Posterior stabilized knee replacement with bearing translation for knees with retained collateral ligaments
First Claim
1. A knee joint prosthesis comprising:
- a femoral component having a superior surface for mounting to a femur, an inferior articular bearing surface with medial and lateral convex condyles, a cam box extending between the superior and inferior surfaces in a posterior portion of said femoral component, said cam box comprising medial and lateral walls;
a tibial component;
a bearing disposed between the femoral and tibial components, the bearing having a concave superior bearing face in articular bearing engagement with the convex condyles of the femoral component, the bearing further having an inferior bearing face in sliding and rotational bearing engagement with the tibial component, a notch extending anteriorly into a posterior face of the bearing and a groove formed in the inferior bearing face of the bearing and extending anteriorly from the notch; and
a control arm assembly comprising a control arm slidably engaged in the groove of the bearing for permitting movement of the bearing along the control arm, pivotal connection means extending from the control arm for permitting pivotal movement of the control arm relative to the tibial component and a post extending superiorly from the control arm, the post being slidably engaged in the notch of the bearing and disposed in the cam box of the femoral component, the post having medial and lateral surfaces tapered away from one another at locations further from the control arm for increasing contact area with the medial and lateral walls of the cam box in response to valgus-varus moments
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Accused Products
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.
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Citations
15 Claims
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1. A knee joint prosthesis comprising:
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a femoral component having a superior surface for mounting to a femur, an inferior articular bearing surface with medial and lateral convex condyles, a cam box extending between the superior and inferior surfaces in a posterior portion of said femoral component, said cam box comprising medial and lateral walls;
a tibial component;
a bearing disposed between the femoral and tibial components, the bearing having a concave superior bearing face in articular bearing engagement with the convex condyles of the femoral component, the bearing further having an inferior bearing face in sliding and rotational bearing engagement with the tibial component, a notch extending anteriorly into a posterior face of the bearing and a groove formed in the inferior bearing face of the bearing and extending anteriorly from the notch; and
a control arm assembly comprising a control arm slidably engaged in the groove of the bearing for permitting movement of the bearing along the control arm, pivotal connection means extending from the control arm for permitting pivotal movement of the control arm relative to the tibial component and a post extending superiorly from the control arm, the post being slidably engaged in the notch of the bearing and disposed in the cam box of the femoral component, the post having medial and lateral surfaces tapered away from one another at locations further from the control arm for increasing contact area with the medial and lateral walls of the cam box in response to valgus-varus moments - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification