FEMORAL-HEAD SHAPE IN LEGG-CALVE-PERTHES DISEASE CORRELATION BETWEEN CONVENTIONAL RADIOGRAPHY, ARTHROGRAPHY AND MR-IMAGING

Twenty-three children with Legg-Calve-Perthes disease were examined to determine the femoral head shape. We evaluated and correlated convent ional radiography, arthrography and MR imaging. In the a.p. view, meas urements were obtained from the center of the femoral head along the b ony or cartilaginous outline at 30 degrees intervals. Maximum flatteni ng of the cartilaginous outline appeared laterally, 60 degrees from th e center of the baseline of the epiphyseal index and the caput index. Maximum flattening of the bony outline was found at 75 degrees. Arthro graphy and MR imaging gave the same information about the shape of the femoral head cartilage. The bony femoral head shape on conventional r adiographs in the a.p. view did not reflect the cartilage shape obtain ed by MR and arthrography.