Bone anchoring device

Patent metadata

Field	Value
Publication number	US-9486245-B2
Application number	US-60980009-A
Country	US
Kind code	B2
Filing date	Oct 30, 2009
Priority date	Nov 22, 2006
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

A bone anchoring device includes a shank to be anchored in a bone or vertebra, a head, and a receiving part receiving the head for connecting the shank to a rod. The shank and the head are separate parts. The head has a bore with a cylindrical inner surface, a ring-shaped groove provided on the inner surface, and at least one slit extending from the inner surface to the outer surface of the head. The shank has a first portion for anchoring in the bone or vertebra and a second portion with a cylindrical outer surface adjoining a free end. A projection is provided on the cylindrical outer surface which engages with the ring-shaped groove of the head, when the cylindrical second portion of the shank is inserted in the bore of the head.

First claim

What is claimed is:

1. A bone anchoring device comprising:
a shank to be anchored in a bone or vertebra, a head having an outer surface that is substantially shaped as a segment of a sphere, a receiving part receiving the head for connecting the shank to a rod, and a pressure element,
the shank and the head being separate parts;
the head having a first end, a second end, and a bore with a cylindrical inner surface having a first diameter at the first and second ends when unbiased, the cylindrical inner surface interrupted by a ring-shaped groove or a projection, wherein a plurality of slits are provided in the head which alternately extend from the first end of the head to a predetermined distance from the second end of the head and from the second end of the head to a predetermined distance from the first end of the head, respectively, and wherein at least one of the slits extends from the inner surface to the outer surface of the head;
the shank having a first portion for anchoring in the bone or vertebra and a second portion with a cylindrical outer surface having a second diameter that is greater than the first diameter, the cylindrical outer surface interrupted by a projection or a ring-shaped groove;
wherein when the cylindrical outer surface of the shank is inserted into the bore of the head, the first end and the second end of the bore each expands to at least the second diameter;
wherein when the projection is provided on the inner surface of the head, the projection is constructed in one-piece with the head, the cylindrical inner surface comprises a first cylindrical section extending from the projection and a second cylindrical section extending from the projection on a side opposite the first cylindrical section of the cylindrical inner surface, and wherein the projection engages with the ring-shaped groove of the shank when the cylindrical outer surface of the shank is inserted in the bore of the head;
wherein when the projection is provided on the cylindrical outer surface of the shank, the projection is constructed in one-piece with the shank, the cylindrical outer surface comprises a first cylindrical section extending from the projection and a second cylindrical section extending from the projection on a side opposite the first cylindrical section of the cylindrical outer surface, and wherein the projection engages with the ring-shaped groove of the head when the cylindrical outer surface of the shank is inserted in the bore of the head; and
wherein the pressure element is arranged in the receiving part for fixing an angular orientation of the shank relative to the receiving part.

2. The bone anchoring device according to claim 1 , wherein the projection is ring-shaped.

3. The bone anchoring device according to claim 1 , wherein a longitudinal bore passes through the receiving part from a first end of the receiving part to a second end of the receiving part and the longitudinal bore has a reduced diameter adjacent to the first end of the receiving part forming a seat for accommodating the head.

4. The bone anchoring device according to claim 3 , wherein the pressure element is arranged in the longitudinal bore.

5. The bone anchoring device according to claim 3 , wherein a U-shaped recess is formed in the receiving part adjacent to the first end of the receiving part and extending substantially perpendicular to the longitudinal bore such that two free legs are formed constituting a channel for receiving the rod.

6. The bone anchoring device according to claim 1 ,
wherein when the projection is provided on the inner surface of the head, the first cylindrical section is positioned closer than the second cylindrical section to an end of the head into which the shank is inserted, and has a length that is less than a length of the second cylindrical section, and
wherein when the projection is provided on the outer surface of the shank, the first cylindrical section is positioned closer than the second cylindrical section to the first portion of the shank, and has a length that is at least a length of the second cylindrical section.

7. The bone anchoring device according to claim 1 , wherein the projection extends a first length along a longitudinal axis of the cylindrical surface on which it is provided, wherein the corresponding first and second cylindrical sections each extends from the projection by more than the first length, and wherein corresponding cylindrical sections of the cylindrical surface on which the groove is provided extend in opposite directions from the groove by more than the first length.

8. The bone anchoring device according to claim 1 , wherein when the projection is provided on the shank, the projection is a continuous one-piece projection extending around a majority of a circumference of the cylindrical surface of the shank.

9. The bone anchoring device according to claim 1 , wherein the inner surface of the head is cylindrical when the shank is not inserted into the bore of the head.

10. The bone anchoring device according to claim 1 , wherein when the cylindrical outer surface of the shank is inserted in the bore of the head from the first end of the head and the projection and the ring-shaped groove are engaged, the cylindrical outer surface of the shank does not extend past the second end of the head.

11. A method of attaching a bone anchoring device to a bone or vertebra, the bone anchoring device comprising a shank to be anchored in a bone or vertebra, a head having an outer surface that is substantially shaped as a segment of a sphere, a receiving part receiving the head for connecting the shank to a rod, and a pressure element, the shank and the head being separate parts, the head having a first end, a second end, and a bore with a cylindrical inner surface having a first diameter at the first and second ends when unbiased, the cylindrical inner surface interrupted by a ring-shaped groove or a projection, wherein a plurality of slits are provided in the head which alternately extend from the first end of the head to a predetermined distance from the second end of the head and from the second end of the head to a predetermined distance from the first end of the head, respectively, and wherein at least one of the slits extends from the inner surface to the outer surface of the head, the shank having a first portion for anchoring in the bone or vertebra and a second portion with a cylindrical outer surface having a second diameter that is greater than the first diameter, the cylindrical outer surface interrupted by a projection or a ring-shaped groove, wherein when the cylindrical outer surface of the shank is inserted into the bore of the head, the first end and the second end of the bore each expands to at least the second diameter, wherein when the projection is provided on the inner surface of the head, the projection is constructed in one-piece with the head, the cylindrical inner surface comprises a first cylindrical section extending from the projection and a second cylindrical section extending from the projection on a side opposite the first cylindrical section of the cylindrical inner surface, wherein when the projection is provided on the cylindrical outer surface of the shank, the projection is constructed in one-piece with the shank, the cylindrical outer surface comprises a first cylindrical section extending from the projection and a second cylindrical section extending from the projection on a side opposite the first cylindrical section of the cylindrical outer surface, and wherein the pressure element is arranged in the receiving part for fixing an angular orientation of the shank relative to the receiving part, the method comprising:
attaching the

Assignees

• Matthis Wilfried
• Biedermann Lutz
• Biedermann Technologies Gmbh

Inventors

• Matthis Wilfried
• Biedermann Lutz

Classifications

• A61B17/7032

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

• A61B17/8605

  Heads, i.e. proximal ends projecting from bone · CPC title

• A61B17/8645

  Headless screws, e.g. ligament interference screws · CPC title

• A61B17/8685

  comprising multiple separate parts · CPC title

• A61B17/864

  hollow, e.g. with socket or cannulated · CPC title