Intramedullary Nailing in Femoral Diaphyseal Fractures: A Retrospective Multicenter Cohort Study.

Intramedullary nails (IMNs) are the most frequent surgical fixation method for femur fractures. Although IMNs provide good healing outcomes and low complication rates, concerns persist regarding potential complications such as malunion, nonunion, and infections. This multicenter retrospective study aims to assess the epidemiology and outcomes of IMNs for diaphyseal femoral fractures. Data from 91 patients who underwent IMN fixation at two Brazilian hospitals between 2020 and 2024 were analyzed, with a mean age of 33.3 years (SD ± 12.7) and 76.9%% of male patients. Traffic accidents were the most common mechanism of trauma (84.61%). The bone healing rate was 96.7% within six months, and 98.9% within one year, with a complication rate of 3.26%, including two cases of pseudoarthrosis, one case of pseudoarthrosis and infection, and two reoperations. There was a significant association between previous external fixation and fracture type (open/closed) (χ(1) = 17.5, p < 0.001). Previous external fixation was also associated with lower consolidation rates six months post-surgery (χ(1) = 9.83, p = 0.031), but not after one year (χ(1) = 8.19, p = 0.11). The retrograde approach was associated with a lower consolidation rate after six months (χ(1) = 6.98, p = 0.027), but no significant association was found after one year (χ(1) = 2.27, p = 0.308). Only one patient with pseudoarthrosis did not consolidate after one year. The outcomes support the efficacy of IMNs in achieving bone consolidation with low complication rates.