Suture anchor for soft tissue fixation

A method and apparatus for anchoring suture to bone includes an anchor formed by twisting a wire to provide a loop with two legs extending distally from the twist. Each leg bends outwardly through 180.degree. to define respective knee segments between inner and outer leg segments, the outer leg segments terminating in sharp points for penetrating a bone tunnel wall. The outer leg segments are initially parallel and define an anchor width smaller than the bone tunnel diameter, thereby permitting the anchor to be inserted into and removed from the tunnel. The anchor is deployed with an insertion tool arranged to deformably pivot the outer leg segments about the knee segments, thereby causing the pointed ends to penetrate the tunnel wall in response to applied withdrawal forces. The anchor wire may be assembled on an anchor sleeve through which the loop projects proximally while the outer leg segments reside in wire relief recesses defined in the sleeve periphery. The insertion tool selectively forces the sleeve against the inside of the knee segments while engaging the loop to thereby deformably pivot the outer leg segments. The insertion tool may include resiliently spaced jaws for engaging the wire loop, the jaws being disposed at the distal end of a rod selectively retractable into a tube to force the jaws closed. Further retraction of the rod applies the axial force for bending the wire legs.

BACKGROUND OF THE INVENTION 
Technical Field 
This invention pertains to methods and apparatus utilized in surgical 
procedures involving fixation of soft tissue to bone tissue and, more 
particularly, to a novel method and apparatus for anchoring sutures to 
bone tissue to permit the aforesaid fixation. 
DISCUSSION OF THE PRIOR ART 
As part of various endoscopic or arthroscopic surgical procedures, it is 
necessary to permanently attach a suture to bone tissue. For example, in 
certain procedures requiring suturing of soft tissue (e.g., muscle, 
cartilage, tendons, ligaments, etc.) to bone tissue, the suture must be 
anchored to the bone tissue before suturing can proceed. The prior art 
includes numerous suture anchors adapted to be secured in pre-drilled 
holes or tunnels in the bone tissue, and most of these anchors have one or 
more disadvantageous characteristics. Some prior art suture anchors are 
required to be hammered into the bone tunnel. These anchors are 
exemplified by U.S. Pat. No. 5,102,421 (Anspach, Jr.); U.S. Pat. No. 
5,141,520 (Goble et al); and U.S. Pat. No. 5,100,417 (Cerier et al). 
Hammering (or impacting as it is often described) has the disadvantage of 
potential trauma and damage to surrounding bone tissue, and has limited 
applicability where the location of the bone tunnel is not axially aligned 
with an arthroscopic portal to permit transmission of the impacting force 
through an impactor to the anchor. 
Some suture anchors are threadedly mounted in the bone tunnel, as 
exemplified by U.S. Pat. No. 5,156,616 (Meadows et al) and U.S. Pat. No. 
4,632,100 (Somers et al). The screw insertion procedure tends to be 
time-consuming in that a pilot hole must first be drilled into the bone 
and then the hole may have to be tapped to receive the screw. 
Many suture anchors involve an insertion procedure wherein the inserter 
device must partially enter the bone tunnel, thereby requiring a larger 
diameter tunnel than would be necessary for the anchor alone. Examples of 
such suture anchors are found in U.S. Pat. No. 5,037,422 (Hayhurst et al); 
U.S. Pat. No. 4,741,330 (Hayhurst); U.S. Pat. No. 4,968,315 (Gatturna) and 
U.S. Pat. No. 4,899,743 (Nicholson et al). 
Most of the foregoing exemplar prior art suture anchors suffer from the 
disadvantage of being automatically deployed upon initial insertion into 
the bone tunnel. Specifically, such anchors typically have permanently 
projecting barbs, or the like, that are forced into the tunnel during 
initial insertion and preclude proximally directed movement in the tunnel 
after at least one barb engages the surrounding bone tissue. It sometimes 
happens that a particular tunnel turns out to be unsuitable, either 
because of location or configuration, but the surgeon does not recognize 
this until after the anchor has been inserted. With most prior art anchors 
there is no possibility of removing the inserted anchor; thus, a new 
tunnel must be drilled and a second anchor inserted. Accordingly, two (or 
possibly more) anchors may be left at the surgical site, only one of which 
is functional. This problem is addressed in U.S. Pat. No. 5,176,682 (Chow) 
wherein a suture anchor is disclosed as having normally retracted fins 
capable of being selectively projected radially to engage the bone tunnel 
walls in a barb-like manner. Selective projection of the fins is effected 
by hammering a pin axially through the anchor to force the fins radially 
outward. Prior to hammering the pin, the inserted anchor is readily 
removable from the bone tunnel, thereby permitting the surgeon to test the 
adequacy of the drilled tunnel and its location. If the tunnel is 
unsatisfactory, the anchor can be removed, rather than being left in 
place. Although this technique solves the problem of having an unused 
anchor left in an unsatisfactory tunnel, it has some other disadvantages. 
