WO 99/08627
`
`PC'I‘lUS98/ 16650
`
`_27-
`
`23.
`
`A method of making a resorbable interbody spinal fusion
`
`device, comprising the steps of:
`
`providing a mold for said resorbable interbody spinal
`
`fusion device;
`
`orienting reinforcing fibers under tension in said.mold;
`
`introducing a resorbable material into said mold;
`
`molding said resorbable material under pressure; and
`
`releasing tension on said reinforcing fibers prior to
`
`removing said device from said mold.
`
`24.
`
`The method
`
`of
`
`claim 23 wherein
`
`said resorbable
`
`reinforcing fibers are made of
`
`the same material as said
`
`resorbable interbody material.
`
`25.
`
`The method of
`
`claim 23 wherein
`
`said resorbable
`
`reinforcing fibers do not contain a buffer.
`
`26.
`
`The resorbable interbody spinal fusion device of claim
`
`10 wherein said buffering or neutralizing agent is selected
`
`from the group consisting of compounds wherein the pKa of the
`
`conjugate acids of said compounds is greater than the pKa of
`
`acids produced by hydrolysis of
`
`the polymer(s)
`
`from which
`
`said device is prepared.
`
`27.
`
`The resorbable interbody spinal fusion device of claim
`
`1, wherein. said device is fabricated fron1 at
`
`least
`
`two
`
`resorbable polymers.
`
`28.
`
`The resorbable interbody spinal fusion device of claim
`
`27, wherein one of
`
`said resorbable
`
`polymers
`
`is poly
`
`(propylene fumarate).
`
`29.
`
`The resorbable interbody spinal fusion device of claim
`
`27, wherein one of said resorbable polymers has been cross-
`
`linked in the presence of
`
`a crosslinking agent
`
`and an
`
`initiator, whereby said crosslinked resorbable polymer forms
`
`a reinforcing interpenetrating network.
`
`101
`
`MSD 1009
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`101
`
`

`
`WO 99108627
`
`_
`
`PCTfUS98ll 6650
`
`-28..
`
`30.
`
`The resorbable interbody spinal fusion device of claim
`
`29, wherein said crosslinking agent is vinyl pyrrolidone.
`
`31.
`
`The resorbable interbody spinal fusion device of claim
`
`29, wherein said initiator is benzoyl peroxide.
`
`32.
`
`The resorbable interbody spinal fusion device of claim
`
`1, wherein said device is fabricated from a polymer wherein
`
`molecular chains of said polymer have been aligned to be
`
`10
`
`essentially parallel.
`
`33.
`
`The resorbable interbody spinal fusion device of claim
`
`32, wherein said device has been cut such that the aligned
`
`polymer molecular chains are at approximately a 45° angle to
`
`15
`
`a surface of said device.
`
`102
`
`102
`
`

`
`WO 99/08627
`
`PCT/US98/16650
`
`103
`
`103
`
`

`
`WO 99/0862?
`
`2
`
`/
`
`10
`
`PCT/US98/16650
`
`24
`
`@
`I
`
`26
`
`/
`
`24
`
`22
`
`PEI II-can-I-U-I cl-E rs: pr-I--— trial II v- Ho‘-I
`
`104
`
`

`
`WO 99108627
`
`3
`
`I
`
`10
`
`PCT/US98/16650
`
`105
`
`105
`
`

`
`WO 99/08627
`
`Best Available Copy
`
`106
`
`106
`
`

`
`WO 99/08627
`
`5
`
`/
`
`PCT/US98/16650
`
`Besi’ Available Copy
`
`--
`
`-mg.
`
`a.. ..... .
`
`.3-
`
`107
`
`107
`
`

`
`W0 99/0862‘?
`
`6
`
`/
`
`10
`
`PCT/US98/16650
`
`62
`
`65
`
`61
`
`63
`
`84\
`
`60
`
`66
`
`65
`
`Fig. 6A
`
`108
`SUBSTITIITF RI-u=I=T Ian: I: am
`
`108
`
`

`
`WO 99108627
`
`7
`
`I
`
`-10
`
`PCT/US98/16650
`
`109
`SUBSTITUTE SHEET (RULE26)
`
`109
`
`

`
`WO 99/08627
`
`PCT/US98ll6650
`
`C")
`CO
`
`63
`
`Fig.6G
`
`86
`
`411%
`
`
`
`
`
`
`
`‘QIEIRIISIIEIISIKEIIS
`
`V L
`
`
`
`83
`
`84
`
`110
`rIiIl'Il'5'!'l'FI |-!-r- (ht Il"l'.'1' Ibl II C ')R\
`
`110
`
`

`
`K Besi Available COW
`
`WO 99/08627
`
`9/10
`
`PCT/IAJS98/16650
`
`
`
`
`
`:o_mmm§Eo.Qm@_uo>>...2%<9:...\..o31=
`
`$13__
`
`xmawpaow
`
`111
`
`111
`
`
`
`

`
`WO 99/08627
`
`10
`
`/
`
`10
`
`PCT/U593/15650
`
`Efl85:15 PLGA, NO BUFFER
`
`D60% PLGA 85:15, 40% HA
`
`LOAD (kN)
`
`Fig. 8
`
`112
`¢llI:c'rI1-un-u- ¢-on-.—-.- ,...... .. __.
`
`112
`
`

