CA2362993C - Method and apparatus for intervertebral implant anchorage - Google Patents

Abstract

Methods and devices are provided for intervertebral implant anchorage. An implantable device for insertion into an intradiscal section between adjacent vertebrae is provided. The implantable device includes at least one anchor plate which comprises a plate member sized to be positioned within an intradiscal section between adjacent vertebrae an d a plurality of anchoring elements extending from a surface of the plate member, each anchoring element including a distal portion capable of being introduced into the vertebra through the vertebral end plate; and an intradiscal component coupled to the anchor plate.

Description

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:. -Method and Apparatus for intonrartebrai Implant Anchomgo FIELD OF THE INVENTIQN
The present invention relates to methods and devices for s treating intervertebmi disc diseases and more particularly to intetvertebrai prostheses for positioning in an intervertebral space to treat intorvertebrat disorders.

Back pain remains a major public heaith problem, especiatiy arnong aged people. Persistent and severe back pain often causes debility and disabiiity, and such a pain.is closely mociated with intervertebral disc abnormaiities of the spine.
The human spine is a flexibie structure comprised of thirty-three 1s vertebrae. intervertebrai discs separate and cushion adjacent vertebrae, and act as shock absorbers and allow bending between the vertebrae.
An intervertebral disc comprises two rnajor components: the nucleus puiposus and the annuius fibrosis. The nucleus puiposus is centrally kxated In the disc and occupies 25-40116 of the disc's total cross-so s ctional area. The annulus fibrosis surrounds the nucleus puiposus and resist torsional and bending force applied to the disc. Vertebral end-pintes separate the disc from the vertebrae on either side of the disc, Because of exerdon, injury, illness, accident or abuse, one or more of the vertebras andlor one or more discs may become damaged 25 and malfunctioning. Speciflcally, disorders of the vertebrae and discs inciude but are not limited to 1) disruption of the disc annulus such as annular fissures; 2) chronic Inflammation of the disc; 3) localized disc hemi tions with contained or escaped extrusions; and 4) relative lnstability of the vertebrae surrounding the disc.
ao Various approaches have been developed to treat back pain.
Minor back pain can be treated with medica#ion and other non-invasive therapy. However, it is often necessary to remove at least a portion of -~-:<
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the damaged andlor malfunctioning back component For example, when a disc becomee ruptured, the ruptured disc may be surgically removed and the two vertebrae between the rsmoved disc fuse together. In one approach, the end plates of two adjacent vertebra are fused posterior-ist rally by ecrews. However, such posterfor fusion with rigid end-plate fusion can be aasociated with pseudoarthroais.
To promote fusion or arthrodesis across the intradiacal space, intervertebrei impiants are used to support and fuse together adjacent vertebrae by posterior-fusion or anterior grafting. For example, surgical pnosthetic implants for vertebree described in US Patent No. 5,827,328 include rigid annular plugs that have ridged faces to engage adjacent vertebrae to resist displacement and allow ingrowth of blood caplliaries and packing of bon graf#. These annular implants are usually made of blocompatibie carbon ftber reinforced polymers, or Vaditlonai ~s orthopaedic implant materials such as nickel, chromium, cobait, stainless steel or titanium. The individuai implants are internally grooved and are stacked against each other to form a unit between the two adjacent vertebrae. One of the disadvantages of thsse interlocked implants is that, the implants may not be stable enough to withstand rotation and may lead to implant loosening and failure of the prosthesis.
Another intervertebrai fusion device described by Kozslc, et al.
(US Patent No. 5,397,384) includes an asaembly of two laterel spacers and two central spacens, which defines a channei In the center of the fusion device for insertion of the bone graft material. The spacers are maintained in their configuration within the intradiscal space by scr+ews threaded into a vertebra from the outside of the disc. A disadvantage of this device is a tendency for the anchoring screws to become dislodged.
SUMiUM OF THE INVENTION
An anchoring plate is provided for anchoring an intradiscal device to an end plate of a vertebra. The anchoring plate Includes a plate mernber sized to be positioned withln an intradiscal section .2.
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bstwNeen adjacent vertebrae and a pluraiity of anchoring elements extending from a surface of the pWft member, each anchoring eiement including a distal portion capable of being lntroduoed into the vertebra through the vertebral end plate. In one embodiment, at teast one of the anchoring elements indudes a iumen. The lumen allows ingrowth of the bone graft material through ths lumen to the end-piats- of the vertebra.
The furren preferably has a diameter between about a.3mm - Smm.
An impiantable devioe for insertion into an intradiscal section between adjacent vertebrae is also provided which includes an anchor 1.0 plate comprising of a plate member sized to be positloned vwlthin an intradiscal section between adjacent vertebram and a plurality of anchoring elements extending from a surface of the plate nic:mber, each anchoring element including a distal porfion capable of being introducxd into an and plate of one of the adjacent vertebrae; and an intradlecal s.s component coupled to the anchor plate. In one embodiment, the intradiscai component Includes a spacer separating the anchor plate from the end plate of the other adjacent vertebra. In another embodiment, the Intradisoal component includes a cage having afitst side for positloning adjacent a first vertebra and a second side for zo positioning adjacent a seaond vertebra, the first side including a piuratity of holes through which tho anchoring elements on the anchor plate can be positioned, and the second side inciuding at least one hoilow bore for ingrowth of bone materiai. In yet another embodiment, the intradiscai component includes an arNticiat disc.
25 Another implantable device for insertion into an intradiscal section between adjacent vertebrae is provided which includes a first anchor plate comprising a plate member sized to be positioned within an intradiscai section adjacent a first vertebrae and a pluraiity of anchoring elements extending from a surface of the plate member, each anchoring 30 element including a distal portion capabte of being introduced into an end plate of the first vertebra; a se ond anchor plate comprising a plate member sized to be positioned within an intradiscai section adjacent a ;:'..::ii::'.::':::+::L'i''f<:::!;:.:..
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3'i?P~: > ' second vertebrae and a piursilty of anchoring elements extending ftm a surtace of the ptate member, each anchoring element Including a distal portion capable of being introduced Into an end plate of the second vertebra; and an lntmdiscal component coupled to the first and second s anchor platas. In one embodiment, the intradiscal component includes a spacer separating the firat anchor plate from the second anchor plate. In another embodiment, the lntradiscal component indudes a cage having a first side for poaitioning adjacent the first vertebra and a second side for positioning adjacent the second vertebra, the first and second sides each Including a plurality of holes through which the anchoring elements on the first and second anchor plates can be positioned. In yet another ernbodiment, the intradiscal oomponent includes an artiffi'cial disc.
A method Is also provided for anchoMng an implantable device within an intradiscal section batween adjacent vertebrae which includes:
3.3 cr+eating a space between adjacent vertebrae;
Inserting into the space created an intrad[scal device comprising an anchor plate comprleing a plate member sized to be positioned wtthin the space and a pluratity of anchoring elements extending from a surface of the plate member, each anchoring eiement including a distal portion capable of being introduced into an end plate of one of the adjacent vertebrae; and causing the anchoring eiements on the anchor plate to be introduced into the vertebrae through the vertebral end plate.
In one embodiment acoording to the method, the anchorin9 elements are Introduced Into the vertebrae by applying a force to the anchor plate, anchor plate having a vector positioned entirely within the intradiscai space. In one variatton, the force is applied to the anchor plate approximately p rpendicutar to a plane of the end plate, In another embodiment, the anchoring elements are introduced into the vertebrae without rotating the anchor elements.

