Method for inserting interbody spinal fusion implants

• US 7,291,149 B1
• Filed: 10/04/1999
• Issued: 11/06/2007
• Est. Priority Date: 06/07/1995
• Status: Expired due to Fees

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Michelson, Gary Karlin
• Primary Examiner(s): Brown; Michael A.
• Application Number:
  US09/412,082
• Time in Patent Office: 2,955 Days
• Field of Search: 606 60- 61, 623/16, 623/17, 623/17.1, 623/17.3
• US Class Current: 606/86.00A
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61B 17/809 with bone-penetrating elements, e.g. blades or prongs bone staples A61B17/0642; intramedullary nails with a plate at an end A61B17/7233
• CPC Class Codes: A61B 17/8888 at its central region
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• 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 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• 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 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/3013 figure-"8"- or hourglass-shaped
• CPC Class Codes: A61F 2002/30131 horseshoe- or crescent- or C-shaped or U-shaped
• CPC Class Codes: A61F 2002/30143 hexagonal
• CPC Class Codes: A61F 2002/30148 lozenge- or diamond-shaped
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30426 Bayonet coupling
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/30777 : Oblong apertures
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30795 : Blind bores, e.g. of circular cross-section
• CPC Class Codes: A61F 2002/30797 : internally-threaded
• CPC Class Codes: A61F 2002/30836 : knurled
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30879 : Ribs
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/30906 : shot- sand- or grit-blasted
• CPC Class Codes: A61F 2002/448 : comprising multiple adjacent spinal implants within the same intervertebral space or within the same vertebra, e.g. comprising two adjacent spinal implants
• CPC Class Codes: A61F 2002/449 : comprising multiple spinal implants located in different intervertebral spaces or in different vertebrae
• CPC Class Codes: A61F 2002/4619 : for extraction
• 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 2002/4687 : Mechanical guides for implantation instruments
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/001 : Figure-8-shaped, e.g. hourglass-shaped
• CPC Class Codes: A61F 2230/0013 : Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0017 : Angular shapes
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite

Abstract

The present invention is directed to methods of inserting a variety of interbody spinal fusion implants across a disc space between adjacent vertebral bodies. The variety of implants have at least a partially frusto-conical configuration or opposed arcuate portions in an angular relationship to one another along the length of the implant. One of the methods of the present invention contemplates distracting the adjacent vertebral bodies, forming a bore from the anterior or posterior aspect of the spinal column across a distracted disc space between the adjacent vertebral bodies and into the adjacent vertebral bodies, and inserting into the bore the spinal implant having opposed arcuate portions in an angular relationship to one another along the length of the implant and oriented toward the adjacent vertebral bodies.

Claims

1. A method for inserting a spinal implant across a disc space between adjacent vertebral bodies of a human spine, said method comprising the steps of:

distracting the adjacent vertebral bodies;

forming a bore from the anterior or posterior aspect of the spinal column across the distracted disc space between the adjacent vertebral bodies and into the adjacent vertebral bodies, said bore having opposed arcuate portions in an angular relationship to one another along at least a portion of each of the adjacent vertebral bodies; and

inserting into said bore said spinal implant having opposed arcuate portions in an angular relationship to one another along the length of said implant and oriented toward the adjacent vertebral bodies.

2. The method of claim 1, wherein said inserting step includes the sub-step of inserting said implant having a generally frusto-conical configuration.

3. The method of claim 2, wherein said inserting step includes the sub-step of inserting said implant having a generally round cross section transverse to the longitudinal axis of said implant.

4. The method of claim 1, wherein said inserting step includes the sub-step of inserting said implant having a generally oval cross section transverse to the longitudinal axis of said implant.

5. The method of claim 1, wherein said inserting step includes the sub-step of inserting said implant having at least one truncated side.

6. The method of claim 1, wherein the distracting step includes the sub-step of inducing angulation to the adjacent vertebral bodies.

7. The method of claim 1, wherein the distracting step includes the step of inserting a spinal distractor into the disc space between the adjacent vertebral bodies.

8. The method of claim 7, further comprising the step of positioning a sleeve over said spinal distractor and into contact with the adjacent vertebral bodies.

9. The method of claim 1, wherein the distracting step includes the step of positioning a sleeve having an extension so that the extension is inserted into the disc space and bears against end plates of the adjacent vertebral bodies.

10. The method of claim 9, wherein the step of inserting includes the sub-step of inserting said implant through said sleeve and into the bore.

11. The method of claim 9, wherein the positioning step includes the sub-step of inducing angulation to the adjacent vertebral bodies.

12. The method of claim 1, wherein the forming step includes the sub-step selected from one of milling and drilling the bore.

13. The method of claim 1, wherein the forming step further comprises the sub-step of placing a drill having a diameter greater than the disc space through said sleeve prior to the sub-step of drilling.

14. The method of claim 1, further comprising the step of loading said implant with a material selected from one of a fusion promoting substance, a bone growth promoting material, bone morphogenetic protein, and bone prior to the step of inserting.

15. The method of claim 1, further comprising the step of coating said implant with a material selected from one of bone morphogenic protein, a fusion promoting substance, and a bone growth promoting material prior to the step of inserting.

16. The method of claim 1, wherein the step of inserting includes inserting an implant containing a material selected from one of a fusion promoting substance, a bone growth promoting material, bone morphogenetic protein, and bone.

17. The method of claim 1, wherein the step of inserting includes inserting an implant comprising a material selected from one of a bone growth promoting material, bone morphogenetic protein, and bone.

18. The method of claim 1, wherein the step of inserting includes inserting an implant in combination with a material selected from one of a bone growth promoting material, bone morphogenetic protein, and bone.

19. The method of claim 8, further comprising the step of placing an inner sleeve within said sleeve prior to the step of forming the bore.

20. The method of claim 19, further comprising the step of removing said inner sleeve prior to the step of inserting said implant.

21. A method for preparing a spinal disc space between a pair of vertebral endplates for insertion of an implant therebetween, comprising:

inserting a guide sleeve to the disc space from an anterior approach, the guide sleeve having a working channel providing access to a first disc space location and a second disc space location;

distracting the disc space to a desired disc space height;

preparing the first disc space location through the working channel for insertion of a first implant therein;

inserting a reamer plug through the working channel into the first disc space location;

preparing the second disc space location through the working channel for insertion of a second implant therein after inserting the reamer plug;

inserting the second implant through the working channel into the second disc space location, the second implant being tapered to establish a desired lordotic angle between the vertebral endplates;

removing the plug from the first disc space location after inserting the second implant; and

inserting the first implant through the working channel into the first disc space location, the first implant being tapered to establish a desired lordotic angle between the vertebral endplates.