`
`WORLD INTELLECTUAL PROPERTY ORGANIZATION
`International Bureau
`
`
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`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`(1DInternational Publication Number:
`WO 97/33525
`(51) International Patent Classification 6;
`
`AG1B 17/56 Al
`
`(43) International Publication Date:
`
`18 September 1997 (18.09.97)
`
`
`
`(22) InternationalFiling Date:
`
`(30) Priority Data:
`08/616,120
`
`14 March 1996 (14.03.96)
`
`INC.
`SURGICAL DYNAMICS,
`(71) Applicant:
`Glover Avenue, Norwalk, CT 06856 (US).
`
`[US/US];
`
`
`(21) International Application Number: PCT/US97/03869|(81) Designated States: AU, CA, JP, European patent (AT, BE,
`CH, DE, DK, ES, FI, FR, GB, GR, JE, IT, LU, MC, NL,
`
`13 March 1997 (13.03.97)
`PT, SE).
`
`Published
`
`US
`With international search report.
`
`
`111
`
`
`(72) Inventors: WINSLOW,Charles, J.; 27 Hilton Court, Walnut
`Creek, CA 94520 (US). MITCHELL,Steven, T.; 776 Duke
`Circle, Pleasant Hill, CA 94523 (US).
`
`
`
`
`
`(74) Agent: GERSHON,Neil, D.; United States Surgical Corpora-
`tion, 150 Glover Avenue, Norwalk, CT 06856 (US).
`
`(54) Titles APPARATUS AND METHOD FOR IMPLANT INSERTION
`
`(57) Abstract
`
`Apparatus for, and methods of, inserting implants (200) are disclosed wherein the
`apparatus includes a handle portion (112) and a body portion attached to the handle portion
`(112). The body portion includes an outer tubular member (110), an inner tubular member
`(118) and an inner shaft (132), The outer tubular member(11) is fixed to the handle portion
`(112) for rotation therewith and with implant engaging structure (116) on its distal end. The
`inner tubular member (118) is disposed within the outer tubular member (110) and can move
`longitudinally and rotationally therein. Second implant engaging structure (130) is positioned
`at the distal end of the inner tubular member (118). The inner shaft (132) rotates relative
`the inner and outer tubular members and has a third implant engaging structure (144). At
`least one of the engaging structures attaches to a removable cap (206) of the implant.
`
`
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`
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`FOR THE PURPOSES OF INFORMATION ONLY
`
`Codes used to identify States party to the PCT on the front pages of pamphlets publishing international
`applications under the PCT,
`
`Viet Nam
`
`United Kingdom
`Georgia
`Guinea
`Greece
`Hungary
`Treland
`taly
`Japan
`Kenya
`Kyrgystan
`Democratic People's Republic
`of Korea
`Republic of Korea
`Kazakhstan
`Liechtenstein
`Sri Lanka
`Liberia
`Lithuania
`Luxembourg
`Latvia
`Monaco
`Republic of Moldova
`Madagascar
`Mali
`Mongolia
`Mauritania
`
`AM
`AT
`AU
`BB
`BE
`BF
`BG
`BJ
`BR
`BY
`CA
`CF
`CG
`CH
`cr
`CM
`CN
`cs
`CZ
`DE
`DK
`EE
`ES
`FI
`FR
`GA
`
`Armenia
`Austria
`Australia
`Barbados
`Belgium
`Burkina Faso
`Bulgaria
`Benin
`Brazil
`Belarus
`Canada
`Central African Republic
`Congo
`Switzerland
`Cite d'Ivoire
`Cameroon
`China
`Czechoslovakia
`Czech Republic
`Germany
`Denmark
`Estonia
`Spain
`Finland
`France
`Gabon
`
`Malawi
`Mexico
`Niger
`Netherlands
`Norway
`New Zealand
`Poland
`Portugal
`Romania
`Russian Federation
`Sudan
`Sweden
`Singapore
`Slovenia
`Slovakia
`Senegal
`Swaziland
`Chad
`Togo
`Tajikistan
`Trinidad and Tobago
`Uline
`Uganda
`United States of America
`Uzbekistan
`
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`PCT/US97/03869
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`APPARATUSANDMETHODFORIMPLANTINSERTION
`
`BACKGROUND
`This application is a continuation-in-part of U.S. application Serial No.
