Systems and methods for providing an asymmetrical tibial component
Systems and methods for providing deeper knee flexion capabilities. In some instances, such systems and methods include a tibial component that has an asymmetrical articular plateau that includes a medial tibial condylar surface and a lateral tibial condylar surface. In some cases, at least one of the medial condylar surface and the lateral condylar surface includes a concave articulation surface having a lowest point that disposed from a posterior edge of the tibial component by between about 18% and less than about 35% of a total anteroposterior dimension of the tibial component. Other implementations are also discussed.
1. A tibial component, comprising:
at least one of a medial tibial condylar surface and a lateral tibial condylar surface; and
a first raised articulation feature disposed posteriorly on the tibial component,
wherein a first articular surface disposed posterior to a proximal-most portion of the first raised articulation feature is configured to articulate against a femoral component configured to replace a distal portion of a femur.
2. The tibial component of claim 1 , wherein the first raised articulation feature is disposed at the medial tibial condylar surface.
3. The tibial component of claim 2 , wherein the first raised articulation feature is disposed at a posterior edge of the medial tibial condylar surface.
4. The tibial component of claim 2 , further comprising a second raised articulation feature comprising a second articular surface that is disposed posterior to a proximal-most portion of the second raised articulation feature, wherein the second articular surface is configured to articulated against the femoral component, and wherein the second raised articulation feature is disposed at a posterior edge of the lateral tibial condylar surface.
5. The tibial component of claim 1 , further comprising a stem extending from an undersurface of the tibial component, wherein a portion of the stein is configured to contact an inner, anterior surface of a tibia when the stem is inserted into the tibia and the undersurface of the tibial component is in contact with a resected surface of the tibia.
6. The tibial component of claim 1 , wherein the first raised articulation feature comprises a projection that projects from the at least one of the medial tibial condylar surface and the lateral tibial condylar surface such that an articulation surface that is configured to articulate with the femoral component is disposed posterior on the tibial component to the first raised articulation feature.
7. The tibial component of claim 1 , further comprising the femoral component, wherein a proximal portion of a posterior condyle of the femoral component comprises an incurvate articulation surface that is configured to articulate with the first raised articulation feature when the tibial component and the femoral component are seated in a knee joint and the knee joint is flexed.
8. The tibial component of claim 1 , wherein the first raised articulation feature comprises an articular ridge that runs in a general media-lateral direction.
9. The tibial component of claim 1 , wherein a portion of the first raised articulation feature runs at an angle that is at least one of perpendicular to and acute to an anteroposterior direction of an intercondylar surface of the tibial component.
10. The tibial component of claim 1 , wherein the first raised articulation feature comprises a spherical articular surface disposed at a medial portion of the tibial component.
11. The tibial component of claim 1 , wherein the medial tibial condylar surface comprises a concave articulation surface having a fixed center of rotation with a lowest point disposed from a posterior edge of the tibial component by between about 18% and about 35% of a total anteroposterior dimension of the tibial component, and wherein the lateral tibial condylar surface comprises a substantially flat articulation surface having a length that extends in an anteroposterior direction.
12. A tibial component, comprising:
a medial tibial condylar surface; and
a raised articulation feature disposed posteriorly at the medial tibial condylar surface,
wherein an articular surface disposed posterior to a proximal-most portion of the raised articulation feature is configured to articulate against an articulation surface of a femoral component.
13. The tibial component of claim 12 , wherein the raised articulation feature is disposed at a posterior edge of the medial tibial condylar surface.
14. The tibial component of claim 12 , further comprising the femoral component, wherein a proximal portion of a posterior, medial condyle of the femoral component comprises an incurvate articulation surface that is configured to articulate with the raised articulation feature when the tibial component and the femoral component are seated in a knee joint and the knee joint is flexed.
15. The tibial component of claim 14 , wherein the raised articulation feature is configured to function as a fulcrum for the femoral component.
16. The tibial component of claim 12 , further comprising a stem extending from an undersurface of the tibial component, wherein a portion of the stem is configured to contact an inner, anterior surface of a tibia when the stem is inserted into the tibia and the undersurface of the tibial component is in contact with a resected surface of the tibia.
17. A tibial component, comprising:
a medial tibial condylar surface;
a raised articulation feature disposed at a posterior edge of the medial tibial condylar surface; and
a stem extending from an undersurface of the tibial component,
wherein a portion of the stem is configured to contact an inner, anterior surface of a tibia when the stem is inserted into the tibia and the undersurface of the tibial component is in contact with a resected surface of the tibia, and
wherein an articular surface disposed posterior to a proximal-most portion of the raised articulation feature is configured to articulate against an articulation surface of a femoral component.
18. The tibial component of claim 17 , wherein the raised articulation feature comprises an articular ridge that runs in a general media-lateral direction on the tibial component and at an angle that is at least one of perpendicular to and acute to an anteroposterior direction of an intercondylar surface of the tibial component.
19. The tibial component of claim 17 , further comprising the femoral component, wherein a proximal portion of a posterior, medial condyle of the femoral component comprises an incurvate articulation surface that is configured to articulate with the raised articulation feature when the tibial component and the femoral component are seated in a knee joint and the knee joint is flexed.
20. The tibial component of claim 19 , wherein the raised articulation feature is configured to function as a fulcrum for the femoral component.