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In yet another embodiment, the anchoring elements are introduced into the vertebrae without fsrst cn3atiny one or more holes In the vertebrae for the anchoring elements.
In yet another embodiment, the implantable device includes an s intradiscai component Examples of intradiscai components Include an intradiscal spacer, a cage, and an artificial disc.
In yet another embodiment, the implantable device includes first and second anchor plates. lnserting the intradiscai device indudes induding posidoning the Arat anchor plate adjacent a first of the adjacent vertebre and poaitioning the second anchor plate adjetont a second of the adjacent vertebra, causing the anchoring elements to be introduced into the vertebrae includes causing anchoring elements on the frst anchor plate to be Introduced into the first vertebra and causing anchoring elements on the second anchor plate to be introduced into the second vertebra.
In the apparatuses and methods of the present invention, the plate member preferably has a non-smooth surface so as to promote ingrowth of bone material on the surface. The plate member also pn:ferabiy has at least one hoilow bore through the plate to aifow ingrowth of bone matsrial through the plate to the end plate of the vertebra.
The anchoring elements can have a pluraiity of shapes including cone, cylinder, triangls, square, rectangle and other irregular shapes so long as the anchoring elements are capable of being Introduced Into an end plate of a vertebra. The anchoring elements can extend from the plate member substantially vertically, angulariy or curved. The anchoring elements are preferably shaped so as to minimize the risk of splinterinfl the vertebra by introducing the anchoring elements into the vertebra.
The apparatuses and methods of the present invention may be used for a variety of medical procedures in spine surgery. For example, the anchor plate may be used to secure an implant inserted between adjacent vertebrae, the implant inciuding bone grafts, artiflcial annular .~.
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plugs, compnmsible fusion meftrial, artificiai lntravertebral disc or other prosthetic devices. The implantable devioe may be used to replaoa the damaged andlor maftnctioning intravertebral disc with an artificial disc attached to the anchor plate on the device, or to replace the whole vertebral body with an artificial vertebra which Is blomechanicaliy compadble to the spine. The implantable device can be customized to the individuals being treated. In one embodiment, the anchor plate has substantially the shape of a naturally-occurring intervertebral disc and the size of the patient's disc.
io Additionel advantages of the present invention are set forth In the description which foilows.

