Instrument for inserting, adjusting and removing a surgical implant

• US 20070043378A1
• Filed: 07/21/2005
• Published: 02/22/2007
• Est. Priority Date: 07/21/2005
• Status: Active Grant

• Current Assignee: Depuy Spine Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Spine Incorporated (Johnson & Johnson)
• Inventors: Kumar, Rakesh, Doherty, Thomas, Murphy, Raymond
• Granted Patent: US 8,100,916 B2
• Time in Patent Office: Days
• US Class Current: 606/104
• 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 17/7082 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: Y10S 606/916 Tool for installing or removing orthopedic fastener

Abstract

An instrument for inserting, adjusting and engaging an implant, such as a polyaxial screw of a spinal fixation system, includes at least one retractable tab for engaging a corresponding recess on the implant and a shaft that moves relative to the retractable tab. The movable shaft selectively moves the tab between an expanded position for engaging the recess and a retracted position out of engagement with the recess. The shaft selectively engages a portion of the implant to rigidify the implant after the retractable tab engages the recess. The axially extending shaft may be disposed within an axially extending passageway of a body assembly. A rotatable collar surrounding the body assembly is coupled to the shaft for moving the shaft relative to the retractable tab.

Claims

1. ) An instrument for manipulating an implantable device, comprising:

an engagement mechanism for selectively engaging a first portion of the implantable device,

an alignment mechanism moveable relative to the engagement mechanism for selectively engaging a second portion of the implantable device, and

a counter-rotation mechanism movable relative to the alignment mechanism for selectively orientating the second portion of the implantable device relative to the first portion of the implantable device during operation of the implantable device.

2. ) The instrument of claim 1 further comprising a handle assemble, said handle assembly sized and oriented to provide rotational energy to the instrument for operating an implantable device.

3. ) The instrument of claim 1, wherein the first portion of the implantable device is the shank of a polyaxial screw.

4. ) The instrument of claim 1, wherein the second portion of the implantable device is the head of a polyaxial screw.

5. ) The instrument of claim 1, wherein said alignment mechanism is selectively engaged or disengaged from the implantable device.

6. ) The instrument of claim 5, wherein said alignment mechanism has a threaded tip portion for engagement with the second portion of the implantable device.

7. ) The instrument of claim 5, wherein the implantable device is rigidified upon engagement of the alignment mechanism with the implantable device.

8. ) The instrument of claim 1, further comprising a first and second stop, said first and second stop defining an extended and retracted position of said alignment mechanism.

9. ) The instrument of claim 1, wherein the counter-rotation mechanism further comprises an engagble protrusion, sized for mating with a corresponding feature of the implantable device, to orientate the second portion of the implantable device.

10. ) The instrument of claim 1, wherein the counter-rotation mechanism further comprises a collar, said collar allowing orientation of the second portion of the implantable device.

11. ) The instrument of claim 1, wherein the engageable mechanism further comprises a hex head for engaging a first portion of the implantable device.

12. ) A driver device for a polyaxial screw having a head portion moveable relative to a shaft portion, the driver device comprising:

an engagement mechanism defining a first axis, said engagement mechanism sized for engaging the shaft portion of the polyaxial screw,

an alignment mechanism orientated along the first axis, said alignment mechanism capable of engaging the head portion of the polyaxial screw and rigidifying the head portion relative to the shaft portion of the polyaxial screw, and

a counter-rotation mechanism orientated along the first axis for selectively orientating the head portion of the polyaxial screw relative to the shaft portion of the polyaxial screw,

wherein the engagement mechanism, alignment mechanism and counter-rotation mechanism rotate along the first axis independently of each other.

13. The driver device of claim 12, wherein the engagement mechanism further comprises a hex shaped tip for engaging the shaft portion of the polyaxial screw

14. The driver device of claim 12, wherein the alignment mechanism is a threaded region which engages the inner region of the head portion of the polyaxial screw.

15. The driver device of claim 12, wherein the counter-rotation mechanism further comprises an indicating mechanism associated with the counter-rotation mechanism for displaying the orientation of the head portion of the polyaxial screw.

16. The driver device of claim 12, further comprising a plurality of stops, said stops defining an extended alignment mechanism position and a retracted alignment mechanism position.

