Abstract: A system for surgically stabilizing the spine is useful for preventing shifting of the joining bars on the vertebral units of fixation. For this purpose, the joining bars are provided at predetermined intervals with anti-shifting spherical bosses having a greater diameter than each bar. Thus the anti-shifting unit is dumbbell-shaped and has a length required for the morphological features of the spine.

Abstract: An artificial hip joint between a femur and a pelvis having increased rotational clearance on an internal side of the joint, including an acetabular cup for anchoring to the pelvis. The hip joint includes a femoral prosthesis having an elongated stem for anchoring to the femur with an upper end. A collar extends outwardly from the upper end and terminates in an end part opposite the upper end of the stem. A head portion is supported on the end part and pivotally mounted within the acetabular cup. The head and the end part have a common central axis. The collar includes a surface on the internal side that contacts the acetabular cup. The surface is offset from the common central axis in a direction away from the internal side so that the acetabular cup has increased rotational clearance on the interior side.