Total knee joint prosthesis

Claim 1

Complete knee joint prosthesis intended to be implanted with ablation of the posterior cruciate ligament, of the type comprising an element which is anchored in the end of the femur and reproduces the femoral condyles, an element which is anchored in the end of the tibia and has an essentially plane upper wall perpendicular to the longitudinal axis of the tibia, and an intermediate plate which provides for the sliding of these two elements in relation to one another, this plate being capable of pivoting in relation to the tibial element, which prosthesis is characterized in that , in combination: the prosthetic condyles (5) of the femoral element (1) have a curvature in the shape of a circular arc in their rear part (5a), and the femoral element (1) has, between these condyles (5), a convex cylindrical wall (9) which has an axis which coincides with the axis of the circle in which the rear parts (5a) of the condyles (5) lie; the glenoid cavities (25) of the intermediate plate (3) have rear parts (25a) in the shape of a circular arc which have essentially the same radius, play excepted, as the rear parts (5a) of the condyles (5) and an axis which coincides with that of the circle in which these same rear parts (5a) lie, while the intermediate plate (3) comprises a central projecting rib (30) in which a concave bearing surface (31) in the shape of a circular arc is arranged, which has essentially the same radius, play excepted, as the convex cylindrical wall (9) of the femoral element (1) and has an axis which coincides with that of this wall (9), and the intermediate plate (3) or the tibial element (2) has a cylindrical pin (20) forming a pivot, while the tibial element (2) or, respectively, the intermediate plate (3) comprises a cavity (35) of a section which is greater than the cross section of this pin (20), this cavity (35) being intended to receive this pin (20) with the possibility of multidirectional movement.