PCT
`
`WORLD INTELLECl'UAL_ PROPERTY ORGANIZATION
`lntematronal Bureau
`
`
`
`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCI')
`
`(51) International Patent Classification 5 :
`A61B 17/56
`
`(11) International Publication Number:
`
`WO 97133525
`
`(43) International Publication Date:
`
`18 September 1997 08.09.97)
`
`(21) International Application Number:
`
`PCT/US97/03869
`
`(22) International Filing Date:
`
`13 March 1997 (r3.o3.97)
`
`(81) Designated States: AU, CA, IP, European patent (AT, BE.
`CH, DE. DK, ES, Fl. FR. GB. GR, IE, IT, LU. MC, NL,
`PT, SE).
`
`(30) Priority Data:
`08l6l6,l20
`
`14 March 1996 (l4.03.96)
`
`Published
`With international Search report.
`
`US
`
`INC. {USIUS];
`(71)AppIicant: SURGICAL DYNAMICS,
`Glover Avenue, Nonvallt. CT 06856 (US).
`
`lll
`
`(72) Inventors: WINSLOW, Charles, J.; 27 Hilton Court, Walnut
`Creek, CA 94520 (US). MI'I‘CHEl.L, Steven, T.; 776 Dulte
`Circle, Pleasant Hill, CA 94523 (US).
`
`(74) Agent: GERSHON, Neil, D.; United States Surgical Corpora-
`tion. 150 Glover Avenue. Norwallt. CI‘ 06856 (US).
`
`(54) Title: 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
`(1 I2). The body portion includes an outer tubular member (110). an inner tubular member
`(H8) and an inner shaft (132). The outer tubular member (1 1) is fixed to the handle portion
`(112) for rotation therewith and with implant engaging structure (I I6) 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 (I18). ‘me 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.
`
`688
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`

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`FOR THE PURPOSES OF INFORMATION ONLY
`
`Codes used to identify States party to the PC!‘ on the from pages of pamphlets publishing international
`applications under the PCT.
`
`Armenia
`Ansnia
`Australia
`Barbados
`Belgium
`Butflnl F30
`Bulgaria
`Benin
`Brazil
`Belarus
`Canada
`Central African Republic
`Congo
`Swiauimrd
`can cflvoire
`
`§3=Ei'-13353899
`
`United Kingdan
`Georgia
`Guinea
`Greece
`Hungary
`‘Ireland
`Italy
`Japan
`Kenya
`Kyrgyuan
`Democratic People's Republic
`of Korea
`Republic of Korea
`Kuaklman
`Liuhtenalein
`Sri lanka
`Liberia
`
`Republic of Moldova
`Madagascar
`Mali
`Mongolia
`
`MW
`Mx
`NE
`N1.
`NO
`NZ
`PL
`P!‘
`R0
`RU
`SD
`SE
`S0
`8]
`SK
`SN
`SZ
`TD
`Tc
`1':
`1"!‘
`UA
`UG
`US
`Ul
`VN
`
`Malawi
`Mexico
`Nigu
`Netherlands
`Norway
`New Zuland
`Poland
`Portugal
`Romania
`Russian Federation
`Sudan
`Sweden
`Singapore
`Slovenia
`Slovakia
`Suregal
`Swaziland
`Onrl
`T030
`Tajikistan
`Trinidad and Tobago
`Uknlne
`Uganda
`United State: of America
`Uzbekistan
`Viet Nam
`
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`This application is a continuation-in-part of U.S. application Serial No.
` , filed on , which is a continuation-in-part of U.S.
`application Serial No. 9_8L1Q§,,8_'_7_2. filed on . The contents of these
`
`applications are incorporated herein by reference.
`
`I.
`
`I.t.t.ltnical_£i.tls|
`This disclosure relates generally to apparatus and methods for implant
`insertion. More particularly, to apparatus and methods for insertion of implants to facilitate
`
`fusion of adjacent bony structure.
`
`2. rt
`A large number of orthopedic procedures involve the insertion of either
`natural or prosthetic implants into bone or associated tissues. These procedures include.
