HIP-JOINT CONGRUENCE - EXPERIMENTAL STUDIES

Three-dimensional imaging of hip joint preparations was carried out by means of computed tomography (CT). On the assumption that the head of the femur and acetabulum are incongruent, a special experimental desi gn was used to quantify the extent and direction of the gliding moveme nt of the head and socket. A series of CT images in the supine and pro ne positions was made from hip preparations, and the cartilage was vis ualized by injecting a contrast medium. In all the preparations dorsal movement was noted in the supine position, and ventral movement in th e prone position. Cryomicrotome slices of the hip preparations were us ed to verify the results of our CT scans and the measurements correlat ed with the anatomical examinations. Thus, there is a certain amount o f play in the hip joint - it is not an ideal ball-and-socket joint. Th is knowledge is important for the planing and success of hip adjustmen t surgery.