Characteristics of Femoral Shaft Fractures That Predict Ipsilateral Femoral Neck Fractures

This study aims to characterize radiographic features and fracture characteristics in femoral shaft fractures with associated femoral neck fractures, with the goal of establishing predictive indicators for the presence of ipsilateral femoral neck fractures (IFNFs).

A retrospective cohort was collected from the electronic medical record of three level I trauma centers over a 5-year period (2017 to 2022) by current procedural terminology (CPT) codes. Current CPT codes for combined femoral shaft and IFNFs were identified to generate our study group. CPT codes for isolated femur fractures were identified to generate a control group.

One hundred forty patients comprised our IFNF cohort, and 280 comprised the control cohort. On univariate, there were significant differences in mechanism of injury (P < 0.001), Orthopedic Trauma Association (OTA)/Arbeitsgemeinshaft fur Osteosynthesefragen (AO) classification (P = 0.002), and fracture location (P < 0.001) between cohorts. On multivariate, motor vehicle crashes were more commonly associated with IFNFs compared with other mechanism of injuries. OTA/AO 32A fractures were more commonly associated with IFNFs when compared with OTA/AO 32B fractures (adjusted odds ratio = 0.36, P < 0.001). Fractures through the isthmus were significantly more commonly associated with IFNFs than fractures more proximal (adjusted odds ratio = 2.52, P = 0.011).

Detecting IFNFs in femoral shaft fractures is challenging. Motor vehicle crashes and motorcycle collisions, OTA/AO type 32A fractures, and isthmus fractures are predictive of IFNFs.