Patent ID: 8764841

Claim:
A mobile tibial assembly comprising: a monolithic tibial tray configured to be coupled to a surgically-prepared surface of the proximal end of a tibia, the tibial tray having a closed track having an elongated opening defined in an upper surface, the elongated opening having a length extending in an anterior-posterior direction and a width extending in a medial-lateral direction, the length being greater than the width of the elongated opening; and a tibial insert having a bottom surface and a stem extending downwardly from the bottom surface, the stem having a neck extending through the elongated opening and a flange defined at an end of the neck configured to be received in the closed track, the flange having (i) a first dimension greater than the width of the elongated opening of the closed track, (ii) a second dimension less than the first dimension and less than the width of the elongated opening of the closed track and extending transverse to the first dimension, and (iii) a concave bearing surface configured to engage a femoral prosthetic component, the bearing surface having a surface width and a surface length that is greater than the surface width, wherein the tibial insert is engaged with the tibial tray and is rotatable between a plurality of orientations relative to the tibial tray while engaged with the tibial tray, the plurality of orientations including: (i) a first orientation in which the first dimension of the flange and the surface width of the bearing surface are orthogonal to the width of the elongated opening and the second dimension of the flange and the surface length of the bearing surface are parallel to the width of the elongated opening such that the flange is permitted to be received in the closed track, and (ii) a second orientation in which the first dimension of the flange and the surface width of the bearing surface are parallel to the width of the elongated opening such that the flange is retained in the closed track.