`
`INTERNATIONAL SEARCH REPORT
`
`lntemational application No.
`PC'l‘lUS98Il6650
`
`A.
`
`CLASSIFICATION OF SUBJECT MATTER
`lPC(6)
`:A6lF 2/44
`us CL :623l17
`
`_
`
`According to International Patent Classification (IPC) or to both national classification and lPC
`B.
`FIELDS SEARCHED
`
`Minimum documentation searched (classification system followed by classification symbols)
`
`US.
`
`2
`
`606,65, 77; 623117
`
`Documentation searched other then minimum documentation to the extent that such documents are included in thc fields searched
`
`Electronic data base consulted during the international search (neme of data base and. where practicable, search terms used)
`Please See Extra Sheet.
`
`C.
`
`DOCUMENTS CONSIDERED TO BE RELEVANT
`
`Category*
`
`Citation of document, with indication. where appropriate, of the relevant paseges
`
`Relevant to claim No.
`
`US 5,225,129 A (VAN DEN BERG) 06 July 1993, entire document ' 23-25
`especially col. 6 lines 2149, and claims 19-24.
`
`US 5,527,864 A (SUGGS et al) 18 June 1996, entire document.
`
`US 5,522,875 A (MIKOS) 04 June 1996, entire document.
`
`US 4,349,921 A (KUNTZ) 21 September 1982, entire document.
`
`Further documents are listed in the continuation of Box C. E Sec patent family annex.
`letor document published after the intermtionel filing date or priority
`Specie] cetegoriee of cited documents:
`dnte end not in conflict with the epplicetion but cited to understend
`the principle or theory underlying the invention
`document defining the general rule of the en which is not considered
`to be of perticulu relevenoe
`
`earlier document published on or after the intemetionel filing date
`document which rney throw doubt: on priority clei.rn(e) or which is
`cited to eetnblish the publicetion dole of mother citation or other
`epeoiel reuon (II Ipecifild)
`document referring to en orel disclosure. use. exhibition or other
`means
`
`document publilhed prior to the interactions! filing date but leler then
`the priority dete eleimed
`
`document of perticuler relevence; the cleimed invention cennot be
`considered novel or cennot he considered to involve an inventive mp
`when the document is taken elene
`
`document of pnrtieuler relevence; the cieimcd invention cannot be
`considered to involve ea inventive etep when the document
`in
`combined with one or more other euch documcnu. such cotnbinetion
`being obviotn to I pereon ekilled in the on
`document member of the nine puent femily
`
`Date of the actual complaion of the international search
`
`Date of meiling of the international search report
`
`14 SEPTEMBER 1998
`
`Name and mailin address of the ISA/US
`Commissioner of
`stems and Tredcrnerks
`Box PCT
`Washington. DC. 2023]
`Facsimile No.
`(703) 305-3230
`
`Fonn PCT/lSAI?.l0 (second sheet)(.luly 1992)-tr
`
`A T ephonc No.
`
`(703) 308-2905
`
`113
`
`

`
`INTERNATIONAL SEARCH REPORT
`
`111'-Cmlliomll application No-
`PCT! U598! 16650
`
`C (Continuation). DOCUMENTS CONSIDERED TO BE RELEVANT
`
`Category‘
`
`Citation of document, with indication, where appropriate, of the relevant passages
`
`Relevant to claim No.
`
`US 4,655,777 A (DUNN at al) 07 April 1987, entire document.
`
`1, 9-13, 15-20,
`
`US 4,968,317 A (TORMALA et al) 06 November 1990, entire
`document.
`
`Form PCTllSAl210 (continuation of second shot-.t)(Iuly 1992):
`
`114
`
`114
`
`

`
`INTERNATIONAL SEARCH REPORT
`
`International application No.
`PCT/US98ll6650
`
`B. FlELDS SEARCHED
`Electronic data bases consulted (Nam: of data base and when: practicable terms used):
`
`APS
`
`Search Tenns: (rcsorbable or bioncsorbnblc or absorbable or bioabsorbable or dcgradablc or biodegradablc) and buffer?
`and (glycoli? or lacti? or polyglycol? or polylacti'I); and propylcnc fumnrntc.
`search tcrma: 264/257/ccls and
`(rcsorbable or bioresorbablc or nbsorbable or bioabaorable or degradable or biodegradable).
`
`Form PCTIISAIZIO (extra shee!)(July 1992):?
`
`115
`
`115
`
`

