High performance knee prostheses

Patent metadata

Field	Value
Publication number	US-11369477-B2
Application number	US-201816157463-A
Country	US
Kind code	B2
Filing date	Oct 11, 2018
Priority date	Dec 20, 2002
Publication date	Jun 28, 2022
Grant date	Jun 28, 2022

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 knee prosthesis, comprising:
(a) a tibial component, comprising:
(i) a medial bearing surface;
(ii) a lateral bearing surface; and
(iii) a post between the medial and lateral bearing surfaces, the post comprising a medial side, a lateral side, and a posterior side extending between the medial and lateral sides, wherein the posterior side extending between the medial and lateral sides includes a concavely curved surface, wherein at least a superior portion of the posterior side extends in a straight line in a superior to inferior direction; and

(b) a femoral component, comprising:
(i) a medial condyle configured to articulate relative to the medial bearing surface;
(ii) a lateral condyle configured to articulate relative to the lateral bearing surface;
(iii) an intra-condylar notch between the medial and lateral condyles; and

(iv) a posterior cam extending between the medial and lateral condyles in the intra-condylar notch, wherein an inferior portion of the posterior cam extending between the medial and lateral condyles includes a concavely curved surface; and
wherein at least one of the femoral and tibial components is custom-designed for a specific patient based on radiographic data obtained from the specific patient.

2. The knee prosthesis of claim 1 , wherein the medial condyle projects further than the lateral condyle distally and posteriorly.

3. The knee prosthesis of claim 2 , further comprising a tibial tray, the tibial component configured to lock to the tibial tray such that the tibial component is non-rotatably secured to the tibial tray.

4. A knee prosthesis, comprising:
(a) a tibial component, comprising:
(i) a medial bearing surface;
(ii) a lateral bearing surface; and
(iii) a post between the medial and lateral bearing surfaces, the post comprising a medial side, a lateral side, and a posterior side extending between the medial and lateral sides, wherein the posterior side extending between the medial and lateral sides includes a concavely curved surface; and

(b) a femoral component, comprising:
(i) a medial condyle configured to articulate relative to the medial bearing surface;
(ii) a lateral condyle configured to articulate relative to the lateral bearing surface;
(iii) an intra-condylar notch between the medial and lateral condyles; and
(iv) a posterior cam extending between the medial and lateral condyles in the intra-condylar notch, wherein an inferior portion of the posted or cam extending between the medial and lateral condyles includes a concavely curved surface; and
wherein the tibial and femoral components are configured such that, during flexion of the femoral component on the tibial component, the lateral condyle rolls back a greater distance in a posterior direction than a corresponding distance of medial condyle rollback.

5. The knee prosthesis of claim 4 , wherein the medial condyle projects further than the lateral condyle distally and posteriorly.

6. The knee prosthesis of claim 4 , wherein at least a superior portion of the posterior side of the post extends in a straight line in a superior to inferior direction.

7. The knee prosthesis of claim 6 , wherein the femoral and tibial components are configured such that the posterior cam is in contact with the posterior side of the post at an articulation of the femoral component on the tibial component of at least 50 degrees of flexion.

8. The knee prosthesis of claim 6 , wherein the femoral and tibial components are configured such that the posterior cam is in contact with the posterior side of the post at an articulation of the femoral component on the tibial component of at least 90 degrees of flexion.

9. The knee prosthesis of claim 8 , wherein the tibial and femoral components are configured such that, during flexion of the femoral component on the tibial component, the tibial component internally rotates relative to the femoral component.

10. The knee prosthesis of claim 8 , wherein the tibial and femoral components are configured such that, during flexion of the femoral component on the tibial component, the tibial component internally rotates relative to the femoral component while the posterior cam is in contact with the posterior side of the post.

11. The knee prosthesis of claim 8 , wherein the tibial and femoral components are configured such that, at a flexion angle greater than 120 degrees, an anterior, tapered portion of the post extends out of the intra-condylar notch.

12. The knee prosthesis of claim 6 , wherein the femoral and tibial components are configured such that the posterior cam is in contact with the posterior surface at an articulation of the femoral component on the tibial component of at least 130 degrees of flexion.

13. A knee prosthesis, comprising:
(a) a tibial component, comprising:
(i) a medial hearing surface;
(ii) a lateral bearing surface; and
(iii) a post between the medial and lateral hearing surfaces, the post comprising a medial side, a lateral side, and a posterior side extending between the medial and lateral sides, wherein the posterior side extending between the medial and lateral sides includes a concavely curved surface; and

(b) a femoral component, comprising:
(i) a medial condyle configured to articulate relative to the medial bearing surface;
(ii) a lateral condyle configured to articulate relative to the lateral bearing surface;
(iii) an intra-condylar notch between the medial and lateral condyles; and
(iv) a posterior cam extending between the medial and lateral condyles in the intra-condylar notch, wherein an inferior portion of the posterior cam extending between the medial and lateral condyles includes a concavely curved surface; and

wherein at least one of the femoral and tibial components is custom-designed for a specific patient based on radiographic data obtained from the specific patient.

14. The knee prosthesis of claim 13 , wherein the tibial and femoral components are configured such that, during flexion of the femoral component on the tibial component, the tibial component internally rotates relative to the femoral component.

15. The knee prosthesis of claim 14 , wherein the tibial and femoral components are configured such that, during flexion of the femoral component on the tibial component, the lateral condyle glides in a posterior direction on the tibial component.

16. The knee prosthesis of claim 14 , wherein the tibial and femoral components are configured such that, during at least 130 degrees flexion of the femoral component on the tibial component, the tibial component internally rotates by at least 8 degrees relative to the femoral component.

17. The knee prosthesis of claim 14 , wherein the tibial and femoral components are configured to accommodate at least 8 degrees of internal rotation of the tibial component relative to the femoral component during flexion.

18. The knee prosthesis of claim 13 , wherein the tibial and femoral components are configured such that, during flexion of the femoral component on the tibial component, the lateral condyle rolls back a greater distance in a posterior direction than a corresponding distance of medial condyle rollback.

19. The knee prosthesis of claim 13 , wherein the tibial and femoral components are configured to define a joint line at zero degrees of flexion in which a medial side of the joint line is inferior to a lateral side of the joint line.

20. The knee prosthesis of claim 13 , wherein the medial condyle projects further than the lateral condyle distal

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

• A61F2/3868

  with sliding tibial bearing · CPC title

• A61F2/3836

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

• A61F2/389

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

• A61F2/3859

  Femoral components · CPC title

• A61F2/3886 Primary

  for stabilising knees against anterior or lateral dislocations · CPC title