Laminoplasty implants and methods of use

• US 20020120335A1
• Filed: 08/29/2001
• Published: 08/29/2002
• Est. Priority Date: 02/28/2001
• Status: Abandoned Application

• Current Assignee: Synthes USA LLC (Johnson & Johnson)
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Paul, David C., Boyer, Michael L. II, Sinha, Amit, Ryan, Christopher J., Angelucci, Christopher M., Walther, Martin
• Application Number:
  US09/942,137
• Publication Number:
  US 20020120335A1
• Time in Patent Office: Days
• US Class Current: 623/17.16
• CPC Class Codes: A61B 17/0401 Suture anchors, buttons or pledgets, i.e. means for attaching sutures to bone, cartilage or soft tissue; Instruments for applying or removing suture anchors A61B17/0642 takes precedence; fixation devices for tendons or ligaments A61F2/0811
• CPC Class Codes: A61B 17/0642 for bones, e.g. for osteosynthesis or connecting tendon to bone
• CPC Class Codes: A61B 17/68 Internal fixation devices , including fasteners and spinal fixators, even if a part thereof projects from the skin bone staples A61B17/0642
• CPC Class Codes: A61B 17/683 comprising bone transfixation elements, e.g. bolt with a distal cooperating element such as a nut
• CPC Class Codes: A61B 17/7059 Cortical plates A61B17/7007, A61B17/7058 take precedence
• CPC Class Codes: A61B 17/7071 Implants for expanding or repairing the vertebral arch or wedged between laminae or pedicles; Tools therefor
• CPC Class Codes: A61B 17/80 Cortical plates , i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates
• CPC Class Codes: A61B 17/8085 with pliable or malleable elements or having a mesh-like structure, e.g. small strips A61B17/8071, A61B17/8076 take precedence
• CPC Class Codes: A61B 2017/0648 threaded, e.g. tacks with a screw thread
• CPC Class Codes: A61F 2/00 Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents as cosmetic articles, see the relevant subclasses, e.g. wigs, hair pieces, A41G3/00, A41G5/00; artificial nails A45D31/00; dental prostheses A61C13/00; materials for prostheses A61L27/00; artificial hearts A61M60/00; artificial kidneys A61M1/14
• CPC Class Codes: A61F 2/08 Muscles; Tendons; Ligaments sutures A61B17/04
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/2803 for mandibular reconstruction temporo-mandibular joints A61F2/3099; bone plates for the jaw A61B17/8071
• CPC Class Codes: A61F 2/2846 Support means for bone substitute or for bone graft implants, e.g. membranes or plates for covering bone defects nets or sleeves applied to surface of endoprostheses A61F2/30907; bone plates A61B17/80; bone regeneration in dental surgery A61C8/0006
• CPC Class Codes: A61F 2/2875 Skull or cranium A61F2/2803 and A61F2/3099 take precedence
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• 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 2/4465 having a circular or kidney shaped cross-section substantially perpendicular to the axis of the spine
• CPC Class Codes: A61F 2002/2807 : Chin implants
• CPC Class Codes: A61F 2002/2825 : Femur
• 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 2002/2839 : Bone plugs or bone graft dowels
• CPC Class Codes: A61F 2002/30011 : differing in porosity
• CPC Class Codes: A61F 2002/30014 : differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30016 : differing in hardness, e.g. Vickers, Shore, Brinell
• CPC Class Codes: A61F 2002/30057 : made from both cortical and cancellous adjacent parts
• CPC Class Codes: A61F 2002/30059 : differing in bone mineralization, e.g. made from both mineralized and demineralized adjacent parts
• CPC Class Codes: A61F 2002/30075 : swellable, e.g. when wetted
• CPC Class Codes: A61F 2002/30092 : using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30113 : circular
• CPC Class Codes: A61F 2002/30126 : oval-O-shaped
• 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 2002/30153 : rectangular
• CPC Class Codes: A61F 2002/30154 : square
• CPC Class Codes: A61F 2002/30159 : Concave polygonal shapes
• CPC Class Codes: A61F 2002/30166 : H-shaped or I-shaped
• CPC Class Codes: A61F 2002/30169 : Pi-shaped
• CPC Class Codes: A61F 2002/30172 : T-shaped
• CPC Class Codes: A61F 2002/30233 : Stepped cylinders, i.e. having discrete diameter changes
• CPC Class Codes: A61F 2002/30235 : tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30261 : parallelepipedal
• CPC Class Codes: A61F 2002/30293 : Cylindrical body made by spirally rolling up a sheet or a strip around itself
• CPC Class Codes: A61F 2002/30324 : differing in thickness
• CPC Class Codes: A61F 2002/30387 : Dovetail connection
• CPC Class Codes: A61F 2002/30433 : using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30462 : retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/30578 : having apertures, e.g. for receiving fixation screws
• 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 2002/30784 : Plurality of holes
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30828 : parallel
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30843 : Pyramidally-shaped
• CPC Class Codes: A61F 2002/30879 : Ribs
• CPC Class Codes: A61F 2002/30892 : parallel
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/30909 : Nets
• CPC Class Codes: A61F 2002/30914 : Details of the mesh structure, e.g. disposition of the woven warp and weft wires
• CPC Class Codes: A61F 2002/30973 : Two joined adjacent layers having complementary interlocking protrusions and recesses
• CPC Class Codes: A61F 2002/444 : for replacing the nucleus pulposus
• CPC Class Codes: A61F 2002/4649 : Bone graft or bone dowel harvest sites
• CPC Class Codes: A61F 2210/0014 : using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2210/0061 : swellable
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2220/0075 : sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/0006 : circular
• CPC Class Codes: A61F 2230/0008 : elliptical or oval
• 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 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0021 : square
• CPC Class Codes: A61F 2230/0028 : Shapes in the form of latin or greek characters
• CPC Class Codes: A61F 2230/0047 : Pi-shaped
• CPC Class Codes: A61F 2230/0052 : T-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0082 : parallelepipedal
• CPC Class Codes: A61F 2230/0091 : helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• CPC Class Codes: A61F 2250/0018 : differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0019 : differing in hardness, e.g. Vickers, Shore, Brinell
• CPC Class Codes: A61F 2250/0023 : differing in porosity
• CPC Class Codes: A61F 2250/0029 : differing in bending or flexure capacity
• CPC Class Codes: A61F 2250/0036 : differing in thickness
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61L 2430/02 : for reconstruction of bones; weight-bearing implants
• CPC Class Codes: A61L 2430/38 : for reconstruction of the spine, vertebrae or intervertebral discs
• CPC Class Codes: A61L 27/3608 : Bone, e.g. demineralised bone matrix [DBM], bone powder
• CPC Class Codes: A61L 27/365 : Bones