Specifically, permanent installation of the anchor requires tools (i.e., a 
hammer and impactor) that are separate and apart from the inserter. 
Additionally, during impacting, the pin may be inadvertently driven 
entirely through the anchor and thereby damage bone tissue at the closed 
end of the tunnel. 
OBJECTS AND SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide improved 
methods and apparatus for anchoring suture to bone. 
It is another object of the invention to provide a suture anchor capable of 
being temporarily inserted into a bone tunnel to determine the 
desirability of the site, and then easily actuated for permanent 
deployment. 
A further object of the invention is to provide a suture anchor that can be 
inserted and positively engaged in a bone tunnel without requiring 
hammering of the anchor or threading the tunnel. 
It is yet another object of the present invention to provide a method and 
apparatus for securing a suture anchor in a bone tunnel without requiring 
the tunnel diameter to be larger than necessary to accommodate the anchor. 
In accordance with the present invention, a suture anchor wire is 
configured from a deformable wire bent to provide a loop at the 
approximate center of the wire length. The loop constitutes the proximal 
end of the anchor. The wire is twisted to close off the loop at a twist 
juncture from which two legs extend generally distally and then bend away 
from one another through approximately 180.degree. each to extend in a 
proximal direction along opposite transverse sides of the anchor. Ends of 
the wire are cut on a bias to define sharp points at the outer transverse 
sides of the leg ends. The 180.degree. bend in each leg forms a U-shaped 
knee dividing the leg into substantially parallel inner and outer leg 
segments. 
An anchor insertion tool includes an elongated hollow outer tube and an 
inner tube telescopically movable therein. Jaws at the distal end of the 
inner tube include one or more projections configured to permit the anchor 
wire loop to be selectively engaged between the jaws. With the anchor 
engaged, a generally annular actuator edge of the outer tube of the 
inserter tool, or of a sleeve disposed about the inner tube and extending 
forwardly of the outer tube, is axially spaced from the anchor wire legs. 
The actuator edge has an outside diameter made smaller than the transverse 
spacing between the outward sides of the outer leg segments, but larger 
than the transverse spacing between the inward sides of the outer leg 
segments. Suture or similar material can be looped about the twist between 
the two inner leg segments of the anchor wire and pulled back proximally 
before the engaged anchor is inserted into a pre-drilled tunnel in bone 
tissue. The transverse spacing between the proximally-directed anchor leg 
segments permits the anchor to be moved freely into and out of the tunnel. 
When the anchor wire is positioned as desired, the actuator inner tube is 
retracted into the outer tube, thereby causing the actuator edge to move 
distally relative to the anchor wire and into the space between the leg 
segments of each wire leg. As the actuator edge moves between the leg 
segments it forces the outer segments outwardly, thereby deforming the 
wire knee so that the pointed ends of the outer segments engage the wall 
in the bone tunnel. The entire tool can then be pulled in the proximal 
direction, with the anchor loop still engaged by the actuator, to cause 
the pointed ends of the now outwardly bent outer leg segments of the 
anchor to firmly engage the wall of the tunnel. Disengagement of the 
inserter tool from the anchor wire is effected by opening the jaws of the 
inner tube to disengage the wire loop. The tool can then be removed from 
the surgical site and the suture remains in the bone tunnel, firmly 
engaged about the anchor wire twist. 
In one embodiment, the anchor also includes a sleeve on which the anchor 
wire, as described above, is mounted. The anchor sleeve has an open distal 
end and a proximal end wall having a central opening. The wire is mounted 
with its loop protruding rearwardly through the hole in the proximal end 
wall, and with its U-shaped knee bent over the edge of the open distal 
sleeve end. Recessed channels extend longitudinally along the outside of 
the sleeve from its distal end to receive the outer leg segments of the 
anchor wire. When thusly received, the entire diametric thickness of the 
outer leg segment is recessed in the channel. As in the first described 
embodiment, the rearward projecting wire loop is engageable between the 
jaws of the insertion tool. During deployment, instead of spreading the 
outer leg segments directly by means of the distal end of the insertion 
tool outer tube, the distal end of the tube is forced against the proximal 
end wall of the anchor sleeve. The sleeve, in turn, is thusly movable 
distally relative to the engaged anchor wire to force the outer leg 
segments of the wire radially outward. In this embodiment the anchor 
sleeve remains in the bone tunnel along with the anchor wire after 
deployment. 
