CA2670661C - Knotless tissue anchor - Google Patents

Abstract

A mounting member for use with a surgical implantation apparatus comprising a shaft having structure for releasably engaging corresponding structure on an implantation apparatus, the shaft having at least one longitudinal access chamber for receipt of driving structure associated with the implantation apparatus.

Description

KNOTLESS TISSUE ANCHOR
BACKGROUND
This is a division of Canadian 2,422,283, filed September 14, 2001.
1. Technical Field The present disclosure relates to knotless tissue and suture anchors and, more particularly to radially expandable anchors and methods for use of the expandable anchors.

2. Background of Related Art During surgery it is often necessary to attach prosthetic implants or soft tissue such as muscle tissue, ligaments, or tendons to hard tissue such as bone. Various types of surgical fasteners are employed for accomplishing this function, including staples, screw and washer systems, suture anchoring devices, and tissue anchors.
The first of these types is illustrated in US Pat. Nos. 4,454,875 and 4,570,623, which show metal staples with spikes on the underside of the crosspiece to secure ligaments.
Fasteners included in the second of these types are available as screw-washer combinations wherein the screw is fabricated from a surgically suitable metal, such as titanium or stainless steel alloy, and is usually of self-tapping design. Suture anchors are adapted to be inserted into predrilled holes in bone and can be made of bioabsorbable material. When securing a ligament or suture within a bore drilled in bone, the self-tapping screws may abrade the ligament or suture as they are threaded in.
Suture anchors are also used to draw tissue adjacent bone. The anchor, having a first end and a suture attached thereto is anchored in bone and a second end of the suture is threaded through tissue and a knot is tied to secure the tissue to the bone.

Expandable tissue fasteners adapted for use in minimally invasive surgical procedures (e.g., arthroscopic procedures) are employed, for example, in the repair of shoulder and knee injuries. In such procedures, the operating instrumentation is usually deployed through a long, narrow cannula inserted through a small incision in the skin. Knots in the suture are typically tied remotely and pushed down to the anchor to secure the tissue and the site.
What is needed is an expandable tissue fastener or anchor for knotlessly securing tissue to bone, and for atraumatically securing a graft to bone, especially in minimally invasive surgical procedures.

SUMMARY
In accordance with an embodiment of the present invention, there is provided a mounting member for use with a surgical implantation apparatus comprising: a shaft having structure for releasably engaging corresponding structure on an implantation apparatus, the shaft having at least one longitudinal access chamber for receipt of driving structure associated with the implantation apparatus.
Preferably the mounting member, further comprises an expandable tissue anchor wherein the shaft has mounting structure at a distal end thereof for releasably engaging the expandable tissue anchor such that the combined mounting member and tissue anchor form a disposable loading unit.
A knotless tissue anchor is also disclosed which includes an expandable member defining a bore therethrough and having a radially expandable portion. The expandable member may also have an enlarged head portion. Preferably the radially expanding portion includes at least two distally extending legs defining a pair of slots therebetween. The tissue anchor further includes an inner member slidably disposed within the bore of the expandable member and having a camming surface engageable with the distal ends of the legs to force the distal ends of the legs radially outwardly in response to the distal movement of the expandable member relative to the inner member. The inner member also includes a length of suture having a first end affixed to the distal end of the inner member and a second free end and preferably the second free end is affixed to a surgical needle for passing the suture through tissue. More preferably the second end of the suture is affixed to a double pointed surgical needle or surgical incision member configured to pass the suture through tissue.
Importantly, a distal end of the inner member is provided with a transverse bore of sufficient diameter to allow the surgical needle and suture to pass therethrough in order to secure tissue or a Iength of ligament ad}acent the distal end of the inner member.

The proximal end of the inner membermay be provided with an enlarged head for engagement and retention within a mounting member associated with an implantation apparatus.
Furthermore, the inner member maybe p.rovided with a plurality of f ns configured to slide within and be guided by the slots defined between the legs of the outer member. Ridges may also be provided on a shaft section of the inner rae.r,nber to prevent a distal movernent of the inner member relative to the expandable member afte,r the lcgs have bceu expanded.
FinaIiy, the inner member may also be prvvided with a breakaway notch such that upon full expansion of the legs of the expandable member, the notch is severed and a portion of the inner member is broken off to leave the surface of the tissue anchor ilush with bone.

