The present invention relates to a knee joint prosthesis having a tibial component and a femoral component. The tibial component includes a fixation portion fixed to an upper end of a prepared tibia and a ceramic bearing portion presenting articulation surface(s). The femoral component is fixed to a lower end of a prepared femur and comprises a ceramic body portion presenting articulation surface(s). The respective articulation surfaces of the tibial and femoral components are configured for essentially congruent engagement over a full range of movement of the prosthesis, and the bearing portion of the tibial component is adapted for movement relative to the fixation portion. Also disclosed is an apparatus and a method for finishing articulation surfaces of ceramic components of a knee joint prosthesis, including the steps of combining the ceramic bearing portion and the ceramic body portion, and imparting relative movement to the bearing portion and/or the body portion.