A prosthetic total knee replacement system comprises a distal femoral implant component, a tibial tray implant component and a mobile bearing tibial tray insert. The mobile bearing tibial tray insert is rotatably mountable on the tibial tray for articulation with the distal femoral implant component. The mobile bearing tibial tray insert rotates with respect to the tibial tray around a substantially vertical first rotational axis offset laterally from the medial-lateral centerline of the mobile bearing tibial tray insert and the distal femoral implant component rotates with respect to the tibial tray insert about a substantially vertical second rotational axis offset medially from the first rotational axis.