Abstract

Implants for maintaining a distance between cut spinal bones are disclosed. The implants are made of metal, polymer or bone allograft having ends configured to conform to the cut bone ends. The implants have hollow regions for packing osteogenic material. The implant ends have surface projections to reduce slippage. Implants made of bone allograft also have spine contacting ends made of demineralized bone to speed fusion of spine and implant; they may also have bone flaps to fix the implant to the spine. Methods of using the implants are also disclosed.

Claims

1. An implant for use in the spinal column, said implant comprising:

(a) a body portion having a length, a width and a depth, and configured to be insertable between first and second cut bone segments, the body portion having an outer surface, and an inner surface defining a substantially hollow portion, the body portion further having first and second ends which communicate with said hollow portion, the first and second ends comprising bone engaging portions;

wherein at least one of the bone engaging portions comprises a cutout configured and adapted to engage and retain at least one of the first and second cut bone segments.

2. The implant of claim 1 wherein the perimeter of the outer surface of the implant is a substantially geometric shape.

3. The implant of claim 2 wherein the geometric shape is an ellipse having a width and a depth.

4. The implant of claim 1 wherein the length ranges from about 11.5 to about 15.5 millimeters, the width ranges from about 8.0 to about 9.0 millimeters and the depth ranges from about 5.5 to about 6.5 millimeters.

5. The implant of claim 2 wherein the geometric shape is a circle.

6. The implant of claim 1 wherein the implant comprises a substantially tubular shape.

7. The implant of claim 1 wherein the implant is formed of bone allograft material.

8. The implant of claim 7 wherein at least a portion of at least one said bone engaging portion is comprised of demineralized cortical bone.

9. The implant of claim 7 further comprising first and second bone flaps, the flaps connecting to and extending from the body portion at the first and second ends, each said flap further comprising at least one hole suitable for receiving a bone fastener for securing said implant to said first and second bone segments.