BR1EF pESCRIPTION OF THE D,gA1MNC3S
Figure 1 iilustrates an Implantable device according to the present invention.
Figure 2 illustrates two hemi-implantable devices.
Figure 3A illustrates an Implantable devioe having anchoring elements extending from one side of the device.
20 Figure 3B illustrates an implantable device having anchoring elements extending from opposing sides of the device.
Figure 4 illustrates an embodiment of an anchor plate Figures 5A-D iliustrate an implantable device having a cage.
Figure aA is a side view of the implantable device.
zs Figure 5B is a sagittal view the imp(antable device.
Fuigure 5C "3 a sagittat view of an anchor plate of the impiantabfe device.
Figure 50 is a sagittal view of a spacer inside of the implantable .device.
30 Figure 5E iliustrates a disassembled implantable device with opposing anchor plates and sidewalls for maintaining a separation between the anchor plates.

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Figure 5F iliustrot s side view of an ass mbied irnplantable device with opposing anchor plates and sidewaiis for maintaining a separation between the anchor ptates.
Figure 50 illustrates another side view of an assembled s impiantabte devlce with opposing anchor plates and sidewalis for maintaining a sepamtion between the anchor plates.
Figure 6 illustrat+ss an implantable device containing an artifcial intervertebral disc.
Figures 7 A-E iilustrate assembly of an implantable device.
za Figure 7A Is a frontal view of the assembly of an Implantable device.

Figure 7B is a side view of the assembly of an implantable device.

Figure 7C iliustrates the assembled impiantable device.
3.5 Figure 7D is a rear view of the assembled impiantabie device.
Figure 7E is a side view of the assembled implantable device.
Figure 7F illustrates assembly of the impiantabie device illustrated in Figures 5A.D.
Figure 8A Illustrates an impiantable device of Figure 7A-E
20 Inserted In an intradiscal space prior to extension of anchoring elements.
Figure 8B iliustrates the implantable device of Figure 7A-E
where the anchoring elements have been extended into the end plates of adjacent vertebrae.
Figures 9A-D iiiuatrate a method for impianting an implantable, ss device accordtng to the present invention.
Figure 9A iilustrates inserting a spacer between two adjacent vertebrae.
Figure 9B iliustrates putting a guide over the spacer.
Figure 9C iitustrates inserting an impiantabie devtce Into the 30 guide.
Figure 9D ifiustrates using a wedge spreader to introduce anchoring elements into the end plate of the vertebra.

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Figur+s 10 iUustrates an example of a guide used In tha method described in Figures SA-D.