There is also disclosed a method oflnotlessly secuTing a section of tissue to a bone. This is particularly advantageous in surgezies such as shoulder, ligament or muscle repair surgery.
Tne method generally includes providing the disclosed tissu.e fastener having an expandable outer member defining a bore and the irmer member movably mounted within the outer member.
Additionally, d]ength of suture affixed to the dista] end of the inner member and having a suturing needle at tiie opposite end of the suture is also provided. The method further includes the steps ofpassing the free end of the suture through the tissue to be fastened Preierably, this is accomplished with a suturing instrtunent utilized to pass the surgical needle through the tissue.
-Iberealter, the fissue fastener, having the section of tissue attached t,be7cto, is posiraoned with a bore forrned in bone wbile the section of tissue remains outside the bore.
Additionally, ttu length of suture extending from the distal end of the inner member is also positioned in the bore formed in the bone and extending pardlleI to the tissue fastener and ourward2y of the bore. The expandable member is expanded by driving the expandable member distally relative to the inner member to'thereby expand the expandable rnember into engagement with the suture against the bone.

The method may also include the step of passing the $ee end of the sutuse through a transverse bore in a distal end of thc inner member after the suture has been passed through tissue to secure the tissue adjacent the distal end of the inner member. ARer the suture has been passed ihtou.gh the trarisversa bore, tension may be applied to the suture to either draw the fissue adjacent the bore dri)led in bone.

There is also disclosed a method of securing a ligament within an elongated bore drilled in bone such as that used in knee repair surgery. Method includes providing the tissue fastener descnbed hcrein and piercing the ligament one or more times with the needle attached to the suture. Thereafter the needle=and suture are-passed through the hub to a transverse bore in the distal end of an inner member of the tissue fastener and d1e ligament is snugly secured adjacent the distal end of the izmer member. Furthermore, the suture may be wrapped several times about the ligament and distal Gnd of the inner member thereby secutelylasbing the liganient to the distal end of the inner member. The tissue fast.ener is either provided with a mounting portion for attachment to an implautation apparatus or may be manually assembled into a mounting metntier which is then releasably mounted into an implantation member.

Once thc assembled tissue fastcner and ].igament have been mounted on the implantation . . . . .. . . ..... _ _. .... .,.. . . . . ... , . . : . . ......

apparatus, the implantation apparatus may be inserted througb an enlarged bore foz7ned tbrough a pair of Irnee bones. Thc bores are of surFicient diameter tha't the attached Iigatnent is not abraded or destroyed as it is advanaed through the enlarge'd bore. Preferably, at the distal most end of the bores, a reduced diameter section is provided for receipt of the tissue fastener and associated ligament. Thereafter the implantation apparatus is actuated to expand the expandable member thus compressing the figament a.djacent the wall of the bore of the bone to secure the ligament betwean the expandable member and the bone. Thus, the ligament can be implanted with only radially extending farces acting on the ligament thereby providing avattmatic delivery and securcrnent of the Iigarnent within knee bone.

Bj?ZF DESCRIPTIOIV OF THE PRA.WINGS

Various embodiments are described below with reference to the drawings wherein:

FIG. 1 is a perspective view, with parts separated, of a prcferred embodimcnl of a radially expandable tissne fastener including an associated length of suture and needle and a mounting portion for use with an implantation device;

FIG. 2 is a cross-sectional view of the assembled tissue fastener in an unfired state;

FIG. 3 is a cross-sectional view of the assembled tissue fastener in thc radially expanded fired state;

FIG. 4 is a cross-sectional view of the tissue fastener loaded into the mounting pori~on to form a disposable loading unit;

FIG. 5 is a perspective view of the disposable loading tmit mo=ted on a tissue fasteuer implantation apparatus and tbc associated needle mounted on a jaw of a sututirtg apparatus;

.:... .: :. _ ......... ... . .. ... __- :...... .._ . . . .._.... .. .......
_. ~ ......_ ,.._.. ... .. . .. . . ,,..,, ... .