`
`woaw lN'l'ELLECI'UAL_ raopaarv ORGANIZATION
`Intemattonal Bureau
`
`
`
`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`
`(51) International Patent Classification 6 =
`(11) International Publication Number:
`WO 99/38461
`A61F 2/44
`
`(43) International Publication Date:
`
`5 August 1999 (0508.99)
`
`(21) International Application Number:
`
`PCT/EP99/00433
`
`(22) International Filing Date:
`
`22 January 1999 (22.01.99)
`
`(81) Designated States: CA, JP, European patent (AT, BE. CH, CY,
`DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT,
`SE).
`
`(30) Priority Data:
`60/073,271
`60/095,425
`
`30 January 1998 (30.0l.98)
`5 August 1998 (O5.08.98)
`
`Published
`Without international search report and to be republished
`upon receipt of that report.
`
`US
`US
`
`(71) Applicant (for all designated States except CA): SYNTHES AG
`CHUR [CH/CH]; Grabenstrasse 15, CH—7002 Chur (CH).
`
`(71) Applicant (for CA only): SYNTHES (U.S.A.) [USIUS]; I690
`Russell Road, P.O. Box 1766, Paoli, PA I930]-1222 (US).
`
`(72) Inventors: PAUL, David, C.; 1513 Valley Road, Drexel Hill,
`PA [9026 (US). EMCH,
`I-Iansjuerg, w.; 1527 Spruce
`Street, Philadelphia, PA l9l02 (US).
`SCHENK, Beat;
`59 Cobblestone Drive, Paoli, PA 19301 (US). CARVER,
`Jeffrey, L.; 1011 Welsh Ayres Way, Downington, PA 19335
`(US). BAKER, Kelly, 1.; 1878 Shadyside Road, Coatesvilie,
`PA 19320 (US).
`
`Dr.
`LUSUARDI, Werther‘,
`(74) Agent:
`Kreuzbilhlstrasse 8, CH—8008 Ztlrich (CH).
`
`Lusuardi AG,
`
`(54) Title: ALLOGENIC INTERVERTEBRAL IMPLANT
`
`(57) Abstract
`
`An allogenic intervertebral implant (l0) for fusing vertebrae is disclosed. The implant (I0) is an annular plug conforming in size and
`shape with end plates of vertebrae. The implant has either an exterior surface identical to that of the harvest bone or an exterior surface
`machined to have a uniform shape such as an oval or a rectangle. The top and bottom surfaces (14. 16) of the implant (10) have a plurality
`of teeth (12) to resist expulsion and provide initial stability. The top and bottom surfaces (14, 16) can be either flat planar surfaces or
`curved surfaces. Preferably, the anterior height of the implant is greater than the posterior height so that the implant is wedge-shaped
`profile to help restore disc height and the natural curvature of the spine.
`In one embodiment, the top and bottom surfaces each have a
`channel oriented in the anterior, lateral, or antero—lateral direction for receiving a surgical instrument. The implant can also have a hole for
`attachment of an inserter. Although the interior space fonned by the annular plug can be the natural shape defined by the medullary canal,
`the medullary canal walls can be machined so that the implant has a uniform interior space.
`
`116
`
`

`
`-|
`
`FOR THE PURPOSES OF INFORMATION ONLY
`
`Codes used to identify States party to the PCI‘ on the front pages of pamphlets publishing international applications under the PCT.
`Albania
`ES
`Annenia
`FI
`Austria
`FR
`Australia
`GA
`GB
`Azerbaijan
`GE
`Bosnia and Hemegovina
`GH
`Barbados
`GN
`Belgium
`GR
`fiurkina Faso
`HU
`Bulgaria
`IE
`Benin
`Brazil
`[L
`Belarus
`IS
`IT
`Canada
`JP
`Central African Republic
`KE
`Congo
`Switzerland
`KG
`Cote d'Ivoim
`KP
`Cameroon
`China
`Cuba
`Czech Republic
`Gennany
`Denmark
`Estonia
`
`Spain
`Finland
`France
`Gabon
`United Kingdom
`Georgia
`Ghana
`Guinea
`Greece
`Hungary
`Ireland
`Israel
`Iceland
`Italy
`Japan
`Kenya
`Kyrgyzstan
`Democratic People's
`Republic of Korea
`Republic of Korea
`Kazakstan
`Saint Lucia
`Liechtenstein
`Sri Lanka
`Liberia
`
`KR
`KZ
`LC
`LI
`LK
`LR
`
`SI
`SK
`SN
`SZ
`TD
`TG
`TJ
`TM
`TR
`T1‘
`UA
`UG
`US
`UZ
`VN
`YU
`ZW
`
`Slovenia
`Slovakia
`Senegal
`Swaziland
`Chad
`Togo
`Tajikistan
`Turinnenistan
`Turkey
`Trinidad and Tobago
`Ukraine
`Uganda
`United States of America
`Uzbekistan
`Viet Nam
`Yugoslavia
`Zimbabwe
`
`Lesotho
`Lithuania
`Luxembourg
`Latvia
`Monaco
`Republic of Moldova
`Madagascar
`The former Yugoslav
`Republic of Macedonia.
`Mali
`Mongolia
`Mauritania
`Malawi
`Mexico
`Niger
`Netherlands
`Norway
`New Zealand
`Poland
`Portugal
`Romania
`Russian Federation
`Sudan
`Sweden
`Singapore
`
`LS
`LT
`LU
`LV
`MC
`MD
`MG
`M K
`
`ML
`MN
`MR
`MW
`MX
`NE
`NL
`NO
`NZ
`PL
`PT
`RO
`RU
`SD
`SE
`SG
`
`117
`
`117
`
`

`
`wo 99/33451
`
`PCT/EP99/00433
`
`ALLOGENIC
`
`INTERVERTEBRAL
`
`IMPLANT
`
`This
`
`invention concerns
`
`a device
`
`in
`
`accordance with the
`
`pre—characterising portion of Claim 1. More particularly, it
`
`refers
`
`to
`
`an allogenic intervertebral
`
`implant for use
`
`in the
`
`treatment of back pain.
`
`A number of medical conditions such as compression of spinal cord
`
`nerve
`
`roots,
`
`degenerative disc disease,
`
`and trauma can cause
`
`severe back pain.
`
`Intervertebral fusion is a surgical method of
`
`alleviating back pain.
`
`In intervertebral fusion,
`
`two adjacent
`
`vertebral bodies
`
`are fused together
`
`by
`
`removing
`
`the affected
`
`intervertebral disc and inserting an implant that would allow for
`
`bone to grow between the two vertebral bodies
`
`to bridge the gap
`
`left by
`
`the disc
`
`removal.
`
`A number of different
`
`implants and implant materials have been
`
`used for fusion with varying success.
`
`Current
`
`implants used
`
`include titanium cages and allografts.
`
`Titanium cages suffer
`
`from the disadvantage of requiring drilling and tapping of the
`
`vertebral endplates for insertion.
`
`In addition,
`
`the incidence of
`
`subsidence
`
`in long
`
`term use
`
`is
`
`not
`
`known.
`
`Due
`
`to MRI
`
`118
`
`118
`
`

