[Value of computed tomography in congenital hip dysplasia and hip luxation]

A lot of methods of measurement have been developed to record precisely the degrees of luxation and the deviations from the normal form in the hip joints of the child and adult. The orthopaedic surgeon needs those data for a preoperative "coxometric program" before performing acetabuloplastic operations with osteotomy, osteotomy of the pelvis and combined operations. Computed tomography yields a series of informations and of possibilities of measurements which can determine the operative procedure in particular. These informations concern among other things the dimensions of the dysplasia of the acetabulum in the horizontal plane with the extension of the posterior lip and the angle of the acetabular opening, furthermore the physiological or pathological congruence between the head of the femur and the acetabulum, the angle of antetorsion of the neck of the femur and, in the small infant, the direct noninvasive imaging of the tube of the capsule with imaging of possible obstacles to reposition.