Value of magnetic resonance imaging in early assessment of proximal femoral focal deficiency (PFFD).

Proximal femoral focal deficiency (PFFD) is a developmental defect of the proximal femur and acetabulum. PFFD includes a spectrum of findings ranging from mild femoral shortening with varus deformity to complete absence of both the acetabulum and the proximal femur. Most attempts to classify the severity of the abnormality are based on the radiographic findings. The most commonly used system is that of Aitken. This classification scheme is based upon the presence and location of the femoral head and neck on conventional radiography and provides an assessment of future limb function and plan treatment. Since this scheme however relies on conventional radiography for classification, it is difficult to classify a child until skeletal maturity which is often delayed in children with PFFD. Nevertheless, the earlier patients can be treated, the earlier normal growth can start. This case report illustrates the value of Magnetic Resonance Imaging (MRI) in addition to the standard radiographs, for early and more accurate assessment of the articular cartilaginous anatomy and soft tissue prior to ossification of the femoral capital epiphysis. As a consequence, the patient could be treated earlier to benefit treatment outcome.