17. A method of implanting a polyaxial screw having a head and shaft portion, comprising:

engaging the shaft portion of the polyaxial screw with an engagement mechanism of a screwdriver;

fixing the head portion of the polyaxial screw relative to the shank portion of the polyaxial screw using an alignment mechanism of the screwdriver;

driving the fixed head and shaft using the engagement mechanism,

disengaging the alignment mechanism from the polyaxial screw; and

adjusting the orientating of the head portion of the polyaxial screw with a counter-rotation mechanism of the screwdriver.

18. The method of claim 17, wherein rigidifying the head portion of the polyaxial screw relative to the shaft portion of the screw further comprises the steps of:

extending the alignment mechanism to an extended position; and

coupling the alignment mechanism to the head portion of the polyaxial screw;

wherein said coupling of the alignment mechanism to the head portion of the screw results in a rigidified polyaxial screw.

19. The method of claim 17, wherein the coupling of the alignment mechanism to the head portion of the polyaxial screw is accomplished using a threaded coupling mechanism.

20. The method of claim 17, wherein fixing the orientating of the head portion of the polyaxial screw to a known position further comprises the steps of:

providing a reference indicator associated with a counter-rotation mechanism;

engaging the counter-rotation mechanism into the head portion of the polyaxial screw; and

orientating the head portion of the polyaxial screw based upon the position of the reference indicator.

21. The method of claim 20, further comprising orientating the head portion of the polyaxial screw by rotating a second collar associated with the counter-rotation mechanism.

22. An apparatus for operating an implantable polyaxial screw, comprising:

an engagement shaft with a drive tip for selectively engaging a shaft of a polyaxial screw;

an alignment sleeve moveable relative to the engagement shaft, wherein the distal end of the alignment sleeve selectively engages a head of a polyaxial screw; and

a counter-rotation sleeve movable relative to the alignment sleeve, wherein the distal end of the counter-rotation sleeve selectively orientates the head of the polyaxial screw relative to the shank of the polyaxial screw device during operation of the polyaxial screw.

23. A method for adjusting a polyaxial surgical screw implanted in a vertebrae using a driver device, comprising

connecting an alignment mechanism of the driver device to a head portion of a polyaxial screw implanted in the vertebrae;

orientating the head of the polyaxial screw using the alignment mechanism to align a longitudinal axis of the head portion with a longitudinal axis of a shank portion of the polyaxial screw;

advancing a drive feature of an engagement mechanism of the driver device into a corresponding drive feature of the shank portion;

adjusting a depth of the implanted polyaxial screw using the engagement mechanism.

24. The method of claim 23, wherein the alignment mechanism has a hollow central cavity sized for advancement of the engagement mechanism of the driver device relative to the alignment mechanism.

25. A method of removing a screwdriver from a polyaxial bone screw, comprising;

advancing an engagement mechanism of the screwdriver into a shank of a polyaxial screw;

driving the polyaxial screw into bone with the screwdriver;

advancing a sleeve of the screwdriver relative to the engagement mechanism into a head of the polyaxial bone screw;

fixing the sleeve relative to the engagement mechanism;

retracting the engagement mechanism from the shank of the polyaxial bone screw by retracting the sleeve from the head of the polyaxial bone screw.

26. A method for inserting a favored angle polyaxial screw having a head and a shank, comprising:

engaging a drive tip of a shaft of a screwdriver with the shank of the favored angle screw;

advancing a sleeve of the screwdriver relative to the shaft into the head of the polyaxial screw;

aligning the head of the screw based on alignment indicia provided on the sleeve during driving of the screw with the shaft of the screwdriver.

27. A method of implanting a polyaxial screw having a head and a shank, comprising;

engaging a drive tip of a shaft of a screwdriver with the shank of the screw;

advancing a sleeve of the screwdriver relative to the shaft of the screwdriver to engage the head of the polyaxial screw;

driving the screwdriver with the sleeve in the advanced position relative to the shaft of the screwdriver;

removing the screwdriver from the polyaxial screw;

reengaging the drive tip with the shank of the polyaxial screw;

driving the screw with the sleeve in a retracted position relative to the shaft of the screwdriver.