A tibial prosthesis assembly including a tibial component and a tibial insert. The tibial component includes an inferior bone engaging surface, a superior surface, and a first retention feature. The tibial insert includes an inferior tibial component engaging surface, a superior bearing surface, and a second retaining feature. The first and the second retaining features cooperate to mate the tibial insert with the tibial component at one of a plurality of fixed rotational orientations relative to the tibial component.
