BONE SCREW EXTENDER REATTACHMENT SYSTEM AND METHODS

• US 20130103039A1
• Filed: 10/25/2011
• Published: 04/25/2013
• Est. Priority Date: 10/25/2011
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: McBride, Larry T., Hopkins, Timothy E.
• Granted Patent: US 9,241,743 B2
• Time in Patent Office: Days
• US Class Current: 606/104
• CPC Class Codes: A61B 17/708 with tubular extensions coaxially mounted on the bone anchors
• 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 17/7086 Rod reducers, i.e. devices providing a mechanical advantage to allow a user to force a rod into or onto an anchor head other than by means of a rod-to-bone anchor locking element; rod removers

Abstract

A bone screw extender reattachment system including an elongated reattachment rod having a proximal and a distal end. The distal end of the elongated reattachment rod includes a tip configured to attach to a head of a bone screw. The elongated reattachment rod is configured so that a screw extender assembly having an inner sleeve, an outer housing and an extender head can slide over the reattachment rod. The bone screw extender reattachment system also includes a tension plunger having a plunger-type head and an elongated shaft configured to slide over the reattachment rod so as to communicate with the screw extender assembly.

Claims

1. A bone screw extender reattachment system comprising:

an elongated reattachment rod having a proximal end and a distal end, the distal end having a tip configured to contact a head of a bone screw, the elongated reattachment rod configured so that a screw extender assembly having an inner sleeve, an outer housing and an extender head can slide over the reattachment rod; and

a tension plunger having a plunger-type head and an elongated shaft configured to communicate with the screw extender assembly.

2. The system according to claim 1, wherein the elongated shaft of the tension plunger is solid and is configured to contact a top portion of the screw extender assembly so as to transmit tension along the outer housing to the screw head when tension is applied to the tension plunger.

3. The system of claim 1, wherein the elongated shaft of the tension plunger is cannulated so that it can slide over the reattachment rod and contact the outer housing, wherein tension applied to the tension plunger is transmitted along the outer housing of the screw extender assembly to the screw head so that locking tabs on the extender head are opened so that the screw extender assembly attaches to the screw head.

4. The system of claim 1, wherein the proximal end of the reattachment rod further comprises markings set a defined distance from the distal end so as to indicate alignment of the extender head.

5. The system of claim 1, wherein the configuration of the tip of the reattachment rod is selected from the group consisting of polygonal, oval, circular, rectangular, square, triangular, parabolic, pointed, and flat, as long as the tip is configured to fit within the inside diameter of the head of the screw.

6. The system of claim 5, wherein the tip is parabolic and is configured to fit within the inside diameter of the screw head.

7. The system of claim 1, wherein the reattachment rod further comprises at least one circumferential mark at the proximal end so as to provide visual confirmation of the position of the screw extender assembly on the reattachment rod,

8. A method for reattaching a screw xtender to a screw head in situ comprising:

advancing a reattachment rod through the skin of a patient towards the spine to communicate with a head of a screw in the spine;

capturing the screw head;

advancing a screw extender assembly having an inner sleeve, and outer housing and an extender head and locking tabs, over the reattachment rod until the outer housing is adjacent to the screw head;

inserting a cannulated tension plunger having a head attached to a cannulated elongated shaft over the reattachment rod and sliding the plunger down to contact the outer housing;

applying pressure on the cannulated tension plunger while the locking tabs on the extender head are in an open position so that the outer housing engages the screw head;

manipulating the locking tabs to a locked position so as to lock the screw extender assembly to the head of the screw; and

removing the plunger and the reattachment rod leaving the screw extender assembly attached to the screw head.

9. The method of claim 8, further comprising aligning a proximal end of the extender head with a mark on the reattachment rod so as to provide visual confirmation that the screw extender assembly has engaged the head of the screw without line-of-sight view of the screw head.

10. The method of claim 8, wherein the locking tabs of the extender head are in the locked or closed position when the screw extender assembly is positioned over the reattachment rod.

11. The method of claim 8, wherein force applied on the cannulated tension plunger is transmitted to the inner sleeve of the extender independent of the outer housing of the screw extender assembly.

12. The method of claim 8, wherein the reattachment rod is manipulated through the skin of a patient towards the spine so as to tactilely feel for when a tip of the reattachment rod is seated within the head of the screw.

13. The method of claim 8, further comprising pulling up on the extender head while applying pressure on the cannulated tension plunger so as to manipulate the locking tabs to an unlocked position so that the screw extender assembly captures the head of the screw.

14. The method of claim 13, wherein the locking tabs of the extender head are manipulated to a locked position thereby locking the screw extender assembly to the head of the screw and leaving the screw extender assembly attached to the head of the screw.

15. A method for reattaching a screw extender to a screw head with a rod already in place comprising:

advancing a screw extender assembly having an extender and a housing positioned within the extender, wherein the extender comprises an extender head having locking tabs into position with a spine having a screw with a rod positioned therein;

inserting a solid tension plunger having a head attached to a solid shaft into a top portion of the extender head;

applying pressure on the solid tension plunger so as to apply tension to the housing positioned within the extender while the locking tabs on the extender head are in an open position so as to advance the screw extender assembly over the screw head such that the screw extension assembly engages the screw head;

manipulating the locking tabs of the extender into a locked position so as to lock the screw extender assembly onto the screw head; and

removing the solid tension plunger thereby leaving the screw extender assembly attached to the screw head.

16. The method of claim 15, further comprising aligning the proximal end of the extender assembly with a mark on the reattachment rod so as to provide visual confirmation that the extender head has engaged the head of the screw.

17. The method of claim 15, wherein the locking tabs of the extender are in the closed position when the screw extender assembly is advanced into the skin towards the spine.

18. The method of claim 15, wherein the screw extender assembly is manipulated through the skin of a patient towards the spine so as to tactilely feel for when a distal end of the screw extender assembly is seated within the head of the screw.

19. The method of dam 15, further comprising pulling up on the extender while applying tension on the solid tension plunger so as to move the locking tabs from the locked position to the unlocked position.

20. The method of claim 19, further comprising releasing the tension of the solid tension plunger while releasing the extender so as to manipulate the locking tabs from the unlocked position to the locked position.