Expandable implant with expander

• US 20060079962A1
• Filed: 11/30/2005
• Published: 04/13/2006
• Est. Priority Date: 04/19/2000
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Michelson, Gary K.
• Granted Patent: US 8,007,534 B2
• Time in Patent Office: Days
• US Class Current: 623/17.110
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• 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 2/446 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 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• 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 2002/30261 parallelepipedal
• CPC Class Codes: A61F 2002/30331 made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2002/30392 Rotation
• CPC Class Codes: A61F 2002/30517 using a locking plate
• CPC Class Codes: A61F 2002/30538 for adjusting angular orientation
• CPC Class Codes: A61F 2002/30556 for adjusting thickness
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30624 Hinged joint, e.g. with transverse axle restricting the movement
• CPC Class Codes: A61F 2002/30632 with rotation-limiting stops, e.g. projections or recesses
• CPC Class Codes: A61F 2002/30774 internally-threaded
• CPC Class Codes: A61F 2002/30777 Oblong apertures
• CPC Class Codes: A61F 2002/30779 arcuate
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30789 : perpendicular with respect to each other
• CPC Class Codes: A61F 2002/3079 : Stepped or enlarged apertures, e.g. having discrete diameter changes
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30891 : Plurality of protrusions
• CPC Class Codes: A61F 2002/30975 : made of two halves
• 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 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 2230/0082 : parallelepipedal
• CPC Class Codes: A61F 2250/0006 : for adjusting angular orientation
• CPC Class Codes: A61F 2250/0009 : for adjusting thickness
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures

Abstract

An at least in part cylindrical threaded interbody spinal fusion implant having an expandable height.

Claims

1. An apparatus comprising:

an expandable implant for use in the human body, said implant having a leading end, a trailing end, a mid-longitudinal axis through said leading and trailing ends, moveable portions, and an interior; and

an expander for moving apart said moveable portions of said implant, said expander including;

an upper surface, a lower surface, and side surfaces, said side surfaces intersecting said upper and said lower surfaces at a pair of diametrically opposed corners and a pair of diametrically opposed arcs;

a first distance between said upper and lower surfaces, a second distance between said side surfaces, and a third distance between said opposed arcs, the first distance being greater than the second distance; and

an axis of rotation about which said expander is rotatable so that said expander moves apart the moveable portions of said implant when said opposed arcs are rotated against the moveable portions of said implant, the axis being perpendicular to said first and second distances.

2. The apparatus of claim 1, wherein said third distance generally approximates said first distance.

3. The apparatus of claim 1, wherein said third distance is greater than said first distance.

4. The apparatus of claim 1, wherein said third distance is less than said first distance.

5. The apparatus of claim 1, further comprising a fourth distance between said opposed corners, said fourth distance being greater than said third distance.

6. The apparatus of claim 1, further comprising a depth parallel to the axis of rotation of said expander, said depth being less than said first distance.

7. The apparatus of claim 1, further comprising a depth parallel to the axis of rotation of said expander, said depth being less than said second distance.

8. The apparatus of claim 1, wherein said expander has an outer perimeter adapted to contact a portion of said implant, said outer perimeter being non-threaded.

9. The apparatus of claim 1, wherein each of said upper and lower surfaces lie generally in a plane.

10. The apparatus of claim 1, wherein said upper and lower surfaces are generally parallel to one another.

11. The apparatus of claim 1, wherein said side surfaces and said upper and lower surfaces are oriented to substantially form a parallelogram.

12. The apparatus of claim 1, wherein said two diametrically opposed arcs are each of the same radius.

13. The apparatus of claim 1, wherein said two diametrically opposed arcs are arcs of the same circle.

14. The apparatus of claim 1, wherein said two diametrically opposed corners each form a 90-degree angle.

15. The apparatus of claim 1, wherein said expander has a fixed shape during movement from an initial insertion position to a final deployed position within said implant.

16. The apparatus of claim 1, wherein said expander includes an opening adapted to cooperatively engage a tool used to move said expander from an initial position to a final position to increase the height of said implant.

17. The apparatus of claim 16, wherein said opening is non-threaded.

18. The apparatus of claim 16, wherein said opening is coaxial with the axis of rotation.

19. The apparatus of claim 16, wherein said opening is offset from the axis of rotation.

20. The apparatus of claim 1, wherein said expander has an outer perimeter, the outer perimeter including at least one removed portion for engaging a tool used to move said expander from an initial position to a final position to increase the height of said implant.

21. The apparatus of claim 20, wherein said removed portion is concavedly-shaped.

22. The apparatus of claim 1, wherein at least two of said moveable portions include at least one opening in communication with said interior of said implant to permit bone growth through said implant.

23. The apparatus of claim 1, wherein said implant has a depth between said leading and trailing ends, said expander having a depth dimension that is less than half the depth of said implant.

24. The apparatus of claim 1, wherein said implant has a width perpendicular to the mid-longitudinal axis of said implant, said second distance being approximately one-half the width of said implant.

25. The apparatus of claim 1, wherein said expander is adapted to rotate in a plane perpendicular to the mid-longitudinal axis of said implant.

26. The apparatus of claim 1, wherein said expander is adapted to remain in a fixed location along the mid-longitudinal axis while transitioning said implant from an unexpanded position to an expanded position.

27. The apparatus of claim 1, wherein said implant comprises:

an upper member having a portion being at least in part arcuate adapted for contact with an adjacent bone portion; and

a lower member having a portion being at least in part arcuate adapted for contact with an adjacent bone portion, at least a portion of said upper and lower members being moveable relative to one another.

28. The apparatus of claim 27, wherein said expander is adapted to slide along at least a portion of at least one of said upper and lower members.

29. The apparatus of claim 27, wherein said arcuate portions of said upper and lower members are arcs of the same circle.

30. The apparatus of claim 27, wherein said upper and lower members each have a length, the entire length of said upper and lower members being movable relative to the mid-longitudinal axis.

31. The apparatus of claim 1, wherein said implant is adapted for insertion at least in part between two adjacent vertebral bodies of the spine.

32. The apparatus of claim 31, wherein said implant comprises:

an upper member having a portion being at least in part arcuate adapted for placement toward and at least in part within one of the adjacent vertebral bodies; and

a lower member having a portion being at least in part arcuate adapted for placement toward and at least in part within the other of the adjacent vertebral bodies, at least a portion of said upper and lower members being moveable relative to one another.