DETAILED DFSCRIPTION Ot=THE pREFERRED EMBnJ1jBdENT
s The present fnvention relates to devices which may be anchored to vertebrae of the spine by introducing anchoring elements through an end plate of the vertebrae.ln particular, an anchoring plaW which comprises a pluraiity of anchoring elements such as spikes or prongs extending from the plate, Is provided for anchoring an intradiscai device.
zo to an end plate of a ver'tebra. By securing the anchor plate to an end plate of the vertebra, a surgeon operating on a patient's spine can attach a variety of intradisca) components to the anchor plates. The secured anchorege and support provided by the apparatus of the preQent invention prevents loosening of the apparatus and enhances the 15 fusion of the adjacent vertebrae.
A variety of lntradiscal components can be incorporated into the apparatus of the present Invention. In one embodiment, the intradiscal component includes a cage within which the anchor plate is contained.
Bone graft material can be filled into the cage which is attached to and 20 stabilized by the anchor plate on an end plate of a vertebra, thereby prornoting bone ingnawth through the holes on the cage. Alternatively, an artificial intravertebral disc can be included in the apparatus.
1t should be noted that other-intervertebral fusion devices may also be attached to the anchor plate for restoring or maintaining the 25 normal geometry of the intradiscai space, such as disc height and sagittal angle. Moreover, an artificial vertebral body which Is biomechanically compatible with the spine may be atta-ched to the anchor plate to replace a damaged vertebra and restore normal functions to the spine, 30 One embodiment of the invention is illustrated in Figure 1, showing a frontal view of an Implantable device 141nsertod between two adjacent vertebrae L4 and L5. In this embodiment, the implantable _g-:>::;:<::>:
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device 10 includes a firat anchor piaft 12, a second anchor plate 14 and an intradiecal component 16. Each of the first and second anchor plates incrtudes a plurality of anchoring elements 20 extending trom a surt:ace 11 of the anchor plate. The anchoring elements 20 on each of the s anchor plates 12 and 14 are introduced into vertebrae L4 and L5 through end plates E4 and E5 of vertebrae L4 and L5, respectively. This embodiment of tfie Implantable device has a size approximating the intradiscai space between adjacent vertebrae. This device is particulatly suitable for positioning via an anterior approach. 8ecause intervertebral zo discs are located in frront of the spine and anterior to the spinal cord 15, prosthetic operations such as disc replaoement through an anterior approach eliminates the need to remove or netract nerve, thus reducing the risk of nerve injury.
Altemativety, the implantable devioe according to the present ~s Invention may also be sized to a hemicircle or hemioval. As iiiustrated in Figure 2, two hemiovei Implantable devices 30 and 32 can be used to approximate the in#radiscal space and conform with the general outline perimeter of the vertebrae. Such an implantable device with a hemloval size allows better access to the posterior portion of tfie spine when the 20 devices are implanted through a posterior approach. For example, the first hemi- device 30 can be Inserted Into and fill In half of the intradlseai space without colliding with the spinal cord 15, then followed by placing the second hemi- implantable device 32 to fill In the other half of the intradiscai space, Similar to the implantabie device 10 Illustrated In 25 Figure 1, the anchoring elements on the hemi- Implantable device are introduced into the end plate E4 and E5 of the vertebrae L4 and L5, nrspectivety. Bone graft material or artificial disc can be put into the device for posterior-lateral fusion or rigid posterior instrumentation.
Positioning the bone graft material between first and second anchor 30 plates 12, 14 to attain fusion and prevent the anchor plates from being dislodged from the vertebrae.

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In another embodiment, as liiustr'ated in Figure 3A, the Implantable device 40 inciudes an anchor plate 42 and an intradiscai component 44. The anchor plate 42 Includes a piate member 48 and a pluraiity of anchoring etements 46 extending from the piate member 46.
s The anchoring elements 48 can be introduced into an end plate of a vertebra by applying a fonce In a dinsction 43 approximateiy perpendicular to the end plate, thereby securing the device 40 within an intradiscal space. In this regard, the forve appiied to the anchoring elements may have a vector positjoned entirely within the intradiscai io spece.
In yet another embodiment, as illustrated in Figure 319, an impiantabie device 50 includes a first anchor plate 52, a second anchor plate 54 and an intradiscal component 58. Each of the first and second anchor plates 52 and 54 Includes a plate member 58 and a plurality of ~s anchoring elements 80 extending from the plate member 58. The anchoring elements 60 on anchor plate 52 can be introduced into an end plate of a vertebra in directions 55, 57 approximateiy perpendicular to the end plates, thereby securing the device 50 within an intradiscal space between the two adjacent vertebrae.
20 An illustration of an embodiment of an anchor plate is iliustrated In Figure 4. In this embodiment, the anchor plate 70 Includea a plate member 72 and a piurality of anchoring elements 74 extending from a surface 71 of the plate member 72. It is preferred that a piate member 72 has at least one hollow bore or hole 75 through surface 71 and 73 of 25 the plate member 72 to allow bone ingrowth through the hole 75 to the end plate E4 of vertebra L4, thereby enhancing fusion of adjacent vertebrae. The hole 75 may be positioned such that the hole is adjacent nucleus pulposus N4 of the operative intravertebrai disc when the device is positioned Intervertebrally. The hole is preferably smaller than and ac optionaliy as large as the nucleus pulposus N4. This positioning and sizing of the hole 75 allows fusion of bone graft materiai with a weaker portion of the vertebra known to be highly vascular and biological active.