`
`wo 99/33451
`
`PCT/EP99/00433
`
`incompatibility of
`
`titanium,
`
`determining fusion is problematic.
`
`Finally,
`
`restoration of lordosis, i.e.,
`
`the natural curvature of
`
`the cervical and lumbar spine
`
`is very difficult when
`
`a titanium
`
`cage is used.
`
`Allografts are sections
`
`of
`
`bone
`
`taken from the diaphysis of a
`
`long bone,
`
`such as the radius,
`
`ulna, fibula, humerus,
`
`tibia, or
`
`femur of
`
`a donor.
`
`A cross section of
`
`the bone
`
`is taken and
`
`processed using known techniques to preserve the allograft until
`
`implantation and reduce
`
`the
`
`risk of
`
`an
`
`adverse immunological
`
`response when implanted.
`
`For example, U.S. Patent No. 4,678,470
`
`discloses a method for processing a bone grafting material which
`
`uses glutaraldehyde
`
`tanning
`
`to
`
`produce
`
`a non-antigenic,
`
`biocompatible material. Allografts
`
`have mechanical properties
`
`which are similar to the mechanical properties of vertebrae even
`
`after processing.
`
`'This prevents stress shielding that occurs
`
`with metallic
`
`implants.
`
`They
`
`are also MRI
`
`compatible so that
`
`fusion can
`
`be more
`
`accurately ascertained and promote
`
`the
`
`formation
`
`of bone,
`
`i.e.,
`
`osteoconductive.
`
`Although
`
`the
`
`osteoconductive nature
`
`of
`
`the allograft provides
`
`a biological
`
`.___-,_,,
`
`interlocking between the allograft
`
`and
`
`the vertebrae
`
`for long
`
`term mechanical
`
`strength,
`
`initial
`
`and
`
`short
`
`term mechanical
`
`strength of the interface between the allograft and the vertebrae
`
`are
`
`lacking such
`
`that there
`
`is a possibility of the allograft
`
`being expelled after
`
`limplantation.
`
`119
`
`119
`
`

`
`wo 99/38461
`
`~
`
`PCT/EP99/D0433
`
`U.S. Patent No.
`
`5,728,159 discloses an allograft having grooves
`
`on end faces in an attempt to try to promote stability, but there
`
`are more effective ways for resisting expulsion.
`
`For example, W0 98/17209,
`
`published April 30, 1998,
`
`is directed
`
`to a spinal spacer and has
`
`one embodiment which
`
`is an allograft
`
`cortical ring having teeth on superior
`
`and/or inferior surfaces.
`
`These
`
`teeth provide the initial,
`
`secure
`
`interlocking with the
`
`vertebrae.
`
`Most allografts are simply sections of bone which,
`
`although cut
`
`to the approximate height
`
`of
`
`the disc being replaced, have not
`
`been sized and/or machined on
`
`the exterior
`
`surface to have a
`
`uniform shape.
`
`As a result,
`
`the fusion of the vertebral bodies
`
`does not occur
`
`in optimal
`
`anatomic position in a consistent
`
`manner along the surface of
`
`the endplates. While a surgeon may
`
`do some minimal intraoperative shaping and sizing to customize
`
`the allograft for the patient's anatomy,
`
`significant shaping and
`
`sizing of the allograft is not possible due to the nature of the
`
`allograft.
`
`Even if extensive shaping and sizing were possible, a
`
`surgeon's ability to manually shape and size the allograft to the
`
`desired dimensions is
`
`severely limited.
`
`As the discussion above illustrates,
`
`there
`
`is
`
`a
`
`need
`
`for an
`
`improved allogenic implant
`
`for
`
`fusing vertebrae
`
`and relieving
`
`back pain.
`
`The invention as claimed aims at
`
`solving the
`
`above
`
`described problems.
`
`120
`
`120
`
`