FIG. 6 is a side view of the jaws of the suturingapparatus passing the needle through a section of tissue to be fastened to bone;

FIG. 7 is a aide view of the suturing instrument having passed the needle througb a bore in the l3sslle faSteilCr, FIG. 8 is a cross-sertional view of the tissue fastener in an unfired state, positioned in a bore drilled in bone;

FIG. 9 is a cross-scctional view of the tissue fastmer in the bore formed in the bone, in the fued state, to anchor both ends of the suture therein;

FIG. 10 is a cross-sectional view taken along linel0-10 of FIG. 9;

FIG.17 is a side view of a piece of ligament or gratt.material having been penetrated by the needle and suture associated with the tissue fastener;

FIG. 12 is a partial cross-sectional view of the gtaft material sccured to an end of the tissue fasteacr;

FIG. 13 is a perspective view of the assembled tissue fastener and graft material mounted on the irnplantation apparatus and positioned in a bore drilled througlt bone;
and FIG. 14 is a partial cross-sectional, view of the expanded tissue fastener securing a first end of the graft ttiaterial within the bore in the bone, DETAILED DESC'R7PTION OF PREFERRED F1~1$ODI ENTS=

The preferred embodiments of the apparatus and methods disalosed herein are discussed in tertns of otthopedic expandable tissue fastener implantation. It is aLso cnvisioned, however, that the disclosure is applicable to a wide vaiiety ofprocedurEs including, but not limited to ligament repair, joint repair or rcplacement, non-union fractures, facial reconstruction, etc. In :..: . .

aaaition, it is believed that the preseat apparatus finds application in both open and mirimally invasive procedures including endoseopic and arthroscopic procedures wherein aceess to the surgical site is achicvcd tlmugh a caanula or small incision.

1n the description which follows, the term "proxiamal", as is uaditianal, will refer to the portion of the structure which is closest to the operator, while the term "distal" will refer to the portion which is fiuthest from the operator.

The device and methods described hcrein are specifically configured for securing tissue or suture material by applying a rradielly expandable tissuc fastener to a predrilled hole in bone and securing the tissue or suture between the fastener and the bone. The orthopedic tissue fastener is preferably provided as part of a disposable loading unit including a mounling anit.

Referring now to FIG.1, tissue fasteoer 10 includes an expandable body 12' and a setting pin More particularly, body 12 and the setting pin are preferably fabricated from a bioabsorbable materia] such as polymers of glycolide, lactide, caprolactrone, p-dioxanone, trimethylene carbonate and physical and chemical combinations thereof. Body 12 includes a shait 14 with an axial aperture 15 extending therethrough. An enlarged head '16 may be provided at a proximal end of shaft 14 to engage an implantation instrument.

Shaft 14 includes at least two, and preferably four, distally extending legs 18 which are defined by lengthwise slots 20. Body 12 is fabcicated frnm'a material with sufficient flexibility and resilienry to allow legs 18 to radially expand by splaying outward. When body 12 is placed in a hole and legs 18 are expanded, barbs 22 provided on the outer surface of legs 18 engage the wall ofbone tissue sufrounding the bole and fric#ionally secure the body therein, Expanded legs IS also kaot3essly seoure a section of srntwe or graft tnaterial positionet7 between legs 18 and . . . . . _.... .,..:.:.. . ... , ... _ ..:.,.. ...... .,.... . , _:...-_-...
....:.:..... .. ... .... . .~._:... . ..:.. _. . . . . . . . .. ,.....; . _ .
.

adjacent bone. Legs 18 are expanded in response to engage7nent with a setting pin 24 as described below.

Setting pin 24 is part of expandable tissue fastener 10 and includes an elongated shaft 26 with at least one, and preferably four, lengthwise exlending fins 28 adapted to engagc and be guided by sloTs 20 in body 12. A series of circurnferential barbs 30 on the shaft 26 irtlu'bit distsl motion of sett.ing pin 14 relative to body 12. Shaft 24 also includes a wider diameter head 32 at its proximal end to facilitate grasping of setting pin 24 by an implantation instrument. At its distal end portion, shaft 26 includes an expanded diameter bulbous portion 34 which ineludes a proximally facing camming surface 36 and distally facing beveled tip 38.
Casnming surface 36 is provided to engage and radially expand legs 18 on body 12. A first end 42 of an associated length of sutwn 40 is affixed to shaft 26 within a bore 44 in tip 38. A needle 46 is afffixed to a second end 48 of sunxTe 40. Needle 46 may be aknown sutttring needle or, preferably, a surgical incision m8rnber such as that disclosed in United States Patent No. 5,569,301 to Graager er al., the entire disclosure of which is incorporated by reference herein. A
transverse bore 50 for receipt of suture 40 is provided in bulbous portion 38. Shaft 26 also in.cludes a proxiTqa] end portion desnarcated by a circumferentiat breakaway notch 52.

