INSTRUMENT FOR ASSEMBLING A POLYAXIAL BONE ANCHOR

• US 20140107708A1
• Filed: 10/08/2013
• Published: 04/17/2014
• Est. Priority Date: 10/09/2012
• Status: Active Grant

• Current Assignee: Biedermann Technologies GmbH & Co. KG
• Original Assignee: Biedermann Motech GmbH
• Inventors: Biedermann, Lutz, Matthis, Wilfried, Fischer, Bernd
• Granted Patent: US 9,517,092 B2
• Time in Patent Office: Days
• US Class Current: 606/278
• CPC Class Codes: A61B 17/7037 wherein pivoting is blocked when the rod is clamped
• CPC Class Codes: A61B 17/7076 for driving, positioning or assembling spinal clamps or bone anchors specially adapted for spinal fixation
• CPC Class Codes: A61B 17/7082 for driving, i.e. rotating, screws or screw parts specially adapted for spinal fixation, e.g. for driving polyaxial or tulip-headed screws driving other bone screws A61B17/8875
• CPC Class Codes: A61B 2090/067 for measuring angles
• CPC Class Codes: A61B 2090/0808 for indicating correct assembly of components, e.g. of the surgical apparatus
• CPC Class Codes: A61B 90/92 coded with colour
• CPC Class Codes: A61B 90/94 coded with symbols, e.g. text

Abstract

An instrument for assembling a polyaxial bone anchor is provided, the polyaxial bone anchor including a bone anchoring element (2) and a receiving part (4) that is configured to pivotably receive the bone anchoring element wherein the instrument (1, 1′) includes a first member (30, 30′) that is configured to engage the receiving part (4) a second member (50, 50′) that is configured to contact the anchoring element (2) when it is received in the receiving part, and a position indicator (50b, 45b) that is configured to indicate the position of the anchoring element relative to the receiving part based on the position of the second member relative to the first member.

Claims

1. Instrument for assembling a polyaxial bone anchor, the polyaxial bone anchor including a bone anchoring element and a receiving part that is configured to pivotably receive the bone anchoring element wherein the instrument includes

a first member that is configured to engage the receiving part

a second member that is configured to contact the anchoring element when it is received in the receiving part, and

a position indicator that is configured to indicate the position of the anchoring element relative to the receiving part based on a position of the second member relative to the first member.

2. The instrument of claim 1, wherein the first member is an elongate hollow member with a longitudinal axis and the second member is an elongate member extending at least partially through the first member.

3. The instrument of claim 2, wherein the second member is configured to move within the first member in an axial direction.

4. The instrument of claim 1, wherein a cap member is provided that is configured to be fixedly connected to the first member and wherein the position indicator is configured to indicate the position of the second member relative to the cap member.

5. The instrument of claim 1, wherein the first member comprises a first end that is configured to engage the receiving part and an opposite second end and wherein the second member comprises a first end that is configured to contact the anchoring element and an opposite second end.

6. The instrument of claim 5, wherein the position indicator includes the second end of the second member and indicates the relative position of the second end relative to the first member.

7. The instrument of claim 1, wherein a stop is provided that limits the engagement of the first member with the receiving part.

8. The instrument of claim 1, wherein the first member and the second member are biased with respect to each other by a first spring such that the second member follows the movement of the head when the second member is in contact with the head.

9. The instrument of claim 1, wherein bone anchor further comprises a pressure element to exert pressure onto the anchoring element to lock the anchoring element in an angular position and wherein the instrument further comprises a third member that is configured to contact the pressure element.

10. The instrument of claim 9, wherein the position indicator is configured to indicate the position of the pressure element relative to the receiving part based on the position of the third member relative to the first member.

11. The instrument of claim 9, wherein the third member comprises a first end that is configured to contact the pressure element and a second end and wherein the position indicator is includes the second end of the third member.

12. The instrument of claim 9, wherein the third member is biased against the second member by a second spring.

13. The instrument of claim 9, wherein a movement of the second member relative to the third member is limited by at least one stop.

14. The instrument of claim 1, wherein the position indicator indicates a correct position of the bone anchoring element relative to the receiving part by two surfaces that are flush with each other.

15. A system of an instrument for assembling a polyaxial bone anchor and a polyaxial bone anchor,

the polyaxial bone anchor including a bone anchoring element and a receiving part that is configured to pivotably receive the bone anchoring element

the instrument being one according to claim 1.

16. The system of claim 15, wherein the polyaxial bone anchor is a bottom loading type polyaxial bone anchor. An instrument for assembling a polyaxial bone anchor, the polyaxial bone anchor including a bone anchoring element and a receiving part configured to pivotably receive the bone anchoring element, the instrument comprising:

a first member configured to engage the receiving part a second member configured to contact the bone anchoring element when the bone anchoring element is received in the receiving part; and

a position indicator configured to indicate a position of the anchoring element relative to the receiving part based on a position of the second member relative to the first member. A system for assembling a polyaxial bone anchor, comprising;

a polyaxial bone anchor comprising

a bone anchoring element and a receiving part configured to pivotably receive the bone anchoring element; and

an instrument comprising

a first member configured to engage the receiving part;

a second member configured to contact the bone anchoring element when the bone anchoring element is received in the receiving part;

a position indicator configured to indicate a position of the anchoring element relative to the receiving part based on a position of the second member relative to the first member.