A tibial component ( 10 ), suitable for use in an orthopedic prosthesis, which prosthesis having a femoral component and a spacer bearing ( 70 ). The tibial component includes a planar tibial plate ( 15 ) having an upper bearing surface ( 30 ) and a bone connecting surface ( 20 ). The tibial plate is adapted to interchangeably in situ receive anteriorly-loaded spacer bearings for either mobile- or fixed-bearing prosthetic assemblies. The tibial plate further having at least one anteriorly located spacer bearing attachment means for removably securing the spacer bearing to the tibial plate. The interchangeability of the spacer bearing between mobile and fixed assemblies is immediate or subsequent to a revision procedure, without disturbing bone connecting surfaces of the tibial component.