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The anchor plate 701nciudes at least two anchoring eiements 74 distributed on the aurfaoe 71 of the plate member 72. The anchor plate may have any regular shape: round, square, rectangle, eiiipticai, or an irregular shape. The anchor plate is preferred to have a surface area s befiNeen about 5mmz - 40mm2; and a thicicness preferably between about 9 mm -10 mm, more pneferabty about 5mm.
The anchoring elements 74 are preferred to be sharp spikes having a cone, cylinder, square or rectangle shape. The height and width of the anchoring elements are pnsferably between about O.5mm -18mm, 0.3mm -15 mm, re-speotively, in a preferred embodiment, the anchoring element 74 inciudes a iumen 80. The lumen preferably has a diameter between about 0.6mm -9mm. The iumen allows ingrowth of the bone graft materiai through the lumen to the end-plate of the vertebra. The lumen siso facili#ates entry 13 of the anchoring element into the end plate without splintering the vertebra. The surface of the lumen is preferably rough.
The distai portion 77 of the anchoring element 74 may be straight or curved. The surfaoe- 79 of the anchoring element 12 is preferred to have a smoath outer surface to facilitate penetration of the element 74 into the end plate E4. In psrttcular, the surface 79 of the anchoring element 74 is preferred not to have a thread for screwing the element 74 into the end plate E4.
The anchoring elements 74 may extend from the plate member 11 substantially vertically, angularly or curved. The direcaon of the force as used to cause the anchoring elements to enter the vertebra will depend on the shape and angular positioning of the anchoring elements.
The materials used to construct the anchor plate and the implantable device are preferred to be able to endure the stresses and .environment to which a vertebra implant is subjected, In addition, such materials should be biocompatibie, and substantially chemically Inert so as not to cause any detrimental ffect to the patient in whom the device is impianted, The anchor plate and Implantable device may be made of -1'!-;::::::;:;:;;;;::~:::.;_:;;;>
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radiolucxnt material such as carbon fiber reinfonxd polymers known commercially as "Peek" (poiyetherether ketone) or "Uitrapek" (poiyether ketone, ether ketone, ketone), poiycarbonate, polyprophylene, polyethylene and polysulfone piastics material filled with glasa or carbon fibers, or tradttional orthopaedic Implant materiai such as nickel stainie$s steel, tbnium alioy, heavy piastic polymer, ceramic, etc. One of ordinary skill in the art witi recognize other euitabie materiais, for exampie, a cobait-chromium alloy or a titanium afioy having 4% vanadium and aluminum, ceramic material such as aluminium oxide and zirconlum oxide. The surface 71 of the anchor plate 70 is prefernsd to be rough to potentiate bone ingrowth on the side of the plate contacting the end plate E4 of the vertebra L4, thereby str+engtheninfl the anchoraQe to.the end plate. The surface 73 of the anchor plate 70 may be porous coated or coated with hydroxyapatfte or bioactive proteins (e.g. bone morphogenic protein) to promote bone ingrowth.
Figures 5A-D Illustrate a preferred embodiment of an implantable device. As Illustrated in Figure SA, the implantable device 100 inctudes an intradiscal component-a cage 102, a first anchor plate 104 and a second anchor plate 106 contained within the cage 102. A
plurality of anchoring elements 108 on each of the anchor plates 104 and 108 extend from the anchor plates and through holes 115 on the surfaces 111 and 113, respectively of the cage 102. The cage 102 includes intervertebral lateral channels 105 and frontal channels 107 which are adapted to receive bone graft.material therein. In addition, channel 109 is configured to receive a screw therethrough for causing the anchoring elements 108 to be pushed Into the end plates of adjacent vertebrae.
Figure 58 is a sagittal view of the implantabie device 100. The surface 111 of cage 102 contacts an 6nd plate of a vertebra and is preferred to be porous and coated with hydroxyapatite or bone morphogenic protein to promote bone ingrowth. As iliustrated, anchoring elements 108 with lumen 101 extend through holes 115 in the cage 102.

