High performance knee prostheses

Patent metadata

Field	Value
Publication number	US-2016310283-A1
Application number	US-201615203038-A
Country	US
Kind code	A1
Filing date	Jul 6, 2016
Priority date	Dec 20, 2002
Publication date	Oct 27, 2016
Grant date	—

Abstract

Knee prostheses that more faithfully replicate the structure and function of the human knee joint in order to provide, among other benefits: greater flexion of the knee in a more natural way by promoting or accommodating internal tibial rotation, replication of the natural screw home mechanism, and controlled articulation of the tibia and femur respective to each other in a natural way. Such prostheses may include an insert component disposed between a femoral component and a tibial component, the insert component featuring, among other things, a reversely contoured posterolateral bearing surface that helps impart internal rotation to the tibia as the knee flexes. Other surfaces can be shaped using iterative automated techniques that allow testing and iterative design taking into account a manageable set of major forces acting on the knee during normal functioning, together with information that is known about natural knee joint kinetics and kinematics.

First claim

What is claimed is:

1 . A prosthesis for replacement of a least part of a knee joint in a leg, the leg including a femur and a tibia, the prosthesis comprising:
a femoral component adapted to fit on a distal end of the femur, the femoral component comprising:
a lateral condylar structure defining a lateral condylar bearing surface; and
a medial condylar structure defining a medial condylar bearing surface;
a tibial component adapted to fit on a proximal end of the tibia, the tibial component comprising:
a medial bearing surface and a lateral bearing surface, wherein:
the medial bearing surface comprises a posterior-most edge;
the lateral bearing surface comprises a posterior-most edge; and
the medial bearing surface has a minimum thickness that is thicker in a superior-inferior direction at the medial bearing surface posterior-most edge than a minimum thickness of the lateral bearing surface at the lateral bearing surface posterior-most edge.

2 . The prosthesis of claim 1 , further comprising a central post positioned between the medial bearing surface and the lateral bearing surface.

3 . The prosthesis of claim 1 , wherein at least one of the medial bearing surface or the lateral bearing surface is concave.

4 . The prosthesis of claim 1 , wherein the posterior-most edge of the medial bearing surface is an outermost edge of the medial bearing surface in a posterior direction and the posterior-most edge of the lateral bearing surface is an outermost edge of the lateral bearing surface in the posterior direction.

5 . The prosthesis of claim 1 , wherein the medial bearing surface and the lateral bearing surface each are concave.

6 . A prosthesis for replacement of a least part of a knee joint in a leg, the leg including a femur and a tibia, the prosthesis comprising:
a femoral component adapted to fit on a distal end of the femur, the femoral component comprising:
a lateral condylar structure defining a lateral condylar bearing surface; and
a medial condylar structure defining a medial condylar bearing surface;
a tibial component adapted to fit on a proximal end of the tibia, the tibial component comprising:
a medial bearing surface and a lateral bearing surface, the medial bearing surface comprising a posterior-most edge and the lateral bearing surface comprising a posterior-most edge,
wherein the medial bearing surface has an average thickness in a superior-inferior direction along the medial bearing surface posterior-most edge that is thicker than an average thickness of the lateral bearing surface along the lateral bearing surface posterior-most edge.

7 . The prosthesis of claim 6 , further comprising a central post positioned between the medial bearing surface and the lateral bearing surface.

8 . The prosthesis of claim 6 , wherein at least one of the medial bearing surface or the lateral bearing surface is concave.

9 . The prosthesis of claim 6 , wherein the posterior-most edge of the medial bearing surface is an outermost edge of the medial bearing surface in a posterior direction and the posterior-most edge of the lateral bearing surface is an outermost edge of the lateral bearing surface in the posterior direction.

10 . The prosthesis of claim 6 , wherein the medial bearing surface and the lateral bearing surface each are concave.