A mountizig member 100 is provided io mount tissue fastener 10 on an implantation apparants and together therewith foims a disposable loading unit 150. Mounting member 100 is a tissue fastaier mounting portion which is ait independent structure for supporting both expandable body 12 of tissue fasteacr 10 and setting pin 24. The cntue disposable loading unit 1$0 mounts to the distai end of the iamplantation apparatas, as dzscn'bed below, Mounting member 100 includes a collar 102 definang a recess 104 into which head 16 of ._. .,. > _ .

body 12 is received and supported. A shaft 106 defines a 1=gthwise axis and includes laterally extehdiag bayonet nlounting pins 106 for releasably engagittg L-shaped slots in the housing tube of an implantatioa instrtunent. A mounting slot 110 for retaining setting pin 24 extends lengthwisethroueb collar 102 and includes at least one abutment wall 112 for contacting and retaining head 32 of secring pin 24. An access port 114 enables liead 32 to be mounted into mounting slot 110 prroximal to abutrnemt wall 112. Mounting member 100 also includes arcuate lengthwise extending access chsmbers 116 which allow passage therethrough of pusher prongs (discussed below) for eonta,ct,ing and pushing head 16 of body 12.

Referring to FIt'sS. 2 and 3, shaft 26 of seiting pin 24 is adapted to be slidably disposed wilhin aperture 15 of body 12. When body 12 is moved distally with respect to setting pin 24, canzrning surface 36 eventuaIly contacts the distal tips of legs 18. Further distal movement of body 12 causes legs 18 to splay radially apatt unde;r the camming action of surface 36 because the diamcter of bulbous portion 34 is greater than that of apernue 15. Distal nwve,maat of body 12 cazi be effected by an instrunment which distally advances body 12 while holding setting pin 24 stationary, or which grips and pulls head 32 of setting pin 24 while holding body=12 stationary.

At a predetemiined point, legs 18 are fully expanded and the setting pin 24 caMot move any furl.her through aperture 1 S. Increased pulling force applied to the proximal end portion of 'shaft 26 causes shaft 26 to fracture at breakaway notch 52 tbereby splitting off th.e proximal end pnrtion shaft 26 when a predetelmined force is applied. 5etting pin 24 is configured and dimensioned such that when setting pin shafft=26 undergoes the controIled fracture at full expansion of legsl 8, breakaway notch 52 will not be positioned outside aperture 15 of the body 12 but rather within apeTture 15.

Referring now to FIG. 4, disposable loading unit 150 is provided to the surgeon in sterilized form and may arrive fully assembled with tissue fastener 10 positioned in mounting member 100 or the components may be separated requiring assembly.

In order to assemble tissue fastener 10 within mounting member 100, elongated shaft 26 of setting pin 24 is inserted into keyhole shaped mounting slot 110 in mounting member 100. Elongated shaft 26 is advanced within slot 1 10 until head 32 is flexed to a position down into slot 110 and abuts abutment wall 112. Thus, head 16 of expandable body 12 is positioned within recess 104 in collar 102. In this manner the disposable loading unit is assembled and is ready for insertion into an implantation instrument. Attached suture 40 and needle 46 may be provided loose or may be provided in a separate loading unit to facilitate loading needle 46 into a surgical suturing instrument.
Referring now to FIG. 5, there is disclosed a suitable tissue fastener implantation apparatus 200, the components and operation of which are more fully described in U.S.
Patent No. 5,928,244 to Tovey et al. In general, implantation apparatus 200 includes an elongated portion 202 extending distally from a handle portion 204. Handle portion 204 generally includes a stationary handle portion 206 and a trigger 208. Operation of trigger 208 acts as operating structure to expand tissue fastener 10.

A distal end of elongated portion 202 is provided with an L-shaped slot 210 configured to receive bayonet mounting pins 108 of mounting member 100. In order to assemble on disposable loading unit 150 into implantation apparatus 200, mounting member 100 is positioned and advanced into the distal end of elongated member 202 such that bayonet mounting pins 108 enter elongated slot 210. Mounting member 100 is then rotated such that the bayonet pins 108 are rotated into the transverse portion 212 of slot 210. Thus, the disposable loading unit 150 including mounting member 100 and tissue fastener 10 are securely attached to the distal end of implantation apparatus 200. As noted above, operation of trigger ....... . .. .. ... . .. .. ,,.-. ... .. .. _ . ..... _... .. .,,. . . . ..
... .. . . ._ { :.,... . .. . .. . . ..... .. ......

will drive expandable body 12 distally relative to setting pin 24 to thereby expand legs 18 radially outward.