`for example. ligament repair. joint repair or replacement, non-union fractures, facial
`
`reconstruction. spinal stabilization and spinal fusion. In a typical procedure, an insert,
`
`dowel or screw is inserted into a prepared bore formed in the bone or tissues to facilitate
`repair and healing. See, for example. U.S. ‘Patent Nos.: 5,470,334 to Ross et al.;
`5.454.811 to Huebner, 5,480,403 to Lee et al.; 5.40.805 to Warren; 5,358,511 to Gatruma
`
`et al.: and 4.877.020 to Web.
`
`Some implants are particularly configured with cavities and bores to
`
`facilitate bony ingrowth and enhance anchoring of the implant at the insertion site. See. for
`
`example, U.S. Patent Nos.: 4,328,593 to Sutter et al.; 4,936,851 to Fox ct al.; and
`
`4,878,915 to Bramigan. Implants in the form of fusion cages having internal cavities to
`
`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 et al.;
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`5,015,247 to Michaelson; and 5,489,307 to Kuslich et al. These types of implants are
`particularly wellisuited for intervertebral spinal fusion pmcedtues necessitated by injury,
`disease or some degenerative disorder of 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 of the specialized
`implants as discussed above and also discussed in commonly assigned U.S. Patent No.
`5,026,373. incorporated herein by reference.
`
`Both anterior (transabdominal) and posterior surgical approaches are used
`for interbody fusions of 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 prefonned cavity inside the interbody. interdiscal space.
`Since it is desirable in these procedures to promote a "bone to bone" bridge. connective
`tissue and at least a portion of the discal tissue is removed. Preferably, relatively deep cuts
`are made in the adjacent bones in order to penetrate into the softer, more vascularized
`cancellous region to facilitate bone growth across the implant.
`‘
`When installing these specialized implants, an insertion tool is used to
`position the implant in the desired intenrertebral location. See. for example, U.S. Patent
`Nos.: 3,848,601 to Ma et 211.; 4,501,269 to Bagby; 4,877,020 to Vich; and 4,878,915 to
`Brantigan. Once in 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
`jn gm. Subsequently, an end cap or other sealing structure is positioned to close the
`implant. See. for example. commonly assigned U.S. Patent No. 4,961,740 to Ray et al.
`incorporated herein by reference.
`
`Typical insertion tools use either a single implant engagement structure or, at
`most. two implant engagement structures to 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
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`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 of the implant, either jg yitm or in yiyg.
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`Further. these tools do not provide structure which separately engages both the implant and
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`the implant clostue, 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 because it is often time consuming and relatively difficult, especially for
`
`example in cervical applications. to pack the cage in vivo. It would also be advantageous if
`
`such insertion tool could be additionally used to insert/position an empty implant for
`
`subsequent in Q9 packing and closure.
`
`SHMMARX
`
`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.
`
`'l'he body portion includes an outer tubular member fixed
`
`relative to the handle portion for rotation therewith about the longitudinal axis. The outer
`tubular member has first implant engaging structure adjacent a distal end. An inner tubular
`
`member is disposed at least partially within the outer tubular member and is mounted for
`
`longitudinal motion relative to the outer mbular member. Second implant engaging
`
`structure is positioned adjacent a distal end of the inner nrbular member. The body portion
`
`further includes an inner shaft, coaxially mounted at least partially within the inner tubular
`
`member for independent rotation relative to the irmer and outer tubular members. the inner
`
`shaft having third implant engaging structure adjacent a distal end.
`
`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 another of the engaging structure attached to the hollow portion. The implant is
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`preferably preloaded with bone chips and/or bone growth inducing substances prior to
`attachment. Thereafter, the preloaded implant is inserted into the desired surgical location.
