Knee replacement system and method for enabling natural knee movement

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, the system comprising:

• a plurality of medial femoral components each implantable on the medial condyle and each having a medial femoral articulating surface with a medial femoral sagittal plane profile including:
• a first superior, a first posterior, a first distal, and a first anterior femoral arcuate portion each scaled by a first femoral scaling factor and each having a first superior, a first posterior, a first distal, and a first anterior femoral radii of curvature respectively with relative lengths that are constant for each one of the plurality of medial femoral components, and wherein the first femoral scaling factor comprises a measure of the offset from a posterior edge of the medial condyle in a central sagittal plane to the first distal femoral radius of curvature which extends to intersect a point of initial articular contact between the medial femoral articulating surface and a medial tibial component;
• wherein the first distal femoral radius of curvature is longer than each of the first posterior and first anterior femoral radii of curvature;
• and
• 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;
• a plurality of lateral femoral components each implantable on the lateral condyle and each having a lateral femoral articulating surface with a lateral femoral sagittal plane profile including:
• a second superior, a second posterior, a second distal, and a second anterior femoral arcuate portion each scaled by a second femoral scaling factor and each having a second superior, a second posterior, a second distal, and a second anterior femoral radii of curvature respectively with relative lengths that are constant for each one of the plurality of lateral femoral components, and wherein the second femoral scaling factor comprises a measure of the offset from a posterior edge of the lateral condyle in a central sagittal plane to the second distal femoral radius of curvature which extends to intersect a point of initial articular contact between the lateral femoral articulating surface and a lateral tibial component;
• wherein the second distal femoral radius of curvature is longer than each of the second posterior and second anterior femoral radii of curvature;
• and
• wherein the second distal femoral arcuate portion sweeps a greater number of degrees than each of the second posterior femoral arcuate portion and the second anterior femoral arcuate portion;
• wherein the first distal femoral arcuate portion sweeps a greater number of degrees than the second distal femoral arcuate portion;
• and
• wherein the second distal femoral radius of curvature is longer than the first distal femoral radius of curvature.

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, the system comprising:

• a plurality of medial femoral components each implantable on the medial condyle and each having a medial femoral articulating surface with a medial femoral sagittal plane profile including:
• a first superior, a first posterior, a first distal, and a first anterior femoral arcuate portion each scaled by a first femoral scaling factor and each having a first superior, a first posterior, a first distal, and a first anterior femoral radii of curvature respectively with relative lengths that are constant for each one of the plurality of medial femoral components;
• wherein the first distal femoral radius of curvature is longer than each of the first posterior and first anterior femoral radii of curvature;
• and
• 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;
• a plurality of lateral femoral components each implantable on the lateral condyle and each having a lateral femoral articulating surface with a lateral femoral sagittal plane profile including:
• a second superior, a second posterior, a second distal, and a second anterior femoral arcuate portion each scaled by a second femoral scaling factor and each having a second superior, a second posterior, a second distal, and a second anterior femoral radii of curvature respectively with relative lengths that are constant for each one of the plurality of lateral femoral components;
• wherein the second distal femoral radius of curvature is longer than each of the second posterior and the second anterior femoral radii of curvature;
• and
• wherein the second distal femoral arcuate portion sweeps a greater number of degrees than each of the second posterior femoral arcuate portion and the second anterior femoral arcuate portion;
• wherein:
• the first scaling factor comprises a measure of the offset from a posterior edge of the medial condyle in a central sagittal plane to the first distal femoral radius of curvature which extends to intersect a point of initial articular contact between the medial femoral articulating surface and a medial tibial component;
• the second scaling factor comprises a measure of the offset from a posterior edge of the lateral condyle in a central sagittal plane to the second distal femoral radius of curvature which extends to intersect a point of initial articular contact between the lateral femoral articulating surface and a lateral tibial component;
• the first scaling factor is the same dimension for each one of the plurality of medial femoral components;
• the second scaling factor is the same dimension for each one of the plurality of lateral femoral components;
• the first distal femoral arcuate portion sweeps a greater number of degrees than the second distal femoral arcuate portion;
• and
• the second distal femoral radius of curvature is longer than the first distal femoral radius of curvature.

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, the system comprising:

• a plurality of medial femoral components each having a medial femoral articulating surface scaled to a distinct medial femoral scaling factor;
• a plurality of lateral femoral components each having a lateral femoral articulating surface scaled to a distinct lateral femoral scaling factor;
• a plurality of medial tibial components each having a medial tibial articulating surface configured to articulate with the medial femoral articulating surface and scaled to a distinct medial tibial scaling factor;
• and
• a plurality of lateral tibial components each having a lateral tibial articulating surface configured to articulate with the lateral femoral articulating surface and scaled to a distinct lateral tibial scaling factor;
• wherein:
• the distinct medial femoral scaling factor comprises a measure of the offset from a posterior edge of the medial condyle in a central sagittal plane to a first distal femoral radius of curvature which extends to intersect a point of initial articular contact between the medial femoral articulating surface and the medial tibial articulating surface;
• and
• the distinct lateral femoral scaling factor comprises a measure of the offset from a posterior edge of the lateral condyle in a central sagittal plane to a second distal femoral radius of curvature which extends to intersect a point of initial articular contact between the lateral femoral articulating surface and the lateral tibial articulating surface.