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

Patent metadata

Field	Value
Publication number	US-11484347-B2
Application number	US-202016937302-A
Country	US
Kind code	B2
Filing date	Jul 23, 2020
Priority date	Sep 30, 2011
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

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

What is claimed is:

1. A system comprising:
a bone anchoring device for coupling a rod to a bone, the bone anchoring device comprising:
a bone anchoring element comprising a shank for anchoring in the bone and a head;
a receiving part for coupling the rod to the bone anchoring element, the receiving part comprising a rod receiving portion having a first end, a second end, a central axis extending between the first and second ends, and a U-shaped recess for receiving the rod, the recess extending from the first end towards the second end to form two free legs, and a second portion at the second end of the rod receiving portion that is connectable and pivotable relative to the head of the bone anchoring element;
a locking ring positionable around the second portion, the locking ring comprising an outer surface and a first engagement surface that deviates from the outer surface; and
a fixation element comprising an advancement surface, wherein when the bone anchoring element and the locking ring are assembled to the receiving part, the advancement surface of the fixation element is engageable with the two free legs for advancing the fixation element in the U-shaped recess to fix the rod in the U-shaped recess and to move the locking ring axially to a locking position where a compressive force is exerted on the head part to lock an angular position of the bone anchoring element relative to the receiving part; and

a tool comprising an inner surface and a second engagement surface for engaging the first engagement surface of the locking ring;
wherein when the bone anchoring element is assembled to the receiving part and the locking ring is at the locking position, the locking ring is configured to maintain the locking position while the first engagement surface is free from any axial forces from outside the bone anchoring device and the U-shaped recess for the rod is vacant or unobstructed, and the second engagement surface of the tool is configured to engage the first engagement surface of the locking ring to move the locking ring axially relative to the receiving part.

2. The system of claim 1 , wherein the first engagement surface of the locking ring comprises a plurality of circumferentially extending ribs.

3. The system of claim 2 , wherein at least two of the ribs are spaced apart from each other in an axial direction.

4. The system of claim 1 , wherein the engagement surface of the locking ring comprises a thread.

5. The system of claim 1 , wherein the locking ring further comprises two projections that are 180° offset from each other for engagement with the rod.

6. The system of claim 1 , wherein the second portion forms a head receiving portion for receiving the head of the bone anchoring element, and 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 to clamp the head.

7. The system of claim 1 , wherein two recesses located diametrically opposite to each other are provided at an end of the tool to facilitate engagement of the tool with the bone anchoring device when the rod is held in the recess of the receiving part, such that the rod is configured to pass through the two recesses of the tool when the second engagement surface of the tool engages the first engagement surface of the locking ring.

8. The system of claim 7 , wherein each of the two recesses has a width configured to allow rotation of the tool about the bone anchoring device when the rod is held in the recess to facilitate the engagement of the second engagement surface of the tool with the first engagement surface of the locking ring.

9. The system of claim 1 , wherein the tool further comprises:
a tubular member having a first end and a second end, wherein the inner surface and the second engagement surface are provided at the first end; 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 at the locking position and the second engagement surface of the tool engages the first engagement surface of the locking ring, the first end of the shaft is engageable with the rod receiving portion of the receiving part and the shaft is movable 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.

10. The system of claim 9 , wherein the first end of the shaft of the tool defines a coaxial bore, and wherein a post provided within the bore of the shaft is configured to extend out of the bore of the shaft and is movable relative to the shaft.

11. A bone anchoring device for coupling a rod to a bone anchoring element that comprises a shank and a head, the bone anchoring device comprising:
a receiving part comprising a rod receiving portion having a first end, a second end, a central axis extending between the first and second ends, and a U-shaped recess for receiving the rod, the recess extending from the first end towards the second end to form two free legs separated circumferentially from one another by opposite ends of the recess, and a second portion at the second end of the rod receiving portion that is connectable and pivotable relative to the head of the bone anchoring element; and
a locking member configured to be assembled to the second portion, the locking member comprising a radially directed surface that extends circumferentially around the central axis when the locking member is assembled to the receiving part and an engagement surface that deviates from the radially directed surface;
wherein when the locking member is assembled to the receiving part, the locking member can assume a locking position where a compressive force is exerted on a head of a connected bone anchoring element to lock an angular position of the bone anchoring element relative to the receiving part, and wherein the engagement surface of the locking member is positioned closer circumferentially to a first one of the ends of the recess than to a second one of the ends of the recess while a first portion of the radially directed surface at a same axial height as the engagement surface remains between the engagement surface and the second end of the recess, such that a tool is movable axially from the first end of the rod receiving portion of the receiving part to the first portion of the radially directed surface and is then rotatable to engage the engagement surface to move the locking member axially relative to the receiving part.

12. The bone anchoring device of claim 11 , wherein the first portion of the radially directed surface has a circular cross-section in a plane perpendicular to the central axis that extends uninterruptedly in the circumferential direction from the engagement surface of the locking member to the second end of the recess.

13. The bone anchoring device of claim 11 , wherein the engagement surface of the locking member comprises a plurality of circumferentially extending ribs.

14. The bone anchoring device of claim 13 , wherein at least two of the ribs are spaced apart from each other in an axial direction.

15. The bone anchoring device of claim 11 , wherein the engagement surface of the locking member is a first engagement surface, and wherein the locking member further comprises a second engagement surface that is spaced apart from the first engagement surface and formed circumferentially at a side of the recess opposite the first engagement surface.

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

• A61B17/86 Primary

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

• A61B17/70

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