`
` GS
`Various embodiments of the subject implant insertion apparatus are
`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 embodiment of the subject disclosure;
`FIG. 2 is a side view in cross-section of the 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 apparatus of FIG. 1;
`FIG. 2B is an enlarged perspective view of the distal ends of the outer and
`inner tubular members of the 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 implant insertion apparatus of 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 of the implant of FIG. 3 with parts
`separated and loading of bone chips in process;
`FIG. 6A is a side View in partial cross-section showing an end cap mounted
`to the innertubularmemberand the innershaft;
`
`FIG. 7 is a perspective view of a preloaded implant with removable end cap
`
`in place:
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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 implant of FIG. 7;
`FIG. 8B is an enlarged side view of the housing and rotadon wheels of the
`body portion illustrating the relative position of the inner tubular member as 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 and third implant
`
`engagement structure attached to the removable cap of the implant of FIG. 7;
`FIG. 9B is an enlarged side view of the housing and rotation wheels of the
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`body portion illustrating the relative position of the inner tubular member and the inner shaft
`
`as shown in 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 the first, second and third
`
`implant engagement so-ucture attached to the implant of HG. 7;
`FIG. 10B is an enlarged side view of the housing and rotation wheels of the
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`body portion illustrating the relative position of the inner shaft. the inner tubular member
`and the outer tubular member as shown in FIG. IOA;
`
`FIG. 11 is a side view illustrating the insertion of the implant of FIG. 7
`
`using the insertion apparatus of FIG. 1; and
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`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.
`
` TS
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`The preferred embodiments of the apparatus and methods disclosed herein
`are discussed in terms of orthopedic spinal fusion procedures and apparatus. It is also
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`envisioned, however, that the disclosure is applicable to a wide variety of procedures
`
`including. but not limited to ligament repair, joint repair or replacement, non-union
`fractures, facial reconstruction and spinal 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 access to 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 of the strucnme 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 which like reference numerals
`identify similar or identical elements. a preferred embodiment of the implant insertion
`apparatus is illustrated in FIGS. 1 and 2 and is designated generally by reference numeral
`100. Implant insertion apparatus 100 includes a removable handle portion 102 and a body
`portion 104. Handle pordon 102 has a T-handle 106 positioned at a proximal end and
`releasable engagement structure 108 at a distal end thereof.
`
`Body portion 104 defines a longitudinal axis "L" and includes an outer
`tubular member 110 fixed to a housing 112 for longitudinal rotation therewith. First
`implant engaging structure 114 is positioned adjacent a distal end of outer tubular member
`110. Outer tubular member 110 preferably includes a removable distal end portion 158
`described below. In the embodiment shown. the implant engaging structure is a pair of
`distally extending tabs 116 projecting from the distal end of outer tubular member 110.
`Body portion 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 motion relative to outer tubular member 110 and is independently
`rotatable relative to outer tubular member 110 by wheel 120. In the illustrated embodiment,
`set screw 122 anchors wheel 120 to the inner tubular member 118. A first cavity 124 is
`defined in housing 112 and is dimensioned to 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 lcnurling 126 to enhance its
`frictional characteristics.
`
`Inner tubular member 118 is normally biased to a distalrnost longitudinal
`position relative to outer tubular member 110 as shown in FIG. 2. Coil spring 127,
`mounted in housing 112, abuts a proximal end of inner nrbular 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 srnrcnrre 128 is a hollow polygonal structure having a plurality of flat
`
`sides 130 extending from the distal end of inner tubular member 118.
`
`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 member 118 and outer tubular member 110 by wheel 134.
`
`As shown. set screw 136 connects wheel 134 to a distal end of inner shaft 132. In a
`
`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 inner shaft 132, to limited longitudinal motion
`
`relative to outer and inner tubular members 110 and 118. respectively between walls 1l2c,
`
`112d. Wheels 120 and 134 preferably extend radially beyond at least one outer peripheral
`
`surface of house 112 to facilitate actuation by the fingers of a 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 engagement structure 108 of
`
`the illustrated embodiment of implant insertion apparatus 100 includes a distal sleeve 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 system 152 from
`
`'l'his enables the removal of handle portion 102 front the body
`annular channel 154.
`portion 104 so the handle portion can be attached to and used with other instrumentation
`
`necessary for performing the surgical procedure.