`08/354,364, filed on December12,1994, whichis a continuation-in-part of U.S.
`application Serial No. 08/306,879, filed on September15,1994. The contents of these
`applications are incorporated herein by reference.
`10
`1. TechnicalField
`This disclosure relates generally to apparatus and methods for implant
`insertion. Moreparticularly, to apparatus and methods for insertion of implants to facilitate
`fusion of adjacent bony structure.
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`2.BackgroundoftheRelatedArt
`A large numberof orthopedic proceduresinvolve the insertion ofeither
`natural or prosthetic implants into boneor associated tissues. ‘These proceduresinclude,
`for example,ligamentrepair, joint repair or replacement, non-union fractures, facial
`reconstruction, spinal stabilization and spinal fusion. In a typical procedure,an insert,
`dowel or screwis inserted into a prepared bore formed in the boneortissuesto facilitate
`repair and healing. See, for example, U.S. Patent Nos.: 5,470,334 to Rosset al.;
`5,454,811 to Huebner, 5,480,403 to Lee et al.; 5,40,805 to Warren; 5,358,511 to Gatturna
`et al.; and 4,877,020 to Vich.
`Some implants are particularly configured with cavities and bores to
`facilitate bony ingrowth and enhance anchoringof the implant at the insertionsite. See, for
`example, U.S. Patent Nos.: 4,328,593 to Sutter et al.; 4,936,851 to Fox et al.; and
`4,878,915 to Brantigan. Implants in the form of fusion cages having internal cavinesto
`receive bone growth stimulation materials such as bone chips and fragments are disclosed,
`for example, in U.S. Patent Nos.: 4,501,269 to Bagby; 4,961,740 to Ray etal.;
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`5,015,247 to Michaelson; and 5,489,307 to Kuslich et al. These types of implants are
`particularly well suited for intervertebral spinal fusion procedures necessitated by injury,
`disease or some degenerative disorderof the spinal disc. Subsequently, there may be
`progressive degeneration leading to mechanical instability between adjacent vertebrae
`necessitating direct fusion of the vertebrae while maintaining a pre-defined intervertebral
`space. This fusion may be accomplished by the insertion of one or more ofthe specialized
`implants as discussed above and also discussed in commonly assigned U.S. Patent No.
`5,026,373, incorporated herein byreference.
`Both anterior (transabdominal) and posterior surgical approachesare used
`for interbody fusionsof the lumbar spine. Fusions in the cervical area of the spine are
`primarily done using an anterior approach. Typically, an implant such as a plug, dowel,
`prosthesis or cage is inserted into a preformed cavity inside the interbody,interdiscal space.
`Sinceit is desirable in these procedures to promote a "bone to bone" bridge, connective
`tissue and at least a portion ofthe discal tissue is removed. Preferably, relatively deep cuts
`are made in the adjacent bonesin order to penetrate into the softer, more vascularized
`cancellous region to facilitate bone growth across the implant.
`|
`Wheninstalling these specialized implants, an insertion tool is used to
`position the implantin the desired intervertebral location. See, for example, U.S. Patent
`Nos.: 3,848,601 to Maet al.; 4,501,269 to Bagby; 4,877,020 to Vich: and 4,878,915 to
`Brantigan. Oncein position, the insertion tool is removed and, where the implant structure
`permits, bone chips or other bone growth inducing substances are packed into the implant
`in vivo. Subsequently, an end cap or other sealing structureis positionedto close the
`implant. See, for example, commonly assigned U.S. Patent No. 4,961,740 to Rayetal.
`incorporated herein by reference.
`Typical insertion tools use either a single implant engagementstructureor, at
`most, two implant engagementstructuresto facilitate positioning of the implant. For
`example, in U.S. Patent No. 4,501,269 to Bagby, prongs are used to engage the implant.
