MULTI-FUNCTION DRIVER INSTRUMENTS AND RELATED METHODS

• US 20180214190A1
• Filed: 02/01/2017
• Published: 08/02/2018
• Est. Priority Date: 02/01/2017
• Status: Active Grant

• Current Assignee: Medos International Sarl (Johnson & Johnson)
• Original Assignee: Medos International Sarl (Johnson & Johnson)
• Inventors: Erramilli, Seetal, Spratt, Frank, Mellor, Grant, Hassan, Areeb, Talis, Joanna, McMahon, Peter
• Granted Patent: US 10,653,457 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 17/7091 for applying, tightening or removing longitudinal element-to-bone anchor locking elements, e.g. caps, set screws, nuts or wedges
• CPC Class Codes: A61B 17/8875 Screwdrivers, spanners or wrenches
• CPC Class Codes: A61B 17/8877 characterised by the cross-section of the driver bit
• 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

Multi-function driver instruments and related methods are disclosed herein, e.g., for applying a fastener to a bone anchor. In some embodiments, a single instrument can include features for driving multiple different types of fasteners, independently driving multiple different components of a single fastener assembly, and so forth, with the instrument being switchable between multiple operating modes to select the feature needed for a particular function. The instrument can include features for retaining a fastener to the instrument, e.g., during initial insertion of the fastener.

Claims

1. A driver instrument, comprising:

an inner driver shaft having an inner drive tip; and

an outer driver shaft in which the inner driver shaft is at least partially disposed, the outer driver shaft having an outer drive tip;

wherein the instrument has;

a first configuration in which the inner drive tip is retracted proximally from the outer drive tip and an input torque applied to the inner driver shaft is transferred to the outer driver shaft and the outer drive tip; and

a second configuration in which the inner drive tip is advanced distally from the outer drive tip and an input torque applied to the inner driver shaft is not transferred to the outer driver shaft or the outer drive tip.

2. The instrument of claim 1, wherein the instrument, in the first configuration, is configured to apply torque to an outer set screw of a fastener independently from an inner set screw of the fastener and, in the second configuration, is configured to apply torque to the inner set screw of the fastener independently from the outer set screw.

3. The instrument of claim 1, wherein the instrument is movable between the first and second configurations by translating the inner driver shaft longitudinally relative to the outer driver shaft.

4. The instrument of claim 1, wherein the inner driver shaft includes an anti-rotation feature configured to selectively engage a corresponding anti-rotation feature of the outer driver shaft to lock relative rotation between the inner and outer driver shafts and transfer torque between the inner and outer driver shafts.

5. The instrument of claim 4, wherein the anti-rotation feature of the inner driver shaft comprises an external spline and the anti-rotation feature of the outer driver shaft comprises an internal spline.

6. The instrument of claim 1, wherein the outer driver shaft is configured to retain a fastener to the instrument.

7. The instrument of claim 6, wherein the outer driver shaft includes a plurality of resilient fingers extending distally therefrom, at least one of the fingers being configured to clamp onto a fastener received within a distal aperture of the outer driver shaft.

8. The instrument of claim 7, wherein at least one of the fingers includes a projection extending radially-inward therefrom and configured to be received within a corresponding recess of a fastener.

9. The instrument of claim 7, wherein each finger interlocks with an adjacent finger at multiple points along its length.

10. The instrument of claim 6, wherein the outer drive shaft has a cut-out formed therein, the cut-out being shaped such that a first finger on one side of the cut-out has an edge that defines one or more recesses, and a second finger on the opposite side of the cut-out has an edge that defines one or more projections, each of the projections being disposed within a corresponding one of the recesses, the edges being defined by the same cut-out.

11. The instrument of claim 10, wherein each projection includes a head portion that is enlarged as compared to a neck portion of the recess in which the projection is disposed, such that the head portion cannot pass through the neck portion.

12. The instrument of claim 1, further comprising a locking mechanism configured to selectively lock the instrument in the first configuration or the second configuration.

13. The instrument of claim 12, wherein the locking mechanism comprises a button movably coupled to the outer driver shaft, the button having an engaged position in which the button interferes with relative longitudinal translation between the inner and outer driver shafts and a disengaged position in which the button does not interfere with relative longitudinal translation between the inner and outer driver shafts.

14. The instrument of claim 13, wherein the button defines an opening through which the inner driver shaft extends.

15. The instrument of claim 14, wherein a central longitudinal axis of the opening is collinear with a central longitudinal axis of the inner driver shaft when the button is in the disengaged position and wherein the central longitudinal axis of the opening is offset from the central longitudinal axis of the inner driver shaft when the button is in the engaged position.

16. A system, comprising:

the instrument of claim 1, and

a fastener having an outer set screw with a first drive feature and an inner set screw threadably mounted in the outer set screw and having a second drive feature;

wherein the outer drive tip of the instrument is configured to apply torque to the outer set screw via the first drive feature and the inner drive tip of the instrument is configured to apply torque to the inner set screw via the second drive feature.

17. A method of applying a fastener to an anchor using a driver instrument having an inner driver shaft with an inner drive tip and an outer driver shaft with an outer drive tip, the method comprising:

positioning the instrument in a first configuration in which the outer drive tip is engaged with a drive feature of an outer component of the fastener and the inner drive tip is not engaged with the fastener;

positioning the fastener at least partially within the anchor;

rotating the inner driver shaft to transfer torque to the outer drive tip and rotate the outer component of the fastener relative to the anchor;

positioning the instrument in a second configuration in which the outer drive tip is engaged with the drive feature of the outer component of the fastener and the inner drive tip is engaged with a drive feature of an inner component of the fastener; and

rotating the inner driver shaft to rotate the inner component of the fastener relative to the outer component of the fastener and relative to the anchor.

18. The method of claim 17, wherein rotating the outer component of the fastener relative to the anchor locks a degree of freedom of the anchor and rotating the inner component of the fastener relative to the outer component of the fastener locks a rod to the anchor.

19. The method of claim 17, further comprising applying a countertorque force to the outer driver shaft while rotating the inner driver shaft to rotate the inner component of the fastener.

20. The method of claim 17, further comprising retaining the fastener to the instrument.

21. The method of claim 20, wherein retaining the fastener comprises inserting a portion of the fastener into an aperture defined by a plurality of fingers of the instrument, thereby moving the fingers radially-outward and causing the fingers to clamp radially-inward onto the fastener.

22. The method of claim 21, wherein each finger includes a projection received within a recess of an adjacent finger, the projection and the recess interlocking to limit relative movement of the fingers.

23. The method of claim 17, wherein positioning the instrument in the second configuration comprises adjusting a relative longitudinal position of the inner and outer driver shafts.

24. The method of claim 17, further comprising positioning the instrument in a third configuration in which the inner drive tip is engaged with a drive feature of a second fastener and the outer drive tip is not engaged with the second fastener;

and

rotating the inner driver shaft to rotate the second fastener relative to a second anchor and thereby tighten the second fastener to the second anchor.