Bone anchoring device and tool cooperating with such a bone anchoring device

Patent metadata

Field	Value
Publication number	US-2017319239-A1
Application number	US-201715597018-A
Country	US
Kind code	A1
Filing date	May 16, 2017
Priority date	Sep 30, 2011
Publication date	Nov 9, 2017
Grant date	—

Abstract

A bone anchoring device includes a receiving part including a rod receiving portion with a first end, a second end, and a U-shaped recess for receiving a rod, the recess defining two free legs, and a head receiving portion at the second end for introducing and clamping the head, and a locking ring configured to be arranged around the head receiving portion, the locking ring including an engagement structure for engagement with a tool, the engagement structure defining a width of the locking ring that is greater than a greatest width of the rod receiving portion, wherein the locking ring can assume a locking position exerting a greatest compressive force on the head receiving portion of the receiving part to lock an inserted head, and wherein the locking ring is movable out of the locking position towards the first end of the rod receiving portion.

First claim

1 . A bone anchoring device comprising:
a receiving part for coupling a rod to a bone anchoring element, the receiving part comprising:
a rod receiving portion with a first end, a second end, and a U-shaped recess for receiving a rod, the recess extending from the first end in a direction of the second end and defining two free legs; and
a head receiving portion at the second end for accommodating a head of a bone anchoring element, the head receiving portion having a free end and being flexible for introducing and clamping the head; and
a locking ring configured to be arranged around the head receiving portion, the locking ring comprising an engagement structure for engagement with a tool; wherein when the locking ring is around the head receiving portion, the locking ring can assume a locking position where the locking ring exerts a compressive force on the head receiving portion of the receiving part to lock an inserted head; and wherein the locking ring is movable out of the locking position towards the first end of the rod receiving portion.

2 . The bone anchoring device of claim 1 , wherein the engagement structure comprises a plurality of ribs extending in a circumferential direction of the locking ring.

3 . The bone anchoring, device of claim 2 , wherein the ribs do not extend around an entire circumference of the locking ring.

4 . The bone anchoring device of claim 1 , wherein the engagement structure comprises at least two ribs spaced apart from each other in an axial direction of the locking ring.

5 . The bone anchoring device of claim 1 , wherein the engagement structure comprises a thread. (Original) The bone anchoring device of claim 1 , wherein the locking ring comprises two projections that are 180° offset from each other for engagement with a rod.

7 . The bone anchoring device of claim 6 , wherein the engagement structures are spaced apart in a circumferential direction of the locking ring and grouped into two groups to the left and right of the projections.

8 . The bone anchoring device of claim 7 , wherein each of the groups is arranged closer to a corresponding one of the projections.

9 . The bone anchoring device of claim 1 , wherein the head receiving portion has an exterior surface with a tapered or curved portion and the locking ring has an interior surface with a tapered or curved portion which are configured to cooperate with one another, such that an inserted head is clamped when the locking ring is moved towards the free end.

10 . The bone anchoring device of claim 1 , further comprising a bone anchoring element having a shank for anchoring in a bone and a head.

11 . A tool for a bone anchoring device comprising a bone anchoring element having a shank and a head, a receiving part comprising a rod receiving portion with a first end, a second end, and a U-shaped recess for receiving a rod, the recess extending from the first end in a direction of the second end and defining two free legs, a head receiving portion at the second end accommodating the head of the bone anchoring element, the head receiving portion having a free end and being flexible for introducing and clamping the head, and a locking ring around the head receiving portion, the locking ring comprising an engagement structure, wherein the locking ring can assume a locking position where the locking ring compresses the head receiving portion of the receiving part to lock the head, the tool configured to move the locking ring out of the locking position towards the first end of the rod receiving portion, the tool comprising:
a tubular member having a first end, a second end, and an engagement portion at an inner wall of the first end for engaging the engagement structure of the locking ring; and a shaft insertable into the tubular member and movable relative to the tubular member in an axial direction, the shaft having a first end; wherein when the locking ring is in the locking position and the head is locked relative to the receiving part and the engagement portion of the tubular member engages the engagement structure of the locking ring, the first end of the shaft abuts against the rod receiving portion of the receiving part, such that the shaft is configured to move relative to the tubular member to move the locking ring out of the locking position towards the first end of the rod receiving portion to release the locking of the head.

12 . The tool of claim 11 , wherein the first end of the shaft has a coaxial bore, wherein a post provided within the bore of the shaft is configured to extend out of the bore of the shaft and to be movable relative to the shaft.

13 . The tool of claim 12 , wherein the post is elastically supported relative to the shaft.

14 . The tool of claim 12 , wherein movement of the post relative to the shaft is limited by at least one stop.

15 . The tool of claim 12 , wherein the post is configured to abut against a portion of the receiving part different from a portion of the receiving part the first end of the shaft is configured to abut against.

16 . The tool of claim 11 , wherein two recesses located opposite to each other are provided at the first end of the tubular member to facilitate engagement of the tool with a bone anchoring device with an inserted rod, such that the inserted rod is configured to pass through the two recesses of the tubular member.

17 . The tool of claim 16 , wherein the recesses are substantially rectangular and have a width configured to allow rotation of the tubular member about the bone anchoring device with the inserted rod, to facilitate the engagement of the engagement portion with the engagement structure.

18 . The tool of claim 16 , wherein an abutment is provided at a distance from the first end of the tubular member for abutting against a portion of the locking ring spaced apart from the engagement structure.

19 - 20 . (canceled)

21 . A method of unlocking a bone anchoring device from a locked position, the bone anchoring device comprising a bone anchoring element having a shank and a head, a receiving part comprising a rod receiving portion with a first end, a second end, and a U-shaped recess for receiving a rod, the recess extending from the first end in a direction of the second end and defining two free legs, a head receiving portion at the second end accommodating the head of the bone anchoring element, the head receiving portion having a free end and being flexible for introducing and clamping the head, and a locking ring around the head receiving portion, the locking ring comprising an engagement structure, wherein when the locking ring is in the locked position, the locking ring compresses the head receiving portion of the receiving part and locks the head, the method comprising:
attaching a tool to the bone anchoring element, the tool comprising a tubular member having a first end, a second end, and an engagement portion at an inner wall of the first end, and a shaft in the tubular member and movable relative to the tubular member in an axial direction, the shaft having a first end, the attaching comprising engaging an engagement portion at an inner wall of the first end of the tubular member to the engagement structure of the locking ring, such that the first end of the shaft abuts against the rod receiving portion of the receiving part; and moving the shaft relative to the tubular member to move the locking ring out of the locking position towards the first end of the rod receiving portion to release the locking of the head.

22 - 23 . (

Assignees

• Biedermann Technologies Gmbh

Inventors

• Biedermann Lutz
• Biedermann Timo
• Matthis Wilfried
• Dannecker Berthold

Classifications

• A61B17/7076

  for driving, positioning or assembling spinal clamps or bone anchors specially adapted for spinal fixation · CPC title

• A61B17/7035 Primary

  Screws or hooks, wherein a rod-clamping part and a bone-anchoring part can pivot relative to each other · CPC title

• A61B17/70

  Spinal positioners or stabilisers, e.g. stabilisers comprising fluid filler in an implant · CPC title

• A61B17/86 Primary

  Pins or screws {or threaded wires; nuts therefor (A61B17/72 take precedence)} · CPC title