Recess-ramp knee joint prosthesis

A prosthetic knee joint comprising:

• a single piece tibial component comprising a concave lateral dished surface defining a first arc projected onto a sagittal plane and a concave medial dished surface, comprising an external rotation axis and anteriorly elevated with respect to said lateral dished surface, said concave medial dished surface defining a second arc projected onto the sagittal plane wherein said first arc has a greater radius then said second arc, and posterior portions of said concave lateral dished surface and said concave medial dished surface each defined by single arcs of constant radius projected on a frontal plane, said single piece tibial component further comprising a protrusion located between said lateral dished surface and said medial dished surface, anterior portion of said protrusion defining an anterior ramp and posterior portion of said protrusion defining a posterior ramp;
• a single piece femoral component comprising lateral and medial condylar shaped surfaces, an anterior femoral groove, and a cupola located between said lateral and medial condylar surfaces, said cupola being a continuation of said femoral groove;
• said lateral condylar shaped surface in sliding contact with said lateral dished surface and operatively configured to posteriorly displace a first distance, with respect to said lateral dished surface, in response to increasing flexure, said medial condylar shaped surface is in sliding contact with said medial dished surface and operatively configured to displace a second distance lesser than said first distance, with respect to said medial dished surface, in response to increasing flexure, wherein said displacements result in rotation of said femoral component with respect to said tibial component about said external rotation axis.