Expandable interbody spinal fusion implant with expansion constraining member and method for use thereof

• US 7,326,248 B2
• Filed: 11/21/2003
• Issued: 02/05/2008
• Est. Priority Date: 03/09/2001
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Michelson, Gary K.
• Primary Examiner(s): Philogene; Pedro
• Application Number:
  US10/719,424
• Publication Number:
  US 20040102848A1
• Time in Patent Office: 1,537 Days
• Field of Search: 623 1711- 1716, 606/61
• US Class Current: 623/17.11
• CPC Class Codes: A61B 17/8042 the additional component being a cover over the screw head
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• 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 2/4611 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 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30143 hexagonal
• CPC Class Codes: A61F 2002/30392 Rotation
• CPC Class Codes: A61F 2002/30397 Limited lateral translation of the rib within a larger groove
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• 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 2002/30517 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 2002/30779 : arcuate
• CPC Class Codes: A61F 2002/30787 : inclined obliquely 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 2002/30873 : Threadings machined on non-cylindrical external surfaces
• CPC Class Codes: A61F 2002/30975 : made of two halves
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/0017 : Angular shapes
• 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 implant cap is disclosed for preventing the over-expansion of an expandable spinal implant and method for use therewith. An implant cap also is disclosed for moving an expandable spinal implant from a collapsed position to an expanded position with less than one full turn of the implant cap and a method for use therewith. A screw lock is disclosed for locking a bone screw to the trailing end of an expandable spinal implant and a method for use therewith.

Claims

1. An apparatus for insertion within an implantation space formed across the height of a disc space between vertebral bodies of a human spine, said apparatus comprising:

an expandable spinal implant having upper and lower portions adapted to move apart from one another to contact adjacent upper and lower vertebral bodies, respectively, said implant having an end having an opening, each of said upper and lower portions having a recess; and

an implant end cap having a head configured to cooperatively engage said end of said implant to at least in part cover said opening, said head having a top surface and a bottom surface opposite said top surface, said bottom surface having at least one protrusion adapted to cooperatively engage said recesses of said upper and lower portions of said implant to prevent said implant from expanding beyond a predetermined height by limiting movement of said upper and lower portions relative to one another, said implant end cap being rotated to engage said at least one protrusion and said recesses.

2. The apparatus of claim 1, wherein said head is configured to cooperatively engage said end of said implant to completely cover said opening.

3. The apparatus of claim 1, wherein said implant has a plurality of bone screw holes, said bottom surface of said head being configured to cover at least a portion of one of said bone screw holes when said cap is engaged to said implant.

4. The apparatus of claim 3, wherein said bottom surface of said head is configured to cover a portion of more than one of said bone screw holes when said cap is engaged to said implant.

5. The apparatus of claim 3, wherein said head is configured to allow the insertion of a bone screw into said implant after said cap is engaged with said implant.

6. The apparatus of claim 3, wherein said head has a perimeter that is configured to permit the insertion of a bone screw into one of said bone screw holes after said cap is engaged with said implant, said head being movable to cover at least a portion of the bone screw after the bone screw is inserted in one of said bone screw holes.

7. The apparatus of claim 1, wherein said upper and lower portions of said implant include at least one opening adapted to communicate with one of the adjacent vertebral bodies, said openings in said upper and lower portions being in communication with one another and adapted for permitting for the growth of bone from adjacent vertebral body to adjacent vertebral body through said implant.

8. The apparatus of claim 7, wherein said implant includes a hollow interior for holding bone growth promoting material, said hollow interior being in communication with at least one openings in each of said upper and lower portions.

9. The apparatus of claim 1, wherein said implant is in combination with a bone growth promoting material.

10. The apparatus of claim 9, wherein said bone growth promoting material is selected from one of bone, bone derived products, demineralized bone matrix, ossifying proteins, bone morphogenetic protein, hydroxyapatite, and genes coding for the production of bone.

11. The apparatus of claim 1, wherein said implant is treated with a bone growth promoting substance.

12. The apparatus of claim 1, wherein said implant comprises at least one of the following materials:

metal, titanium, plastic, and ceramic appropriate for implantation in the human body.

13. The apparatus of claim 1, wherein said implant is at least in part resorbable.

14. The apparatus of claim 1, wherein said implant is formed of a porous material.

15. The apparatus of claim 1, wherein said implant is in combination with a material adapted to inhibit scar formation.

16. The apparatus of claim 1, wherein said implant is in combination with an antimicrobial material.

17. An apparatus for insertion within an implantation space formed across the height of a disc space between vertebral bodies of a human spine, said apparatus comprising:

an expandable spinal implant having upper and lower portions adapted to move apart from one another to contact adjacent upper and lower vertebral bodies, respectively, said implant having an end having an opening, each of said upper and lower portions having at least one protrusion; and

an implant end cap having a head configured to cooperatively engage said end of said implant to at least in part cover said opening, said head having a top surface and a bottom surface opposite said top surface, said bottom surface having a recess adapted to cooperatively receive said protrusions of said upper and lower portions of said implant to prevent said implant from expanding beyond a predetermined height by limiting movement of said upper and lower portions relative to one another, said implant end cap being rotated to facilitate receipt of said protrusions in said recess.