These and other objects, features and many of the attendant advantages of 
the present invention will be appreciated more readily as they become 
better understood from a reading of the following description considered 
in connection with the accompanying drawings wherein like parts in each of 
the several figures are identified by the same reference numerals.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring specifically to FIG. 1, an anchor wire 10 is bent and twisted to 
provide an engagement loop 11 positioned approximately at the center of 
the length of the wire. Engagement loop 11 constitutes the proximal end of 
the anchor device and, in the preferred embodiment, has a generally 
elliptical configuration with its major axis extending longitudinally. The 
forward end of loop 11 terminates in a twist 13 formed in wire 10, the 
preferred twist being 180.degree. about the longitudinal axis of the 
anchor to close off the loop from the distal end of the anchor. 
Specifically, each leg of the wire bends through approximately 90.degree. 
to form twist 13. Extending forwardly from twist 13 are two legs, each 
having a 180.degree. outward bend or knee 17, 23 to separate inner and 
outer leg segments. Specifically, one leg includes an inner segment 15 
extending forwardly from twist 13 to knee 17, and an outer segment 19 
extending rearwardly from knee 17 and substantially parallel to inner 
segment 15. Outer segment 19 constitutes the radially outwardmost part of 
one side of the anchor wire and terminates in a pointed end 20 formed by 
cutting the wire end on a bias in a proximal and outward direction. The 
other leg is a substantially mirror image (about the anchor longitudinal 
axis) of the first leg and has corresponding inner segment 21, knee 23, 
outer segment 25 and pointed end 27. The forward ends of knees 17 and 23 
are longitudinally coextensive and define the distal end of the anchor 
wire. 
Anchor wire 10 is preferably a metal wire, typically stainless steel, that 
is bendable but not significantly resilient. Accordingly, if, in the 
manner described below, outer leg segments 19 and 25 are bent outwardly 
about respective knees 17 and 23 to form some angle other than 180.degree. 
with the inner segments 15 and 21, the resulting deformation of the anchor 
wire remains set after the bending force is removed. 
In an exemplar embodiment of anchor wire 10, the wire has a round 
transverse cross-section with a diameter of 0.015". The overall length 
(i.e., from the proximal end of loop 11 to the distal ends of knees 17, 
23) of the formed anchor wire is 0.220", with the outer leg segments each 
occupying 0.100" of that length. The maximum transverse width of the 
anchor wire between the outermost parts of outer leg segments 19 and 25 is 
0.110". The transverse space between inner leg segments 15 and 21 is 
0.030". Likewise, the transverse space between the long sides of loop 11 
is 0.030". The angle of the bias cut in outer leg segments 19 and 25 to 
form respective points 20 and 27 is 30.degree.. Again, it is to be noted 
that these dimensions are for purposes of example only and are not 
limiting on the scope of the present invention. 
An anchor insertion tool 30 is illustrated in FIGS. 2 and 3 includes 
concentric inner and outer tubes 31 and 33, respectively. Outer tube 33 is 
fixedly secured to and extends forwardly from an actuator housing 35. A 
thumb-engaging handle arm 37 is fixedly secured to the proximal end of 
housing 35, extending rearwardly and transversely therefrom and 
terminating in a thumb-receiving loop 39. A finger-engaging handle arm 40 
is pivotably secured within housing 35 and extends transversely forwardly 
therefrom to form an acute angle with arm 37. A finger-receiving loop 41 
terminates the free end of arm 40. In a conventional manner, arm 40 is 
linked within housing 35 to the proximal end of inner tube 31 such that 
forward movement of arm 40 relative to arm 37 (i.e., increased angular 
separation) results in coaxially forward displacement of inner tube 31 
within outer tube 33. Likewise, rearward movement of arm 40 (i.e., 
decreasing the angular separation) causes inner tube 31 to move axially 
rearward within outer tube 33. In this manner, the distal end of inner 
tube 31 may be selectively projected beyond the distal end of tube 33, or 
fully retracted within the outer tube. The diameters and lengths of tubes 
31, 33 are such to permit their distal ends to be inserted through an 
endoscopic surgical portal and positioned at a surgical site. The 
particular embodiment illustrated herein is best suited for arthroscopic 
procedures. 