`In U.S. Patent Nos. 4,878,915 to Brantigan and 5,015,247 to Michaelson, a threaded rod
`and slot are used to engage the implant. In U.S. Patent Nos.: 4,961,740 to Ray et al.;
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`5,489,308 and 5,489,307, both to Kuslich et al.; and 4,936,838 to Bagby, a single central
`shaft is used. In all of these insertion tools, no structure is provided to permit the insertion
`tool to attach to an outer peripheral portion ofthe implant, either in vitro or in vivo.
`Further, these tools do not provide structure which separately engages both the implant and
`the implantclosure, e.g. an end cap.
`Accordingly, a need exists for an insertion tool which is capable of either
`inserting an implant preloaded with bone chips, etc. Such in vitro packing facilitates the
`surgical procedure becauseit is often time consumingandrelatively difficult, especially for
`example in cervical applications, to pack the cage in vivo. It would also be advantageousif
`such insertion tool could be additionally used to insert/position an empty implantfor
`subsequent in vivo packing and closure.
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`SUMMARY
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`Apparatus for and methods of inserting implants are disclosed wherein the
`apparatus includes a handle portion and a body portion attached to the handle portion and
`defining a longitudinal axis. The body portion includes an outer tibular memberfixed
`relative to the handle portion for rotation therewith aboutthe longitudinal axis. The outer
`tmbular memberhas first implant engaging structure adjacent a distal end. An inner tubular
`memberis disposed at least partially within the outer tubular memberand is mounted for
`longitudinal motionrelative to the outer tubular member. Second implant engaging
`structure is positioned adjacent a distal end of the inner tubular member. The body portion
`further includes an inner shaft, coaxially mounted at least partially within the inner tubular
`member for independentrotation relative to the inner and outer tubular members, the inner
`shaft having third implant engaging structure adjacentadistal end.
`25
`In a method for inserting an implant having a hollow portion with a closed
`distal end and a removable cap,the first, second and third implant engaging structures are
`attached to the implant with at least one of the engaging structures attached to the removable
`cap and anotherof the engaging structure attached to the hollow portion. The implantis
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`preferably preloaded with bone chips and/or bone growth inducing substancesprior to
`attachment. Thereafter, the preloaded implantis inserted into the desired surgical location.
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`BRIEFDESCRIPTIONOFTHEDRAWINGS
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`Various embodiments of the subject implant insertion apparatusare
`described below with reference to the drawings wherein:
`FIG. 1 is a perspective view of an implant insertion apparatus constructed in
`accordance with a preferred embodimentof the subject disclosure:
`FIG. 2 is a side view in cross-section ofthe implant insertion apparatus
`taken along line 2-2 of FIG.1;
`FIG. 2A is an enlarged side view in cross-section of the connection between
`the handle portion and the body portion of the implant insertion apparatusofFIG.1:
`FIG. 2B is an enlarged perspective view of the distal ends of the outer and
`innertubular members ofthe implant insertion apparatus of FIG.1;
`FIG. 2C is an enlarged perspective view of an interchangeable distal end of
`the outer tubular member of the implantinsertion apparatusof FIG.1;
`FIG. 3 is an enlarged perspective view of one type of implant configured for
`interbody fusion;
`FIG. 4 is an enlarged proximal end view of the implant of FIG.3
`illustrating the structure of the removable end cap;
`FIG. 5 is an enlarged end view in cross-section of the implant taken along
`line 5-5 of FIG. 3.
`FIG.6 is an enlarged perspective view ofthe implant of FIG. 3 with parts
`separated and loading of bone chipsin process;
`FIG.6A is a side view in partial cross-section showing an end cap mounted
`to the inner tubular memberandthe innershaft:
`FIG. 7 is a perspective view of a preloaded implant with removable end cap
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`FIG. 8A is an enlarged side view in partial cross-section illustrating the
`distal end of the implant insertion apparatus of FIG. 1 and the implantof FIG.7;
`FIG. 8B is an enlarged side view of the housing and rotation wheelsof the
`body portion illustrating the relative position of the inner tubular memberas shown in FIG.
