Intervertebral implant with integrated fixation

• US 8,821,555 B2
• Filed: 12/17/2009
• Issued: 09/02/2014
• Est. Priority Date: 02/11/2009
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Inventors: Bae, Hyun W., Hushka, Dylan M., Butters, Joshua A., Slater, Nicholas, Justin, Daniel F., Delamarter, Rick
• Primary Examiner(s): BECCIA, CHRISTOPHER J
• Application Number:
  US12/640,892
• Publication Number:
  US 20100204739A1
• Time in Patent Office: 1,720 Days
• Field of Search: 606246-279, 606300-331, 623 1711- 1716
• US Class Current: 606/300
• CPC Class Codes: A61B 17/846 Nails or pins, i.e. anchors without movable parts, holding by friction only, with or without structured surface A61B17/72, A61B17/86 take precedence
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• 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 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2002/3007 Coating or prosthesis-covering structure made of elastic material, e.g. of elastomer
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30115 circular-O-shaped
• CPC Class Codes: A61F 2002/30126 oval-O-shaped
• CPC Class Codes: A61F 2002/30138 Convex polygonal shapes
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30166 H-shaped or I-shaped
• CPC Class Codes: A61F 2002/30168 L-shaped
• CPC Class Codes: A61F 2002/30172 T-shaped
• CPC Class Codes: A61F 2002/30176 V-shaped
• CPC Class Codes: A61F 2002/30181 Y-shaped
• CPC Class Codes: A61F 2002/30316 The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
• CPC Class Codes: A61F 2002/30352 Protrusion and recess of D-shaped cross-section
• CPC Class Codes: A61F 2002/30367 with additional means for preventing said rotation
• CPC Class Codes: A61F 2002/30387 : Dovetail connection
• CPC Class Codes: A61F 2002/30401 : with additional means for preventing or locking said sliding
• CPC Class Codes: A61F 2002/305 : Snap connection
• CPC Class Codes: A61F 2002/30522 : releasable, e.g. using a releasable ratchet
• 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 2002/30604 : modular
• CPC Class Codes: A61F 2002/30649 : Ball-and-socket joints
• CPC Class Codes: A61F 2002/30736 : Augments or augmentation pieces, e.g. wedges or blocks for bridging a bone defect
• CPC Class Codes: A61F 2002/30738 : Sleeves
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30845 : with cutting edges
• CPC Class Codes: A61F 2002/30879 : Ribs
• CPC Class Codes: A61F 2002/30884 : Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2230/0006 : circular
• CPC Class Codes: A61F 2230/0008 : elliptical or oval
• CPC Class Codes: A61F 2230/0017 : Angular shapes
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0028 : Shapes in the form of latin or greek characters
• CPC Class Codes: A61F 2230/0043 : L-shaped
• CPC Class Codes: A61F 2230/0052 : T-shaped
• CPC Class Codes: A61F 2230/0054 : V-shaped
• CPC Class Codes: A61F 2230/006 : Y-shaped
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite

Abstract

A system for spinal surgery includes a prosthesis comprising a plurality of bone anchors which engage an intervertebral construct for fusion or motion preservation. The fusion construct comprises a spacer optionally encircled by a jacket. The motion preservation construct may comprise an articulating disc assembly or an elastomeric disc assembly. Any of the constructs may occupy the intervertebral disc space between adjacent vertebrae after removal of an intervertebral disc. The anchors slidingly engage the construct to securely fix the prosthesis to the vertebrae. The anchors and jacket of the fusion construct provide a continuous load path across opposite sides of the prosthesis so as to resist antagonistic motions of the spine.

Claims

1. A bone anchor, comprising:

an interconnection portion to slidingly engage a prosthesis;

a fixation portion spaced apart from the interconnection portion to fix the anchor to a bone; and

a leg connecting the fixation portion to the interconnection portion, the leg including a cutting edge capable of cutting through bone.

2. The anchor of claim 1, wherein the anchor is substantially elongate and comprises a generally H-shaped cross section, wherein the interconnection portion comprises a first upright of the H shape, the fixation portion comprises a second upright of the H shape, and the leg completes the H shape.

3. The anchor of claim 1, wherein the interconnection portion comprises a dovetail beam.

4. The anchor of claim 1, wherein the fixation portion comprises a plate oriented substantially perpendicular to the leg.

5. The anchor of claim 1, comprising:

a prosthesis lock portion to resist disengagement of the anchor from the prosthesis.

6. The anchor of claim 5, wherein the prosthesis lock portion comprises a resilient tab integral with the interconnection portion.

7. The anchor of claim 5, wherein the prosthesis lock portion is biased to resist disengagement of the anchor from the prosthesis.

8. The anchor of claim 5, wherein the prosthesis lock portion is selectively releasable to permit disengagement of the anchor from the prosthesis.

9. The anchor of claim 1, comprising:

a stop portion to limit engagement of the anchor to the prosthesis to a predetermined maximum engagement.

10. The anchor of claim 9, wherein the stop portion comprises a flange integral with an end of the interconnection portion.

11. The anchor of claim 1, wherein the fixation portion comprises a sharpened cutting edge that penetrates the bone when the anchor is urged against the bone.

12. The anchor of claim 11, wherein the cutting edge biases the fixation portion to diverge from the interconnection portion as the anchor is urged against the bone.

13. The anchor of claim 11, wherein the fixation portion resists penetrating the bone when the anchor is urged out of the bone.

14. The anchor of claim 1, wherein the leg comprises an aperture bounded by the interconnection portion and the fixation portion.

15. The anchor of claim 1, wherein the fixation portion comprises an aperture.

16. The anchor of claim 1, wherein the leg is a first leg coupled with the interconnection portion adjacent the leading end thereof, and further comprising a second leg connecting the fixation portion to the interconnection portion and coupled with the interconnection portion adjacent the trailing end thereof.

17. A bone anchor, comprising:

an interconnection portion to slidingly engage a prosthesis, the interconnection portion including a leading end, a trailing end, and a stop portion adjacent the trailing end to limit engagement of the anchor to the prosthesis to a predetermined maximum engagement in a direction extending between the leading and trailing ends;

a fixation portion spaced apart from the interconnection portion to fix the anchor to a bone; and

a leg connecting the fixation portion to the interconnection portion.

18. The anchor of claim 17, wherein the stop portion comprises a flange integral with the trailing end of the interconnection portion.

19. A bone anchor, comprising:

an interconnection portion to slidingly engage a prosthesis;

a fixation portion spaced apart from the interconnection portion to fix the anchor to a bone; and

a leg connecting the fixation portion to the interconnection portion,

wherein the fixation portion is biased to diverge from the interconnection portion as the anchor is urged against the bone.