As noted hereinabove, tissue fastener 10 includes a length of suture 40 and a needle 46.
Needle 46 may be of any suitable tissue suturing variety. However, the preferred needle 46 is a surgical incision member 46 of the type noted in U.S. Patent No. 5,569,301.
When utilizing surgical incision member 46, the use of a particular suturing apparatus disclosed in U.S. Patent No. 5,569,301 is advantageous. Suturing apparatus 250 generally includes a handle portion 252 having a pair of pivoting handles 254 affixed thereto. An elongated member 256 extends distally from handle portion 252 and terminates in a pair of movable jaws 258 and 260. Actuation of handles 254 opens and closes jaws 258 and 260. As discussed in U.S. Patent No. 5,569,301, operation of a toggle-lever 262 functions to releasably and alternatively secure surgical incision member 46 within jaws 258 and 260.
Thus, by closing handles 254, jaws 258 and 260 close and cause surgical incision 46 to penetrate tissue positioned therebetween, upon operation of toggle lever 262, surgical incision member 46 can be released from a first jaw and secured in a second jaw to thereby pass the needle through tissue upon opening of jaws 258,260.

Referring now to FIG. 6, the use of tissue fastener 10 to secure a piece of tissue such as muscle tissue relative to bone will now be described. While this discussion has broad applicability to any situation where muscle tissue, ligaments or other soft tissue are to be secured to bone, the following discussion is in terms of securing tissue adjacent a bone drilled in bone as .. . . . .. .... . . . . ... . .... ... ....: ........ ....:. ._.... ... .
...... .. . . . i .. _. ,. ....,. . .... , . ... ... . ... .. ... .

in typical shouider surgeries. As shown in FIG. 6, the sutvririg apparatus has been operated to pass surgical incision member 46 and a portion of associated length of suturc 40 through a tissue section A. As niore fvlly discussed in U.S. Patent No.5,569,301, this is accomplished by positioning the surgical incision member in jaw 258, operating suturing apparatus 250 to close jaws 2S8 and 260 togetlier so as to pierce tissue section A with surgical incision member46 and actuating the surgical sututing iastrnment so as to release surgical incision member 46 from upper jaw 258 and securely grasping it in lowerjaw 260, thus on opening ofjaws 258 and 260 surgical incision member 46 and portion of suture 40 is pulled through tissue section A.

Referring now to FIG. 7, in order to secure tissue section A to distal end of setting pin 24, suturing apparatus 250 is again operated so as to pass surgieal incision member 46 througb bore transverse 50 in bulbous portion 34 of setting pin 24. By manipulating surgical suturing apparatus 250, tension may be applied to suture 40 so as to draw tissue section A tightly again.st the distal cnd of setting pin 24.

Referring now to FIG. 8, in order to secure and draw a tissue section adjacent a particular section of bone, a bore B is drilled in the desired seciion of shoulder bone C. Once a bore B has been drilled in bone C, implantation apparatus 200 can be manipulated so as to position the unfired tissue fastener] 0 having a length of dssue A secuied adjaccnt to it within bore B.

Referring to FIGS, 8-10, actuation ofimplantation apparatus 200 drives a pair ofpusher prongs 212 throug,h access chamber 116 in mount7ng member 100 to engage head 16 of expandable member 12 and thus drive expandable membrr 12 distally relative to setting 24.
Mounting member 100 may have access chamber 116 tapered toward the center of member 100 to allow use with txisting instrumentation and engage the relatively srnall =diameter head 16 of _. . _ _ _ ,.. , .

,_; ...

expandable member 12. As r,Dted hereinabove, when tissue fastener 10 is loaded in mounLing member 100, head 32 of setting pin 24 is restra.ined from moverntnt. Thus, as the prongs drive expandable member 12 distally, the distal ends of legs 18 axe engaged by caaanming surface 36 on setting pin 24 and drivea radially outwardly. As noted above, fins 28 are engaged and are guided by slots 20 formed in expandable member 12. As legs 18 are driven radially outward, barbs 22 engage and secure a portion of suture 40 against the bone C within bore B.
Alternatively tissue section A may be drawn into bore B prior to expanding expandabl e member 12.
A.s discussed above, when sufficient force has been applied to expandable member 12 by pusher prongs, expandable member 12 can advance no further relative to setting pin 24 and the additional force severs or breaks setting pin 24 at breakaway notch 52, As shown in FTG. 9, after actuation, setting pin 24 is disposed inwardly ofhead 16 of expandable member 12. I.o this maaner, tbe section of tissue A is secured adjacent the opening of the bore in bone C. The suture 40 will be suf~iciently tensioned so that the tissue section A
remains outside the bore. Thus tension can be provided to suture 40 so as to smg an extreme end of the tissue section adjacent tissue fastener 10 without drawing it down into the bore. Actuation of the expandable member 12 secures and locks tho suture in place within bore B thereby facilitating securernent of the tissue section without the need for any external knots. Thus, this is a convenient, secure and easy knotless suture securing procedure.

