Tibial bearing component for a knee prosthesis with improved articular characteristics

Patent metadata

Field	Value
Publication number	US-9655728-B2
Application number	US-201514918721-A
Country	US
Kind code	B2
Filing date	Oct 21, 2015
Priority date	Nov 18, 2011
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

An orthopedic knee prosthesis includes a tibial bearing component with articular features which operate to protect adjacent soft tissues of the natural knee, promote and/or accommodate desired articulation with an abutting femoral component, and facilitate expedient and effective implantation by a surgeon.

First claim

What is claimed is:

1. A knee prosthesis assembly, comprising:
a femoral component having a medial femoral condyle and a lateral femoral condyle; and
a tibial bearing component for articulation with the medial and lateral femoral condyles, the tibial bearing component comprising:
a medial compartment having a medial articular surface and an opposing distal surface bounded by a first portion of a tibial bearing periphery, the medial articular surface having at least a medial sagittal conformity with the medial femoral condyle, wherein the medial sagittal conformity comprises a ratio of a sagittal radius of the medial compartment measured along a medial articular track to a corresponding sagittal radius of the medial femoral condyle; and
a lateral compartment separated from the medial compartment by a bearing component sagittal plane and having a lateral articular surface and an opposing distal surface bounded by a second portion of tibial bearing periphery, the lateral articular surface having at least a lateral sagittal conformity with the lateral femoral condyle, wherein the lateral sagittal conformity comprises a ratio of a sagittal radius of the lateral compartment along a lateral articular track to a corresponding sagittal radius of the lateral femoral condyle, and wherein the lateral sagittal conformity is greater than the medial sagittal conformity by at least 0.2 through at least a portion of a range of flexion between the medial and lateral femoral condyles and the tibial bearing component.

2. The tibial bearing component of claim 1 , wherein the tibial bearing component comprises an ultra-congruent type prosthesis and the lateral sagittal conformity is between 1.0 and 1.7 through the range of flexion and the medial sagittal conformity is between 1.0 and 1.9 through the range of flexion, and wherein the range of knee flexion comprises at least 130 degrees.

3. The tibial bearing component of claim 1 , wherein the tibial bearing component comprises a posterior-stabilized type prosthesis and the lateral sagittal conformity is between 1.4 and 1.8 through the range of flexion and the medial sagittal conformity is between 1.0 and 1.8 through the range of flexion, and wherein the range of knee flexion comprises at least 130 degrees.

4. The tibial bearing component of claim 3 , wherein the lateral sagittal conformity exceeds the medial sagittal conformity by at least 0.4 through at least a portion of the range of flexion.

5. The tibial bearing component of claim 1 , wherein the tibial bearing component comprises a cruciate-retaining type prosthesis and the lateral sagittal conformity is between 1.1 and 2.6 through the range of flexion and the medial sagittal conformity is between 1.1 and 2.2 through the range of flexion, and wherein the range of knee flexion comprises at least 130 degrees.

6. The tibial bearing component of claim 5 , wherein the lateral sagittal conformity exceeds the medial sagittal conformity by at least 0.5 through at least a portion of the range of flexion.

7. The tibial bearing component of claim 1 , wherein the tibial bearing component comprises an ultra-congruent type prosthesis and the range of flexion comprises at least 130 degrees.

8. The tibial bearing component of claim 1 , wherein the tibial bearing component is configured to be implantable on a tibia at an anteroposterior slope angle as measured in a bearing component sagittal plane, the anteroposterior slope angle formed between a bearing component transverse plane and a transverse reference plane when the high-flexion tibial bearing component is implanted, the transverse reference plane positioned normal to an anatomic axis of the tibia, the anteroposterior slope angle having a positive value when an anterior edge of the tibial bearing component is elevated with respect to a posterior edge thereof.

9. The tibial bearing component of claim 8 , wherein the lateral articular track includes a distal-most point on the lateral articular compartment and the medial articular track includes a distal-most point on the medial articular compartment, and locations of the distal-most points of the medial and lateral articular tracks depend on the anteroposterior slope angle.

10. The tibial bearing component of claim 1 , wherein the lateral compartment includes a lateral jump height defined as a proximal-distal distance measured from the distal-most point on the lateral articular compartment to a proximal-most point at a posterior end of the lateral articular track and the medial articular compartment includes a medial jump height defined as a proximal-distal distance measured from the distal-most point on the medial articular compartment to a proximal-most point at a posterior end of the medial articular track, the lateral jump height being less than the medial jump height such that the lateral articular compartment presents a lower barrier to posterior femoral translation than the medial articular compartment, wherein a height differential between the lateral jump height and the medial jump height is at least 0.4 mm.

11. A knee prosthesis assembly, comprising:
a femoral component having a medial femoral condyle and a lateral femoral condyle; and
a tibial bearing component for articulation with the medial and lateral femoral condyles, the tibial bearing component comprising:
a medial compartment having a medial articular surface and an opposing distal surface bounded by a first portion of a tibial bearing periphery, the medial articular surface having at least a medial sagittal conformity with the medial femoral condyle, wherein the medial sagittal conformity comprises a ratio of a sagittal radius of the medial compartment measured along a medial articular track to a corresponding sagittal radius of the medial femoral condyle; and
a lateral compartment separated from the medial compartment by a bearing component sagittal plane and having a lateral articular surface and an opposing distal surface bounded by a second portion of tibial bearing periphery, the lateral articular surface having at least a lateral sagittal conformity with the lateral femoral condyle; the lateral sagittal conformity comprises a lateral sagittal conformity ratio that is a value of a sagittal radius of the lateral compartment along a lateral articular track to a corresponding sagittal radius of the lateral femoral condyle, and wherein the medial sagittal conformity comprises a medial sagittal conformity ratio that is a value of a sagittal radius of the medial compartment along a medial articular track to a value of a corresponding sagittal radius of the medial femoral condyle, wherein the lateral sagittal conformity comprises a ratio of a sagittal radius of the lateral compartment along a lateral articular track to a corresponding sagittal radius of the lateral femoral condyle, wherein the lateral sagittal conformity is between 1.0 and 2.6 through the range of flexion and the medial sagittal conformity is between 1.0 and 2.2 through the range of flexion between the medial and lateral femoral condyles and the tibial bearing component, and wherein the range of knee flexion comprises at least 130 degrees.

12. The tibial bearing component of claim 11 , wherein the tibial bearing component comprises an ultra-congruent type prosthesis and the lateral sagittal conformity is between 1.0 and 1.7 through the range of flexion, and wherein the medial sagittal conformity is between 1.0 and 1.9 through the range of flexion.

13. The tibial bearing component of claim 12 , wherein the lateral sagittal conformity exceeds the medial sagittal conformity by at least 0.2 through at least a portion of the range of flexion.

14. The

Assignees

• Zimmer Inc

Inventors

• Parisi Raymond C
• Blaylock Jeff
• Macke Kathleen

Classifications

• A61F2002/30616

  Sets comprising a plurality of prosthetic parts of different sizes or orientations · CPC title

• A61F2/3886 Primary

  for stabilising knees against anterior or lateral dislocations · CPC title

• A61F2/3868 Primary

  with sliding tibial bearing · CPC title

• A61F2/389

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

• A61F2002/30604

  modular · CPC title