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Figure 5C Itiustnatas the first anchor plafe 104 induded in the implantabie device 100, A plurality of anchoring elements 108 extend substantiaiiy vertically from a plate member 112. The anchor plate 104 have hollow bores 117 to form part of channel 103 and recessed portion oonflgured to be scoommodated within the cage 102 and to receive force applied to introduce the anchoring elements 108 Into the end plates of adjaoent vertebrae.
Figure 50 iliustrates a spacer 116 tnciuded In the cage of the implantable device 100. The hollow bores 119 foRn part of the channels 103, 105, 107 and 109.
Figures SE-G Illustrate an aiternate embodiment of an implantable devioe with opposing anchor plates and sidewalis for maintaining a separation between the anchor plates. Figure 5E
illustrates the device disassembled with two opposing anchor plates 104,106 and two sidewaii support mernbers 129A and 129B. The sidewall support members each inciude recessed grooves 131 for attaching the sidewall support members to the anchor plates.
Figures 5F and 5t3 iliustrate side views of the device illustrated in Figure 5E once assembled. Assembly is achieved by attaching each sidewali support member to a side of the anchor plates. The device iiiustrated in Figures 5E-G have an advantage of being smailer than the devices illustrated in Figures 5A-5D since the gidewali spacers remove the need for the cage.
Figure 6 iiiustrates an embodiment of an artificiai disc 120. As illustrated in Figure 8, oval-shaped nucleus 121 made of ceramic or stainless steel ia housed inside of the cage 122. Anchoring ei ments 128 extend from the anchor plates 124 and 126 nd can be Introduced into the end plates of adjacent vertebrae, thereby replacing the damaged andlor maifunctioning digc with an art>ficial one.
i3etaiis of the assembly of an embodiment of an impiantabie device are illustrated in Figures 7A-C. According to this embodiment, the implantabie device 130 includes a first anchor plate 132, a second :: tc:..ir':.::;:i:.:f; :<..:i.. `:;;:: [
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anchor ptate 134, and a cage comprising an upper cover 138 and a bottom plate 140 (Figure 7A). The firat and second anchor plates 132 and 134 are adapted to fit Into the cage with a portion of the plates flanked by two supporting rnembers 146. The anchoring elements 142 s on the anchor plate are posidoned through the hole 141 on the upper cover 138 and bottom plate 140. As iilustrated In Figure 7B showing a side view of the assembly, a wedge 144 Is inserted between the upper cover 138 and bottom plate 140 of the cage 138. Through a channel formed by holes 146 and 147, a fixation screw 146 can be used to drive zo the wedge 144 which pushes the anchor plate$132 and 134 toward end plates of adjacent vertebrae, thereby introducing the anchoring elements 142 Into the end plates and aecuring the device 130 intradiscaliy.
Further, as illustrated in Figure 7C showing the assembled implantable device 130, there are also a plurality of holes 143 throughout the anchor ~s plates, the upper cover 138 and the bottom plate 140 to allow bone lngrowth through the device 130 to enhance intervertebral fusion.
Figure 7F iilustrates assembly of the implantable device illustrated in Figures SA-D.
A method is also provided for anchoring an impiantabie device 20 within an intradiscal section between adjacent vertebrae which includes:
areating a space between adjaaent vertebrae:
inserUng into the space created an Implantable device comprising an anchor plate comprising of a plate member sized to be positioned within the space and a plurality of anchoring elements 25 extending from a surfece of the plate member, each anchoring element Including a distal portion capable of being introduced into an end plate of one of the adjacent vertebrae; and causing the anchoring elements on the anchor plate to be Jntroduced into the vertebrae through the vertebral end piate.
30 Another method Is provided for anchoring an implantable device within an intradiscal section between adjacent vertebrae which Includes:
creating a space between adjacent vertebrae;

