DRIVER INSTRUMENTS AND RELATED METHODS

• US 20180177536A1
• Filed: 12/23/2016
• Published: 06/28/2018
• Est. Priority Date: 12/23/2016
• Status: Active Grant

• Current Assignee: Medos International Sarl (Johnson & Johnson)
• Original Assignee: Medos International Sarl (Johnson & Johnson)
• Inventors: Divincenzo, John, Martin, Thomas, Pavento, Nicholas, Murray, James
• Granted Patent: US 10,441,326 B2
• Time in Patent Office: Days
• 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 17/7083 Tools for guidance or insertion of tethers, rod-to-anchor connectors, rod-to-rod connectors, or longitudinal elements
• CPC Class Codes: A61B 17/7091 for applying, tightening or removing longitudinal element-to-bone anchor locking elements, e.g. caps, set screws, nuts or wedges
• CPC Class Codes: A61B 17/8877 characterised by the cross-section of the driver bit
• CPC Class Codes: A61B 17/888 the driver bit acting on the central region of the screw head
• CPC Class Codes: A61B 17/8888 at its central region
• CPC Class Codes: A61B 17/8894 holding the implant into or through which the screw is to be inserted A61B17/7082, A61B17/7091 take precedence

Abstract

Driver instruments and related methods are disclosed herein, e.g., for applying a fastener to a bone anchor. Various features are disclosed for retaining the fastener to the driver instrument, such as tapered drive tips, as are various features for impacting the driver instrument into the fastener, such as slidable slap-hammer type handles. Driver instruments with interchangeable handles or handle geometries that can be changed without separating the instrument from an attached fastener are also disclosed.

Claims

1. A method of applying a fastener to a bone anchor, comprising:

inserting a drive tip of a driver instrument into a drive recess of the fastener;

applying an axial force to a driver shaft of the instrument to impact the drive tip into the drive recess of the fastener and retain the fastener to the drive tip by an interference fit;

positioning the instrument and the fastener retained thereto with respect to a bone anchor; and

rotating a handle of the instrument to rotate the driver shaft and apply the fastener to the bone anchor.

2. The method of claim 1, wherein the fastener is a set screw and wherein applying the fastener comprises threading the set screw into opposed threaded arms of the bone anchor to retain a spinal rod within the bone anchor.

3. The method of claim 1, wherein applying the axial force comprises sliding a handle of the instrument distally along the driver shaft to exert an axial force on a shoulder of the driver shaft.

4. The method of claim 1, wherein retaining the fastener comprises wedging a tapered portion of the drive tip within the drive recess of the fastener.

5. The method of claim 4, wherein the tapered portion tapers continuously from a reduced distal diameter to an enlarged proximal diameter, and wherein the drive recess of the fastener has a diameter that is greater than or equal to the reduced distal diameter and less than the enlarged proximal diameter.

6. The method of claim 1, further comprising locking the handle at a fixed longitudinal position along the driver shaft.

7. The method of claim 6, wherein locking the handle comprises rotating a locking collar coupled to the handle with respect to the handle about a central longitudinal axis of the driver shaft to a locked position.

8. The method of claim 7, wherein, when the locking collar is in the locked position, a projection formed in a central passage of the locking collar is received within a corresponding recess formed in the driver shaft to prevent longitudinal translation of the locking collar relative to the driver shaft.

9. The method of claim 8, wherein, when the locking collar is in the locked position, an indicator finger of the locking collar is received within a first groove formed in the handle to maintain the locking collar in the locked position and provide an indication to a user that the locking collar is in the locked position.

10. The method of claim 1, further comprising unlocking the handle from a fixed longitudinal position along the driver shaft.

11. The method of claim 10, wherein unlocking the handle comprises rotating a locking collar coupled to the handle with respect to the handle about a central longitudinal axis of the driver shaft to an unlocked position.

12. The method of claim 11, wherein, when the locking collar is in the unlocked position, a projection formed in a central passage of the locking collar is positioned outside of a corresponding recess formed in the driver shaft to allow longitudinal translation of the locking collar relative to the driver shaft.

13. The method of claim 12, wherein, when the locking collar is in the unlocked position, an indicator finger of the locking collar is received within a second groove formed in the handle to maintain the locking collar in the unlocked position and provide an indication to a user that the locking collar is in the unlocked position.

14. The method of claim 1, further comprising rotating a locking collar of the instrument to lock or unlock a longitudinal position of the handle with respect to the driver shaft, wherein rotating the locking collar comprises rotating a plurality of retention fingers extending from the locking collar within an annular groove formed in the handle.

15. The method of claim 1, further comprising, without separating the driver shaft from the fastener, sliding the handle to a distal position along the driver shaft, attaching a second handle to a proximal end of the driver shaft, and rotating the second handle to further tighten the fastener to the bone anchor.

16. An instrument for applying a fastener to a bone anchor, comprising:

a driver shaft having a proximal end and a distal end that define a central longitudinal axis extending therebetween, the distal end of the driver shaft including a drive tip;

a handle non-rotatably coupled to the driver shaft; and

a locking collar having an unlocked position in which the locking collar and the handle are free to translate longitudinally along the driver shaft and a locked position in which the locking collar and the handle are maintained at a fixed longitudinal position along the driver shaft;

wherein the handle is slidable along the driver shaft when the locking collar is in the unlocked position to apply an axial force to the driver shaft to impact the drive tip into a drive recess of a fastener and thereby retain the fastener to the drive tip.

17. The instrument of claim 16, wherein the drive tip is tapered and is configured to frictionally retain a fastener thereto.

18. The instrument of claim 17, wherein the drive tip tapers continuously from a reduced distal cross-section to an enlarged proximal cross-section.

19. The instrument of claim 17, wherein the drive tip includes a distal section that defines a ramped lead-in surface, an intermediate tapered section that tapers from a smaller distal diameter to a larger proximal diameter, and a proximal section that transitions from the larger proximal diameter to a diameter of a body of the driver shaft.

20. The instrument of claim 17, further comprising a fastener having a non-tapered drive recess in which the tapered drive tip is received.

21-32. -32. (canceled)