Abstract: The present invention is directed to prosthetic knee joints having femoral and tibial components.

Abstract: A knee joint prosthesis includes femoral and tibial components, a bearing and a control arm. The bearing includes an inferior surface in sliding bearing engagement with the tibial component and a superior surface in articular bearing engagement with the femoral component. A notch extends into the posterior end of the bearing and a groove extends anteriorly from the notch in the inferior surface of the bearing. The posterior portions of the femoral component define a cam box having medial and lateral walls and a cam extending therebetween. The control arm is slidably engaged in the groove of the bearing and pivotally engage on the tibial component. The control arm further includes a post that extends into the cam box. The post includes a cam surface that engages the femoral cam to generate roll back of the femoral component on the bearing during flexion.

Abstract: A knee prosthesis and method for use are provided, in which the knee prosthesis provides anterior and posterior stability and controlled femoral roll-back, while also providing rotational kinematics. The femoral component has a pair of convexly shaped condyles which are spaced apart to form an intercondylar notch. Anterior and posterior cams are provided within the notch. The tibial component comprises a platform upon which a tibial bearing is mounted to provide for rotational movement about the tibial axis. The tibial bearing is provided with surfaces to engage the condyles and has an upwardly extending spine which is positioned to engage the anterior and posterior femoral cams. At full extension, the spine engages the anterior femoral cam to provide a 3° hyperextension stop. Between full extension and approximately 50° of flexion, the spine is free to translate between the anterior and posterior femoral cams.

Abstract: A prosthetic replacement knee joint includes a tibial component, a femoral component, a bearing and a control arm. The tibial component has a superior bearing surface and a conical recess extending into the superior bearing surface. The bearing has an inferior surface slidably engaged with the superior surface of the tibial component and formed with a dovetailed groove therein. The bearing also has a concave superior surface. A notch extends into the posterior extreme of the bearing. The femoral component has a pair of convex arcuate condyles in articular bearing engagement with the superior surface of the bearing. The femoral component also includes a posterior notch having a minor medial-lateral width at the inferior surface of the femoral component and a major width at more superior locations on the femoral component. The control arm has a conical bearing rotatable positioned in the conical recess of the tibial component.

Abstract: The invention relates to a (knee) joint for positioning two pivoting parts in such a way that they can pivot within a limited range. According to the invention, a combined turning and sliding movement is produced by means of curved guides (6, 6′, 7, 7′). A cam body (8) connected to one pivoting part, e.g. the lower leg, has two cams (10, 11; 13, 14), preferably on each side. Said cams interact with the curved guides (6, 6′, 7, 7′). The curved guides (6, 6′, 7, 7′) are located in half-shells (3, 4) which are connected to the second pivoting part, e.g. the upper leg. Parts of the inventive knee joint which are subject to wear are relatively easy to replace and movement sequences can also be modified when replacements are made.

Abstract: A knee joint prosthesis includes femoral and tibial components, a bearing and a control arm. The bearing includes an inferior surface in sliding bearing engagement with the tibial component and a superior surface in articular bearing engagement with the femoral component. A notch extends into the posterior end of the bearing and a groove extends anteriorly from the notch in the inferior surface of the bearing. The posterior portions of the femoral component define a cam box having medial and lateral walls and a cam extending therebetween. The control arm is slidably engaged in the groove of the bearing and pivotally engage on the tibial component. The control arm further includes a post that extends into the cam box. The post includes a cam surface that engages the femoral cam to generate roll back of the femoral component on the bearing during flexion. Roll back substantially avoids climb of the femoral component on the bearing during flexion and hence reduces shearing forces on the post.

Abstract: A complete prosthetic of the knee includes a femoral part (6) and a meniscus (3), with said femoral part (6) comprising at least one condyle (3) and a trochlea part, wherein said one or a plurality of condyles each have an external surface, the shape of which complements the respective upper surface of said meniscus (3) in order to obtain a congruence of said surfaces on at least part of the normal flexing range. At least one cavity is implemented in said trochlea such that the femoral part is blocked in its flexion by rotation in the case of negative angles beyond an inferior negative angle limit when the anterior upper edge of the meniscus comes to rest against said cavity.

Abstract: A knee prosthesis and method for use are provided, in which the knee prosthesis provides anterior and posterior stability and controlled femoral roll-back, while also providing rotational kinematics. The femoral component has a pair of convexly shaped condyles which are spaced apart to form an intercondylar notch. Anterior and posterior cams are provided within the notch. The tibial component comprises a platform upon which a tibial bearing is mounted to provide for rotational movement about the tibial axis. The tibial bearing is provided with surfaces to engage the condyles and has an upwardly extending spine which is positioned to engage the anterior and posterior femoral cams. The posterior surface of the upwardly extending spine is arranged coincident with the tibial axis. At full extension, the spine engages the anterior femoral cam to provide a 3° hyperextension stop.

Abstract: An artificial knee joint comprising: a femoral component comprising a femoral condylar portion made of a medial condylar section and a lateral condylar section which extend in an anteroposterior direction of the knee joint and have convex exterior surfaces, and a tibial component comprising a tibial condylar portion made of a medial condylar section and a lateral condylar section which extend in an anteroposterior direction of the knee joint and have concave interior surfaces so as to slidably receive the medial and lateral condylar sections of the fermoral condylar portion therein; and a space between the respective medial and lateral condylar sections of the femoral condylar portion and of the tibial condylar portion being formed so as to be gradually narrower toward the rear side of the knee joint, thus forming a “rear-in” configuration.

