Intervertebral implant for transforaminal posterior lumbar interbody fusion procedure

• US 7,223,292 B2
• Filed: 12/12/2005
• Issued: 05/29/2007
• Est. Priority Date: 05/03/2001
• Status: Expired due to Term

• Current Assignee: Synthes USA LLC (Johnson & Johnson)
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Messerli, Dominique, Gerber, David, Paul, David, Kobayashi, Kenneth Isamu
• Primary Examiner(s): BARRETT, THOMAS C
• Application Number:
  US11/301,759
• Publication Number:
  US 20060106460A1
• Time in Patent Office: 533 Days
• Field of Search: 623 1711- 1716
• US Class Current: 623/17.16
• CPC Class Codes: A61B 17/1604 Chisels; Rongeurs; Punches; Stamps
• CPC Class Codes: A61B 17/1659 Surgical rasps, files, planes, or scrapers
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• 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 2/4465 having a circular or kidney shaped cross-section substantially perpendicular to the axis of the spine
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2/4684 Trial or dummy prostheses
• 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 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/30383 made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
• CPC Class Codes: A61F 2002/30492 using a locking pin
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30538 for adjusting angular orientation
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30594 slotted, e.g. radial or meridian slot ending in a polar aperture, non-polar slots, horizontal or arcuate slots
• CPC Class Codes: A61F 2002/30599 stackable
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30797 : internally-threaded
• CPC Class Codes: A61F 2002/30843 : Pyramidally-shaped
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/30975 : made of two halves
• CPC Class Codes: A61F 2002/4628 : with linear motion along or rotating motion about an axis transverse to the instrument axis or to the implantation direction, e.g. clamping
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/0015 : Kidney-shaped, e.g. bean-shaped
• CPC Class Codes: A61F 2250/0006 : for adjusting angular orientation
• CPC Class Codes: A61F 2250/0063 : Nested prosthetic parts
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00359 : Bone or bony tissue

Abstract

An intervertebral implant for fusing vertebrae is disclosed. The implant has a body with curved, substantially parallel posterior and anterior faces separated by, two narrow implant ends, superior and inferior faces having a plurality of undulating surfaces for contacting vertebral endplates, and at least one depression in the anterior or posterior face for engagement by an insertion tool, at least two vertical through-channels extending through the implant, a chamfer on the superior and inferior surfaces at one of the narrow implant ends, and a beveled edge along a perimeter of the superior and inferior faces. The implant configuration facilitates transforaminal insertion of the implant into a symmetric position about the midline of the spine so that a single implant provides balanced support to the spinal column. The implant may be formed of a plurality of interconnecting bodies forming a single unit. An implantation kit and method are also disclosed.

Claims

1. An intervertebral implant for posterior insertion via a transforaminal window comprising;

curved, substantially parallel posterior and anterior faces, the posterior and anterior faces extending along a longitudinal axis of the implant;

a pair of convex narrow ends separating the posterior and anterior faces;

superior and inferior faces for contacting upper and lower vertebral endplates, the superior and inferior faces defining a thickness of the implant;

at least one depression in the anterior or posterior face for engagement by an insertion tool;

at least two vertical through-channels extending through the implant from the superior face to the inferior face, each vertical through-channel having a width and walls on posterior and anterior sides of the width, the walls on the posterior and anterior sides of the width of the vertical through-channels having a thickness greater than the width of the vertical through channels; and

a chamfer on the superior and inferior faces at one of the convex narrow ends to facilitate implant insertion.

2. The implant of claim 1, wherein a first convex narrow end is configured and adapted to be inserted first into an affected disc space before a second convex narrow end, and the chamfer is at the first convex narrow end.

3. The implant of claim 2, further comprising a beveled edge along a perimeter of the superior and inferior faces.

4. The implant of claim 3, further comprising at least two anterior-posterior horizontal through-channels extending through the implant from the posterior face to the anterior face.

5. The implant of claim 4, further comprising at least one lateral horizontal through-channel extending through the implant from at least one of the convex narrows ends to an adjacent anterior-posterior horizontal through channel.

6. The implant of claim 3, further comprising a plurality of bone-engaging undulating surfaces on the superior and inferior faces.

7. The implant of claim 6, wherein the undulating surfaces are teeth.

8. The implant of claim 1, wherein the width of the vertical through-channels in the anterior-posterior direction is approximately 3.0 mm and the thickness of the walls on the posterior and anterior sides of the vertical through-channels is approximately 3.5 mm.

9. The implant of claim 3, wherein the superior and inferior faces are convex.

10. The implant of claim 9, wherein the thickness of the implant between the superior and inferior faces is greatest at a mid-section between the narrow ends of the implant and the thickness tapers toward the narrow ends.

11. The implant of claim 3, wherein the implant is formed of polyaryl ether ketone (PAEK).

12. The implant of claim 3, wherein the implant is formed of polyether ether ketone (PEEK), polyether ketone ketone (PEKK), or titanium.

13. The implant of claim 1, further comprising one or more radiopaque markers extending substantially through the thickness of the implant.

14. The implant of claim 13, wherein the radiopaque markers indicate a size of the implant.

15. The implant of claim 1, wherein the implant is formed of a plurality of interconnecting bodies assembled to form a single unit.

16. The implant of claim 15, further comprising at least one pin extending through an opening in the plurality of bodies to hold the bodies together as a single unit.

17. The implant of claim 16, wherein the plurality of bodies have mating interlocking surfaces that aid in holding the bodies together as a single unit.

18. An intervertebral implant comprising:

a body having a posterior face, an anterior face, a pair of curved ends separating the posterior and anterior faces, and superior and inferior faces for contacting upper and lower vertebral endplates, the superior and inferior faces defining a thickness of the implant;

wherein the body includes at least one vertical through-channel extending from the superior face to the inferior face, the vertical through-channel having a width and walls on posterior and anterior sides of the width, the walls on the posterior and anterior sides of the width of the vertical through-channel having a thickness greater than the width of the vertical through channel; and

the anterior and posterior faces include at least one slot configured and adapted to mate with an insertion tool, wherein the slots each include at least one recess for engaging a corresponding projection formed on the insertion tool.

19. The implant of claim 18, further comprising a chamfer on the superior and inferior faces at one of the curved ends to facilitate implant insertion.

20. The implant of claim 18, further comprising a plurality of bone-engaging undulating surfaces on the superior and inferior faces.