`8A;
`
`FIG.9A is an enlarged side view in partial cross-section illustrating the
`distal end of the implant insertion apparatus of FIG. 1 with the second andthird implant
`engagementstructure attached to the removable cap of the implant ofFIG.7;
`FIG.9B is an enlarged side view of the housing and rotation wheels of the
`body portion illustrating the relative position of the inner tubular memberand the innershaft
`as shownin FIG. 9A;
`FIG. 10A is an enlarged side view in partial cross-section illustrating the
`distal end of the implant insertion apparatus of FIG. 1 with thefirst, second and third
`implant engagementstructure attachedto the implantof FIG.7;
`FIG. 10B is an enlarged side view of the housing and rotation wheels of the
`body portion illustrating the relative position of the inner shaft, the inner tubular mernber
`and the outer tubular member as shownin FIG. 10A;
`FIG. 11 is a side view illustrating the insertion ofthe implant of FIG. 7
`using the insertion apparatus of FIG. 1; and
`FIG.12 is an enlarged top view in partial cross-section of a pair of implants
`in place in the intervertebral space of a lumbar spinal section.
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`DETAILEDDESCRIPTIONOFPREFERREDEMBODIMENTS
`
`The preferred embodiments of the apparatus and methods disclosed herein
`are discussed in terms of orthopedic spinal fusion procedures and apparatus. It is also
`envisioned, however, that the disclosure is applicable to a wide variety of procedures
`including, but not limited to ligamentrepair, joint repair or replacement, non-union
`fractures, facial reconstruction andspinal stabilization. In addition,it is believed that the
`present apparatus finds application in both open and minimally invasive procedures
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`including endoscopic and arthroscopic procedures wherein accessto the surgical site is
`achieved through a cannula or small incision.
`In the description which follows,the term "proximal", as is traditional, will
`refer to the portion ofthe structure which is closer to the operator, while the term "distal"
`will refer to the portion which is further from the operator.
`Referring now in detail to the drawings in whichlike reference numerals
`identify similar or identical elements, a preferred embodimentof the implantinsertion
`apparatusis illustrated in FIGS. 1 and 2 andis designated generally by reference numeral
`100. Implant insertion apparatus 100 includes a removable handle portion 102 and a body
`portion 104. Handle portion 102 has a T-handle 106 positioned at a proximal end and
`releasable engagementstructure 108ata distal end thereof.
`Body portion 104 defines a longitudinal axis "L" and includes an outer
`tubular member 110fixed to a housing 112 for longitudinal rotation therewith. First
`implant engaging structure 114is positioned adjacenta distal end of outer rubular member
`110. Outer tubular member110 preferably includes a removable distal end portion 158
`described below. In the embodiment shown,the implant engaging structureis a pair of
`distally extending tabs 116 projecting from thedistal end of outer tubular member110.
`Bodyportion 104 further includes an inner tubular member 118 disposed at
`least partially within outer tubular member 110. Inner tubular member 118 is mounted for
`limited longitudinal motionrelative to outer tubular member 110 and is independently
`rotatable relative to outer mbular member 110 by wheel 120. In the illustrated embodiment,
`Set Screw 122 anchors whee] 120 to the inner tubular member 118. A first Cavity 124 is
`defined in housing 112 and is dimensionedto limit the relative longitudinal motion of inner
`tubular member 118 by confining wheel 120 between walls 112a,112b. As shown in
`FIG.1, the periphery of wheel 120 may be provided with knurling 126 to enhanceits
`frictional characteristics.
`Inner tubular member 118 is normally biased to a distalmost longitudinal
`position relative to outer tubular member 110 as shownin FIG. 2. Coil spring 127,
`mounted in housing 112, abuts a proximal endof inner tubular member 118 and biases
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`inner tubular member distally. Second implant engaging structure 128 is formed adjacent a
`distal end of the inner tubular member 118. In the illustrated embodiment, the second
`implant engaging structure 128 is a hollow polygonal structure having a plurality of flat
`sides 130 extending from the distal end of inner tubular member118.
