Spinal intervertebral implant insertion tool

• US 6,666,866 B2
• Filed: 10/25/2001
• Issued: 12/23/2003
• Est. Priority Date: 11/07/2000
• Status: Expired due to Term

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Osteotech Incorporated (Medtronic Plc)
• Inventors: Boyle, John, Germakis, Perry, Sybert, Daryl, Martz, Erik
• Primary Examiner(s): REIP, DAVID OWEN
• Application Number:
  US10/086,041
• Publication Number:
  US 20020188295A1
• Time in Patent Office: 789 Days
• Field of Search: 606/61, 606/99, 623/17.11, 623/17.16
• US Class Current: 606/86.00A
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/2839 Bone plugs or bone graft dowels
• CPC Class Codes: A61F 2002/30131 horseshoe- or crescent- or C-shaped or U-shaped
• CPC Class Codes: A61F 2002/30158 trapezoidal
• CPC Class Codes: A61F 2002/30324 differing in thickness
• CPC Class Codes: A61F 2002/30797 internally-threaded
• CPC Class Codes: A61F 2002/30904 serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/4622 having the shape of a forceps or a clamp
• CPC Class Codes: A61F 2002/4627 with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2002/4629 connected to the endoprosthesis or implant via a threaded connection
• CPC Class Codes: A61F 2002/4649 Bone graft or bone dowel harvest sites
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0026 trapezoidal
• CPC Class Codes: A61F 2250/0036 differing in thickness
• CPC Class Codes: A61F 2310/00359 Bone or bony tissue

Abstract

An insertion tool for a C-shaped bone spinal wedge shaped intervertebral implant comprises an outer shank with a hollow core in which is placed a shaft with a threaded stud which passes through a bore in the shank at an implant insertion end of the shank. A flat extension member defines a plane and extends from the shank overlying the stud, the stud for receiving a threaded bore of the spinal implant. The shaft has a knob distal the stud for rotatably attaching the stud to the implant. The extension member abuts the implant at mating flat surfaces which are spaced by a medial recess formed by a portion of the medullary canal of a long bone. A cap slides over the shank at an end opposite the extension member to capture the shaft in the shank core. A guide rod is attached to a collar on the shank normal to the plane of the extension member to assist the surgeon in orienting the implant to the disc space orientation during insertion of the implant. The extension member prevents rotation of the implant and in some implementations may absorb insertion stresses to minimize damage to the implant during insertion.

Claims

1. A spinal implant insertion tool for inserting the implant into the disc space between two adjacent vertebra, the disc space having a given orientation relative to the spine, the implant having opposing first and second end surfaces and first and second opposing sides extending generally in a longitudinal direction between and toward the end surfaces, at least a third side having a flat surface located between the end surfaces, and a threaded bore in the first end surface, the tool comprising:

an elongated shank having a central longitudinal axis, the shank having an implant receiving surface at one end transverse to the axis for abutting the implant first end surface;

an extension member extending from the one end in the axial direction and offset from the axis arranged to abut the third side surface of the implant, the extension member being arranged relative to the implant to preclude rotation of the implant relative to the shank about the axis;

a threaded member extending axially from the implant receiving surface for engagement with the threaded bore; and

a guide member secured to the shank having a predetermined orientation relative to the extension member for providing visual alignment of the extension member relative to the disc space orientation during insertion of the implant.

2. The tool of claim 1 wherein the extension member has a flat surface for abutting the flat third side of the implant.

3. The tool of claim 2 wherein the guide member comprises a rod extending from the shank at the predetermined orientation relative to the plane of said flat surface.

4. The tool of claim 3 wherein the extension member flat surface defines a plane, the shank including a transverse threaded bore spaced from the extension member for receiving and securing the guide member normal to the axis and normal to the plane.

5. The tool of claim 4 wherein the shank includes an annular collar extending about the shank periphery, the threaded bore being formed in the collar.

6. The tool of claim 1 wherein the implant is C-shaped with a concave recess in the third side wall and forming fourth and fifth sides, the extension member having a length sufficient to overlap the concave recess of the received implant including at least a portion of the fourth and fifth sides and cooperating with the implant concave surface for entrapping bone growth material in the recess therebetween.

7. The tool of claim 6 wherein the implant comprises a fourth side wall coextensive with the third side wall, the extension member for abutting said fourth side wall and for fully overlying said concave recess.

8. The tool of claim 1 including a shaft secured to the threaded member and rotatably secured to the shank for rotating the threaded member independently of the shank and extension member to secure the implant to the shank.

9. The tool of claim 8 including a knob secured to the shaft distal the threaded member for assisting in the manually gripping of the shaft and rotating the threaded member.

10. The tool of claim 9 further including a bore in said knob for receiving a rod transversely the shaft length to assist in the manual rotation of the knob.

11. The tool of claim 8 wherein the shank comprises a tubular member with a hollow core, said shaft being rotatably mounted in said core.

12. The tool of claim 1 wherein the shank is tubular with a hollow core further including a shaft fixedly attached to the threaded member rotatably secured to the shank in the core, a collar surrounding the shank adjacent to the shank end distal the extension, the shank forming a sleeve between the shank end distal the extension and collar, and an end cap member secured to the sleeve for enclosing the core and shaft.

13. A spinal implant insertion tool comprising:

a tubular shank having a longitudinal axis and a hollow core terminating at one end in an end surface with a bore therethrough along said axis;

a collar extending about the shank adjacent to one shank end;

a guide member extending normal to the shank and attached to the collar;

a shaft rotatably mounted in the core with a threaded member at one end and extending through the bore;

a flat elongated extension member defining a plane fixedly secured to and extending from the shank one end offset from the axis, the plane being at a predetermined orientation relative to the guide member; and

a cap attached to the shank at an end distal said extension member for releaseably enclosing said core and received shaft.

14. The tool of claim 13 wherein the guide member has a longitudinal axis that is normal to the plane of the extension member.

15. A spinal implant insertion tool for inserting the implant into the disc space between two adjacent vertebra, the disc space having a given orientation relative to the spine, the implant having opposing first and second end surfaces and first and second opposing sides extending generally in a longitudinal direction between and toward the end surfaces, third and fourth coplanar flat sides spaced by an intervening chamber in communication with the first, second, third and fourth sides and located between the third and fourth sides, the third side located adjacent to the first end and the fourth side located adjacent to the second end, and a threaded bore in the first end surface, the tool comprising:

an elongated shank having a central longitudinal axis, the shank having an implant receiving surface at one end transverse to the axis for abutting the implant first end surface;

an extension member extending from the one end in the axial direction and offset from the axis arranged to abut the third and fourth sides surfaces and over lie the chamber; and

a threaded member extending axially from the implant receiving surface for engagement with the threaded bore, the extension member being arranged relative to the implant to preclude rotation of the implant relative to the shank about the axis.

16. The tool of claim 15 further including a guide member secured to the shank having a predetermined orientation relative to the extension member for providing visual alignment of the extension member relative to the disc space orientation during insertion of the implant.

17. The tool of claim 15 wherein the threaded member comprises a rod secured thereto including a knob for rotation of the threaded member independently of the shank.