Orthopaedic femoral component having controlled condylar curvature

Patent metadata

Field	Value
Publication number	US-9931216-B2
Application number	US-201514983079-A
Country	US
Kind code	B2
Filing date	Dec 29, 2015
Priority date	Jun 30, 2008
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

An orthopaedic knee prosthesis includes a femoral component having a condyle surface. The condyle surface is defined by one or more radii of curvatures, which are controlled to reduce or delay the onset of anterior translation of the femoral component relative to a tibial bearing.

First claim

The invention claimed is:

1. An orthopaedic knee prosthesis comprising:
a femoral component having a condyle surface curved in the sagittal plane; and
a tibial bearing having a bearing surface configured to articulate with the condyle surface of the femoral component,
wherein the condyle surface (i) contacts the bearing surface at a first contact point on the condyle surface at a first degree of flexion, the first degree of flexion being in the range of 0 degrees to 10 degrees, (ii) contacts the bearing surface at a second contact point on the condyle surface at a second degree of flexion, the second degree of flexion being in the range of 10 degrees to 75 degrees, and (iii) contacts the bearing surface at a third contact point on the condyle surface at a third degree of flexion, the second degree of flexion being greater than the first degree of flexion and the third degree of flexion being greater than the second degree of flexion,
wherein (i) the condyle surface in the sagittal plane has a first radius of curvature at the first contact point, a second radius of curvature at the second contact point, and a third radius of curvature at the third contact point, and (ii) the second radius of curvature is greater than the first radius of curvature and the third radius of curvature is less than the second radius of curvature,
wherein the third radius of curvature is greater than the first radius of curvature by at least 0.5 millimeters, and
wherein a curved surface section having a non-constant radius of curvature is defined between the first contact point and the third contact point.

2. The orthopaedic knee prosthesis of claim 1 , wherein the second degree of flexion is about 30 degrees.

3. The orthopaedic knee prosthesis of claim 1 , wherein the second radius of curvature is greater than the first radius of curvature by a distance of at least 2 millimeters.

4. The orthopaedic knee prosthesis of claim 3 , wherein the second radius of curvature is greater than the first radius of curvature by a distance of at least 5 millimeters.

5. The orthopaedic knee prosthesis of claim 1 , wherein the ratio of the first radius of curvature to the second radius of curvature is in the range of 0.50 to 0.99.

6. The orthopaedic knee prosthesis of claim 5 , wherein the ratio of the first radius of curvature to the second radius of curvature is in the range of 0.90 to 0.99.

7. The orthopaedic knee prosthesis of claim 1 ,
wherein the third degree of flexion is greater than the second degree of flexion and less than about 90 degrees.

8. The orthopaedic knee prosthesis of claim 1 , wherein:
(i) the condyle surface of the femoral component is a medial condyle surface and the bearing surface of the tibial bearing is a medial bearing surface,
(ii) the femoral component further includes a lateral condyle surface curved in the sagittal plane, and
(iii) the tibial bearing further includes a lateral bearing surface configured to articulate with the lateral condyle surface of the femoral component.

9. The orthopaedic knee prosthesis of claim 8 , wherein the lateral condyle surface and the medial condyle surface are substantially symmetrical in the sagittal plane.

10. The orthopaedic knee prosthesis of claim 8 ,
wherein the lateral condyle surface (i) contacts the lateral bearing surface at a first contact point on the lateral condyle surface at a third degree of flexion, the third degree of flexion being less than about 30 degrees, and (ii) contacts the lateral bearing surface at a second contact point on the lateral condyle surface at a fourth degree of flexion, the fourth degree of flexion being greater than the third degree of flexion, and
wherein (i) the lateral condyle surface in the sagittal plane has a first radius of curvature at the first contact point, (ii) the lateral condyle surface in the sagittal plane has a second radius of curvature at the second contact point, and (iii) the second radius of curvature of the lateral condyle is greater than the first radius of curvature of the lateral condyle by at least 0.5 millimeters.

11. The orthopaedic knee prosthesis of claim 10 , wherein the second radius of curvature of the lateral condyle is different from the second radius of curvature of the medial condyle.

12. The orthopaedic knee prosthesis of claim 10 , wherein the second degree of flexion is different from the fourth degree of flexion.

13. The orthopaedic knee prosthesis of claim 10 , wherein a difference between the first radius of curvature and the second radius of curvature is different from a difference between the third radius of curvature and the fourth radius of curvature.

14. An orthopaedic knee prosthesis comprising:
a femoral component having a condyle surface curved in the sagittal plane; and
a tibial bearing having a bearing surface configured to articulate with the condyle surface of the femoral component,
wherein the condyle surface (i) contacts the bearing surface at a first contact point on the condyle surface at a first degree of flexion, the first degree of flexion being less than 30 degrees, (ii) contacts the bearing surface at a second contact point on the condyle surface at a second degree of flexion, the second degree of flexion being in the range of 30 degrees to 75 degrees, and (iii) contacts the bearing surface at a third contact point on the condyle surface at a third degree of flexion that is greater than the second degree of flexion,
wherein (i) the condyle surface in the sagittal plane has a first radius of curvature at the first contact point, (ii) the condyle surface in the sagittal plane has a second radius of curvature at the second contact point, (iii) the ratio of the first radius of curvature to the second radius of curvature is in the range of 0.80 to 0.99, and (iv) the condyle surface in the sagittal plane has a third radius of curvature at the third contact point that is less than the second radius of curvature,
wherein the third radius of curvature is greater than the first radius of curvature by at least 0.5 millimeters,
wherein a curved surface section having a non-constant radius of curvature is defined between the first contact point and the third contact point.

15. The orthopaedic knee prosthesis of claim 14 , wherein the ratio of the first radius of curvature to the second radius of curvature is from 0.90 to 0.99.

Assignees

• Depuy Ireland Ultd Co

Inventors

• Williams John L
• Gomaa Said T
• Armacost John M

Classifications

• A61F2/3886

  for stabilising knees against anterior or lateral dislocations · CPC title

• A61F2/389

  Tibial components (A61F2/3868 takes precedence) · CPC title

• A61F2/38

  for elbows or knees · CPC title

• A61F2/3859 Primary

  Femoral components · CPC title

• A61F2/3868 Primary

  with sliding tibial bearing · CPC title