The distal end of inner tube 31 terminates in a pair of resiliently spaced 
jaws 43 and 45. When inner tube 31 is fully extended forwardly, jaws 43 
and 45 are exposed and maximally separated. In this position the spacing 
between the outside surfaces of the jaws exceeds the inner diameter of 
outer tube 33. As the inner tube is retracted into the outer tube, the 
interior wall of outer tube 33 serves as a cam to gradually urge jaws 43 
and 45 together in opposition to their resilient separation bias. The 
interior or mutually facing surfaces of jaws 43 and 45 have respective 
engagement pins 44 and 46 projecting inwardly toward one another. In the 
fully open position of the jaws (i.e., in the fully extended position of 
inner tube 31), the spacing between engagement pins 44 and 46 is at least 
equal to the diameter of the wire used for anchor wire 10. The 
cross-sectional shape of pins 44 and 46 (i.e., transversely of their 
mutual projection directions) is chosen to permit the pins to fit into the 
loop 11 of the anchor wire when the jaws are closed. Preferably, the 
engagement pins are cylinders having a radius equal to or just slightly 
smaller than the radius of curvature of the proximal end of the interior 
portion of wire loop 11. 
Referring to FIGS. 4 and 5, when it is desired to load anchor wire 10 onto 
insertion tool 30, inner tube 31 is extended to its most distal position 
relative to the outer tube by angularly separating handle arms 37 and 40 
to their maximum separation. Jaws 43 and 45 are resiliently spread and 
pins 44 and 46 thereby are spaced from one another. The anchor wire loop 
may then be inserted between jaws 43, 45 and their engagement pins 44, 46. 
As illustrated in FIG. 6, the jaws may be closed, bringing engagement pins 
44, 46 into contact through anchor wire loop 11. Closure of the jaws is 
effected by pivoting handle arm 40 partway toward handle arm 37, thereby 
causing partial retraction of inner tube 31 into outer tube 33. This 
retraction, in turn, causes the distal edge of the outer tube to force 
jaws 43 and 45 together in opposition to their resilient separation bias. 
To ready the anchor wire for insertion into a bone tunnel, inner tube 31 is 
further retracted into outer tube 33, as illustrated in FIGS. 7 and 9, 
until the loaded anchor wire is disposed with the proximal end of loop 11 
abutting the distal end of outer tube 33. In this position, a suture 50 
can be disposed with an intermediate portion of its length between inner 
leg segments 15 and 21 and at the distal end of wire twist junction 13. 
The two ends of suture 50 are pulled rearwardly to extend along the outer 
tube 33 of the insertion tool. Suture 50 and the anchor wire 10, engaged 
by the insertion tool, can then be inserted into a pre-drilled bone tunnel 
51. The bone tunnel diameter is substantially equal to or slightly larger 
than the maximum transverse spacing between the outer edges of outer legs 
segments 19 and 25 to readily permit insertion of the entire anchor wire 
and the distal end of the insertion tool into the bone tunnel. With the 
anchor wire thusly inserted in the tunnel, the surgeon can determine 
whether or not the tunnel and its location are satisfactory for the 
contemplated soft tissue anchoring procedure. If the bone tunnel is not 
satisfactory, the insertion tool and the engaged anchor wire may be 
readily withdrawn from the tunnel and inserted into a new tunnel 
appropriately drilled and positioned. 
If the bone tunnel is determined to be satisfactory for the contemplated 
procedure, the anchor wire may be permanently deployed. In particular, and 
as illustrated in FIGS. 8 and 10, the outer leg segments 19, 25 of the 
inserted anchor wire are forced outwardly by fully retracting inner tube 
31 into outer tube 33 while pulling rearwardly on the insertion tool and, 
in turn, on the engaged anchor wire. As the inner tube is retracted, the 
interior sides of knees 17 and 23 move axially toward the distal edge of 
outer tube 33. The outer tube end begins wedging between inner leg segment 
15 and outer leg segment 19, and between inner leg segment 21 and outer 
leg segment 25, thereby causing the outer leg segments to bend outwardly 
about their respective knees. Pointed wire ends 20 and 27 diverge by 
virtue of this bending and dig into the wall of the bone tunnel as the 
assembly is pulled in a rearward direction. When sufficient resistance to 
rearward movement is encountered, the anchor wire is deemed properly 
implanted and the insertion tool can be disengaged from the anchor wire 
loop 11. This disengagement is effected by moving inner tube 31 proximally 
to permit jaws 43 and 45 to resiliently separate and release wire loop 11. 
