A tibial prosthesis has tibial articular surfaces including a medial articular surface in a medial compartment and a lateral articular surface in a lateral compartment. The medial articular surface follows a first arcuate track having a first radius of curvature and a first posterior segment extending along a posterior aspect of the medial compartment to a first superior-interior location. The lateral articular surface follows a second arcuate track having a second radius of curvature and a second posterior segment extending along a posterior aspect of the lateral compartment to a second superior-inferior location. The second posterior segment has a slope extending in an inferior direction along the posterior aspect of the lateral compartment such that the second superior-inferior location is spaced a predetermined distance in an inferior direction from the first superior-inferior location.