A medially stabilising knee endoprosthesis for a total knee arthroplasty while retaining or dissecting the posterior cruciate ligament, the medially stabilising knee endoprosthesis comprising: - a femur bearing surface, which is provided on a femur part for alignment in the distal direction, said femur part being designed to be fixed to a distal end of a femur; and - a tibia bearing surface, which is provided on a tibia part for alignment in the proximal direction, said tibia part being designed to be fixed to a proximal end of a tibia, wherein in particular the tibia bearing surface is formed as a proximal surface of an inlay proximally arranged and/or arrangeable on the tibia part, - wherein the femur bearing surface comprises a convex medial femur-condyle bearing surface and a convex lateral femur-condyle bearing surface, - wherein the tibia bearing surface comprises a concave medial bearing shell and a concave lateral bearing shell and is designed for receiving and displaceably slidably bearing the femur bearing surface, without a fixed medial center point of the femur bearing surface, in the medial bearing shell; - wherein the medial bearing shell and the lateral bearing shell form an asymmetric tibia bearing surface with respect to one another; - and the medial femur-condyle bearing surface and the lateral femur-condyle bearing surface form a non-asymmetrical or quasi-symmetrical femur bearing surface with respect to one another, characterized in that - the medial femur-condyle bearing surface and the lateral femur-condyle bearing surface correspond at least in an anterior femur-condyle radius of relevant anterior surface portions. - the asymmetric tibia bearing surface forms an external continuous proximal height contour; - the height contour comprises an anterior height contour portion having at least one anterior height point (H-ant) and a posterior height contour portion having at least one posterior height point (H-post), wherein the anterior height point (H-ant) is proximally raised compared with the posterior height point (H-post) in respect of at least one sagittal plane; and - an antero-medial height contour portion of the anterior height contour portion on the medial bearing shell forms an anterior height point (H-ant), raised mostly proximally, as an antero-medial peak point. - a femur bearing surface, which is provided on a femur part for alignment in the distal direction, said femur part being designed to be fixed to a distal end of a femur; and - a tibia bearing surface, which is provided on a tibia part for alignment in the proximal direction, said tibia part being designed to be fixed to a proximal end of a tibia, wherein in particular the tibia bearing surface is formed as a proximal surface of an inlay proximally arranged and/or arrangeable on the tibia part, - wherein the femur bearing surface comprises a convex medial femur-condyle bearing surface and a convex lateral femur-condyle bearing surface, - wherein the tibia bearing surface comprises a concave medial bearing shell and a concave lateral bearing shell and is designed for receiving and displaceably slidably bearing the femur bearing surface, without a fixed medial center point of the femur bearing surface, in the medial bearing shell; - wherein the medial bearing shell and the lateral bearing shell form an asymmetric tibia bearing surface with respect to one another; - and the medial femur-condyle bearing surface and the lateral femur-condyle bearing surface form a non-asymmetrical or quasi-symmetrical femur bearing surface with respect to one another, characterized in that - the medial femur-condyle bearing surface and the lateral femur-condyle bearing surface correspond at least in an anterior femur-condyle radius of relevant anterior surface portions. - the asymmetric tibia bearing surface forms an external continuous proximal height contour; - the height contour comprises an anterior height contour portion having at least one anterior height point (H-ant) and a posterior height contour portion having at least one posterior height point (H-post), wherein the anterior height point (H-ant) is proximally raised compared with the posterior height point (H-post) in respect of at least one sagittal plane; and - an antero-medial height contour portion of the anterior height contour portion on the medial bearing shell forms an anterior height point (H-ant), raised mostly proximally, as an antero-medial peak point. - wherein the medial bearing shell and the lateral bearing shell form an asymmetric tibia bearing surface with respect to one another; - and the medial femur-condyle bearing surface and the lateral femur-condyle bearing surface form a non-asymmetrical or quasi-symmetrical femur bearing surface with respect to one another, - the medial femur-condyle bearing surface and the lateral femur-condyle bearing surface correspond at least in an anterior femur-condyle radius of relevant anterior surface portions. - the asymmetric tibia bearing surface forms an external continuous proximal height contour; - the height contour comprises an anterior height contour portion having at least one anterior height point (H-ant) and a posterior height contour portion having at least one posterior height point (H-post), wherein the anterior height point (H-ant) is proximally raised compared with the posterior height point (H-post) in respect of at least one sagittal plane; and - an antero-medial height contour portion of the anterior height contour portion on the medial bearing shell forms an anterior height point (H-ant), raised mostly proximally, as an antero-medial peak point.