`
`W0 99/3846]
`
`PCT/EP99/00433
`
`The present
`
`invention provides
`
`an allogenic
`
`intervertebral
`
`implant
`
`for use when
`
`surgical" fusion of vertebral bodies is
`
`indicated as defined in Claim 1.
`
`The annular plug of allogenic bone is
`
`dimensioned in such a way
`
`that it conforms
`
`in size and shape with end plates
`
`of adjacent
`
`vertebrae,
`
`i.e. a rounded or appriximately circular form.
`
`In a preferred embodiment the three-dimensional structure of the
`
`intervertebral implant
`
`includes a plurality of teeth. Preferably
`
`the
`
`three-dimensional structure has a minimum height of 0,5 mm
`
`and a maximum height of
`
`1,5 mm relative to the top and bottom
`
`surfaces of the implant.
`
`The teeth preferably have a pyramid shape or
`
`a
`
`saw—tooth shape.
`
`In one embodiment,
`
`the implant has an exterior
`
`surface machined
`
`to have
`a uniform shape,
`such as an oval or a
`rectangle.
`The
`interior space delineated by
`the annular plug also can have a
`
`machined wall
`
`to provide the implant with a uniform interior
`
`space.
`
`The interior space delineated by the annular plug can be
`
`filled with spongiosa,
`
`bone graft substitutes or artificial bone
`
`material.
`
`The top and bottom surfaces may be flat planar surfaces or curved
`
`surfaces
`
`to mimic the
`
`topography of
`
`the
`
`end plates
`
`of the
`
`adjacent vertebrae.
`
`In a preferred embodiment,
`
`the anterior
`
`121
`
`121
`
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`W0 99/38461
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`PCT/EP99/00433
`
`height of the implant is greater than the posterior height of the
`
`implant so
`
`that the implant has a wedge—shaped profile to help
`
`restore disc height and the natural curvature of the spine.
`
`In one embodiment,
`
`the implant has channels on the top and bottom
`
`surfaces for receiving a surgical tool, e.g. a distractor. These
`
`channels can run
`
`in the anterior,
`
`lateral,
`
`or antero~lateral
`
`direction to accommodate a variety of different tools
`
`used in
`
`surgical procedures.
`
`Finally,
`
`a threaded hole on the anterior,
`
`antero—lateral,
`
`or lateral side can be provided for
`
`receiving a
`
`threaded arm of
`
`an
`
`insertion tool.
`
`The allogenic bone is preferably in the form of
`
`a cross section
`
`transverse to the longitudinal axis a human long bone,
`
`typically
`
`with a height
`
`of 5
`
`to 8 mm. Preferably the allogenic bone has
`
`been process frozen or freeze dried.
`
`The allogenic bone may also
`
`be treated with an antiseptic solution.
`
`In the drawings:
`
`FIG.
`
`1
`
`is
`
`a top view of
`
`a first
`
`embodiment
`
`of
`
`the implant
`
`according to the present invention;
`
`FIG.
`
`2
`
`is a front view of the implant of FIG. 1;
`
`FIG.
`
`3 is a top view of a second embodiment of the implant;
`
`FIG.
`
`4
`
`is a side view of the implant of FIG. 1;
`
`122
`
`122
`
`

`
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`
`“ W0 99/3846]
`
`PCT/EP99/00433
`
`FIG.
`
`5 is a side view of a third embodiment of the implant;
`
`FIG.
`
`6 is a close up of region A from FIG.
`
`4 and FIG. 8-I
`
`FIG.
`
`7
`
`is
`
`a top view of
`
`a fourth embodiment
`
`of the implant
`
`according to the present invention;
`
`FIG.
`
`8
`
`is a side view of the implant of FIG.
`
`7;
`
`FIG.
`
`9 is a top view of a sixth embodiment of the implant; and
`
`FIG.
`
`10
`
`shows an alternative tooth configuration.
`
`FIG.
`
`1
`
`shows a top view of a first embodiment
`
`of
`
`an allogenic
`
`intervertebral implant 10
`
`according to the present invention.
`
`Implant 10 is annular and conforms in size and shape with the end
`
`plates
`
`of
`
`the vertebrae
`
`between which
`
`implant
`
`10
`
`is
`
`to be
`
`implanted.
`
`Because implant 10
`
`is annular, new bone can form in
`
`interior 11.
`
`Interior 11
`
`can be filled with bone chips or any
`
`other osteoconductive material to promote the formation of bone.
`
`Although implant 10 will probably be predominantly used
`
`in the
`
`lumbar region of
`
`the spine,
`
`implant 10
`
`can be
`
`configured for
`
`implantation in any region of
`
`the
`
`spine.
`
`Implant
`
`10
`
`has a
`
`plurality of teeth 12
`
`on
`
`superior and inferior surfaces
`
`14, 16
`
`which provide a mechanical interlock between implant
`
`10
`
`and the
`
`end plates.
`
`These teeth 12 provide the mechanical interlock by
`
`123
`
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`
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`
`wo 99/33451
`
`PCT/EP99/00433
`
`penetrating the end plates.
`
`The
`
`initial mechanical stability
`
`afforded by
`
`teeth 12 minimizes
`
`the
`
`risk_ of post-operative
`
`expulsion of implant 10. Preferably,
`
`teeth 12 are pyramid—shaped
`
`in which the angle formed from the tip to the base may be between
`
`about
`
`45
`
`and 75° and is preferably about 60°.
`
`The details of
`
`teeth 12
`are best seen in FIG. 6.
`The teeth provide an enhanced
`interlock with the adjacent vertebrae compared
`to the use of
`
`channels,
`
`because the teeth impale
`
`the vertebrae
`
`surfaces.
`
`In
`
`comparison,
`
`channels impart grooves into the vertebrae surfaces
`
`and the implant can slide out along the direction of the channels
`
`or grooves.
`
`In an alternative embodiment,
`
`teeth 12
`
`have a
`
`saw—tooth shape (FIG. 10).
`
`As shown in FIG.
`1 and FIG. 2, superior surface 14 has a channel
`18
`and inferior surface 16 has a channel 20 which is parallel to
`
`channel
`
`18.
`
`Channels
`
`18,
`
`20
`
`are sized to receive a surgical
`
`instrument such as an inserter
`
`and/or distractor. As the names
`
`imply,
`
`an inserter
`
`is
`
`a
`
`surgical
`
`instrument
`
`used to insert
`
`implant
`
`10
`
`and a distractor
`
`is
`
`a surgical
`
`instrument used to
`
`separate the adjacent vertebrae so that the surgeon has access to
`
`the
`
`intervertebral space.
`
`If the inserter has a
`
`threaded arm,
`
`implant 10
`
`can be provided with optional threaded hole 21.
`
`In
`
`FIG.
`
`1
`
`and FIG.
`
`2,
`
`channels
`
`18
`
`and 20
`
`are oriented in the
`
`anterior/posterior direction.
`
`This orientation is useful if the
`
`surgeon prefers an anterior
`
`surgical
`
`approach.
`
`124
`
`124
`
`