The insertion tool may then be fully withdrawn from the surgical site, 
leaving the anchor wire firmly positioned within the bone tunnel and 
suture 50 looped around the anchor wire. The 180.degree. twist 13 in the 
anchor wire prevents the suture from being drawn into loop 11 when the 
ends of the suture are pulled to achieve desired tension. 
It is to be noted that, although the preferred embodiment of the insertion 
tool includes respective engagement pins secured to the jaws 43 and 45, 
other jaw configurations are possible and fall within the scope of the 
present invention. For example, only one of the jaws may have a projecting 
pin configured to engage the opposing jaw when the jaws are closed. 
Alternatively, the opposing jaw may have a recess or bore defined 
therethrough in position to receive the engagement pin from the 
first-mentioned jaw. The configurations of the engagement pins need not be 
cylindrical; rather, any configuration capable of serving the functions 
described above is appropriate for the engagement pins. 
Likewise, the specific manner by which the jaws are opened and closed 
should not be a limiting feature of the invention. In particular, the 
preferred insertion tool described above effects closure of the jaws by 
withdrawing the resiliently spaced jaws into an outer tube. Rather than 
providing the illustrated inner tube and outer tube combination, a single 
tube may be provided with non-resilient jaws formed at its distal end. One 
of the jaws would be pivotable relative to the tubes so as to selectively 
close the jaws in a manner similar to that employed for arthroscopic 
graspers and cutters well known in the prior art. An outer sleeve may then 
be disposed over the distal end of the insertion tool to be selectively 
axially movable relative to the jaws to bend the outer leg segments of the 
anchor wire in a manner described. 
An alternative embodiment of the anchor assembly and insertion tool are 
illustrated in FIGS. 11-18 to which specific reference is now made. In 
this embodiment the anchor assembly includes anchor wire 10, configured as 
described above, and a biocompatable anchor sleeve 60. The anchor sleeve 
60 has a generally cylindrical configuration with a proximal end wall 61 
having a central hole or opening 63 defined therethrough. The diameter of 
hole 60 is sufficient to permit loop 11 of the anchor wire to project 
proximally therethrough when the anchor wire is received in sleeve 60 in 
the manner described below. The opposite or distal end 65 of sleeve 60 is 
open to receive the anchor wire. Longitudinally extending wire relief 
channels or recesses 67, 69 are defined in the outer surface of sleeve 60 
and extend along the entire length of the sleeve. Channels 67 and 69 are 
disposed at 180.degree.-spaced locations about the sleeve circumference 
and are sufficiently deep to receive most, if not all, of the diametric 
thickness of respective outer leg segments 19 and 25. That is, anchor wire 
10, when received in sleeve 60, has the inside surfaces of its knees 17 
and 23 disposed in abutting relation with the distal edge of the sleeve. 
Further, the natural spacing between the outermost edges of inner leg 
segments 15 and 21 is greater than the inner diameter of sleeve 60. 
Accordingly, sleeve 60 is retained on anchor wire 10 by a forced fit 
created by the limited resilience of the anchor wire. In the preferred 
embodiment, distal end 65 has a pair of recesses 66, 68 serving as 
extensions of respective channels 67, 69 to receive the entire thickness 
of respective knees 17 and 23. In this received position of the anchor 
wire, inner leg segments 15, 21 and twist junction 13 are disposed inside 
sleeve 60. 
At two 180.degree. -spaced locations, spaced 90.degree. from wire relief 
channels 67 and 69, the wall of sleeve 60 is completely removed along the 
entire sleeve length. The resulting open spaces 71, 73 are continued as 
respective arcuate recesses 75, 77 defined in the circumferential edge of 
proximal end wall 61. Spaces 71, 73 serve as suture relief spaces through 
which suture 50 extends when looped about the proximal end of wire twist 
13 between inner leg segments 15 and 21. 
The insertion tool 80 employed with the anchor assembly of wire 10 and 
sleeve 60 may be substantially the same tool described above. As shown in 
FIGS. 11-18, the outer tube 33' of the tool may have a pair of 
180.degree.-spaced slots 81, 83 cut through the entire tube wall thickness 
and extending a short distance rearward from the outer tube distal end. 
The suture ends thus extend through spaces 71, 73 and recesses 75, 77 to 
reside along the slots 81 and 83. 
