Dynamic bone fixation element and method of using the same

Patent metadata

Field	Value
Publication number	US-9763712-B2
Application number	US-201615211482-A
Country	US
Kind code	B2
Filing date	Jul 15, 2016
Priority date	Dec 17, 2007
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

The present invention relates to dynamic bone fixation elements and a surgical method to stabilize bone or bone fragments. The dynamic bone fixation elements preferably include a bone engaging component and a load carrier engaging component. The bone engaging component preferably includes a plurality of threads for engaging a patient's bone and a lumen. The load carrier engaging component preferably includes a head portion for engaging a load carrier (e.g., bone plate) and a shaft portion. The shaft portion preferably at least partially extends into the lumen. Preferably at least a portion of an outer surface of the shaft portion is spaced away from at least a portion of an inner surface of the lumen via a gap so that the head portion can move with respect to the bone engaging component. The distal end of the shaft portion is preferably coupled to the lumen.

First claim

We claim:

1. A bone fixation system comprising:
a bone plate defining a first surface configured to face bone, a second surface that is opposite the first surface, and at least one internal surface that defines an opening that extends through the bone plate from the first surface to the second surface;
at least one bone fixation element comprising a head, and a shaft that extends from the head to a distal end of the shaft along a central axis of the bone fixation element, the head having a portion that is configured to be disposed in the opening, wherein the portion defines a cross-sectional dimension along a direction that is perpendicular to the central axis, the cross-sectional dimension being greater than any other dimension of the head along the direction; and
a resilient member configured to be disposed in the opening such that, when the resilient member and the head are disposed in the opening, the bone plate is moveable relative to the central axis of the bone fixation element.

2. The bone fixation system of claim 1 , wherein the bone fixation system is configured such that, when the resilient member and the head are disposed in the opening, the bone plate is movable along a first direction and the resilient member applies a biasing force that biases the bone plate along a direction opposite the first direction.

3. The bone fixation system of claim 1 , wherein the resilient member is disposed between the internal surface of the bone plate and the central axis when the resilient member and the head are received in the opening.

4. The bone fixation system of claim 1 , wherein the resilient member is disposed on opposed sides of the central axis when the resilient member and the head are received in the opening.

5. The bone fixation system of claim 4 , wherein the resilient member is configured such that the resilient member expands on one of the opposed sides as the resilient member compresses on the other of the opposed sides.

6. The bone fixation system of claim 1 , wherein the resilient member includes a damper material.

7. The bone fixation system of claim 1 , wherein the resilient member includes a spring.

8. The bone fixation system of claim 1 , wherein the resilient member applies a biasing force to the bone fixation element in a direction that is perpendicular to the longitudinal axis when the resilient member and the head are received in the opening.

9. The bone fixation system of claim 1 , wherein the shaft is threaded.

10. The bone fixation system of claim 1 , wherein the bone plate is moveable along a direction having a direction component that is transverse to the central axis.

11. A method of fixing a bone plate to a bone of a patient, the method comprising steps of:
aligning the bone plate with the bone such that a first surface of the bone plate faces the bone and a second surface of the bone plate is opposite the first surface; and
coupling the bone plate to the bone via at least one bone fixation element having a head and a shaft that extends from the head along a central axis and via at least one resilient member such that (i) the at least one resilient member and at least a portion of the head of the at least one bone fixation element are disposed in an opening that extends through the bone plate from the first surface to the second surface, the portion defining a cross-sectional dimension along a direction that is perpendicular to the central axis, the cross-sectional dimension being greater than any other dimension of the head along the direction, (ii) the shaft of the bone fixation element extends into the bone, and (iii) the at least one resilient member permits the bone plate to move relative to the central axis of the bone fixation element.

12. The method of claim 11 , wherein the coupling step includes inserting the shaft of the at least one bone fixation element through the opening and into the bone until the head is received in the opening.

13. The method of claim 11 , comprising coupling the bone plate to the bone such that the bone plate is movable along a first direction and the resilient member applies a biasing force that biases the bone plate along a direction opposite the first direction.

14. The method of claim 11 , wherein the coupling step comprises disposing the at least one bone fixation element in the opening such that the resilient member is disposed between the central axis of the at least one bone fixation element and an internal surface of the bone plate that defines the opening.

15. The method of claim 11 , wherein the coupling step comprises disposing the at least one bone fixation element in the opening such that the resilient member is disposed on opposed sides of the central axis.

16. The method of claim 15 , wherein the coupling step comprises disposing the at least one bone fixation element in the opening such that the resilient member expands on one of the opposed sides of the central axis as the resilient member compresses on the other of the opposed sides.

17. The method of claim 11 , wherein the resilient member includes a damper material.

18. The method of claim 11 , wherein the resilient member includes a spring.

19. The method of claim 11 , wherein the coupling step comprises disposing the at least one bone fixation element in the opening such that the resilient member applies a biasing force to the bone fixation element in a direction that is perpendicular to the central axis.

20. The method of claim 11 , wherein the coupling step comprises rotating the bone fixation element such that threading on the shaft engage the bone.

21. A bone fixation system comprising:
a bone plate defining a first surface configured to face bone, a second surface that is opposite the first surface, and at least one internal surface that defines an opening that extends through the bone plate from the first surface to the second surface;
at least one bone fixation element comprising a head configured to be disposed in the opening, and a shaft that extends from the head to a distal end of the shaft along a central axis of the bone fixation element; and
a resilient member configured to be disposed in the opening and on opposed sides of the central axis within the opening when the resilient member and the head are received in the opening such that, when the resilient member and the head are disposed in the opening, the bone plate is moveable relative to the central axis of the bone fixation element.

22. The bone fixation system of claim 21 , wherein the resilient member is configured such that the resilient member expands on one of the opposed sides as the resilient member compresses on the other of the opposed sides.

23. The bone fixation system of claim 21 , wherein the resilient member is disposed between the internal surface of the bone plate and the central axis when the resilient member and the head are received in the opening.

24. The bone fixation system of claim 21 , wherein the resilient member includes a damper material.

25. The bone fixation system of claim 21 , wherein the resilient member includes a spring.

Assignees

• Depuy Synthes Products Inc

Inventors

• Appenzeller Andreas
• Frigg Robert
• Lechmann Beat
• Voisard Cyril
• Zurschmiede Silas
• Hulliger Urs

Classifications

• A61B17/861

  specially shaped for gripping driver · CPC title

• A61B17/866

  Material or manufacture · CPC title

• A61B17/686

  Plugs, i.e. elements forming interface between bone hole and implant or fastener, e.g. screw · CPC title

• A61B17/8047

  wherein the additional element surrounds the screw head in the plate hole (A61B17/8052 takes precedence) · CPC title

• A61B17/7037

  wherein pivoting is blocked when the rod is clamped · CPC title