`
`Referring to FIGS. 23 and 2C irt 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 contains first implant engagement structure 114. is
`interchangeably attached via a friction fit. This allows the user to position another distal
`end portion 160, such as that shown in Fig. 2C, mounting either a different size (e.g.
`diameter) implant or configtn-ation of implant engagement structure on the same implant
`insertion apparatus. Thus, the insertion apparatus can be readily adapted to insert different
`implants.
`
`An implant designed for use in spinal fusion procedures is shown in FIGS.
`
`3-5 and designated gene:rally 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. Subsequent discussion regarding an exemplary
`use of the implant insertion 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 beyond either anterior or posterior spinal fusion.
`
`Fusion cage 200 includes a body portion 202 with a closed distal end 204
`
`and a proximal end 206. The distal end 204 is rounded or bull nosed to facilitate insertion
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`of the fusion cage 200 relative to one or more bone structures. The proximal end 206
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`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 208 is 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 which is
`
`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 member 118.
`
`The proximal end 206 further defines first and second peripheral
`
`indentations 220. 222 which are centered about transverse axis "T". These peripheral
`
`indentations 220, 222 are configured to receive first implant engagement structure 114, in
`
`this case tabs 116. These indentations may also be used to line up the fusion cage 200 for
`
`proper insertion and placement between the 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 through the fusion cage
`
`200. In the illustrated fusion cage 200, apertures 26 are formed by breaching grooves
`228 (FIG. 5) in the internal surface 230 of internal cavity 210. This technique removes
`
`material from the valleys between the turns of the thread 224, thus defining apertures 26 to
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`advantageously provide immediate contact between the vertebral body and the bone chips
`
`located inside the cage when the cage is positioned in the body.
`
`Refening now to FIGS. 6, 6A and 7, two methods of closing the end cap
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`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
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`threaded into opening 208 either by hand or with a socket wrench-type instrument.
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`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
`
`positioning the flat 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
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`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 stnrcntre 128. 142. The implant insertion
`apparatus 100 is positioned with theengaged 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. pacicing 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 and lightly tapped, e.g., compacted. inside the cage.
`This is especially advantageous where access to the cage once implanted is limited and/or
`with sma.ller cages such as in cervical applications.
`Mounting a packed fusion cage (FIG. 7) onto the insertion apparatus 100
`and subsequent insertion into an intervertebral space will now be described with reference
`to FIGS. 8 through 12. In FIGS. 8A and 8B. the packed fusion 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 engagement with inner tubular member 118 such that flat sides 130 are
`disposed in square depression 218 of end cap 212. Further proximal motion (indicated by
`the arrows in FIGS. 9A and 9B) of inner shaft 118 relative to inner shaft 132 by either
`pressing cage 200 against the apparatus or moving wheel 120 proximally brings threads
`144 into engagement with threaied bore 216 and tabs 116 of outer tubular member 110 into
`simultaneous engagement with indentations 220 and 22.2. (FIG. 10A) Wheel 120 can be
`slightly rotated to ensure alignment of tabs 116 and indentations 220. 222. Then, wheel
`134 is rotated to cause the threaded inner shaft to engage the fusion cage 200 by end cap
`212 thus securely mounting the fusion cage 200 on the distal end of the implant insertion
`apparatus 100 as the cage 200 is pulled proximally via the engagement of the threads.
`Thereafter. the implant insertion apparatus 100 is positioned adjacent the
`implant site (FIG. 11) which typically includes a pretapped bore fon-ned in an intervertebral
`space between two adjacent vertebra. (Altemately, the fusion cage could be self-tapping.)
`The implant insertion apparatus 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 of the fusion cage 200
`(shown in phantom) in the intervertebral space 302.
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`Once the fusion cage 200 is in position, wheel 134 is rotated to disengage
`threads 144 from threaded bore 215. This releases the implant insertion apparatus 100
`
`from the implanted fusion cage 200. (FIG. 12)
`Note that since the fusion cage 200 is gasped 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 bone chips in the internal cavity 210.
