Device for osteosynthesis

Patent metadata

Field	Value
Publication number	US-9271771-B2
Application number	US-14714005-A
Country	US
Kind code	B2
Filing date	Jun 6, 2005
Priority date	Dec 6, 2002
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

Abstract

A device of performing osteosynthesis includes an osteosynthesis element, e.g., a bone plate, having an upper face, a lower face and an opening with a central axis linking the upper and lower faces. The opening receives a multi-axial pivotable insert for a longitudinal bone fixing element, such as a bone screw. The insert has a central passage with a longitudinal axis for housing the bone fixing element. The insert may be configured as a helical spring with an external sheath surface and an internal sheath surface that defines the central passage. When placed in the through hole, the insert is rotationally fixed relative to its longitudinal axis, but remains pivotally adjustable within the through hole relative to the osteosynthesis element.

First claim

The invention claimed is:

1. A device for holding a bone fixation element at a user selected angle, comprising:
an osteosynthesis element having a bone fixation element receiving opening defining a central axis extending therethrough; and
a helical spring insert sized and shaped to be mounted in the opening, a radial inner surface thereof defining an engaging surface for mounting a threaded head of a bone fixation element therein at any user selected angle relative to the central axis of the opening within a permitted range of angulation.

2. The device of claim 1 , wherein the helical spring is non-round.

3. The device of claim 2 wherein the helical spring is prismatic.

4. The device of claim 1 , wherein the opening in the osteosynthesis element has a non-round cross-section.

5. The device of claim 4 , wherein the opening in the osteosynthesis element has a prismatic cross-section.

6. The device of claim 4 , wherein a longitudinal cross-section of an outer surface of the helical spring has substantially the same shape as the cross-section of the opening through the osteosynthesis element.

7. The device of claim 1 , wherein the helical spring is one of radially compressible and expandable.

8. The device of claim 1 , wherein the insert is fixed in the opening to prevent rotation thereof relative to a longitudinal axis thereof and configured and adapted to remain partially axially movable within the opening relative to the osteosynthesis element.

9. The device of claim 1 , wherein the cross-section of the opening in the osteosynthesis element is polygonal.

10. The device of claim 9 , wherein the cross-section of the opening in the osteosynthesis element is hexagonal.

11. The device of claim 1 , wherein the opening is generally prismatic.

12. The device of claim 1 , wherein the opening through the osteosynthesis element conically widens in at least one direction along its central axis.

13. The device of claim 1 , wherein a central passage of the insert conically widens in at least one direction along a longitudinal axis thereof.

14. The device of claim 1 , wherein a central passage of the insert is generally prismatic.

15. The device of claim 1 , wherein a shape of a central passage of the insert is generally cylindrical.

16. The device of claim 1 , wherein at least one surface of the insert is roughened.

17. The device of claim 1 , wherein at least one surface of the insert is coated with a harder material than the insert.

18. The device of claim 1 , wherein the opening through the osteosynthesis element is roughened.

19. The device of claim 1 , wherein the opening through the osteosynthesis element is provided with a coating of a harder material than that of the osteosynthesis element.

20. The device of claim 1 , wherein the opening through the osteosynthesis element includes peripheral grooves that extend around a circumference of the opening.

21. The device of claim 1 , wherein the opening through the osteosynthesis element narrows in cross-section at first and second ends thereof to maintain the insert therein.

22. The device of claim 1 , wherein an outer surface of the insert is convex.

23. The device of claim 1 , wherein the opening through the osteosynthesis element is concave.

24. The device of claim 1 , wherein the osteosynthesis element and the insert are formed of different materials.

25. The device of claim 24 , wherein the osteosynthesis element is formed of plastic and the insert is metallic.

26. The device of claim 1 , wherein the insert has a height measured along its longitudinal axis that is smaller than a height of the opening through the osteosynthesis element measured in the direction of its central axis.

27. The device of claim 26 , wherein the height of the insert ranges from 40% to 85% of the height of the opening.

28. The device of claim 1 , further comprising a bone screw having a threaded shaft for engagement of bone and a threaded head sized and shaped for mounting in the central passage of the insert at an angle relative to the central axis thereof selected by a user.

29. The device of claim 1 , wherein the osteosynthesis element is a bone plate.

30. The device of claim 1 , wherein the osteosynthesis element is one of a pedicle screw and a pedicle hook.

31. The device of claim 1 , wherein the osteosynthesis element is an external fixator.

32. The device of claim 1 , wherein the osteosynthesis element is an intervertebral implant.

33. The device of claim 28 , wherein a pitch of windings of the helical spring corresponds to a pitch of an outside thread of the screw head.

34. A device for holding a bone fixation element at a user selected angle, comprising:
a bone plate having a bone fixation element receiving opening defining a central axis extending therethrough; and
a helical spring insert sized and shaped to be mounted in the opening, a radial inner surface thereof defining an engaging surface for mounting a threaded head of a bone fixation element at any surgeon selected angle relative to the central axis of the opening within a permitted range of angulation, wherein the insert is configured and adapted to be secured against rotation relative to a longitudinal axis thereof while remaining pivotally adjustable relative to the central axis of the opening.

35. The device of claim 34 , wherein a shape of the insert is substantially hexagonal.

Assignees

• Mathieu Claude
• Frigg Robert
• Schneider Rolf
• Appenzeller Andreas
• Depuy Synthes Products Inc

Inventors

• Mathieu Claude
• Frigg Robert
• Schneider Rolf
• Appenzeller Andreas

Classifications

• A61B17/8047 Primary

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