`Body portion 104 also includes an inner shaft 132, coaxially mounted at
`least partially within the inner tubular member 118. Inner shaft 132 is longitudinally
`rotatable relative to inner tubular member118 and outer tabular member 110 by wheel 134.
`As shown, set screw 136 connects wheel 134 to a distal end of inner shaft 132. Ina
`preferred embodiment, the outer periphery of wheel 134 is provided with a friction
`enhancing surface such as knurling 138.
`A second cavity 140 is defined in housing 112 proximal to first cavity 124
`and serves to confine wheel 134, and thus innershaft 132, to limited longitudinal motion
`relative to outer and inner tubular members 110 and 118, respectively between walls 112c,
`112d. Wheels 120 and 134 preferably extend radially beyond at least one outer peripheral
`surface of house 112 to facilitate acmation bythefingers ofa user.
`Inner shaft 132 has third implant engaging structure 142 positioned adjacent
`a distal end (See Figs 2 and 6A). In the illustrated embodiment, this structure is threads
`144 formed on a distal end of inner shaft 132.
`
`Referring now to FIGS. 2 and 2A,releasable engagementstructure 108 of
`the illustrated embodimentof implant insertion apparatus 100 includes a distal sieeve 146
`having an inner surface configured to engage hexagonal projection 148 formed on a
`proximal end of housing 112.
`Proximal sleeve 150 is operatively associated with distal sleeve 146 and
`includes an internal spring loaded ball system 152 configured to releasably engage an
`annular channel 154 which extends proximally from hexagonal projection 148. Proximal
`sleeve 150 is mounted on a distal end of handle portion 102 for relative longitudinal motion
`between a locked position (FIG. 2) and an unlocked position (FIG. 2A). In the locked
`position, ball system 152 is forced radially inward into annular channel 154. Spring 156
`normally biases proximal sleeve 150 into this locked position. As shown in FIG.2A,in
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`the unlocked position, proximal sleeve 150 is retracted to release ball systern 152 from
`annular channel 154. This enables the removal of handle portion 102 from the body
`portion 104 so the handle portion can be attached to and used with other instrumentation
`necessary for performingthe surgical procedure.
`Referring to FIGS. 2B and 2C in view of FIG. 1, a versatile feature of the
`illustrated embodiment is shown. In this preferred embodiment, a distal end portion 158 of
`outer tubular member 110, which containsfirst implant engagementstructure 114,is
`interchangeably artached via a friction fit. This allowstheuser to position anotherdistal
`end portion 160, such as that shown in Fig. 2C, mounting either a different size (e.g.
`diameter) implantor configuration of implant engagementstructure on the same implant
`insertion apparatus. Thus, the insertion apparatus can be readily adaptedto insert different
`implants.
`
`An implant designed for use in spinal fusion procedures is shown in FIGS.
`3-5 and designated generally by the reference number 200. This implant is commonly
`referred to as a “fusion cage” and, in this embodiment, is specifically configured for a
`posterior access spinal fusion procedure. Subsequentdiscussion regarding an exemplary
`use ofthe implantinsertion tool 100 will be focused on this posterior spinal fusion
`procedure inserting fusion cage 200. It is contemplated, however, that the disclosed
`implant insertion tool has broad application in a wide variety of implant insertion
`procedures beyondeither anterior or posterior spinal fusion.
`Fusion cage 200 includes a body portion 202 with a closed distal end 204
`and a proximal end 206. Thedistal end 204 is roundedorbull nosedto facilitate insertion
`of the fusion cage 200 relative to one or more bonestructures. The proximal end 206
`defines an opening 208 (FIG. 6) which communicates with an internal cavity 210 (FIG. 5)
`defined by fusion cage 200. In the illustrated embodiment, opening 208is threaded to
`receive an end cap 212. This end cap 212 is used to close off the proximal end 206 and to
`retain bone growth inducing substances, such as bone chips 214 (FIG. 6), packed therein.