The operation of the anchor assembly of FIGS. 11-18 is similar to that 
described above in relation to FIGS. 1-10. Anchor wire loop 11, exposed 
through sleeve hole 63, is engaged in the same manner between jaws 43 and 
45, and the sequence of deployment proceeds as previously described with 
two significant exceptions. First, instead of the outer leg segments 19 
and 25 being deformably bent directly by the distal end of the outer tube 
33' upon retraction of the inner tube, the outer tube distal end urges 
sleeve 60 forwardly relative to the anchor wire. The distal end of the 
sleeve thus deformably bends the outer leg segments of the wire outwardly 
under the urging of the distal end of the outer tube as the inner tube 
retracts. 
A second significant distinction resides in the fact that biocompatable 
sleeve 60 may remain deployed with the anchor wire in the bone tunnel. The 
forced fit between the sleeve and the inner leg segments 15 and 21 assures 
that the sleeve will not become disengaged. Of course, the sleeve can be 
designed to be removed after deployment of the wire, if desired. 
Sleeve 60 is made of any suitable bio-compatible metal or plastic material. 
In an exemplar embodiment, the sleeve has a length of 0.157" and an 
outside diameter of 0.100". Hole 63 in proximal end wall 61 has a diameter 
of 0.060" which is substantially equal to the maximum transverse dimension 
of anchor wire loop 11. Channels 67 and 69 are generally semi-cylindrical 
with a depth of 0.015", while spaces 71, 73 each subtend a circumferential 
angle on the order of 60.degree.. The transverse space between interior 
walls across spaces 71, 73 is 0.040". 
It may be desirable, in some instances, to configure the anchor wire in the 
manner illustrated in FIG. 19 wherein anchor wire 10' is configured to 
have its pointed ends 20', 27' curved outwardly and way from the 
longitudinal axis of the anchor. This curvature at the tips of the anchor 
facilitates penetration into the bone upon outward bending of outer 
segments 19 and 25 during deployment. In all other respects anchor wire 
10' is substantially the same as anchor wire 10. 
It will be understood that some of the specific details of the exemplary 
embodiments described above are not limiting on the scope of the 
invention. In particular, the feature of primary importance in the anchor 
is the presence of two or more wire legs capable of being deformably bent 
outward while in a bone tunnel to permit their pointed ends to penetrate 
the bone tunnel wall upon being pulled proximally toward the tunnel 
opening. On the other hand, prior to being bent, the wire legs are 
retracted such that the maximum transverse dimension of the anchor permits 
it to be readily inserted into and removed from the tunnel. In this 
regard, the anchor may comprise only the wire, or the wire engaged by a 
biocompatable anchor sleeve (both as described above); or it may comprise 
a body of biocompatable metal or plastic material having the bendable 
pointed legs embedded therein or otherwise secured at the distal end of 
the body, and with a loop or other anchor engagement structure at the 
proximal end of the body. The configuration of the anchor body is not, of 
itself, critical to the invention, although certain configurations, such 
as those described herein, are more advantageous than others. The key 
features, again, are the fact that the legs are deformable to effect 
deployment while the anchor is in the bone tunnel to permit the anchor to 
be removed after insertion but prior to bending for deployment, a passage 
for engaging a suture looped about or through the anchor, and a mechanism 
for engaging the anchor with a removable insertion tool capable of 
selectively deploying the anchor in the tunnel by causing the legs to 
deformably bend outwardly without hammering or impacting the anchor. The 
specific insertion tool configurations described herein, although 
particularly advantageous, can also be varied within the scope of the 
invention. The key features of the tool are the capability of engaging the 
anchor for selective insertion into and removal from the bone tunnel, and 
the capability of selectively deploying the anchor by causing deformation 
of the anchor legs. It should also be noted that inner tube 31 of the 
illustrated insertion tool may be any rod-like member, whether or not 
tubular. 
From the foregoing description it will be appreciated that the invention 
makes available a novel suture anchor for soft tissue fixation 
characterized by being removable from a bone tunnel after insertion but 
before deployment, easily actuated for permanent deployment, and 
deployable without requiring hammering of the anchor suture or threading 
of the bone tunnel. 
In accordance with the present invention, it is believed that other 
modifications, variations and changes will be suggested to those skilled 
in the art in view of the teachings set forth herein. It is therefore 
understood that all such variations, modifications and changes are 
believed to fall within the scope of the present invention as defined by 
the appended claims.