Dynamic stabilization device for bones, in particular for vertebrae

• US 20040049190A1
• Filed: 08/07/2003
• Published: 03/11/2004
• Est. Priority Date: 08/09/2002
• Status: Active Grant

• Current Assignee: Biedermann Technologies GmbH & Co. KG
• Original Assignee: Biedermann Motech GmbH
• Inventors: Biedermann, Lutz, Jeszensky, Dezso
• Granted Patent: US 7,722,649 B2
• Time in Patent Office: Days
• US Class Current: 606/61
• CPC Class Codes: A61B 17/7008 with parts of, or attached to, the longitudinal elements, bearing against an outside of the screw or hook heads, e.g. nuts on threaded rods A61B17/7007 takes precedence
• CPC Class Codes: A61B 17/702 having a core or insert, and a sleeve, whereby a screw or hook can move along the core or in the sleeve
• CPC Class Codes: A61B 17/7032 Screws or hooks with U-shaped head or back through which longitudinal rods pass
• CPC Class Codes: A61B 17/7035 Screws or hooks, wherein a rod-clamping part and a bone-anchoring part can pivot relative to each other
• CPC Class Codes: A61B 2017/00845 of moving parts with respect to each other

Abstract

A dynamic stabilization device for bones, in particular vertebrae, is made with two bone anchoring elements and a rigid rod with a longitudinal axis connecting them. An elastic element is inserted between the two bone anchoring elements. It acts on the bone anchoring elements to exert a force in a direction of the longitudinal axis. Each bone anchoring element has a first section to be anchored in a bone and a second section to be connected to the rod. At least one of the bone anchoring elements is fixedly connected to the rod to prevent translational movement of the rod relative to it. Further, at least one of the bone anchoring elements is a polyaxial bone screw. Also disclosed is a method for stabilizing vertebrae adjacent to a defective intervertebral disc. A dynamic stabilization device is provided. The anchoring elements are attached to two vertebrae on opposite sides of the defective intervertebral disc. Then, the bone anchoring elements are alligned to connect the rod therebetween with the elastic element positioned between the bone anchoring elements. Finally, one of the bone anchoring elements is connected fixedly to the rod to prevent translational movement of the rod relative to it.

Claims

1. A dynamic stabilization device for bones, said device comprising:

a first bone anchoring element;

a second bone anchoring element;

a rod having a longitudinal axis connecting the two bone anchoring elements; and

an elastic element between the first and the second bone anchoring element and acting on the first and the second bone anchoring element to exert a force in a direction of the longitudinal axis;

each bone anchoring element comprising a first section to be anchored in a bone and a second section to be connected to the rod;

at least one of the bone anchoring elements comprising a polyaxial bone screw.

2. The dynamic stabilization device according to claim 1, wherein the rod is a rigid rod.

3. The dynamic stabilization device according to claim 1, wherein at least one of the bone anchoring elements is fixedly connected to the rod so as to prevent translational movement of the rod relative to the at least one of the bone anchoring elements.

4. The dynamic stabilization device according to claim 1, wherein one of the bone anchoring elements is slideably connected to the rod and wherein the device further comprises a stop to limit the movement of the slideably connected bone anchoring element.

5. The dynamic stabilization device according to claim 1, wherein the first section comprises a shank with a second longitudinal axis for anchoring in the bone and the second section comprises a receiving part with a cylindrical axis, the receiving part being connected in an articulated manner to the shank for receiving the rod, and wherein the shank and the receiving part can be fixed relative to one another at an angle between the second longitudinal axis and the cylindrical axis.

6. The dynamic stabilization device according to claim 1, further comprising a stop, wherein the polyaxial bone anchoring element is slideably connected to the rod and and located adjacent to the stop to limit the movement thereof.

7. The dynamic stabilization device according to claim 1, wherein the rod is coated with a material having a low coefficient of friction.

8. The dynamic stabilization device according to claim 6, wherein the material is a high molecular weight polyethylene.

9. The dynamic stabilization device according to claim 1, wherein one of the bone anchoring elements comprises a material having a low coefficient of friction for contacting the rod.

