Knee replacement system and method for enabling natural knee movement

Abstract

A knee replacement system, and a method for supplying and implanting a knee replacement system, for enabling natural knee movement in a leg in a patient, including: a medial femoral component having a medial femoral articulating surface with a sagittal plane profile including four medial femoral arcuate portions scaled by a first femoral scaling factor; a lateral femoral component having a lateral femoral articulating surface with a sagittal plane profile including four lateral femoral arcuate portions sealed by a second femoral scaling factor; a medial tibial component having a medial tibial articulating surface that articulates with the medial femoral articulating surface and includes a first raised medial edge that increases in width in an anterior direction; and a lateral tibial component having a lateral tibial articulating surface that articulates with the lateral femoral articulating surface and includes a second raised medial edge that increases in width in the anterior direction.

1 . (canceled) 
     
     
         2 . A knee replacement system for enabling natural knee movement in a leg with a femur having medial and lateral condyles and a tibia having medial and lateral tibial plateaus in a patient, the system comprising:
 a femoral component including at least one of:
 a medial femoral portion having a medial femoral articulating surface, wherein the medial femoral articulating surface has a medial femoral sagittal plane profile including at least four medial radii of curvature, each of the four medial radii of curvature are sized relative to one another by a first femoral scaling factor that comprises a measure of the offset from a posterior edge of the medial condyle in the medial femoral sagittal plane to a medial point of initial articular contact between the medial femoral portion and a medial tibial portion of a tibial component; and 
 a lateral femoral portion having a lateral femoral articulating surface, wherein the lateral femoral articulating surface has a lateral femoral sagittal plane profile including at least four lateral radii of curvature, each of the four lateral radii of curvature are sized relative to one another by a second femoral scaling factor that comprises a measure of the offset from a posterior edge of the lateral condyle in the lateral femoral sagittal plane to a lateral point of initial articular contact between the lateral femoral portion and a lateral tibial portion of the tibial component. 
   
     
     
         3 . The system of  claim 2 , wherein the at least four medial radii of curvature comprise a first superior radius of curvature, a first posterior radius of curvature, a first distal radius of curvature, and a first anterior femoral radius of curvature, and wherein the first superior radius of curvature remains a same length for a first superior arcuate portion of the medial femoral articulating surface, the first posterior radius of curvature remains a same length for a first posterior arcuate portion of the medial femoral articulating surface, the first distal radius of curvature remains a same length for a first distal arcuate portion of the medial femoral articulating surface, and first anterior radius of curvature remains a same length for a first anterior arcuate portion of the medial femoral articulating surface. 
     
     
         4 . The system of  claim 3 , wherein the first distal femoral arcuate portion sweeps a greater number of degrees than each of the first posterior femoral arcuate portion and the first anterior femoral arcuate portion. 
     
     
         5 . The system of  claim 3 , wherein the first distal femoral radius of curvature is longer than each of the first posterior radius of curvature and the first anterior femoral radius of curvature. 
     
     
         6 . The system of  claim 3 , wherein the first superior, first posterior, first distal, and first anterior femoral arcuate portions have superior, posterior, distal and anterior femoral arc centers, respectively; wherein the superior, posterior, distal, and anterior femoral arc centers are distinct points in the medial femoral sagittal plane. 
     
     
         7 . The system of  claim 2 , wherein relative lengths of the four medial radii of curvature are maintained so as to be constant with respect to one another over all sizes of the medial femoral component. 
     
     
         8 . The system of  claim 3 , wherein the at least four lateral radii comprise a second superior radius of curvature, a second posterior radius of curvature, a second distal radius of curvature, and a second anterior femoral radius of curvature, and wherein the second superior radius of curvature remains a same length for a second superior arcuate portion of the lateral femoral articulating surface, the second posterior radius of curvature remains a same length for a second posterior arcuate portion of the lateral femoral articulating surface, the second distal radius of curvature remains a same length for a second distal arcuate portion of the lateral femoral articulating surface, and second anterior radius of curvature remains a same length for a second anterior arcuate portion of the lateral femoral articulating surface. 
     
     
         9 . The system of  claim 8 , wherein the first distal femoral arcuate portion sweeps a greater number of degrees than the second distal femoral arcuate portion. 
     
     
         10 . The system of  claim 8 , wherein the second distal femoral radius of curvature is longer than the first distal femoral radius of curvature. 
     
     
         11 . The system of  claim 2 , wherein the tibial component includes at least one of:
 the medial tibial portion, configured to be implantable on the medial tibial plateau and having a medial tibial articulating surface that articulates with the medial femoral articulating surface, wherein the medial tibial articulating surface includes a first plateau and a first raised medial edge that increases in width in an anterior direction and curves distally to the first plateau; and   the lateral tibial portion, configured to be implantable on the lateral tibial plateau and having a lateral tibial articulating surface that articulates with the lateral femoral articulating surface, wherein the lateral tibial articulating surface includes a second plateau and a second raised medial edge that increases in width in the anterior direction and curves distally to the second plateau.   
     
