Patent ID: 8147558

Claim:
A mobile tibial assembly comprising: a tibial tray configured to be coupled to a surgically-prepared surface of the proximal end of a tibia; a unicompartmental tibial insert having an upper bearing surface configured to contact a femoral condyle and a bottom surface, the bottom surface having a first track defined therein extending in a generally medial-lateral direction; and a platform separate from the tibial tray and the unicompartmental tibial insert, the platform is configured to be coupled to the tibial tray and the unicompartmental tibial insert; wherein: (i) a first portion of the platform is configured to be inserted into the first track of the unicompartmental tibial insert such that the first portion of the platform is configured to freely slide along the first track of the unicompartmental tibial insert and the unicompartmental tibial insert is constrained so as to slide relative to the platform in only the generally medial-lateral direction when the unicompartmental tibial insert is coupled to the platform, (ii) the tibial tray includes an upper surface and a second track defined therein extending in a generally anterior-posterior direction, and (iii) a second portion of the platform is configured to be inserted into the second track of the tibial tray such that the second portion of the platform is configured to freely slide along the second track of the tibial tray and the platform is constrained so as to only slide relative to the tibial tray in only the generally anterior-posterior direction when the platform is coupled to the tibial tray.