SCFE: Which radiographic view is preferred and shows posterior and medial displacement of the epiphysis?

• A. AP pelvis radiograph
• B. Lateral knee radiograph
• C. Frog-leg lateral pelvis radiograph showing posterior and medial displacement of the epiphysis
• D. Thoracic spine radiograph

Answer: (D)

In slipped capital femoral epiphysis, the femoral head epiphysis slips posteromedially through the growth plate. The frog-leg lateral pelvis radiograph is the view that best demonstrates this posteromedial displacement because the hip is flexed and abducted, placing the proximal femur in profile and allowing the slip to be seen clearly as the epiphysis moves behind and toward the inner aspect of the neck. The AP pelvis can miss or underestimate the slip, especially in early disease, whereas a lateral knee or thoracic spine view does not visualize the hip slip at all. So, use the frog-leg lateral pelvis view to confirm posterior and medial displacement of the epiphysis in SCFE.