     
         12 . The system of  claim 11 , wherein the tibial component is a full tibial component that includes both the medial tibial portion and the lateral tibial portion. 
     
     
         13 . The system of  claim 11 , wherein the lateral tibial articulating surface has a lateral tibial sagittal plane profile including a second posterior tibial arcuate portion, located posterior to the second plateau and having a posterior tibial radius of curvature, and a second anterior tibial arcuate portion located anterior to the second plateau and having an anterior tibial radius of curvature; wherein the anterior tibial radius of curvature is greater than the posterior tibial radius of curvature 
     
     
         14 . The system of  claim 2 , further comprising a patellar flange component, monolithic with the femoral component and implantable on an anterior distal portion of the femur and configured to provide a contacting surface for a patella of the leg. 
     
     
         15 . The system of  claim 14 , further comprising a patellar component implantable to replace the patella of the leg that articulates with the patellar flange component. 
     
     
         16 . A knee replacement system for enabling natural knee movement in a leg with a femur having medial and lateral condyles and a tibia having medial and lateral tibial plateaus in a patient, the system comprising:
 a first femoral component of a first size including at least one of:
 a first medial femoral portion having a first medial femoral articulating surface, wherein the first medial femoral articulating surface has a first medial femoral sagittal plane profile including a first group at least four medial radii of curvature, each of the four medial radii of curvature of the first group are sized relative to one another according to a first femoral scaling factor that comprises a measure of the offset from a posterior edge of the medial condyle in the first medial femoral sagittal plane to a medial point of initial articular contact between the medial femoral portion and a medial tibial portion of a tibial component; and 
 a first lateral femoral portion having a first lateral femoral articulating surface, wherein the first lateral femoral articulating surface has a first lateral femoral sagittal plane profile including a first group at least four lateral radii of curvature, each of the four lateral radii of curvature of the first group are sized relative to one another according to a second femoral scaling factor that comprises a measure of the offset from a posterior edge of the lateral condyle in the first lateral femoral sagittal plane to a lateral point of initial articular contact between the lateral femoral portion and a lateral tibial portion of the tibial component; and 
   a second femoral component of a second size including at least one of:
 a second medial femoral portion having a second medial femoral articulating surface, wherein the second medial femoral articulating surface has a second medial femoral sagittal plane profile including a second group at least four medial radii of curvature, each of the at least four medial radii of curvature of the second group are sized relative to one another by the first femoral scaling factor; and 
 a second lateral femoral portion having a second lateral femoral articulating surface, wherein the second lateral femoral articulating surface has a second femoral sagittal plane profile including a second group of at least four lateral radii of curvature, each of the at last four lateral radii of curvature of the second group are sized relative to one another by the second femoral scaling factor. 
   
     
     
         17 . The system of  claim 16 , wherein the at least four medial radii of curvature of the first group correspond to the at least four medial radii of curvature of the second group and have corresponding relative lengths according to being sized by the first femoral scaling factor such that the at least four medial radii of curvature of the first group comprise constantly scaled up or constantly scaled down versions of the at least four medial radii of curvature of the second group. 
     
     
         18 . The system of  claim 16 , wherein the at least four medial radii of curvature of the first group comprise a first superior radius of curvature, a first posterior radius of curvature, a first distal radius of curvature, and a first anterior femoral radius of curvature, and wherein the first superior radius of curvature remains a same length for a first superior arcuate portion of the first medial femoral articulating surface, the first posterior radius of curvature remains a same length for a first posterior arcuate portion of the first medial femoral articulating surface, the first distal radius of curvature remains a same length for a first distal arcuate portion of the first medial femoral articulating surface, and first anterior radius of curvature remains a same length for a first anterior arcuate portion of the first medial femoral articulating surface. 
     
     
         19 . The system of  claim 18 , wherein the first distal femoral arcuate portion sweeps a greater number of degrees than each of the first posterior femoral arcuate portion and the first anterior femoral arcuate portion. 
     
     
         20 . The system of  claim 18 , wherein the first distal femoral radius of curvature is longer than each of the first posterior radius of curvature and the first anterior femoral radius of curvature. 
     
     
         21 . The system of  claim 18 , wherein the first superior, first posterior, first distal, and first anterior femoral arcuate portions have superior, posterior, distal and anterior femoral arc centers, respectively; wherein the superior, posterior, distal, and anterior femoral arc centers are distinct points in the medial femoral sagittal plane.