[Radiologic dislocation value of the dysplastic hip joint in the child].

The discussed index is determined by the comparison of the proportion of localisation of the proximal and of the femur and transverse dimension of the pelvis by x-ray examination. It has been found by radiological measurements of 400 hip joints children in the age of 3-24 months, in whom dysplasia of the hip joint with dislocation was diagnosed. The displacements were divided into 5 grades on the basis of extent of lateral and superior dislocation. The index makes displacement objective, replacing the visual assessment; it allows to compare the displacements on x-ray pictures performed at different ages and in different conditions of x-ray exposition. It has proved to be very useful in diagnosis and analysis of treatment result of large material of congenital dysplasia of the hip with dislocation.