`Referring to FIG. 4, end cap 212 defines a threaded bore 216 whichis
`configured to receive third implant engaging structure 142 of inner shaft 132 as will be
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`discussed in further detail below. End cap 212 also defines a substantially square
`depression 218 coaxial with thread bore 216 and configured to receive second implant
`engaging structure 128 on inner tubular member118.
`The proximal end 206 further defines first and second peripheral
`indentations 220, 222 which are centered about transverse axis "I". These peripheral
`indentations 220, 222 are configured to receive first implant engagementstructure 114, in
`this case tabs 116. These indentations mayalso be usedto line up the fusion cage 200 for
`proper insertion and placement betweenthe adjacent vertebral structure.
`A helical thread 224 is formed on the outer peripheral surface of the fusion
`cage 200. A plurality of apertures 226 are defined by and extend throughthe fusion cage
`200. In the illustrated fusion cage 200, apertures 226 are formed by broaching grooves
`228 (FIG.5) in the internal surface 230 of internal cavity 210. This technique removes
`material from the valleys berween the turnsof the thread 224, thus defining apertures 226 to
`advantageously provide immediate contact between the vertebral body and the bone chips
`located inside the cage when the cageis positioned in the body.
`Referring now to FIGS. 6, 6A and 7, two methods of closing the end cap
`212 in the opening 208 of proximal end 206 are illustrated. In FIG. 6, bone chips 214 are
`deposited into internal cavity 210 using forceps. Thereafter, end cap 212 can be manually
`threaded into opening 208 either by hand or with a socket wrench-type instrument.
`Alternatively, end cap 212 can be positioned into engagement with second and third implant
`engaging structure 128, 142 of implant insertion apparatus 100. This is done by
`positioningtheflat sides 130 of second implant engaging structure 128 into square
`depression 218 of end cap 212. The distal end of inner shaft 132 is then threaded into bore
`216 of end cap 212 by rotating wheel 134 (FIG. 1). End cap 212 is then securely engaged
`by the second and third implant engaging structure 128, 142. The implant insertion
`apparatus 100 is positioned with the engaged end cap 212 in juxtaposed axial alignment
`with opening 208 in proximal end 206 of fusion cage 200. Rotation of wheel 120 threads
`the end cap 212 into the fusion cage 200. As shown,in both methods, packing of the cage
`occurs outside the body. This facilitates insertion of bone chips since the chips are
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`individually placed with a forceps andlightly tapped, ¢.g., compacted, inside the cage.
`This is especially advantageous where access to the cage once implanted is limited and/or
`with smaller cages such as in cervical applications.
`Mounting a packed fusion cage (FIG. 7) ontotheinsertion apparatus 100
`and subsequentinsertion into an intervertebral space will now be described with reference
`to FIGS. 8 through 12. In FIGS. 8A and 8B,the packedfusion Cage is positioned in axial
`alignment with the proximal end of fusion cage 200, aligning tabs 116 with indentations
`220, 222; flat sides 130 with square depression 218; and threads 144 with threaded bore
`216.
`
`Referring now to FIGS. 9A, 9B, 10A and 10B,fusion cage 200 is moved
`initially into engagementwith inner tubular member 118 such thatflat sides 130 are
`disposed in square depression 218 of end cap 212. Further proximal motion (indicated by
`the arrowsin FIGS. 9A and 9B)ofinner shaft 118 relative to inner shaft 132 by either
`pressing cage 200 against the apparatus or moving wheel 120 proximally brings threads
`144 into engagementwith threaded bore 216 and tabs 116 of outer tubular member 110 into
`simultaneous engagement with indentations 220 and 222. (FIG. 10A) Wheel 120 can be
`slightly rotated to ensure alignmentof tabs 116 and indentations 220, 222. Then, wheel
`134 is rotated to cause the threaded innershaft to engage the fusion cage 200 by end cap
`212 thus securely mountingthe fusion cage 200 onthedistal end ofthe implant insertion
`apparatus 100 as the cage 200is pulled proximally via the engagementof the threads.
