BONE ANCHORING DEVICE, TOOL AND METHOD FOR ASSEMBLING THE SAME AND TOOL FOR USE WITH THE SAME

• US 20110046683A1
• Filed: 08/13/2010
• Published: 02/24/2011
• Est. Priority Date: 08/20/2009
• Status: Active Grant

• Current Assignee: Biedermann Technologies GmbH & Co. KG
• Original Assignee: Biedermann Technologies GmbH & Co. KG
• Inventors: Meer, Martin, Biedermann, Lutz
• Granted Patent: US 9,254,150 B2
• Time in Patent Office: Days
• US Class Current: 606/305
• CPC Class Codes: A61B 17/7032 Screws or hooks with U-shaped head or back through which longitudinal rods pass
• CPC Class Codes: A61B 17/7035 Screws or hooks, wherein a rod-clamping part and a bone-anchoring part can pivot relative to each other
• 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 2017/00526 Methods of manufacturing
• CPC Class Codes: A61B 2017/00716 simulating physical properties
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A bone anchoring device includes an anchoring element having a shaft for anchoring in the bone and a head, a receiving part formed in one piece, and a pressure element formed in one piece. The receiving part has a seat for receiving the head and an outer channel for receiving a rod to be connected to the anchoring element, which is pivotable with respect to the receiving part and can be fixed at an angle by exerting pressure via the pressure element onto the head. The pressure element is movable in the receiving part and includes an inner channel for receiving the rod and a spring element that engages a portion of the receiving part via a detent connection so that the pressure element can be held in a position that allows pivoting of the anchoring element. The spring element is formed by at least a first portion of one of two side walls forming the inner channel, the first portion being spaced apart from a second portion of the one side wall by a slot. At least a portion of the detent connection is located on the one side wall.

Claims

1. A bone anchoring device comprising:

an anchoring element having a shaft for anchoring in a bone and having a head,

a receiving part formed in one piece, the receiving part comprising a seat for receiving the head and an outer channel for receiving a rod to be connected to the anchoring device,

a pressure element formed in one piece, the pressure element comprising an inner channel for receiving the rod, the inner channel formed by two side walls of the pressure element, the pressure element being movable in the receiving part to exert pressure onto the head,

wherein the anchoring element is pivotable with respect to the receiving part and can be fixed at an angle by exerting pressure via the pressure element onto the head, and

wherein the pressure element further comprises a spring element, the spring element being movable from a first position wherein the spring element is unlocked from the receiving part, to a second position wherein the spring element is locked to the receiving part via a detent connection, wherein in the second position the pressure element is held in a position that allows pivoting of the anchoring element,

wherein the spring element is formed by at least a first portion of one of the two side walls forming the inner channel, the first portion spaced apart from a second portion of the one side wall by a slot,

wherein at least a portion of the detent connection is located on the one side wall.

2. The bone anchoring device of claim 1, wherein the spring element is formed integrally in the first portion of one of the two side walls of the pressure element.

3. The bone anchoring device of claim 1, wherein the two side walls that form the inner channel each have open ends, wherein the open ends are each configured to extend beyond the rod and wherein the slot extends beyond the rod on the one side wall.

4. The bone anchoring device of claim 1, wherein the detent connection comprises a detent portion on the spring element and a recess formed at an inner wall of the receiving part, wherein the detent portion can be resiliently depressed radially inward toward the slot and can engage in the recess.

5. The bone anchoring device of claim 4, wherein the detent portion is shaped asymmetric with respect to the direction of movement of the pressure element so as to allow assembling but to inhibit disassembling of the pressure element from the receiving part.

6. The bone anchoring device of claim 5, wherein the detent portion comprises an edge that abuts a wall of the recess.

7. The bone anchoring element of claim 4, wherein the detent portion is symmetric with respect to the direction of movement of the pressure element to allow assembling and disassembling of the pressure element.

8. The bone anchoring device of claim 1, wherein the slot is open at only two opposite sides.

9. The bone anchoring device of claim 1, wherein the slot is closed at only one side.

10. The bone anchoring device of claim 9, wherein the closed side is oriented to the side of the pressure element that faces the head.

11. The bone anchoring device of claim 1, wherein the receiving part comprises a first bore for passing the shaft of the anchoring element therethrough and a second bore at the opposite side for introducing the shaft and the head.

12. The bone anchoring device of claim 1, wherein a locking device is provided that cooperates with the receiving part to lock the head and the rod separately.

13. The bone anchoring device of claim 1, wherein a locking device is provided that cooperates with the receiving part to lock the head and the rod simultaneously.

14. A method of assembling a bone anchoring device using a tool, the bone anchoring device comprising:

an anchoring element having a shaft for anchoring in a bone and having a head,

a receiving part comprising a seat for receiving the head and an outer channel for receiving a rod to be connected to the anchoring device,

a pressure element comprising an inner channel for receiving the rod, being movable in the receiving part and configured to exert pressure onto the head,

wherein the pressure element comprises a spring element configured to engage a portion of the receiving part so that the pressure element can be held in a position that allows pivoting of the anchoring element

the tool comprising a base portion and a dummy rod portion, the dummy rod portion being connectable to the pressure element,

the method comprising the steps;

arranging the tool in a position in which the dummy rod portion is exposed from the base portion;

connecting the dummy rod portion with the pressure element;

placing the receiving part onto the pressure element; and

pressing the receiving part against the base portion until the spring element engages the receiving part.

15. A method for inserting a bone anchoring device into a bone using a tool, the bone anchoring device comprising:

an anchoring element having a shaft for anchoring in the bone and having a head,

a receiving part comprising a seat for receiving the head and an outer channel for receiving a rod to be connected to the anchoring device,

a pressure element comprising an inner channel for receiving the rod, being movable in the receiving part and configured to exert pressure onto the head,

the tool comprising;

a drive member rotatably connected to a counter-holding member, wherein the drive member is sized to extend through the counter-holding member and the receiving part into a head recess on the head, the tool further comprising preferably a stop preventing an escaping movement of the pressure element,

the method comprising the steps of;

introducing the anchoring element into the receiving part until the head is seated in the seat,

introducing the pressure element into the receiving part and aligning the inner channel and the outer channel for receiving the rod,

engaging the counter-holding member with the receiving part,

contacting the stop with the pressure element,

engaging the drive member with the head recess,

and driving the shaft into the bone.

16. A bone anchoring device comprising:

an anchoring element having a shaft for anchoring in the bone and having a head,

a receiving part formed in one piece, the receiving part comprising a seat for receiving the head and an outer channel for receiving a rod to be connected to the anchoring device,

a pressure element formed in one piece, the pressure element being movable in the receiving part and configured to exert pressure onto the head, the pressure element comprising an inner channel for receiving the rod, wherein the inner channel is formed by two side walls, wherein each side wall of the two side walls has a curved portion and a straight portion, the curved portion being closer to the anchoring element,

wherein the anchoring element is pivotable with respect to the receiving part and can be fixed at an angle by exerting pressure via the pressure element onto the head,

wherein the pressure element comprises a spring element configured to engage a portion of the receiving part so that the pressure element can be held in a position that allows pivoting of the anchoring element, and

wherein the spring element is formed by at least a first portion of one of the two side walls forming the inner channel, the first portion spaced apart from a second portion of the one side wall by a slot, wherein the slot extends into the straight portion of the one side wall.