Patent ID: 8715362

Claim:
A prosthesis, comprising: a prosthesis stem, including: a first stem component sized and configured to be installed in an intramedullary path, the first stem component including a first external feature including at least two flats disposed at a first internally threaded female end, the first internally threaded female end disposed opposite a domed end of the first stem component; and a second stem component sized and configured to be installed in the intramedullary path, the second stem component including a first internal feature including at least two flats disposed at a second internally threaded female end that is disposed opposite a first externally threaded male end, a second external feature including at least two flats is disposed at the second internally threaded female end; a tibial tray configured to be attached to the prosthesis stem, the tibial tray defining a channel extending in an anterior-posterior direction between a pair of opposed rails, a notch is defined in the tibial tray between the pair of opposed rails; and an artificial joint surface sized and configured to be received within the channel of the tibial tray, an upper surface of the artificial joint surface including a decent that is sized and configured to be received with the notch, wherein the first external feature is configured to be engaged by a tool to prevent rotation of the first stem component when the second stem component is rotated in response to being driven by a driving tool that engages the first internal feature to connect the first and second stem components to each other in situ.