CONSTRAINED CONDYLAR KNEE DEVICE

A knee joint prosthesis includes a femoral component having a first condylar bearing surface and a second condylar bearing surface. Each of the first and second condylar bearing surfaces has a cross-section in a coronal plane that exhibits at least two different radii. The prosthesis also includes a tibial component and an insert component associated with the tibial component. The insert component has bearing surfaces that are complementary to the first and second condylar bearing surfaces, wherein a contact point is established between the bearing surfaces of the insert component and the first and second condylar bearing surface. In accordance with the present invention and as a result of the above construction, varus and valgus rotation of the femoral component relative to the insert component causes the contact point to move laterally as the knee is rotated. By shifting the contact pointy laterally/outwardly, the knee stability (i.e., stiffness) gradually increased.