10. The implant of claim 9 wherein at least one of the first and second bone flaps is flexible.

11. The implant of claim 9 wherein at least one of the first and second bone flaps is comprised of demineralized cortical bone.

12. The implant of claim 9 wherein at least one of the first and second bone flaps comprises a notch in the region where the at least one bone flap connects to the body portion.

13. The implant of claim 7 wherein said inner surface is defined by the intermedullary canal of the donor bone.

14. The implant of claim 7 wherein said inner surface is configured such that the volume of said substantially hollow portion is greater than the intermedullary canal of the donor bone.

15. The implant of claim 1 further comprising:

(a) a longitudinal axis, and

(b) the at least one cutout further comprises a centerline running parallel to the implant longitudinal axis dividing said ends,

wherein the centerline of the at least one cutout is offset from the longitudinal axis.

16. The implant of claim 1 wherein the at least one cutout has a substantially concave arcuate shape.

17. The implant of claim 1 wherein both bone engaging portions comprise cutouts and further wherein both cutouts have a substantially concave arcuate shape.

18. The implant of claim 1 wherein the at least one cutout comprises at least two angled faces.

19. The implant of claim 1 further comprising at least one surface defining a hole in communication with said outer surface and said inner surface, suitable for attaching a suture to secure said implant to at least one of said first and second bone segments.

20. The implant of claim 1 wherein the implant is fabricated of biocompatable metal.

21. The implant of claim 1 wherein the implant is fabricated of biocompatable polymer.

22. The implant of claim 1 wherein at least one of the bone engaging portions comprises surface projections configured to retain said implant within said first and second bone segments.

24. The implant of claim 23, wherein at least one cutout further comprises at least two angled faces.

25. The implant of claim 23 wherein the at least one cutout has a substantially concave arcuate shape.

26. The implant of claim 23 wherein at least one of the bone engaging portions comprises surface projections configured to retain said implant within said first and second bone segments.

27. The implant of claim 23 wherein the implant is formed of bone allograft material.

29. The implant of claim 28 wherein the body portion further comprises a wall having an outer surface, and an inner surface defining a substantially hollow portion, wherein the hollow portion is in communication with the first and second ends.

30. The implant of claim 29 wherein said hollow portion is defined by the intermedullary canal of the donor bone.

31. The implant of claim 29 wherein said inner surface is configured such that the volume of said substantially hollow portion is greater than the intermedullary canal of the donor bone.

32. The implant of claim 28 wherein the at least one of said first and second bone engaging portions further comprises surface projections configured to retain said implant within said first and second bone segments.

33. The implant of claim 32 wherein the surface projections comprise saw-tooth ridges.

34. The implant of claim 32 wherein the surface projections comprise individual pyramidal teeth.

36. The implant of claim 35 wherein at least one of the bone engaging portions comprises an arcuate surface configured to retain said first and second bone segments.

37. The implant of claim 35 wherein the bone engaging portions are angled with respect to each other.

38. The implant of claim 35 wherein the first and second plates and the intermediate portion form a substantially U-shaped implant.

39. The implant of claim 35 wherein the intermediate portion further comprises a hollow suture attachment portion.

40. The implant of claim 35 wherein the implant is comprised of a biocompatable metal.

41. The implant of claim 35 wherein the implant is comprised of a biocompatable polymer.

42. The implant of claim 35 wherein the implant is comprised of cortical bone allograft.

43. The implant of claim 42 wherein at least one of the bone engaging portions are comprised of demineralized bone.

23. An implant for use in the spinal column, said implant comprising:

a body portion having a longitudinal axis and configured to be insertable between first and second bone segments, the body portion having an outer surface, and an inner surface defining a substantially hollow portion, said body portion further having first and second ends which communicate with said hollow portion, said first and second ends comprising bone engaging portions; and

said first and second bone engaging portions comprise concave cutouts configured and adapted to engage and retain said first and second bone segments, the cutouts further each comprising a centerline running parallel to the implant longitudinal axis and dividing each the cutouts,

wherein the centerline of the cutout of the first end is offset from the implant longitudinal axis in one direction, and the centerline of the cutout of the second end is offset from the implant longitudinal axis in the opposite direction.

28. An implant for use in the spinal column, the implant comprising:

(a) a body portion having an inner side region comprising an inner side length and configured to be insertable between first and second bone segments, the body portion having first and second ends, at least one of the first and second ends comprising a bone engaging portion to engage at least one of the first and second bone segments,

wherein at least one of the first and second bone engaging portions is comprised of demineralized allograft material.