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inserting into the speoe created an implantable device cwmprising a flrst anchor plate comprising of a plate member sized to be posifioned within the space and a plurality of anch=oring elements extending from a surface of the plate member, each anchoring element including a distei pordon capable of being introduoed into an end piate of one of the adjacent vertebrae;
a second anchor plate comptising of a plate member sized to be positioned within the space and a pluraiity of anchoring elements extending from a surface of the plate member, each anchoring element including a distal portion capable of being Introduced into an end plate of one of the adjacent vertebrae; and causing the anchoring elements an the first and second anchor plates to be introduced into the vertebrae through the vertebraE end plate.
As iUustrated in Figure 6A, the anchoring elements 142 of first (132) and second (134) anchor plates of an Implantable device 130 lilustrated in Figures 7A-E are Introduced into the vertebrae by applying a force with fixation screws 146 to the anchor piates approximately 20 perpendicular to a piane of the end plate such as E4 and E5 of vertebrae L4 and L5, n3spectively. Figure eB shows that the implantable device 130 is anchored between the adjacent vertebrao L4 and L5 by the anchoring elements 142 penetrating vertebral end plates 54 and E5.
As also illustrated in Figures 8A and 8B, the anchosing elements 25 142 are introduced into the vertebrae L4 and L5 without rotating the anchor elements 142. Screwing an element into a vertebra can cause the vertebra to spiinter.
As also Illustrated in Figures 8A and 8B, the anchoring elements are Introduced into the vertebrae without first creating one or more holes 30 in the vertebrae for the anchoring eiements.
In yet another embodiment according to the rnethod, the impiantable device inctudes an intradiscai component. Exampies of =15-::>:::>;;:~; ::.<;;:>:>: :>:>:::;
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........ .. P CA 02362993 2001-08-27 intradiscoi cornponents incJude an intradiscal spaaer, a ca8e, and an artificial disc.
In yet another embodirrent according to the method, the impiantable davice Includes first and second anchor piafies, inserting s indudinQ posifioning the firat anchor plate adjacent a first of the adjaoent vertebra and positioning the second anchor plate adjacent a second of the adjacent verb4brat, and causing the anchoring elements to be introduced into the vertebrae including cousing anchoring elements on the first anchor plate to be introduced Into the firat vertebra and ~ o causing anchoring elements on the second anchor plate to be introduced into the second vertebra.
Figures 9A-QC iiiustrata a method for introducing a devict according to the present invention by an anterior approach. Figure 10 illustrates a guide employed'in the method.
is As Illustrated in Figure 10, a guide 160 includes a sleeve 162 and at least two lips 164 that can be inserted intradiscaiiy to maintain the height of the disc space. The sleeve 182 is preferably cyiindric with an elliptical cross section 167, and has multiple vents 161 and 1183 for proper circulation of atr. A replacement disc 168 can be introduced into 20 the intradiscai space throuqh the sleeve 162 in a dfrection 185 approximately along a longitudinal axis of the sieeve.
Figures 9A-0 iHustrate a method for impianUng a device via anterior appraach. As Illustrated In Figure 9A, an tntervertebral disc 180 to be replaced is accesaed through a iaparoscopic anterior approach.
25 The disc 180 ls exposed anterioriy, i.e. beneath the chest and abdomen of the patient. After the disc 180 to be removed has been ldentified, the disc is surgically removed. To prepare the adjacent vertebrae to receive the disc replacement 168t cartilage on the end piates of the adjacent Yerltebrae is removed by an instrument 181 following known procsdures.
30 Care should be taken not to violate the end plates. One or two spaoers 172 are then inserted into the intradiscal space, with the adjacent vertebrae being separately distracted by a wedge so as to allow proper ;: ::>.::t.<::>:::>::::::
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',:' locstion of the spacer 172. The spacer 172 also serves as a measurement of tha height of the di:c:paoe.
As iliustrated in Figure SB, a guide 180 (described in regard to Figure 10) is put over the spacers 172 with the fips 184 of the sleeve s 162 replacing the spacers 172. The spaoers 172 are ftn removed from the disc space. As illustrated In Figure 9C, once the disc replacement guide sieeve 160 is properly posltioned, an impiantabie devios such as a replacement disc 188, Is Inserted through the sleeve 1621nto the intordiscal space. As lliuatnsted In Figure 9D, a wedge spreader 174 is then inserted into a channel 173 deflned by the implantable device to distract the anchor plates 176 and introduce anchoring elements 178 on the anchor plates 176 into the end plates of the adjacent vertebree.
While the pnssent invention is disclosed by reference to the various embodiments and examples detailed above, it should be ~s understood that these examples are Intended in an iiiustrative rsther than limiting sense, as it Is contemplated that modiFications will readliy occur to those skilled in the art which are intended to fati within the scope of the present invention.

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Claims (29)

CLAIMS:

1. An implantable device for insertion into an intradiscal section between adjacent vertebrae, the device comprising:
an anchor plate comprising a plate member sized to be positioned within an intradiscal section between adjacent vertebra and a plurality of anchoring elements extending from a surface of the plate member, each anchoring element including a distal portion capable of being introduced into an end plate of one of the adjacent vertebrae; and an intradiscal component coupled to the anchor plate, the intradiscal component including a cage having a first side for positioning adjacent a first vertebra and a second side for positioning adjacent a second vertebra, the first side including a plurality of holes through which the anchoring elements on the anchor plate can be positioned, and the second side including at least one hollow bore.

2. An implantable device for insertion into an intradiscal space between adjacent vertebra, the device comprising:
a first anchor plate comprising a plate member sized to be positioned within an intradiscal section between adjacent vertebra and a plurality of anchoring elements extending from a surface of the plate member, each anchoring element including a distal portion capable of being introduced into an end plate of one of the adjacent vertebrae;
a second anchor plate comprising a plate member sized to be positioned within an intradiscal section between adjacent vertebra and a plurality of anchoring elements extending from a surface of the plate member, each anchoring element including a distal portion capable of being introduced into an end plate of one of the adjacent vertebrae; and an intradiscal component coupled to the first and second anchor plates, the intradiscal component including a cage having a first side for positioning adjacent a first vertebra and a second side for positioning adjacent a second vertebra, the first side including a plurality of holes through which the anchoring elements on the first anchor plate can be positioned, and the second side including a plurality of holes through which the anchoring elements on the second anchor plate can be positioned.

