Tibial insert with resistance-actuated post

Patent metadata

Field	Value
Publication number	US-10258477-B2
Application number	US-201214363766-A
Country	US
Kind code	B2
Filing date	Dec 6, 2012
Priority date	Dec 7, 2011
Publication date	Apr 16, 2019
Grant date	Apr 16, 2019

Abstract

Trial joint inserts may have posts that slide along a base, compressing or extending a resistance member, such as a spring, as the post slides. During joint replacement surgery, a surgeon can test resistance members with different amounts of resistance using a trial insert, identify a suitable resistance for the resistance member, and then select a permanent insert with a resistance member having the desired resistance. The systems, devices, and methods of this application allow a surgeon to provide an individualized joint replacement for a patient.

First claim

The invention claimed is:

1. A tibial insert of a knee system, the insert comprising;
a base;
a resistance-actuated stabilizing post coupled to the base and configured to move relative to the base;
a resistance member that interfaces with the post thereby modulating anterior-posterior movement of the resistance-actuated stabilizing post relative to the base based on a force applied to the resistance-actuated stabilizing post from direct contact with a femoral component of the knee system; and
an anchoring member adapted to anchor the resistance member to the base; wherein the base has a posterior portion and an anterior portion and a posterior-anterior axis extending therebetween, the resistance-actuated stabilizing post being coupled to the posterior portion of the base and being moveable along the anterior-posterior axis.

2. The insert of claim 1 , wherein the resistance-actuated stabilizing post is slidably coupled to the base.

3. The insert of claim 2 , wherein the base has a trough wherein the resistance-actuated stabilizing post is slidably disposed within the trough.

4. The insert of claim 3 , wherein the resistance member is disposed within the trough.

5. The insert of claim 2 , wherein a rail is coupled to the base and the stabilizing post is slidably mounted on the rail.

6. The insert of claim 1 , wherein the anchoring member comprises a clasp for anchoring the resistance member to the base.

7. The insert of claim 1 , wherein the anchoring member releasably anchors the resistance member to the base.

8. The insert of claim 1 , wherein the resistance member is disposed anterior to an entirety of the resistance-actuated stabilizing post.

9. The insert according to claim 8 , wherein the insert further comprising a second resistance member disposed anterior to the stabilizing post and a resistance member disposed posterior to the stabilizing post.

10. The insert of claim 1 , wherein the resistance member is disposed posterior to the stabilizing post.

11. The insert of claim 1 , wherein the resistance member compresses or extends when the resistance-actuated stabilizing post moves relative to the base.

12. The insert of claim 1 , wherein the resistance member is a spring.

13. The insert of claim 1 , wherein the insert further comprises an adjustment member that adjusts the resistance of the resistance member to the movement of the stabilizing post.

14. The insert of claim 13 , wherein the resistance member is a spring and wherein a first end of the spring exerts a force against the adjustment member and a second end of the spring exerts a force against the stabilizing post.

15. The insert of claim 14 , wherein the adjustment member is locatable at variable distances from the stabilizing post thereby modulating the resistance of the spring by compressing or extending the spring.

16. The insert of claim 14 , wherein the adjustment member comprises a plate.

17. The insert of claim 16 , wherein the adjustment member is disposable within the trough of the base.

18. The insert of claim 1 , wherein the resistance member is a spring and wherein the resistance to movement of the stabilizing post is adjusted by altering the curvature of the spring.

19. The insert of claim 1 , wherein the stabilizing post has an engagement member for engaging with the resistance member and wherein the resistance to movement of the stabilizing post is increased by engaging the engagement member with the resistance member.

20. The insert of claim 19 , wherein the insert comprises at least two resistance members and wherein the engagement member is configured to independently engage with each of the resistance members.

21. The insert of claim 20 , wherein the insert comprises at least two engagement members and wherein each of the engagement members are configured to independently engage with the at least two resistance members.

22. The insert of claim 20 , wherein the resistance members are springs.

23. The insert of claim 22 , wherein the springs have different spring constants.

24. The insert of claim 1 , wherein the stabilizing post and the base are each provided with a reference mark thereby enabling the position of the post relative to the base to be determined.

25. The insert of claim 24 , wherein the reference mark is a visual mark.

26. The insert of claim 25 , wherein the visual mark is a selected from the group consisting of; a raised ridge, a channel, a biocompatible paint or biocompatible dye.

27. The insert of claim 24 , wherein the stabilizing post has a lateral side and a medial side and wherein the reference mark is provided on at least one of the lateral side and a medial side of the stabilizing post.

28. The insert of claim 1 , wherein the insert is a non load-bearing trial insert.

29. The insert of claim 1 , wherein the insert is a load-bearing permanent insert.

30. The insert of claim 1 , further comprising a force meter that indicates the amount of force applied to the stabilizing post by the resistance member.

31. The insert of claim 1 , wherein the resistance member compresses when the resistance-actuated stabilizing post moves anteriorly relative to the base from the force applied to the resistance-actuated stabilizing post from direct contact with the femoral component during movement of a corresponding knee joint from extension to flexion.

32. The insert of claim 31 , wherein the resistance member applies a resistance member force to the resistance-actuated stabilizing force; and
wherein a cam of the femoral component applies a cam force to the resistance-actuated stabilizing force during contact with the resistance-actuated stabilizing post.

33. The insert of claim 32 , wherein the resistance member force is at least as great as the cam force when the corresponding knee joint is in extension; and
wherein the cam force exceeds the resistance member force as the corresponding knee joint is flexed causing the resistance-actuated stabilizing post to move anteriorly relative to the base.

34. The insert of claim 1 , wherein the base is an ovoid-shaped base.

35. The insert of claim 1 , wherein resistance-actuated posterior stabilizing post includes a posterior surface that is perpendicular to the base and an anterior surface that is angled non-perpendicularly relative to the base.

36. The insert of claim 35 , wherein the anterior surface that is angled non-perpendicularly relative to the base is a first anterior surface;
wherein the resistance-actuated posterior stabilizing post includes a superior surface that connects the first anterior surface and the posterior surface; and
wherein the resistance-actuated posterior stabilizing post includes a second anterior surface that is perpendicular to the base and has a shared edge with the first anterior surface.

37. The insert of claim 36 , wherein the second anterior surface and an inferior portion of the posterior surface are disposed within the trough.

38. A tibial insert of a knee system, the insert comprising;
a base;
a resistance-actuated stabilizing post coupled to the base and configured to move relative to the base; and
a resistance member that interfaces with the resistance-actuated stabilizing post th

Assignees

• Smith & Nephew Inc

Inventors

• Jordan Jason S

Classifications

• A61F2002/30568

  Multiple spring systems including two or more helical springs · CPC title

• A61F2/389

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

• A61F2002/30387

  Dovetail connection · CPC title

• A61F2002/30565

  having spring elements · CPC title

• A61F2/3868 Primary

  with sliding tibial bearing · CPC title