Tibial bearing component for a knee prosthesis with improved articular characteristics

Patent metadata

Field	Value
Publication number	US-9295558-B2
Application number	US-201414284028-A
Country	US
Kind code	B2
Filing date	May 21, 2014
Priority date	Nov 18, 2011
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

An orthopaedic 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 posterior-stabilized tibial bearing component for articulation with medial and lateral femoral condyles of a femoral prosthesis, the posterior-stabilized tibial bearing component defining a tibial bearing component coordinate system comprising:
a bearing component transverse plane extending along a medial/lateral direction and an anterior/posterior direction, such that a proximal/distal direction is defined as a direction normal to the bearing component transverse plane;
a bearing component coronal plane extending along the proximal/distal direction and the medial/lateral direction, the bearing component coronal plane perpendicular to the bearing component transverse plane; and
a bearing component sagittal plane extending along the anterior/posterior direction and the proximal/distal direction, the bearing component sagittal plane perpendicular to the bearing component transverse plane and the bearing component coronal plane,
the posterior-stabilized tibial bearing component comprising:
an articular surface and an opposing distal surface bounded by a tibial bearing periphery, the articular surface including medial and lateral dished articular compartments sized and shaped for articulation with the femoral condyles through a range of flexion of at least 130 degrees, the medial and lateral dished articular compartments separated from one another by the bearing component sagittal plane; and
a spine extending proximally from the articular surface, the spine spaced posteriorly from an anterior edge of the tibial bearing periphery, the spine disposed between the medial and lateral dished articular compartments, and a spine centerline formed along an intersection between the bearing component sagittal plane and a posterior face of the spine, and

the posterior face of the spine defining an initial contact line along a proximal/distal extent of the spine centerline and a deep flexion contact line along the proximal/distal extent of the spine centerline, the initial contact line representing a line of contact with a femoral cam of the femoral prosthesis when the femoral cam initially contacts the spine, and the deep flexion contact line located distal to the initial contact line and representing a line of contact when the femoral cam contacts the spine in a deep flexion orientation, wherein the deep flexion contact line is oriented at an angle of up to 10 degrees in the bearing component coronal plane relative to the initial contact line.

2. The posterior-stabilized tibial bearing component of claim 1 , wherein the deep flexion contact line is oriented at an angle of up to 7 degrees relative to the initial contact line.

3. The posterior-stabilized tibial bearing component of claim 1 , wherein the posterior face of the spine defines a plurality of medial/lateral contact lines along the proximal/distal extent of the spine centerline between the initial contact line and the deep flexion contact line, and an angle between a particular medial/lateral contact line and the initial contact line increases as the medial/lateral contact line is located more distally on the posterior face of the spine.

4. The posterior-stabilized tibial bearing component of claim 1 , in combination with a femoral prosthesis comprising:
a medial condyle configured to articulate with the medial articular compartment of the posterior-stabilized tibial bearing component through a range of motion;
a lateral condyle configured to articulate with the lateral articular compartment of the posterior-stabilized tibial bearing component through the range of motion; and
a femoral cam disposed between the medial condyle and the lateral condyle, the femoral cam positioned to initiate contact with the posterior face of the spine at between 75 degrees and 93 degrees flexion.

5. The posterior-stabilized tibial bearing component of claim 4 , wherein the femoral cam of the femoral prosthesis contacts the posterior face of the spine at the deep flexion contact line at between 120 degrees and 155 degrees flexion.

6. The posterior-stabilized tibial bearing component of claim 1 , wherein the spine comprises an anterior face opposite the posterior face, the anterior face substantially symmetrical about the bearing component sagittal plane.

7. The posterior-stabilized tibial bearing component of claim 1 , wherein the spine defines a medial spine portion and a lateral spine portion on medial and lateral sides of the bearing component sagittal plane, respectively, the spine having a spine thickness that is variable such that the lateral spine portion is thicker than the medial spine portion at the deep flexion contact line.

8. A posterior-stabilized tibial bearing component for articulation with medial and lateral femoral condyles, the posterior-stabilized tibial bearing component defining a tibial bearing component coordinate system comprising:
a bearing component transverse plane extending along a medial/lateral direction and an anterior/posterior direction, such that a proximal/distal direction is defined as a direction normal to the bearing component transverse plane;
a bearing component coronal plane extending along the proximal/distal direction and the medial/lateral direction, the bearing component coronal plane perpendicular to the bearing component transverse plane; and
a bearing component sagittal plane extending along the anterior/posterior direction and the proximal/distal direction, the bearing component sagittal plane perpendicular to the bearing component transverse plane and the bearing component coronal plane,
the posterior-stabilized tibial bearing component comprising:
an articular surface and an opposing distal surface bounded by a tibial bearing periphery, the articular surface including medial and lateral dished articular compartments sized and shaped for articulation with the femoral condyles through a range of flexion of at least 130 degrees, the medial and lateral dished articular compartments separated from one another by the bearing component sagittal plane; and
a spine extending proximally from the articular surface and disposed between the medial and lateral dished articular compartments, the spine having a proximal end, a distal end, an anterior face, a posterior face, a distal thickness defined as an anterior/posterior distance between the anterior face and the posterior face of the spine at the distal end, and a spine centerline formed along an intersection between the bearing component sagittal plane and the posterior face of the spine, the spine centerline separating a medial spine portion from a lateral spine portion, wherein the spine is asymmetric such that the distal thickness of the spine in the lateral spine portion is greater than the distal thickness of the spine in the medial spine portion;
wherein the posterior face of the spine defines an initial contact line along a proximal/distal extent of the spine centerline and a deep flexion contact line along the proximal/distal extent of the spine centerline, the initial contact line representing a line of contact between a femoral cam of a femoral prosthesis when the femoral cam initially contacts the spine, the deep flexion contact line located distal to the initial contact line and representing a line of contact when the femoral cam contacts the spine in a deep flexion orientation, and the deep flexion contact line is oriented at an angle of up to 10 degrees relative to the initial contact line.

9. The posterior-stabilized tibial bearing component of claim 8 , wherein the distal thickness of the spine at the spine centerline is greater than the distal thickness of the spine in the medial spine portion and less than the distal thickness of the spine in the lateral spine portion.

Assignees

• Zimmer Inc

Inventors

• Parisi Raymond C
• Blaylock Jeff

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 Primary

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

• A61F2002/30604

  modular · CPC title