One embodiment of the present invention relates to a knee prosthesis system with at least a first tibial portion element (a tibial insert or a tibial insert trial) and a second tibial portion element (a tibial insert or a tibial insert trial), wherein each of the first tibial portion element and the second tibial portion element has a different slope. Another embodiment of the present invention relates to a method of implanting a knee prosthesis, wherein the method utilizes at least a first tibial portion element (a tibial insert or a tibial insert trial) and a second tibial portion element (a tibial insert or a tibial insert trial), wherein each of the first tibial portion element and the second tibial portion element has a different slope.