Comminuted Transverse Femoral Shaft Fractures Are at Risk for Nonunion.

Background: The purpose of this study was to investigate the effect of the main fragment fracture type (oblique or transverse) on the union rate of femoral shaft fractures.

Methods: Patients who underwent surgical treatment with an antegrade intramedullary nail for femoral shaft fracture (Arbeitsgemeinschaft für Osteosynthesefragen / Orthopaedic Trauma Association; AO/OTA type 32 type B or C) between January 2009 and March 2021 were included in this study. Patients with oblique fractures of the two main fragments on radiographs immediately after surgery were classified into the oblique fracture group. Patients with at least one of the two main fractures being transverse fractures were classified into the transverse fracture group. We investigated age, sex, height, weight, body mass index (BMI), AO/OTA classification, time from fracture to surgery, intramedullary nail length and diameter, number of interlocking screws, and bone union rate.

Results: A total of 55 fractures were included. The mean age was 34.4 ± 16.7 (range, 16-77) years. There were 41 fractures classified into the oblique fracture group and 14 fractures classified into the transverse fracture group. There was a significantly higher proportion of men in the transverse fracture group. Patients in the transverse fracture group were significantly younger and taller. Only 1 of 41 (2.4%) patients in the oblique group experienced nonunion, while 3 of 14 (21.4%) patients in the transverse group experienced nonunion (p = 0.030).

Conclusion: Comminuted femoral shaft fractures with transverse fracture components are more prone to nonunion.