union.

Abstract

To evaluate outcomes of a series of consecutive, atypical femur fractures (AFFs) treated exclusively with closed reduction and reamed, statically locked intramedullary nailing. Design: Retrospective review. Single North American Level I trauma center. Patient Selection Criteria: All skeletally mature patients treated between 2012 and 2024 with closed reduction and reamed, statically locked IMN of a complete AFFs (OTA/AO 32) with > 6 months follow-up were eligible. Radiographic inclusion required fractures distal to the lesser trochanter and proximal to the supracondylar flare that met ≥4 of 5 American Society for Bone and Mineral Research (ASBMR) major criteria Outcome Measures and Comparisons: Primary outcome was radiographic and clinical union. Secondary measures included time to union, alignment quality, implant failure, and the relationship of neck-shaft angle (NSA) restoration with union. There was a total of 52 AFFs with a mean age of 68 years (52-89 years). Overall, 46 (88%) patients were female and 6 (12%) were male. The mean BMI was 25.6 ± 4.51 kg/m² and 52 (100%) patients reported bisphosphonate use. The mean follow-up was 21 months (range, 6-102). Thirty-nine (75%) were subtrochanteric and 13 (25%) were diaphyseal femur fractures. Overall, fracture union occurred in 49 AFFs (94%) at a mean of 6 months (range, 3-14). Three fractures (6%) progressed to nonunion. Notably, 7 AFFs were incompletely healed at 6 months, but 6 of 7 united by 12 months. Reduction quality was excellent in 98% of cases. Restoration of native NSA was significantly associated with union; nonunion cases demonstrated greater deviation from the contralateral NSA (p = 0.034). Implant-related variables (nail type, diameter, interlocking configuration) were not associated with union. Complications were limited to two cases of broken distal interlocking screws and one superficial surgical site infection. Treatment of atypical femur fractures with solely closed reduction and reamed, statically locked intramedullary nailing provides reliable healing, with a 94% union rate.