3. An implantable device according to claim 1 wherein the anchor plate includes at least 3 anchoring elements.

4. An implantable device according to claim 2 wherein the first anchor plate includes at least 3 anchoring elements.

5. An implantable device according to claim 1 wherein the anchor plate has a non-smooth surface.

6. An implantable device according to claim 2 wherein the first anchor plate has a non-smooth surface.

7. An implantable device according to claim 1 wherein the anchor plate has at least one hollow bore.

8. An implantable device according to claim 2 wherein the first anchor plate has at least one hollow bore.

9. An implantable device according to claim 1 or 2 wherein at least one of the anchoring elements includes a lumen.

10. An implantable device according to claim 1 or 2 wherein at least one of the anchoring elements includes a lumen at least 0.5 mm in diameter.

11. An implantable device according to claim 1 or 2 wherein the anchoring elements extend substantially perpendicular from the anchor plate.

12. An implantable device according to claim 1 or 2 wherein the anchoring elements extend angularly from the anchor plate.

13. An implantable device according to claim 1 or 2 wherein the anchoring elements have at least one curved distal end.

14. An implantable device according to claim 1 or 2 wherein the anchoring elements have a smooth outer surface.

15. An implantable device according to claim 1 or 2 wherein the anchoring elements do not include a thread for screwing the anchoring element into the vertebrae.

16. An implantable device according to claim 1 or 2 wherein the intradiscal component includes an artificial disc.

17. An implantable device according to claim 1 or 2 wherein the intradiscal component further includes at least one channel adapted to receive bone graft material therein.

18. An implantable device according to claim 1 or 2 wherein the intradiscal component includes a spacer.

19. An implantable device according to claim 1 or 2 wherein the anchoring elements include a distal portion capable of piercing an end plate of a vertebrae which does not already have holes for the anchoring elements.

20. A kit for forming an implantable device for insertion into an intradiscal section between adjacent vertebrae, the kit comprising:
an intradiscal component sized to be positioned within an intradiscal section between first and second adjacent vertebrae, the intradiscal component comprising a cage having a first side for positioning adjacent the first vertebra and a second side for positioning adjacent the second vertebra, the first side of the cage including a plurality of holes; and an anchor plate comprising a plate member and a plurality of anchoring elements extending from a surface of the plate member, the anchor plate being positionable within the cage and the anchoring elements being extendable out of the cage through the plurality of holes.

21. A kit according to claim 20 wherein the anchoring elements are adapted to be extended out of the cage in a direction approximately perpendicular to a plane of an end plate of the first vertebra.

22. A kit according to claim 20 wherein the intradiscal component further includes at least one channel adapted to receive bone graft material therein.

23. A kit according to claim 20 wherein the intradiscal component further includes at least one channel adapted to receive a device for causing the anchoring elements to be introduced into an end plate of the first vertebra.

24. A kit for forming an implantable device for insertion into an intradiscal section between adjacent vertebrae, the kit comprising:
an intradiscal component sized to be positioned within an intradiscal section between first and second adjacent vertebrae, the intradiscal component comprising a cage having a first side for positioning adjacent the first vertebra and a second side for positioning adjacent the second vertebra, the first and second sides of the cage including a plurality of holes;
a first anchor plate comprising a plate member and a plurality of anchoring elements extending from a surface of the plate member, the first anchor plate being positionable within the cage and the anchoring elements being extendable out of the cage through the plurality of holes on the first side of the cage;
and a second anchor plate comprising a plate member and a plurality of anchoring elements extending from a surface of the plate member, the second anchor plate being positionable within the cage and the anchoring elements being extendable out of the cage through the plurality of holes on the second side of the cage.

25. A kit according to claim 24 wherein the anchoring elements of the first and second anchor plates are adapted to be extended out of the cage in a direction approximately perpendicular to the end plate surfaces of the first and second vertebrae.

26. A kit according to claim 24 wherein the intradiscal component further includes at least one channel adapted to receive bone graft material therein.

27. A kit according to claim 24 wherein the intradiscal component further includes at least one channel adapted to receive a device for causing the anchoring elements to be introduced into end plates of the first and second vertebrae.

28. A kit according to claim 24 wherein the anchoring elements include a distal portion capable of piercing an end plate of a vertebrae which does not already have holes for the anchoring elements.

29. A kit according to claim 24 wherein the anchoring elements include a distal portion capable of piercing an end plate of a vertebrae which does not already have holes for the anchoring elements.