A moveable implant may be provided between the distal end portion of a femur and a proximal end portion of a tibia. The implant may be freely moveable relative to both the femur and the tibia. Embodiments may be configured to fit the surfaces on the distal end portion and proximal end portion of the femur and tibia. As a result of imaging a portion of the patient, the actual configurations of the existing surfaces on the femur and tibia can be accommodated.
