Knee prosthesis
OwnerDerek J. W. McMinninventor
Life of this patent
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Abstract
A knee prosthesis comprises a femoral component for securement to a femur, the femoral component defining medial and lateral condyles and an intercondylar groove; and a tibial component for securement to a tibia, the tibial component having respective bearing surfaces shaped to engage with said condyles both when the knee, in use, is extended and also over a range of flexion. At least one of the condyles is part-helical in shape and the respective bearing surface of the tibial component is correspondingly part-helical in at least a medio-lateral direction. In addition, the other bearing surface is incongruent with the other condyle in at least the antero-posterior direction so as to allow for antero-posterior movement of the femoral component relative to the bearing surfaces of the tibial component.
Claims17
A knee prosthesis comprising:
- a femoral component for securement to a femur, the femoral component defining medial and lateral condyles and an intercondylar groove;
- and
- a tibial component for securement to a tibia, the tibial component having respective bearing surfaces shaped to engage with said condyles both when the knee, in use, is extended and also over a range of flexion;
- wherein the medial and lateral condyles are both part-helical in shape and the respective bearing surface for one of the condyles is correspondingly part-helical in at least a medio-lateral direction;
- and
- wherein the other bearing surface is incongruent with the other condyle in at least the antero-posterior direction so as to allow for antero-posterior movement of the femoral component relative to the bearing surfaces of the tibial component.
A knee prosthesis comprising:
- a femoral component for securement to a femur, the femoral component defining medial and lateral condyles and an intercondylar groove;
- and
- a tibial component for securement to a tibia, the tibial component having respective bearing surfaces shaped to engage with said condyles both when the knee, in use, is extended and also over a range of flexion;
- one of the condyles being part-helical in shape and the respective bearing surface of the tibial component being correspondingly part-helical in at least a medio-lateral direction;
- wherein the other bearing surface is incongruent with the other condyle in at least the antero-posterior direction so as to allow for antero-posterior movement of the femoral component relative to the bearing surfaces of the tibial component;
- and
- wherein each of the bearing surfaces is configured for incongruent contact with the respective condyles in the antero-posterior direction so as to allow for the femoral component to freely slide back and forth on the tibial component during flexion and extension.
Dependencies are inferred from the claim text.