Association of femoral head and acetabular fractures on computerized tomography: correlation with the Judet-Letournel classification.

PURPOSE: Tha aims of this study were to identify the incidence of femoral head fractures in the setting of acetabular fractures and to determine the relationship between acetabular fracture pattern, the degree of acetabular fracture displacement, and the incidence of femoral head fractures.

MATERIALS AND METHODS: This is a retrospective cross-sectional study of 274 patients with 300 acetabular fractures diagnosed on pelvic CT. Acetabular fractures were categorized using the Judet-Letournel classification system.

RESULTS: Femoral head fractures were present in 18.0% of acetabular fractures. Fracture patterns with a posterior wall component had a very high (56.3%) incidence of femoral head fracture. Anterior column and anterior column with posterior hemitransverse fractures have a very low (3.4%) incidence of femoral head fracture. Anterior hip dislocation had a 66.7% incidence of femoral head fracture, while posterior dislocation had a 71.9% incidence. Acetabular fractures displaced by more than 5 mm had a 26.9% incidence of femoral head fracture, while acetabular fracture displaced less than 5 mm had only 4.2% incidence of femoral head fracture.

CONCLUSION: Femoral head fractures are a very common associated finding in patients presenting with acetabular fractures. In patients with a posterior wall component of the fracture or associated hip dislocation, a femoral head fracture is more likely than not present. Conversely, in acetabular fractures with less than 5 mm displacement or anterior column fractures without posterior acetabular involvement, femoral head fractures are very unlikely in the absence of a dislocation event.