RADIOLOGICAL STUDY OF SEVERE PROXIMAL FEMORAL FOCAL DEFICIENCY

Twenty-two hips in 20 children, all classified as Amstutz type 3 proxi mal femoral focal deficiency, were studied by means of plain radiograp hs, arthrograms (30), ultrasound examination (six), computed tomograph y (CT) scans (including five arthrographies with CT) and magnetic reso nance imaging (MRI: nine). These investigations demonstrated that in 1 5 hips, the superior femoral epiphysis was mobile in the acetabulum, w hereas in six others, it was fixed and fused to the acetabulum. In one case, it was impossible to prove whether the epiphysis was mobile or fixed. The key radiologic and other image features that allow these co nclusions to be drawn are described. The therapeutic implications are important, as it would be pointless or harmful to attempt to consolida te the femoral neck or put it into valgus when the epiphysis is sponta neously fixed to the acetabulum.