`
`.
`
`two 99/33451
`
`PCT/EP99/00433
`
`FIG.
`
`3
`
`shows a second embodiment of an allogenic intervertebral
`
`implant 110 according to the present invention.
`
`In general, most
`
`of the structure of
`
`implant
`
`110
`
`(as well
`
`as
`
`the embodiments
`
`described below)
`
`is
`
`like or
`
`comparable
`
`to the structure of
`
`implant
`
`10
`
`and,
`
`accordingly the same reference numeral is used
`
`for
`
`like components and discussion of those
`
`like components is
`
`not believed necessary.
`
`As shown in FIG. 3, channels 18, 20 can
`
`run in the antero—lateral direction to facilitate use of implant
`
`110
`
`with an antero-lateral
`
`surgical
`
`approach.
`
`As
`
`another
`
`alternative embodiment,
`
`channels 18, 20 could run in the lateral
`
`direction for a lateral approach.
`
`Similarly, a threaded hole 21
`
`optionally can be located on the lateral or antero-lateral side
`
`of implant 10.
`
`In order to restore the natural curvature of the
`
`spine after the
`
`affected disc
`
`has been removed,
`
`implant 10
`
`is provided with a
`
`wedge—shaped profile.
`
`As shown in FIG.
`
`4, one way to achieve
`
`this wedge shape results from a gradual decrease
`
`in height from
`
`the anterior
`
`side
`
`22
`
`to the posterior side 24.
`
`In anatomical
`
`terms,
`
`the natural curvature of the lumbar spine is
`
`referred to
`
`as lordosis. When implant 10 is to be used in the lumbar region,
`
`angle a should be approximately 4,2° so that the wedge shape is a
`lordotic
`shape which mimics
`the anatomy of
`the
`lumbar spine.
`
`Furthermore, when used in the
`
`lumbar region,
`
`the ratio of the
`
`height of anterior side 22 »(hl)
`
`to the height of posterior side
`
`24
`
`10
`
`(hz) should be approximately 1,1—2 with the length of implant
`
`(1)
`
`being approximately 22 - 30 mm.
`
`125
`
`125
`
`

`
`wo 99/3846l
`
`PCT/EP99l00433
`
`In FIG.
`
`4, superior and inferior surfaces 14, 16 are flat planar
`
`surfaces
`
`so
`
`that
`
`if the
`
`surgeon prepares the
`
`endplates to be
`
`parallel
`
`surfaces with a burr,
`
`implant 10
`
`fits tightly between
`
`the bone surfaces.
`
`FIG.
`
`5 illustrates that superior and inferior surfaces 14, 16 of
`
`a third embodiment of an allogenic intervertebral implant 210 can
`
`be
`
`curved
`
`surfaces
`
`and still retain the wedge—shaped profile.
`
`The curved surface of superior and inferior surfaces 14,
`
`16 is a
`
`mirror-image of
`
`the
`
`topography of
`
`the vertebral
`
`end plates.
`
`Thus,
`
`the
`
`curved surfaces conform to the contours of
`
`the end
`
`plates.
`
`FIG.
`7
`shows a top View of a fourth embodiment of
`an allogenic
`intervertebral implant 310
`according to the present invention.
`
`Although implant 310 will probably be predominantly used in the
`
`cervical region of the spine,
`
`implant 310
`
`can be configured for
`
`implantation in any region of
`
`the spine.
`
`Interior 11 can be
`
`defined by the natural shape of
`
`the medullary canal as was the
`
`case
`
`for implant 10,
`
`110,
`
`210. Alternatively,
`
`the medullary
`
`canal can be machined so that
`
`the wall that formed
`
`interior 11
`
`are uniform in shape and texture.
`
`As previously noted,
`
`teeth 12
`
`are preferably pyramid—shaped in
`
`which the angle formed
`
`from the tip to the base
`
`is preferably
`
`about 60°.
`
`Pyramid—shaped teeth help prevent expulsion of the
`
`implant in all directions.
`
`The prevention of movement between
`
`126
`
`126
`
`

