| 摘要 |
An improved tibial prosthesis is provided for a prosthetic knee wherein the tibial prosthesis includes a mobile bearing member designed to better accommodate a natural range of flex knee motion and force loads applied to the knee joint. The improved tibial prosthesis comprises a tibial component defining a support tray for receiving and supporting a bearing member which in turn defines upwardly presented medial and lateral condylar recesses for respective seated engagement with medial and lateral condyles of a femoral prosthesis. A short lock rim of part-circular shape projects upwardly from the periphery of the tibial support tray, at the medial end thereof, to engage and constrain the bearing member for rotation within the lock rim through a short arcuate path of motion relative to a center axis defined by the geometry of the lock rim, thereby permitting a small degree of anterior-posterior movement of the bearing member lateral end relative to the tibial tray. The range of permissible bearing member displacement can be limited by a stop post projecting upwardly from the tibial tray and received into an elongated guide slot formed in the bearing member. |