18. The apparatus of claim 17, wherein said head is configured to cooperatively engage said end of said implant to completely cover said opening.

19. The apparatus of claim 17, wherein said implant has a plurality of bone screw holes, said bottom surface of said head being configured to cover at least a portion of one of said bone screw holes when said cap is engaged to said implant.

20. The apparatus of claim 19, wherein said bottom surface of said head is configured to cover a portion of more than one of said bone screw holes when said cap is engaged to said implant.

21. The apparatus of claim 19, wherein said head is configured to allow the insertion of a bone screw into said implant after said cap is engaged with said implant.

22. The apparatus of claim 19, wherein said head has a perimeter that configured to permit the insertion of a bone screw into one of said bone screw holes after said cap is engaged with said implant, said head being movable to cover at least a portion of the bone screw after the bone screw is inserted in one of said bone screw holes.

23. The apparatus of claim 17, wherein said upper and lower portions of said implant include at least one opening adapted to communicate with one of the adjacent vertebral bodies, said openings in said upper and lower portions being in communication with one another and adapted for permitting for the growth of bone from adjacent vertebral body to adjacent vertebral body through said implant.

24. The apparatus of claim 23, wherein said implant includes a hollow interior for holding bone growth promoting material, said hollow interior being in communication with at least one openings in each of said upper and lower portions.

25. The apparatus of claim 17, wherein said implant is in combination with a bone growth promoting material.

26. The apparatus of claim 25, wherein said bone growth promoting material is selected from one of bone, bone derived products, demineralized bone matrix, ossifying proteins, bone morphogenetic protein, hydroxyapatite, and genes coding for the production of bone.

27. The apparatus of claim 17, wherein said implant is treated with a bone growth promoting substance.

28. The apparatus of claim 17, wherein said implant comprises at least one of the following materials:

metal, titanium, plastic, and ceramic appropriate for implantation in the human body.

29. The apparatus of claim 17, wherein said implant is at least in part resorbable.

30. The apparatus of claim 17, wherein said implant is formed of a porous material.

31. The apparatus of claim 17, wherein said implant is in combination with a material adapted to inhibit scar formation.

32. The apparatus of claim 17, wherein said implant is in combination with an antimicrobial material.

33. A method for expanding an expandable spinal implant having an end, the method comprising the steps of:

providing an end cap having a stem projecting therefrom;

inserting at least a portion of the stem of the end cap into the end of the implant while the implant is in a collapsed position; and

rotating the stem of the end cap less than one full turn to expand the implant from the collapsed position to an expanded position.

34. The method of claim 33, wherein the step of rotating the stem includes rotating the stem approximately 90 degrees.

35. The method of claim 33, wherein the step of rotating the stem includes rotating a stem having no threads.

36. The method of claim 33, further comprising the step of locking the cap to the implant.

37. The method of claim 33, further comprising the step of locking the implant in an expanded position.

38. The method of claim 33, wherein the implant has a plurality of bone screw holes, further comprising the step of covering at least a portion of the bone screw holes with at least a portion of the end cap.

39. The method of claim 33, further comprising the step of inserting at least one bone screw in the implant after the stem of the end cap is inserted into the end of the implant.

40. The method of claim 33, wherein the end of the implant includes an opening leading to an interior hollow having a bone growth promoting material therein, further comprising the step of covering at least a portion of the opening with the end cap.

41. The method of claim 33, wherein the step of inserting includes inserting a non-threaded stem into the end of the implant.

42. An apparatus for insertion within an implantation space formed across the height of a disc space between vertebral bodies of a human spine, said apparatus comprising:

an expandable spinal implant having upper and lower portions adapted to move apart from one another to contact adjacent upper and lower vertebral bodies, respectively, said implant having an end having an opening, each of said upper and lower portions having a recess, said implant having a plurality of bone screw holes; and

an implant end cap having a head configured to cooperatively engage said end of said implant to at least in part cover said opening, said head having a top surface and a bottom surface opposite said top surface, said bottom surface having at least one protrusion adapted to cooperatively engage said recesses of said upper and lower portions of said implant to prevent said implant from expanding beyond a predetermined height by limiting movement of said upper and lower portions relative to one another, said bottom surface of said head being configured to cover at least a portion of one of said bone screw holes when said cap is engaged to said implant.

43. An apparatus for insertion within an implantation space formed across the height of a disc space between vertebral bodies of a human spine, said apparatus comprising:

an expandable spinal implant having upper and lower portions adapted to move apart from one another to contact adjacent upper and lower vertebral bodies, respectively, said implant having an end having an opening, each of said upper and lower portions having at least one protrusion, said implant having a plurality of bone screw holes; and

an implant end can having a head configured to cooperatively engage said end of said implant to at least part cover said opening, said head having a top surface and a bottom surface opposite said top surface, said bottom surface having a recess adapted to cooperatively receive said protrusions of said upper and lower portions of said implant to prevent said implant from expanding beyond a predetermined height by limiting movement of said upper and lower portions relative to one another, said bottom surface of said head being configured to cover at least a portion of one of said bone screw holes when said cap is engaged to said implant.