[A radiological measurements of growing hip joint in 4,000 normal children].

Roentgenograms of 4,000 hip joints of normal children were analyzed. The indices we used were as follows, the YO-value as the standard of growth (half of the distance between the both Y-cartilages), the CO-value as an index of lateralization (the distance between the center line of the pelvis and the center point of the head of the femur), the EO-value as the index of formation of the acetabulum (the distance between the center line of the pelvis and the tip of the acetabular tegmen), epiphyseal height (A), epiphyseal width (B), the alpha-angle, the CE-angle, the Sharp angle etc. The evaluation method we used consisted basically of comparisons made among values indicating length and by which the pelvis showed nearly proportional growth. The correlation coefficient among the YO-, CO-, and EO-values was extremely good. Accordingly, those indices are considered useful for the prognosis of congenital hip dislocation.