Polyaxial bone anchoring device and system including an instrument and a polyaxial bone anchoring device

Patent metadata

Field	Value
Publication number	US-12440246-B2
Application number	US-202418597710-A
Country	US
Kind code	B2
Filing date	Mar 6, 2024
Priority date	Dec 22, 2017
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

A bone anchoring device includes a receiving part having a central axis, two legs defining a recess for receiving a rod, and a head receiving portion that is at least partially expandable and having an opening for inserting and pivotably holding a head of a bone anchoring element therein, and a locking ring mountable around the head receiving portion in an axial direction while a rotational orientation of the locking ring relative to the receiving part remains constant. When the locking ring is around the head receiving portion, the locking ring is rotatable around the central axis from a first rotational orientation to a second rotational orientation where a compressive force exerted by the locking ring on the head receiving portion is greater than at the first rotational orientation.

First claim

What is claimed is:

1. A bone anchoring device comprising:
a bone anchoring element comprising a head and a shank for anchoring to bone;
a receiving part for coupling a rod to the bone anchoring element, the receiving part having a first end, a second end below the first end, and a central axis extending between the first end and the second end, the receiving part comprising two legs defining a recess at the first end for receiving the rod, and a head receiving portion at the second end configured to hold the head of the bone anchoring element therein; and
a clamping member configured to be assembled to the head receiving portion with a first end positioned closer to the first end of the receiving part and a second end positioned closer to the second end of the receiving part, wherein the second end of the clamping member comprises a plurality of projections;
wherein the head receiving portion comprises a plurality of circumferentially spaced apart recesses each extending to an axial position that is lower than an axial position of a greatest diameter of the head measured in a direction perpendicular to the central axis when the head is in the head receiving portion; and
wherein when the clamping member is assembled to the head receiving portion, the clamping member is rotatable around the central axis from a first rotational orientation where the projections of the clamping member are out of alignment with the recesses of the head receiving portion, to a second rotational orientation where the projections of the clamping member are circumferentially aligned with and configured to extend into the recesses of the head receiving portion.

2. The bone anchoring device of claim 1 , wherein the head receiving portion defines an opening at the second end of the receiving part to facilitate insertion of the head from the second end of the receiving part into the receiving part.

3. The bone anchoring device of claim 1 , wherein the head receiving portion is radially compressible.

4. The bone anchoring device of claim 1 , wherein the clamping member is formed as a locking ring that is mountable around the head receiving portion.

5. The bone anchoring device of claim 1 , wherein each of the plurality of projections extends radially inwardly from an inner surface of the clamping member.

6. The bone anchoring device of claim 1 , wherein when the clamping member is at the second rotational orientation and the projections of the clamping member extend into the recesses of the head receiving portion, the clamping member is rotatable around the central axis from the second rotational orientation to the first rotational orientation to move the projections of the clamping member out of the recesses of the head receiving portion.

7. The bone anchoring device of claim 6 , wherein when the clamping member is rotated from the second rotational orientation to the first rotational orientation, a clamping force exerted on the head is increased.

8. The bone anchoring device of claim 1 , wherein the clamping member is configured to be assembled to the head receiving portion at the second rotational orientation.

9. A bone anchoring device comprising:
a bone anchoring element comprising a head and a shank for anchoring to bone;
a receiving part for coupling a rod to the bone anchoring element, the receiving part having a first end, a second end below the first end, and a central axis extending between the first end and the second end, the receiving part comprising two legs defining a recess at the first end for receiving the rod, and a head receiving portion at the second end configured to hold the head of the bone anchoring element therein;
a clamping member configured to be assembled to the head receiving portion; and
a compressible member separate from the clamping member and configured to compress radially as the compressible member moves axially downwardly towards the second end of the receiving part, the compressible member comprising an upwardly facing surface that defines a seat that directly engages the head when the head and the compressible member are in the head receiving portion;
wherein when the clamping member is assembled to the head receiving portion and the head and the compressible member are in the head receiving portion, the clamping member is configured to directly engage the receiving part at an axial position that is lower than an axial position of a greatest diameter of the head measured in a direction perpendicular to the central axis, and is rotatable around the central axis to adjust a compressive force exerted by the compressible member on the head.

10. The bone anchoring device of claim 9 , wherein the head receiving portion defines an opening at the second end of the receiving part to facilitate insertion of the head from the second end of the receiving part into the receiving part.

11. The bone anchoring device of claim 9 , wherein the head receiving portion is radially compressible.

12. The bone anchoring device of claim 9 , wherein the clamping member is formed as a locking ring that is mountable around the head receiving portion.

13. The bone anchoring device of claim 9 , wherein the compressible member is formed as part of a pressure member that is configured to engage the rod.

14. The bone anchoring device of claim 9 , wherein the clamping member is rotatable around the central axis while an axial position of the clamping member relative to the receiving part remains substantially constant.

15. A bone anchoring device comprising:
a bone anchoring element comprising a head and a shank for anchoring to bone;
a receiving part for coupling a rod to the bone anchoring element, the receiving part having a first end, a second end below the first end, and a central axis extending between the first end and the second end, the receiving part comprising two legs defining a recess at the first end for receiving the rod, and a head receiving portion at the second end configured to hold the head of the bone anchoring element therein, wherein when the head is in the head receiving portion, at least part of the head receiving portion is configured to extend downwardly past an axial position of a greatest diameter of the head measured in a direction perpendicular to the central axis;
a clamping member configured to be assembled upwardly from the second end of the receiving part to an uppermost axial position relative to the head receiving portion, wherein the head is insertable from the second end of the receiving part into the head receiving portion when the clamping member is at the uppermost axial position;
wherein when the clamping member is assembled to the head receiving portion and the head is in the head receiving portion, the clamping member is rotatable around the central axis for adjusting an upwardly directed compressive force exerted by the clamping member that causes a change in a clamping force exerted on the head.

16. The bone anchoring device of claim 15 , wherein the head receiving portion is radially compressible.

17. The bone anchoring device of claim 15 , wherein the clamping member is formed as a locking ring that is mountable around the head receiving portion.

18. The bone anchoring device of claim 15 , wherein the upwardly directed force exerted by the clamping member is applied to a surface of the bone anchoring device located at an axial position that is lower than an axial position of a greatest diameter of the head measured in a direction perpendicular to the central axis.

19. The bone anchoring device of claim 15 , w

Assignees

• Biedermann Technologies Gmbh

Inventors

• Biedermann Timo
• Dannecker Berthold

Classifications

• A61B17/7032

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

• A61B2017/7073

  with intervertebral connecting element crossing an imaginary spinal median surface · CPC title

• A61B17/7091

  for applying, tightening or removing longitudinal element-to-bone anchor locking elements, e.g. caps, set screws, nuts or wedges · CPC title

• A61B17/7076

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