1. A tibial prosthesis, comprising: a tibial component for replacing at least part of a proximal portion of a tibia, the tibial component including a concave articulation surface with a convex articulation surface disposed at a posterior end of the concave articulation surface, wherein a proximal most portion of the convex articulation surface is configured to articulate against an articulation surface of at least one of a femoral condyle of a femur and a femoral component on a distal end of the femur.