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`
`PCT/EP99/00433
`
`1 O
`
`implant 310
`
`and the vertebrae is particularly important when the
`
`surgeon removes all of the annulus
`
`fibrosis,
`
`as may be the case
`
`for cervical vertebrae.
`
`Most allografts
`
`are processed and used without
`
`significant
`
`machining of
`
`the
`
`exterior
`
`surface.
`
`In other words,
`
`the
`
`allografts
`
`have substantially the
`
`shape of the
`
`bone from which
`
`the allograft was harvested.
`
`As shown in FIG.
`
`7,
`
`an exterior
`
`surface 26
`
`of
`
`implant 310
`
`has been machined to have
`
`a uniform
`
`shape.
`
`The
`
`uniform shape promotes
`
`initial
`
`stability until
`
`biological fixation is achieved with bony fusion.
`
`As shown in FIG.
`
`7,
`
`the exterior surface 26 has an oval shape.
`
`The oval shape preferably is
`
`arranged to have
`
`lateral sides 28
`
`along the smaller oval axis and anterior and posterior
`
`sides 22,
`
`24 along the longer axis.
`
`In another embodiment of the invention
`
`shown
`
`in FIG.
`
`9,
`
`the exterior surface 26
`
`of
`
`implant 410 is
`
`rectangular in shape with lateral sides 28 shorter in length than
`
`anterior and posterior sides
`
`22,
`
`24.
`
`The oval
`
`and rectangle
`
`shape and size of implants 310,
`
`410 can be made to closely match
`
`the shape and size of the affected vertebrae. Typically,
`
`lateral
`
`sides
`
`28
`
`and anterior
`
`and posterior
`
`sides
`
`22,
`
`24 would be
`
`approximately 8-18
`
`mm
`
`in length.
`
`In order to restore the intervertebral
`
`space to the proper size
`
`after the affected disc
`
`has been
`
`removed,
`
`implant
`
`310
`
`has a
`
`height,
`
`h,
`
`sized to match the height of the removed disc, as
`
`shown in FIG.
`
`8.
`
`The matched height helps promote fusion by
`
`127
`
`127
`
`

`
`W0 99/38461
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`
`11
`
`PCT/EP99l00433
`
`providing direct Contact
`
`between
`
`the
`
`bone
`
`and
`
`implant 310.
`
`Typically,
`
`h would
`
`be
`
`approximately 4-20
`
`mm
`
`for cervical
`
`vertebrae.
`
`Implant 310 has a uniform height so that the profile
`
`of implant 310 is rectangular. Alternatively, as shown in FIG. 4
`
`and FIG.
`
`5,
`
`implant 310
`
`can have a wedge shaped profile with
`
`either flat planar surfaces or curved surfaces.
`
`It should be noted that
`
`implants
`
`310,
`
`410 can be configured so
`
`that h would be
`
`approximately 10-100 mm.
`
`These
`
`larger sizes
`
`could be used in corpectomy,
`
`a surgical procedure
`
`in which a
`
`section of several vertebrae is removed.
`
`Implants 310, 410 would
`
`be inserted in the space created by the removed
`
`section of bone.
`
`Due
`
`to the nature of
`
`corpectomy,
`
`an accurate preoperative
`
`determination of the size of the implant needed is not possible.
`
`Thus,
`
`implant 310,
`
`410
`
`can be cut
`
`to the proper size
`
`by the
`
`surgeon.
`
`In such cases,
`
`the implants 310,
`
`410 would only have
`
`teeth on either superior surface 14 or inferior surface 16.
`
`128
`
`128
`
`

`
`- W0 99l3846I
`
`PCT/EP99/00433
`
`1 2
`
`CLAIMS
`
`1.
`
`Intervertebral implant
`
`(10)
`
`comprising an
`
`annular plug of
`
`allogenic bone conforming
`
`in size and shape with end plates of
`
`vertebrae, wherein top and bottom surfaces (14,16) of the implant
`
`(10)
`
`include
`
`a
`
`three—dimensional
`
`structure
`
`(12)
`
`positioned
`
`thereon for interlocking with adjacent vertebrae.
`
`2. Intervertebral implant
`
`(10) according to claim 1, wherein said
`
`three—dimensional structure (12)
`
`includes a plurality of teeth.
`
`3. Intervertebral implant
`
`(10) according to claim 1 or 2, wherein
`
`said three—dimensional structure (12) has a minimum height of 0,5
`
`mm relative to the top and bottom surfaces (14,16).
`
`4.
`
`Intervertebral implant
`
`(10)
`
`according to one of the claims 1
`
`to 3, wherein said three—dimensional structure (12) has a maximum
`
`height of 1,5 mm relative to the top and bottom surfaces (14,16).
`
`5.
`
`Intervertebral implant
`
`(10)
`
`according to one of the claims 1
`
`to 4, wherein said allogenic bone has been obtained from a human
`
`long bone, preferably from 'a femur,
`
`humerus,
`
`radius,
`
`ulna or
`
`fibula.
`
`6. Intervertebral implant
`
`(10) according to claim 5, wherein said
`
`allogenic bone is a cross section transverse to the longitudinal
`
`axis of said long bone, preferably with a height of 5 to 8 mm.
`
`129
`
`129
`
`

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`W0 99/3846]
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`PCT/EP99/00433
`
`1 3
`
`7.
`
`Intervertebral implant
`
`(10)
`
`according to one of the claims 1
`
`to 6, wherein said allogenic bone is treated with an antiseptic
`solution.
`
`8.
`
`Intervertebral implant
`
`(10)
`
`according to one of the claims 1
`
`to 7, wherein said allogenic bone
`
`has been process frozen or
`
`freeze dried.
`
`9.
`
`Intervertebral implant
`
`(10)
`
`according to one of the claims 1
`
`to 8, wherein the allogenic bone comprises glutaraldehyde.
`
`10.
`
`Intervertebral implant
`
`(10) according to one of the claims 1
`
`to 9, wherein the interior space delineated by
`
`the annular plug
`
`is
`
`filled with spongiosa,
`
`bone graft
`
`substitutes or artificial
`
`bone material.
`
`11. Intervertebral implant
`
`(10)
`
`according to one of the claims 1
`
`to 10, wherein the top and bottom (14,16)
`
`surfaces each have a
`
`channel
`
`(18,20) for receiving a surgical instrument.
`
`12.
`
`Intervertebral implant
`
`(10)
`
`according to claim 11, wherein
`
`the
`
`channels (18,20)
`
`run in an anterior-posterior direction.
`
`13.
`
`Intervertebral implant
`
`(10)
`
`according to claim 11, wherein
`
`the channels (18,20)
`
`run in an antero—lateral direction.
`
`14.
`
`Intervertebral implant
`
`(10)
`
`according to claim 11, wherein
`
`the channels (18.20)
`
`run in a-lateral direction.
`
`130
`
`130
`
`

