Patent ID: 6491726
Filing Date: 2002-12-10
Classification: A61F

Abstract:
A dislocation resistant knee joint prosthesis comprising:a femoral component having an inferior articular bearing surface with medial and lateral convex condyles, a posterior notch extending anteriorly into a posterior face of the femoral component, said notch being defined by medial and lateral cavity sidewalls and an anterior wall extending between said medial and lateral cavity sidewalls, with parallel medial and lateral flanges extending from said medial and lateral cavity sidewalls adjacent the inferior articular bearing surface of the femoral component; 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 inferior articular bearing surface of the femoral component, the concave superior bearing face being configured for noncongruent bearing engagement with the convex condyles during selected ranges of flexion of the knee joint prosthesis, the bearing further having an inferior bearing face in sliding and rotational bearing engagement with the tibial component, a posterior 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 posterior notch in the bearing; and a control arm assembly comprising a control arm slidably engaged in the groove of the bearing, the control arm being pivotally mounted on the tibial component, a post extending in a superior direction from the control arm through the posterior notches of the bearing and the femoral component, the post having medial and lateral cam projections which slidably engage said medial and lateral cavity sidewalls of the femoral component for enhancing valgus-varus stability of the knee joint prosthesis, said medial and lateral cam projections engaging superior surfaces of the flanges of the femoral component for generating posterior translation of the bearing during flexion of the knee joint prosthesis and preventing dislocation.