Refening now to FIG. 11, the use of tissue fastener 10 in knee ligament repair surgery whem it is drsirable to securc a distal end of a ligamcnt within an elongated bore drilled in a knee bone will now be dcxribed. As noted above, oflen this is aocomplished by thrcading a screw adjacent the ligament thereby abrading the ligament or by wedging the Iigament together with ... .. ..... . .. ... .. . . . . . . ... . . .. ... ......... . . . . . ..., ...

some sort of wedge into the bore in which event the ligament must travel a lomgitudinal distance while being abraded by bone on one side and the wedge on the other. The disclosed method has the distinct advantage of being able to position a ligament section within a bore in a lrnee bone without any trauma to the ligament.

As shown in FIG. 11, initially surgical suturing apparatus 250 is actuated and so as to pass svrgical incision member 46 and thus suture 40 through ligament section D. Preferably, surgical incision member 46 is passed back and forth through ligameat section D sevcra] times so as to gain a secure hold of ligament D with suture 40.

Referring now to FIG. 12, ligament scction D is advanced along suture 40 towards beveled tip 38 until the pierced section of ligament D is adjacent beveled tip 38. Thereaflcr, in order to firmly secure ligament section D to sett'ing pin 24 the suturing apparatus is actuated to pass surgical incision 46 through transverse bore 50 in seiting pin 24. The suture may thcn bc wrapped around bulbous portion 34 and ligament D numerous times to thereby lash Iigament D
to the distal end of setting pin 24.

Subsequently, disposable loading unit 150 containing the attached ligament D
is mounted to the implant apparatus as descn'bed above.

Referring uow to FIG. 13, once disposable loading unit 100 and apparatus 200 have been assembled, implantation apparatus 200 is positioned such that elongated portion 202 and tissue fastener 10 are advanced through bores E and F drilled through knee joints G
and H. Specifically shown in FIG. 13, bores E and F through the ltnee bone seetions are of sufficient diameter such that elangated portion 204 may be passed therethrough, i3oweve,r, because of the reduced diameter of tissue fastenerl 0 and ligament D, the ligament is not traumatfzed as it is advanced ... . .. . .. . . .. .. . .. . .. .. ... . .. .. .... .: . . . . , . .. . . .
.. . . , . . . .. . ..:. . . .. ... .. .. . . . . .... , . ... , .

through bones E and F. A amaller diameter bore I is drtlled at the end of bore F to accommodate them. The point at which the implant is to be r.xpanded is in the reduced diameter bore I.
Referring to FIGS. 13 and 14, actnatioa of implantation apparatus 200 will operate to push expandable m=ber 12 disWly relative to setting pin 24 thereby forcing legs 18 radially outwardly to engage and secure ligaenent section. D adjacent to bone G. Thus, ligaznent D is finnly secuTed within bore F in suturclcss fashion wi thout aauma to ligarnent D and no additional lrnots need be tied:

It will be understood that various rnodifications may be made to the embodiments disclosed berein. For example, barbs 22 are an expandable mamber. 12 may be reconfigured as abraded surfaces or other means to fsictionatly engage suture I2'when casnmed against suture 12 in a bore in bonc. A13ditionally, barbs 22 may assume a rounded conftgurstion to be less traumatic to any assoeiated Ligament or tissue section engaged by. legs 13 as they expand. The above description should not be coastrned as limiting, but merely as exernplifications of prefe=rred embodiments and methods. Those sicilled in the art will envision other tnodifications arid uses within the scope and spirit of the claims appended heret.o.

Claims (2)

1. A mounting member for use with a surgical implantation apparatus comprising:
a shaft having structure for releasably engaging corresponding structure on an implantation apparatus, the shaft having at least one longitudinal access chamber for receipt of driving structure associated with the implantation apparatus.

2. The mounting member as recited in claim 1, further comprising an expandable tissue anchor wherein the shaft has mounting structure at a distal end thereof for releasably engaging the expandable tissue anchor such that the combined mounting member and tissue anchor form a disposable loading unit.