`
`wo 99/33451
`
`PCT/EP99I00433
`
`14
`
`15. Intervertebral implant
`
`(10) according to one of the claims
`
`1
`
`to 14, wherein
`
`the implant has a wedge-shaped profile to help
`
`restore disc height and spine curvature.
`
`16.
`
`Intervertebral implant
`
`(10)
`
`according to claim 15, wherein
`
`said implant has an anterior height which
`
`is greater
`
`than a
`
`posterior height to produce the wedge—shaped profile.
`
`17.
`
`Intervertebral implant
`
`(10) according to one of the claims 1
`
`to 16, wherein the teeth (12) have a pyramidal shape.
`
`18.
`
`Intervertebral implant
`
`(10) according to one of the claims 1
`
`to 17, wherein at
`
`least one side
`
`of
`
`the implant
`
`(10)
`
`has at
`
`least one hole for attachment of an inserter.
`
`19.
`
`Intervertebral implant
`
`(10)
`
`according to claim 18, wherein
`
`the at least one hole is threaded.
`
`20.
`
`Intervertebral implant
`
`(10)
`
`according to claim 19, wherein
`
`the at least one hole is provided in an anterior, antero-lateral,
`
`or lateral side.
`
`21.
`
`Intervertebral implant
`
`(10) according to one of the claims 1
`
`to 20, wherein the top and bottom surfaces
`
`(14,16)
`
`are flat
`
`planar surfaces.
`
`131
`
`131
`
`

`
`- W0 99/38461
`
`'
`
`15
`
`PC'I‘lEP99/00433
`
`22.
`
`Intervertebral implant
`
`(10) according to one of the claims 1
`
`to 20, wherein
`
`the top and bottom surfaces
`
`(14,16) are curved
`
`surfaces which are contoured to mimic
`
`the
`
`end plates of the
`
`adjacent vertebrae.
`
`23.
`
`Intervertebral implant
`
`(10) according to one of the claims 1
`
`to 22, wherein the exterior surface of said implant has a uniform
`
`shape.
`
`24.
`
`Intervertebral implant
`
`(10)
`
`according to claim 23, wherein
`
`the exterior surface has an oval shape.
`
`25.
`
`Intervertebral implant
`
`(10)
`
`according to claim 23, wherein
`
`the exterior surface has a rectangular shape.
`
`26.
`
`Intervertebral implant
`
`(10) according to one of the claims 1
`
`to 25, wherein the annular plug includes an interior surface of a
`
`machined wall.
`
`27.
`
`Intervertebral implant
`
`(10) according to one of the claims 1
`
`to 26, wherein,
`
`the teeth have a saw tooth shape.
`
`132
`
`132
`
`

`
`~ W0 995846]
`
`PCT/EP99/00433
`
`1/2
`
`FIG. 2
`
`14
`
`10
`
`12
`
`12
`
`\
`
`I
`
`20
`
`16
`
`18
`
`
`
`FIG. 5
`
`FIG. 6
`
`12
`14
`/210
`22~d::>—24
`
`12
`
`15
`
`19
`
`50°
`
`SUBSTITUTE s1-1E3=.3r (RULE 26)
`
`133
`
`

`
`' W0 99/3846]
`
`PCT/EP99/00433
`
`2/2
`
`12
`
`@
`
`SUBSTITUTE SHEET (RULE 26)
`
`13 4
`
`134
`
`

`
`OPIC PROPERTY OFFICE
`
`CANADIAN INTELLECTUAL
`
`OFFICE on LA PROPRIETE
`INTELLECTUELLE DU CANADA
`
`(72) Kuslich, Stephen D., US
`(72) Corin, James D., US
`
`(72) Bagby, George W., US
`(73) Spine-Tech, Inc., US
`(51) Int.Cl.° A61B 17/70
`(30) 1989/O7/06 (376,657) US
`(30) 1989/O9/O8 (405,564) US
`(54) IMPLANT RACHIDIEN
`
`(54) SPINAL IMPLANT
`
`(12)(19) (CA) Brevet-Patent
`
`(1 1) (2l)(C) 2,015,507
`(22
`1990/04/26
`(43)
`1991/01/06
`(45)
`1999/01/05
`
`
`
`(5'/)1. ’invention pone sur un implant pour la stabilisation
`rachidienne. Dans un modele privile'gie', 1’implant est
`décrit comme un corps cylindrique creux ayant un
`filetage exteme et une série d’ouvertures formées
`radialement sur tout
`le corps et communiquant avec
`l’intérieur de ce demier. Des bouchons, dont au moins un
`
`est fait d’un matériau permeable aux rayons X, sont
`prévus aux extrémites avant et arriére du corps.
`
`in spinal
`is disclosed for use
`implant
`(57) An
`stabilization. In one preferred embodiment, the implant
`is described as including a hollow, cylindrical body
`having extemal threading and a plurality of openings
`formed radially through the body in communication with
`the body interior. End caps are provided on the leading
`and trailing ends of the body, with at least one