`Thereafter, the implantinsertion apparatus 100 is positioned adjacent the
`implantsite (FIG. 11) which typically includes a pretapped bore formed in an intervertebral
`space between nwo adjacent vertebra. (Alternately, the fusion cage could be self-tapping.)
`The implantinsertion apparams 100 may be guided into position using a cannula or C-
`retractor 300 to facilitate accurate insertion of fusion cage 200. The T-handle 106 is then
`rotated to rotate outer tubular member 110 to engage threads 224 ofthe fusion cage 200
`(shown in phantom)in the intervertebral space 302.
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`Oncethe fusion cage 200 is in position, wheel 134 is rotated to disengage
`threads 144 from threaded bore 216. This releases the implantinsertion apparatus 100
`from the implanted fusion cage 200.
`(FIG.12)
`Note thatsince the fusion cage 200 is grasped and inserted by the apparatus
`100 from its open end, once positioned inside the body, the end cap 212 can be removed if
`the user desires to view or access the bonechips in the internal cavity 210.
`The implantinsertion apparatus 100 can also be utilized to insert an empty
`implantsuch as fusion cage 200 into the intervertebra space and subsequently seal the
`fusion cage after packing the fusion cage with bone growth inducing substance in vivo. In
`this procedure, the empty fusion cage is engaged with thefirst, second andthird implant
`engagementstructure 114, 128, 142 and inserted in the same manneroutlined above. Once
`in place in the body, wheel 120 is rotated to remove end cap 212 from body portion 202
`and the implant insertion apparatus with attached end cap 212 (FIG. 6A)is removed from
`the site.
`
`Thereafter, the fusion cage 200 can be packed and the procedure reversed to
`thread the end cap 212 securely back into place on the body portion 202 using apparatus
`100 as described above without affectingtherelative position of the body portion 202at the
`site. This would avoid the necessity for a separate cap insertion tool since apparatus 100
`could serve the dual function of inserting the cage and attaching the end cap.
`It will be understood that a wide variety of modifications may be made tothe
`embodiments of the apparatus and methods disclosed herein. For example, the first,
`second and/or third implant engaging structures can be modified to facilitate engagement
`with a vast numberof implants, both prosthetic and natural. Also, endoscopic,
`arthroscopic and percutaneous methods ofuse are easily accommodated. Therefore,the
`above description should not be construed as limiting, but merely as
`exemplifications of preferred embodiments. Those skilled in the art will envision other
`modifications within the scope and spirit of the claims appended hereto.
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`WHATIS_CLAIMED Is:
`
`1.
`Apparatus for implant insertion comprising:
`a handle portion; and
`a body portion attached to the handle portion and defining a
`longitudinal axis, the body portion including an outer tubular memberfixed relative to the
`handle portionfor rotation therewith about the longitudinal axis, the outer tubular member
`havingfirst implant engaging structure adjacenta distal end, an inner tubular member
`disposed at least partially within the outer tubular member and mounted for longitudinal
`motionrelative to the outer tubular member,the inner tubular member being rotatable
`independentofthe outer tubular member and having second implant engaging structure
`adjacenta distal end and an innershaft, coaxially mounted atleast partially within the inner
`tubular member for independentrotation relative to the inner and outer tubular members, the
`innershaft havingthird implant engaging structure adjacenta distal end.
`
`10
`
`15
`
`20
`
`Apparatus as in claim 1 wherein the handle portionis releasably
`2.
`attached to the body portion.
`
`Apparatus as in claim 1 further comprising a wheel positioned on the
`3.
`inner tubular memberfor independentrotation thereofrelative to the outer tubular member.
`
`Apparatus as in claim 1 further comprising a wheel positioned on the
`4,
`inner shaft for independentrotation thereofrelative to the outer and inner tubular members.
`
`25
`
`Apparatus as in claim 1 wherein the first implant engaging structure
`5.
`comprisesa pair of tabs projecting from the distal end of the outer tubular member.
