Patent ID: 8540776

Claim:
A total knee prosthesis ( 1 ) including: a femoral implant ( 2 ) including two condyles ( 8 , 9 ) delimiting between them an intercondylar notch ( 10 ), an external profile ( 101 ) of which is convex in a sagittal plane and concave in a frontal plane and is connected in all the planes without any discontinuity with an external profile ( 81 , 91 ) of the condyles, a tibial implant ( 3 ) including at least one supporting plate ( 21 ) intended to rest through a lower surface ( 212 ) thereof on the end of the tibia, if necessary after resection, and an articular insert ( 4 ) interposed between the tibial implant and the femoral implant and capable of co-operating with them through lower ( 44 ) and upper ( 41 ) contact surfaces with shapes respectively mating an upper surface ( 211 ) of the supporting plate of the tibial implant and the external profiles ( 81 , 91 , 101 ) of the condyles and the intercondylar notch of the femoral implant, the upper surface ( 41 ) of the articular insert including two glenoid cavities ( 18 , 19 ) of the external profile ( 181 , 191 ) congruent with the external profile ( 81 , 91 ) of the condyles ( 8 , 9 ) of the femoral implant and connected together through an interglenoidal connecting surface ( 20 ), with a shape congruent with the one of the intercondylar notch ( 10 ), and of an external profile ( 201 ) convex in a frontal plane and concave in a sagittal plane and connecting in all the planes without any discontinuity with the external profile ( 181 , 191 ) of the glenoid cavities, characterized in that the intercondylar notch ( 10 ) and the interglenoidal connecting surface ( 20 ) have congruent contact surfaces ( 101 , 201 ), the contact surface ( 101 ) of the intercondylar notch ( 10 ) having a hyperbolic paraboloid shape and the contact surface ( 201 ) of the interglenoidal connecting surface ( 20 ) having a hyperbolic paraboloid shape mating the one defined by said intercondylar notch 10 and in that the contact surface ( 181 , 191 ) of the glenoid cavities ( 18 , 19 ) has in a horizontal section an ovoid shape and an inclined point (P) is located posteriorly to a line of larger width (L) of the insert, the concave external profile ( 201 ) in a sagittal plane of the connecting surface ( 20 ) defining a first high point at an anterior portion ( 42 ) and a second high point at a posterior portion ( 43 ), the first high point is higher than the second high point so that a straight line (Δ) passing through the first high point and the second high point, has a slope from the anterior portion ( 42 ) towards the posterior portion ( 43 ) of the insert and in that this straight line forms an angle α comprised between 1° and 15°.