Detection of Femoral Neck Fractures in Pediatric Patients With Femoral Shaft Fractures.

BACKGROUND: Ipsilateral femoral neck fractures occur in 1% to 9% of adult trauma patients with femoral shaft fractures making dedicated imaging important. This is not as clear in children. Our purpose is to establish the incidence of ipsilateral femoral neck fractures in children with femoral shaft fractures and to provide recommendations regarding diagnostic imaging protocols.

METHODS: A retrospective analysis of medical records was performed for pediatric patients (below 18 y) with femoral shaft fractures seen at our trauma center over a 10-year period. Mechanism of injury, associated injuries, procedures, and follow-up data were collected, and all radiographs reviewed. Exclusion criteria included peri-implant fractures or evidence of pathologic fracture. A similar retrospective analysis was performed in a cohort of adult patients.

RESULTS: Of 267 pediatric patients with femoral shaft fractures, 2 patients (0.7%) had ipsilateral femoral neck fractures. One femoral neck fracture was detected on initial plain radiographs and the other on a pelvic computed tomography (CT) scan. Both of these fractures resulted from high-energy trauma, which accounted for 92 (42%) of pediatric femoral shaft fractures. The cohort of 100 adults aged 18 to 89 years with femoral shaft fractures revealed 6 adult patients (6%) with ipsilateral femoral neck fractures, all from high-energy trauma. High-energy trauma accounted for 85% of the adult femoral shaft fractures, and was more common than in the pediatric population (P<0.005). The difference in incidence of ipsilateral femoral neck fracture between the pediatric (0.7%) and the adult group (6%) was significant (P=0.007). No missed or delayed diagnoses were identified.

CONCLUSIONS: The incidence of associated ipsilateral femoral neck fracture in pediatric patients with femoral shaft fracture is very low (0.7%). Most (58%) pediatric femur fractures are caused by low-energy trauma. We were unable to demonstrate a need for routine CT scanning of the femoral neck in children with femoral shaft fractures. Given the increased risks of radiation exposure with younger and smaller patients, it does not appear that routine CT scanning low-energy pediatric femoral shaft fractures to evaluate for femoral neck fractures is justified unless there is a high level of clinical suspicion.

LEVEL OF EVIDENCE: Level II.