Abstract: An artificial knee joint comprising: a femoral component comprising a femoral condylar portion made of a medial condylar section and a lateral condylar section which extend in an anteroposterior direction of the knee joint and have convex exterior surfaces, and a tibial component comprising a tibial condylar portion made of a medial condylar section and a lateral condylar section which extend in an anteroposterior direction of the knee joint and have concave interior surfaces so as to slidably receive the medial and lateral condylar sections of the femoral condylar portion therein; and a space between the respective medial and lateral condylar sections of the femoral condylar portion and of the tibial condylar portion being formed so as to be gradually narrower toward the rear side of the knee joint, thus forming a “rear-in” configuration.

Abstract: A knee prosthesis which more accurately reproduces the rollback of natural knee movement and, thus, reduces wear on the tibial component. The knee prosthesis includes a femoral component with two cams, the first located between the posterior condylar sections and the second located towards the anterior end of the condylar sections with a slot surface therebetween. The tibial component includes a spine which engages each cam as it rotates along the femoral component and the slot surface during flexion and extension.

Abstract: A knee joint prosthesis includes femoral and tibial components, a bearing and a control arm. The bearing includes an inferior surface in sliding bearing engagement with the tibial component and a superior surface in articular bearing engagement with the femoral component. A notch extends into the posterior end of the bearing and a groove extends anteriorly from the notch in the inferior surface of the bearing. The posterior portions of the femoral component define a cam box having medial and lateral walls and a cam extending therebetween. The control arm is slidably engaged in the groove of the bearing and pivotally engage on the tibial component. The control arm further includes a post that extends into the cam box. The post includes a cam surface that engages the femoral cam to generate roll back of the femoral component on the bearing during flexion. Roll back substantially avoids climb of the femoral component on the bearing during flexion and hence reduces shearing forces on the post.

Abstract: A knee endoprosthesis comprising: a tibial part comprising a tibial rod bearing a tibial plate, a first tibial insert (11) disposed on the tibial plate, a femoral part comprising a femoral rod bearing two condyles (8, 9) each having a first sliding surface co-operating and congruent with a respective second sliding surface formed on the first tibial insert (11), wherein the tibial part is coupled to the femoral part so that the femur can bend relative to the tibia from a position (&agr;≈0) where the knee is extended to a position (&agr;max) where the knee is bent and vice versa. A progressive locking element is provided for limiting the lateral rotation and proper rotation of the condyles (8, 9) relative to the tibial plate, starting from a knee-bending angle &agr;0 determined in advance and up to a zero angle, the amplitude of proper rotation, when the angle &agr;0 is decreased, varying down to zero amplitude (complete blocking) at zero angle (unbent knee).

Abstract: A condylar total knee replacement prosthesis is disclosed having interacting guide surfaces for control of anterior-posterior displacement. The prosthesis comprises a femoral component (1) having a pair of condylar surfaces (2,3), a tibial component having a tibial platform (4) and a bearing component interposed between the femoral and tibial components. A femoral guide surface (5) is located between the condyles and engages with a tibial guide surface (8) to cause the femoral component to displace posteriorly during flexing movements and displace anteriorly during extending movements. The femoral guide surface is offset posteriorly and downwardly from the center of major curvature of the femoral condyles.

Abstract: The prosthetic knee joint is provided for resisting valgus-varus movements. The joint includes a femoral component having a superior bone engaging surface and an inferior bearing surface. A posterior notch extends anteriorly into the posterior end of the femoral component. The prosthetic knee joint further includes a tibial component having an inferior bone engaging surface and a superior bearing surface. A plastic bearing is disposed between the femoral and tibial components. An inferior surface of the plastic bearing is in bearing engagement with the superior surface of the tibial component. A superior bearing surface of the plastic bearing is in articular bearing engagement with the bearing surface of the femoral component. The bearing includes a post projecting proximally from the superior surface. The post is slidably received in the posterior notch of the femoral component and resists valgus-varus moments imposed upon the joint.

Abstract: A complete knee joint prosthesis having prosthetic condyles as a part of the femoral element, wherein the prosthetic condyles have a curvature in the shape of a circular arc in their rear part, and the femoral element has, between these prosthetic condyles, a convex cylindrical wall with an axis that coincides with the axis of the circle in which the rear parts of the prosthetic condyles lie. Glenoid cavities of an intermediate plate have corresponding rear parts in the shape of a circular arc and a corresponding concave bearing surface in the shape of a circular arc for pivotably receiving the prosthetic condyles. The tibial element has a cylindrical pin and the intermediate plate comprises a cavity which receives this pin to provide the possibility of multidirectional movement of the prosthetic knee joint.

Abstract: Femoral component for a knee prosthesis adapted to cooperate with an insert attached to a tibial plateau anchored at the upper end of a tibia. The femoral component is adapted to be anchored at a lower end of a femur, the femoral component including a first lateral condyle, a second lateral condyle, and an intercondylar space disposed between the first and second condyles for receiving a third removably fixed condyle. The third condyle is removable from the intercondyle space while the femoral component remains moveably engaged with the tibial plateau. The third condyle is adapted to provide posterior stabilization of the prosthesis during flexion between the tibia and the femur when the posterior cruciate ligament is no longer able to substantially perform its function.