Bone anchoring device

Patent metadata

Field	Value
Publication number	US-9289246-B2
Application number	US-201414584287-A
Country	US
Kind code	B2
Filing date	Dec 29, 2014
Priority date	Jul 31, 2007
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A bone anchoring device includes a bone anchoring element having a shaft for anchoring in the bone and a head; and a receiving part for coupling a rod to the bone anchoring element. The receiving part includes a first portion with a first end and a second end and a U-shaped recess for receiving the rod, the recess extending from the first end in the direction of the second end thereby forming two free legs and a second portion at the side of the second end opposite to the first end for accommodating the head, the second portion having a free end and being flexible so as to allow introduction and clamping of the head. The bone anchoring device also includes a locking ring embracing the second portion. The head is locked by means of exerting pressure with the rod onto the locking ring resulting in compression of the second portion of the receiving part and wherein the locking ring is mounted to the receiving part from the free end of the second portion.

First claim

What is claimed is:

1. A bone anchoring device comprising:
a bone anchoring element having a shaft for anchoring to a bone and a head;
a receiving part for coupling a rod to the bone anchoring element, wherein the receiving part comprises:
a first portion comprising two legs each having a free end and defining a U-shaped recess for receiving the rod; and
a second portion defining an accommodation space for accommodating the head, the second portion having a free end and being flexible to allow introduction of the head into the accommodation space and clamping of the head when the head is in the accommodation space; and

a locking ring configured to be mounted to the receiving part from the free end of the second portion and to be positioned around the second portion, the locking ring comprising at least one projection configured to be positioned in the U-shaped recess and a structure on the projection configured to engage the receiving part for restricting axial movement of the locking ring relative to the receiving part; and
wherein when the head is in the accommodation space, the locking ring is configured to compress the second portion of the receiving part to lock a position of the head relative to the receiving part.

2. The bone anchoring device according to claim 1 , wherein the diameter of the second portion of the receiving part adjacent to the first portion of the receiving part is smaller than the diameter of the first portion adjacent to the second portion.

3. The bone anchoring device according to claim 1 , wherein the locking ring is movable along the second portion of the receiving part between a first position limited by the first portion and a second position limited by the free end of the second portion.

4. The bone anchoring device according to claim 1 , wherein the outer diameter of the locking ring is smaller than or equal to the outer diameter of the first portion.

5. The bone anchoring device according to claim 1 , wherein the second portion of the receiving part has a conical outer surface tapering toward the first portion.

6. The bone anchoring device according to claim 5 , wherein the locking ring has a section with a conically tapering inner surface corresponding to the conical outer surface of the second portion.

7. The bone anchoring device according to claim 6 , wherein a cone angle is selected to provide self-locking between the locking ring and the second portion.

8. The bone anchoring device according to claim 7 , wherein the cone angle is between approximately 2° and approximately 10°.

9. The bone anchoring device according to claim 1 , wherein the second portion comprises a plurality of slits open to the free end of the second portion.

10. The bone anchoring device according to claim 9 , wherein at least one of the plurality of slits extends continuously from the second portion into the first portion.

11. The bone anchoring device according to claim 1 , wherein the first portion comprises a plurality of slits extending from a distance from the free end of the legs toward the second end.

12. The bone anchoring device according to claim 1 , wherein the head is spherical segment-shaped and the second portion comprises an inner surface with a corresponding spherical portion to allow a pivotal movement of the head.

13. The bone anchoring device according to claim 1 , wherein the head is cylindrically-shaped and the second portion comprises an inner surface with a corresponding cylindrical portion to restrict the movement of the head to a rotational movement about a single axis.

14. The bone anchoring device according to claim 1 , wherein a closure element is provided for securing the rod in the recess.

15. The bone anchoring device according to claim 1 , wherein a plane going through the free end of the second portion is arranged at an angle to an end defined by the free ends of the legs.

16. The bone anchoring device according to claim 1 , wherein at least the second portion comprises an elastic plastic material with no slits.

17. The bone anchoring device according to claim 1 , wherein the locking ring and the second portion of the receiving part comprise respective contacting surfaces configured to come into contact with one another, and wherein at least one of the contacting surfaces comprises a surface structure to hold a position of the locking ring relative to the receiving part.

18. The bone anchoring device according to claim 17 , wherein the surface structure comprises at least one rib or a roughened surface.

19. The bone anchoring device according to claim 1 , wherein the locking ring has an annular edge extending in a same direction as the projection, and wherein the edge is configured to surround a portion of the first portion of the receiving part when the head is clamped.

20. A method of attaching a bone anchoring device to a bone or vertebrae, the bone anchoring device comprising a bone anchoring element having a shaft for anchoring to a bone and a head, a receiving part for coupling a rod to the bone anchoring element, wherein the receiving part comprises a first portion comprising two legs each having a free end and defining a U-shaped recess for receiving the rod, and a second portion defining an accommodation space for accommodating the head, the second portion having a free end and being flexible to allow introduction of the head into the accommodation space and clamping of the head when the head is in the accommodation space, and a locking ring configured to be mounted to the receiving part from the free end of the second portion and to be positioned around the second portion, the locking ring comprising at least one projection configured to be positioned in the U-shaped recess and a structure on the projection configured to engage the receiving part for restricting axial movement of the locking ring relative to the receiving part, the method comprising:
attaching the bone anchoring element to a bone or vertebrae;
inserting the head of the bone anchoring element into the accommodation space of the the second portion of the receiving part;
inserting the rod in the U-shaped recess; and
exerting pressure on the locking ring by the rod to move the locking ring to a position where the locking ring compresses the second portion of the receiving part to lock a position of the head relative to the receiving part.

Assignees

• Biedermann Technologies Gmbh

Inventors

• Biedermann Lutz
• Matthis Wilfried
• Dannecker Berthold

Classifications

• A61B17/7032

  Screws or hooks with U-shaped head or back through which longitudinal rods pass · CPC title

• A61B17/7034

  characterised by a lateral opening · CPC title

• A61B17/7037 Primary

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

• A61B17/60 Primary

  for external osteosynthesis, e.g. distractors, contractors · CPC title

• A61B17/58

  for osteosynthesis, e.g. bone plates, screws or setting implements (A61B17/14, A61B17/16 take precedence) · CPC title