Mobile Bearing

In mobile-bearing TKA, the polyethylene insert can move, and the tibial component is not fixed. The articular surface of the polyethylene insert was designed to increase the contact area and reduce wear, and the tibial tray surface was designed to move and rotate backward to reduce the shear force and prevent loosening. Mobile-bearing is useful for preventing mismatches between the femoral and tibial components, and tibial coverage may be prioritized. Many kinematic evaluations after mobile-bearing TKA have shown that the kinematics in normal knees have not been obtained. The theoretical usefulness of mobile bearings including range of motion has not been demonstrated in basic research or clinical studies.