11 . A prosthesis for replacement of a least part of a knee joint in a leg, the leg including a femur and a tibia, the prosthesis comprising:
a femoral component adapted to fit on a distal end of the femur, the femoral component comprising:
a lateral condylar structure defining a lateral condylar bearing surface; and
a medial condylar structure defining a medial condylar bearing surface;
a tibial component adapted to fit on a proximal end of the tibia, the tibial component comprising:
a superior surface configured to cooperate with the lateral condylar bearing surface and the medial condylar bearing surface of the femoral component, the superior surface comprising a medial bearing surface and a lateral bearing surface; and
an inferior surface disposed on an opposite side of the tibial component from the superior surface, wherein:
the medial bearing surface comprises a posterior-most edge;
the lateral bearing surface comprises a posterior-most edge; and
a distance between the posterior-most edge of the medial bearing surface and the inferior surface is greater in a superior-inferior direction than a distance between the posterior-most edge of the lateral bearing surface and the inferior surface.

12 . The prosthesis of claim 11 , wherein:
the distance between the posterior-most edge of the medial bearing surface and the inferior surface is an average distance between the posterior-most edge of the medial bearing surface and the inferior surface along the posterior-most edge of the medial bearing surface; and the distance between the posterior-most edge of the lateral bearing surface and the inferior surface is an average distance between the posterior-most edge of the lateral bearing surface and the inferior surface along the posterior-most edge of the lateral bearing surface.

13 . The prosthesis of claim 11 , wherein:
the distance between the posterior-most edge of the medial bearing surface and the inferior surface is a minimum distance between the posterior-most edge of the medial bearing surface and the inferior surface along the posterior-most edge of the medial bearing surface; and the distance between the posterior-most edge of the lateral bearing surface and the inferior surface is a minimum distance between the posterior-most edge of the lateral bearing surface and the inferior surface along the posterior-most edge of the lateral bearing surface.

14 . The prosthesis of claim 11 , further comprising a central post positioned between the medial bearing surface and the lateral bearing surface.

15 . The prosthesis of claim 11 , wherein at least one of the medial bearing surface or the lateral bearing surface comprises a concave portion.

16 . The prosthesis of claim 11 , wherein the posterior-most edge of the medial bearing surface is an outermost edge of the medial bearing surface in a posterior direction and the posterior-most edge of the lateral bearing surface is an outermost edge of the lateral bearing surface in the posterior direction.

17 . The prosthesis of claim 11 , wherein the medial bearing surface and the lateral bearing surface each comprise a concave portion.

18 . A prosthesis for replacement of a least part of a knee joint in a leg, the leg including a femur and a tibia, the prosthesis comprising:
a femoral component adapted to fit on a distal end of the femur, the femoral component comprising:
a lateral condylar structure defining a lateral condylar bearing surface; and
a medial condylar structure defining a medial condylar bearing surface;
a tibial component adapted to fit on a proximal end of the tibia, the tibial component comprising:
a medial bearing surface and a lateral bearing surface, the medial bearing surface comprising a medial posterior-most edge and the lateral bearing surface comprising a lateral posterior-most edge,
wherein the medial bearing surface is thicker in a superior-inferior direction at the medial posterior-most edge than the lateral bearing surface at the lateral posterior-most edge.

19 . The prosthesis of claim 18 , wherein the medial bearing surface is thicker in the superior-inferior direction at an inferior-most point of the medial posterior-most edge than the lateral

Assignees

• Smith & Nephew Inc
• Univ Pennsylvania

Inventors

• Otto Jason K
• Mckinnon Brian William
• Hughes Michael Dean
• Ries Michael D
• Victor Jan
• Bellemans Johan
• Garino Jonathan
• Wilton Timothy

Classifications

• A61F2/389

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

• A61F2/3836

  Special connection between upper and lower leg, e.g. constrained · CPC title

• A61F2/3859

  Femoral components · CPC title

• A61F2/3886 Primary

  for stabilising knees against anterior or lateral dislocations · CPC title

• A61F2/3868

  with sliding tibial bearing · CPC title