A knee joint prosthesis , comprising: a tibial component having an inferior surface and a superior surface that serves as a bearing surface for a femoral component , the superior surface having a generally concave medial compartment configured to receive and articulate with a medial femoral condyle , the medial compartment having a length extending from an anterior end thereof to a posterior end thereof, and a generally concave lateral compartment configured to receive and articulate with a lateral femoral condyle , the lateral compartment being curved about a medial center and having a length extending from an anterior end thereof to a posterior end thereof, characterized in that (i) the medial compartment has an anteroposterior profile that is characterized by a first, anterior arc (R MT1 ) that is concave and a second, posterior arc (R MT2 ) that is concave, wherein the first and second arcs each have a different radius of curvature, and (ii) the medial compartment has a concave anterior region (R MT1 ) having a first length, and a concave posterior region (R MT2 ) having a second length, wherein the first length is greater than the second length. a tibial component having an inferior surface and a superior surface that serves as a bearing surface for a femoral component , the superior surface having a generally concave medial compartment configured to receive and articulate with a medial femoral condyle , the medial compartment having a length extending from an anterior end thereof to a posterior end thereof, and a generally concave lateral compartment configured to receive and articulate with a lateral femoral condyle , the lateral compartment being curved about a medial center and having a length extending from an anterior end thereof to a posterior end thereof, a generally concave medial compartment configured to receive and articulate with a medial femoral condyle , the medial compartment having a length extending from an anterior end thereof to a posterior end thereof, and a generally concave lateral compartment configured to receive and articulate with a lateral femoral condyle , the lateral compartment being curved about a medial center and having a length extending from an anterior end thereof to a posterior end thereof, characterized in that (i) the medial compartment has an anteroposterior profile that is characterized by a first, anterior arc (R MT1 ) that is concave and a second, posterior arc (R MT2 ) that is concave, wherein the first and second arcs each have a different radius of curvature, and (ii) the medial compartment has a concave anterior region (R MT1 ) having a first length, and a concave posterior region (R MT2 ) having a second length, wherein the first length is greater than the second length. (i) the medial compartment has an anteroposterior profile that is characterized by a first, anterior arc (R MT1 ) that is concave and a second, posterior arc (R MT2 ) that is concave, wherein the first and second arcs each have a different radius of curvature, and (ii) the medial compartment has a concave anterior region (R MT1 ) having a first length, and a concave posterior region (R MT2 ) having a second length, wherein the first length is greater than the second length. <EOS>