35. An implant for use in the spinal column, said implant comprising:

(a) first and second plates connected by an intermediate portion whose thickness is smaller than the height of the first and second plates, the first and second plates comprising bone engaging portions for engaging first and second bone segments produced during a laminoplasty procedure,

wherein the implant is configured to be insertable between first and second bone segments produced during a laminoplasty procedure.

44. A method for providing a desired distance between first and second cut bone ends of the spine, comprising the steps of:

(a) cutting at least one segment of a vertebra to produce first and second cut bone ends;

(b) separating the first and second cut bone ends to define a space therebetween;

(c) providing a plate comprising a body portion having a length greater than the space defined by the separation of said first and second cut bone ends, the body portion further having first and second ends, said first and second ends each comprising bone engaging portions, each of the bone engaging portions comprising at least one fastener receiving portion,

wherein the plate is permanently deformable to allow a surgeon to conform the bone engaging portions to the adjacent cut bone ends;

(d) engaging said bone engaging portions with said first and second cut bone ends;

(e) providing at least two bone fasteners;

(f) inserting at least one said bone fastener into the fastener receiving portion of each bone engaging portion; and

(g) engaging the at least one bone fasteners with said cut bone end.

45. The method of claim 44 further comprising the step of deforming the plate to conform the bone engaging portions to the adjacent cut bone ends.

46. The method of claim 44 wherein the step of providing a plate comprises providing a plate having a body comprising a plurality of holes suitable for receiving bone fasteners.

48. The method of claim 47 further comprising the steps of:

(a) providing a plate having first and second ends, the first and second ends further comprising bone engaging portions, the bone engaging portions further comprising bone receiving portions, wherein the length of said plate is greater than the length of said body portion and is sufficient to allow the first and second bone engaging portions to engage said first and second bone segments;

(b) placing said plate over the implant such that the plate covers at least a portion of the implant, and the bone screw receiving portions contact said first and second bone segments;

(c) inserting at least one bone screw within each bone screw receiving portion of said plate; and

(d) engaging each at least one bone screw with the surface of each said first and second bones.

50. The method of claim 49 further comprising the steps of:

(a) providing a plate having first and second ends, the first and second ends further comprising bone engaging portions, each bone engaging portion further comprising a bone screw receiving portion, wherein the length of said plate is greater than the length of said body portion and is sufficient to allow the first and second bone engaging portions to engage said first and second bone segments;

(b) placing said plate over the implant such that the plate covers at least a portion of the implant, and the bone screw receiving portions contact said first and second bone segments;

(c) inserting at least one bone screw within each bone screw receiving portion of said plate; and

(d) engaging each at least one bone screw with the surface of each said first and second bones.

47. A method for providing a desired space in the spinal canal, comprising the steps of:

(a) cutting a first lamina all the way through to produce a first cut bone end having a first bone outer surface and a second cut bone end having a second bone outer surface;

(b) cutting a second lamina to form a hinge therein;

(c) providing an implant having a body portion comprising a length and a longitudinal axis, the body portion having first and second ends, the first and second ends comprising bone engaging portions, at least one of the bone engaging portions comprising an arcuate cutout, the cutout comprising a centerline running parallel to the implant longitudinal axis dividing the first and second ends,

wherein the cutout centerline is offset from the longitudinal axis;

(d) separating the first and second cut bone ends a sufficient distance to accept the implant;

(e) positioning the implant between the first and second cut bone ends; and

(f) contacting at least a portion of each of the first and second cut bone ends with the bone engaging portions.

49. A method for providing a desired space in the spinal canal, comprising the steps of:

(a) cutting a first lamina all the way through to produce a first cut bone end having a first bone outer surface and a second cut bone end having a second bone outer surface;

(b) cutting a second lamina to form a hinge therein;

(c) providing an implant having a body portion comprising a length and a longitudinal axis, the body portion having first and second ends, the first and second ends comprising bone engaging portions,

wherein the implant is formed of a bone allograft material, and at least one of the bone engaging portions is comprised of demineralized bone;

(d) separating the first and second cut bone ends a sufficient distance to accept the implant;

(e) positioning the implant between the first and second cut bone ends; and

(f) contacting at least a portion of each of the first and second cut bone ends with the bone engaging portions.