`
`Apparatusas in claim 1 wherein the second implant engaging
`6.
`structure comprises a polygonal structure extending from the distal endofthe inner tubular
`member.
`
`
`
`WO 97/33525
`
`PCT/US97/03869
`
`13
`
`Apparatus as in claim 1 wherein the third implant engaging structure
`7.
`comprises a threaded portion formed onthe distal end of the inner shaft.
`
`Apparatus as in claim 1 wherein the first implant engaging structure
`8.
`is removably mounted to the body portion.
`
`9.
`
`Apparatusas in claim 2 wherein the handle portionis T-shaped.
`
`10.|Apparatus for implant insertion comprising:
`10
`a handle portion; and
`a body portion defining a longitudinal axis and having a proximal
`end configured to engage the handle portion,a distal end configured to engage an implant,
`and a housingfixed relative to the proximal end and positioned intermediate the proximal
`and distal ends, the body portion including an outer tubular member fixed to the housing
`and extending distally therefrom, the outer tubular memberhavingfirst implant engaging
`structureat a distal end, an inner tabular memberdisposed at least partially within the outer
`tubular member and mounted for longitudinal motion relative to the outer tubular member,
`the inner mbular memberincludinga first wheel confinedat least partially within a first
`cavity in the housing for rotating the inner tubular memberrelative to the outer tubular
`member, the inner mibular member having second implant engaging structure adjacent a
`distal end and an inner shaft, coaxially mounted at least partially within the inner tubular
`member, the inner shaft including a second wheel confined at least partially within a second
`cavity in the housing for independentlyrotating the inner shaft relative to the inner and outer
`tubular members, the inner shaft havingthird implant engaging structure adjacenta distal
`end.
`
`15
`
`20
`
`25
`
`Apparatus as in claim 10 wherein the first implant engaging structure
`11.
`comprisesa pair of tabs projecting from the distal end of the outer tubular member.
`
`
`
`WO 97/33525
`
`,
`
`14
`
`PCT/US97/03869
`
`Apparatus as in claim 10 wherein the second implant engaging
`12.
`structure comprises a polygonal structure extending from the distal end of the inner tubular
`member.
`
`Apparatus as in claim 10 wherein the third implant engaging
`13.
`structure comprises a threaded portion formed onthe distal end of the inner shaft.
`
`10
`
`Apparamusas in claim 10 wherein thefirst implant engaging structure
`14,
`is removably mounted to the body portion.
`
`15.
`
`Apparatus as in claim 10 wherein the handle portion is
`
`T-shaped.
`
`15
`
`20
`
`25
`
`Apparatus as in claim 11 wherein the tabs are on radially opposed
`16.
`Sides of the longitudinal axis and are configured to engage an outer peripheral wall of an
`implant.
`
`‘In an apparatus forinsertion of a hollow implanthaving a closed
`17.
`distal end section accessible through a removable proximal end cap, the apparatus having a
`handle portion and a body portion with implant engaging structure adjacenta distal end
`thereof, the improvement comprising a body portion attached to the handle portion and
`defining a longitudinal axis, the body portion including an outer tubular member fixed
`relative to the handle portionforrotation therewith aboutthe longitudinal axis, the outer
`tubular member having first implant engaging structure adjacenta distal end, an inner
`tubular member disposed at least partially within the outer tubular member and mountedfor
`longitudinal motionrelative to the outer tubular member, the inner tubular member bein£
`rotatable independentof the outer tubular member and having second implant engaging
`structure adjacent a distal end and an innershaft, coaxially mounted atleast partially within
`
`
`
`WO 97/33525
`
`PCT/US97/03869
`
`15
`
`the inner tubular memberfor independentrotation relative to the inner and outer tubular
`members, the inner shaft having third implant engaging structure adjacent a distal end.
`
`18.|Apparamsas in claim 17 wherein the handle portionis releasably
`attached to the body portion.
`
`10
`
`15
`
`20
`
`25
`
`Apparatus as in claim 17 further