A knee prosthetic system includes a femoral component, a fixed tibial bearingcomponent, a mobile tibial bearing component and an integrated or common tibialbase component. The same tibial base component can be used with either the fixedtibial bearing component or the mobile tibial bearing component. The fixed bearingcomponent and tibial base component have mating anti-rotation features. Oneembodiment of the mobile bearing component does not engage the anti-rotationfeature of the tibial base component. Another embodiment engages the anti-rotationfeature to allow for limited rotation.