10. The dynamic stabilization device according to claim 7, wherein the material is a high molecular weight polyethylene.

11. The dynamic stabilization device according to claim 1, wherein the elastic element comprises a spring.

12. The dynamic stabilization device according to claim 1, wherein the elastic element comprises a helical spring that is located around the rod.

13. The dynamic stabilization device according to claim 1, wherein the rod comprises two sleeve-shaped sections and the elastic element comprises a spring positioned inside the two sleeve-shaped sections.

14. The dynamic stabilization device according to claim 1, wherein each of the bone anchoring elements comprise a bone screw or a bone hook.

15. A dynamic stabilization device for bones, said device comprising:

a first bone anchoring element;

a second bone anchoring element;

a rod having a longitudinal axis connecting the two bone anchoring elements; and

an elastic element between the first and the second bone anchoring element and acting on the first and the second bone anchoring element to exert a force in a direction of the longitudinal axis;

each bone anchoring element comprising a comprises a shank with a second longitudinal axis for anchoring in the bone and a receiving part with a cylindrical axis, the receiving part being connected to the rod;

at least one of the bone anchoring elements is a polyaxial bone anchoring element

16. The dynamic stabilization device according to claim 15, wherein the rod is a rigid rod.

17. The dynamic stabilization device according to claim 15, wherein wherein at least one of the bone anchoring elements is fixedly connected to the rod so as to prevent translational movement of the rod relative to the at least one of the bone anchoring elements.

18. The dynamic stabilization device according to claim 15, wherein one of the bone anchoring elements is slideably connected to the rod and wherein the device further comprises a stop to limit the movement of the slideably connected bone anchoring element.

19. The dynamic stabilization device according to claim 15, further comprising a stop, wherein the polyaxial bone anchoring element is slideably connected to the rod and and located adjacent to the stop to limit the movement thereof.

20. The dynamic stabilization device according to claim 15, wherein the elastic element comprises a spring.

21. The dynamic stabilization device according to claim 15, wherein the elastic element comprises a helical spring that is located around the rod.

22. The dynamic stabilization device according to claim 15, wherein the rod comprises two sleeve-shaped sections and the elastic element comprises a spring positioned inside the two sleeve-shaped sections.

23. A method for stabilizing vertebrae adjacent to a defective intervertebral disc, the method comprising:

providing a dynamic stabilization device comprising a first bone anchoring element, a second bone anchoring element, a rod having a longitudinal axis connecting the two bone anchoring elements and an elastic element between the first and the second bone anchoring element and acting on the first and the second bone anchoring element to exert a force in a direction of the longitudinal axis, wherein each bone anchoring element comprises a first section to be anchored in a bone and a second section to be connected to the rod, and wherein at least one of the bone anchoring elements comprising a polyaxial bone screw;

attaching the first and second bone anchoring elements to two vertebrae on opposite sides of the defective intervertebral disc; and

aligning the second section of both of the first and second bone anchoring elements to connect the rod therebetween with the elastic element positioned between the first and second bone anchoring elements.

24. The method for stabilizing vertebrae according to claim 23, wherein the device further comprises a stop on one end of the rod, the method further comprising:

positioning the device with rod oriented with the stop pointed toward the head of a patient; and

slideably connecting one the bone anchoring elements to the rod adjacent to the stop to limit the movement of the slideably connected bone anchoring element.

25. The method for stabilizing vertebrae according to claim 23, wherein the device further comprises a stop on one end of the rod, the method further comprising:

positioning the device with rod oriented with the stop pointed toward the head of a patient; and

slideably connecting the polyaxial bone screw to the rod adjacent to the stop to limit the movement of the slideably connected bone anchoring element.

26. The method for stabilizing vertebrae according to claim 23, wherein the device comprises a rigid rod.

27. The method for stabilizing vertebrae according to claim 23, further comprising fixedly connecting at least one of the bone anchoring elements to the rod so as to prevent translational movement of the rod relative to the at least one of the bone anchoring elements.