`
`The implant insertion apparatus 100 can also be utilized to insert an etrtpty
`
`implant such 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 gig. In
`this procedure, the empty fusion cage is engaged with the first. second and third implant
`engagement structure 114. 128, 142 and inserted in the same manner outlined 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.
`
`'I'he'reafter, 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 affecting the relative position of the body portion 202 at 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 to the
`
`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 number of implants. both prosthetic and natural. Also. endoscopic,
`
`arthroscopic and percutaneous methods of use 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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`10
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`15
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`20
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`25
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`700
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`700
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`: 1
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`.
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`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 member fixed relative to the
`handle portion for rotation therewith about the longtudinal axis. the outer tubular member
`having first implant engaging structure adjacent a distal end, an inner tubular member
`disposed at least partially within the outer tubular member and mounted for longitudinal
`motion relative to the outer tubular member. the inner tubular member being rotatable
`independent of the outer tubular member and having second implant engaging structure
`adjacent a distal end and an inner shaft. coaxially mounted at least partially within the inner
`tubular member for independent rotation relative to the inner and outer tubular members, the
`inner shaft having third implant engaging structure adjacent a distal end.
`
`Apparatus as in claim 1 wherein the handle portion is releasably
`2..
`attached to the body portion.
`
`Apparatus as in claim I further comprising a wheel positioned on the
`3 .
`inner tubular member for independent rotation thereof relative to the outer tubular member.
`
`Apparatus as in claim 1 further comprising a wheel positioned on the
`4.
`inner shaft for independent rotation thereof relative to the outer and inner tubular members.
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`10
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`15
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`20
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`25
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`Apparatus as in claim I wherein the first implant engaging structure
`5.
`comprises a pair of tabs projecting from the distal end of the outer tubular member.
`
`Apparatus as in claim 1 wherein the second implant engaging
`6.
`structure comprises a polygonal structure extending from the distal end of the inner tubular
`member.
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`701
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`701
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`7.
`
`Apparatus as in claim I wherein the third implant engaging structure
`
`comprises a threaded portion formed on the distal end of the inner shaft.
`
`8.
`
`Apparatus as in claim 1 wherein the first implant engaging structure
`
`is rernovably mounted to the body portion.
`
`9.
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`Apparatus as in claim 2 wherein the handle portion is '1‘-shaped.
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`10
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`15
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`20
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`25
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`10.
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`Apparatus for implant insertion comprising:
`
`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 housing fixed 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 member having first implant engaging
`
`structure at a distal end. an inner tubular member disposed at least partially witltin the outer
`
`tubular member and mounted for longitudinal motion relative to the outer tubular member.
`
`the inner tubular member including a first wheel confined at least partially within a first
`
`cavity in the housing for rotating the inner tubular member relative to the outer tubular
`
`member, the inner tubular 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 independently rotating the inner shaft relative to the inner and outer
`
`urbular members. the inner shaft having third implant engaging suucture adjacent a distal
`
`end.
`
`'
`
`l 1.
`
`Apparatus as in claim 10 wherein the first implant engaging structure
`
`comprises a pair of tabs projecting from the distal end of the outer tubular member.
`
`702
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`702
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`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 on the distal end of the inner shaft.
`
`Apparatus as in claim 10 wherein the first implant engaging structure
`14.
`is removably mounted to the body portion.
`
`10
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`15.
`
`Apparatus as in claim 10 wherein the handle portion is
`
`T-shaped.
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`15
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`20
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`25
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`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 for insertion of a hollow implant having 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 adjacent a 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 portion for rotation therewith about the longitudinal axis, the outer
`tubular member having first implant engaging structure adjacent a distal end. an inner
`tubular member disposed at least partially within the outer tubular member and mounted for
`longitudinal motion relative to the outer tubular member. the inner tubular member being
`rotatable independent of the outer tubular member and having second implant engaging
`stmcture adjacent a distal end and an inner shaft. coaxially mounted at least partially within
`
`703
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`the inner tubula