Note: Descriptions are shown in the official language in which they were submitted.
CA 02523108 1997-10-03
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SUTURE ANCHOR INSTALLATION SYSTEM WITH
DISPOSABLE LOADING UNIT
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This application is a division of copending
Canadian Application Serial No. 2,217,406, filed October 3,
1997.
1. Technical Field
The present disclosure relates to a device for
releasably holding a suture anchor.
2. Discussion of Related Art
During surgery, it is often necessary to attach
muscle tissue or prosthetic implants to bone. Suture
anchors are used in the art to facilitate such attachment by
securing a suture to bone. Generally, an anchor is
implanted into a hole pre-drilled into a bone mass. A
suture engaged by the suture anchor extends from the bone
and is used to stitch the muscle tissue or prosthetic device
to the bone. Suture anchors find particular use in joint
reconstruction surgery, especially during attachment of
ligaments or tendons to bones in the knee, shoulder, and
elbow.
Several systems have been proposed in the art to
aid the surgeon in implanting a suture anchor into a bone.
One such system, shown in U.S. Pat. No. 5,100,417 to Cerier
et al., comprises a driver having a handle and elongated
shaft. An anchor snap fits on the end of the shaft over an
anti-rotation pin which mates with slots in the anchor. A
suture engaged in the anchor has its ends affixed to posts
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extending from the driver handle. The Cerier et al. system suffers from the
disadvantage that the driver does not accommodate sutures having preattached
needles. Thus, use of this system requires threading the suture into a needle,
a time-
consuming procedure for the surgeon.
Another suture anchor installation system is shown in U. S. Pat. No.
5,002,550 to Li. The Li system comprises a suture anchor having a normally
curved
barb capable of being elastically deformed to a substantially straight
configuration.
The suture anchor engages a suture having a pair of surgical needles attached
to its
ends. The installation tool is adapted to receive the surgical needles and a
pair of
1 o grooves formed in the tool's outer surface. The tool additionally provides
a member
for selectively covering and uncovering the needles received in the grooves.
The Li suture anchor installation system uses shape-memory alloys to
fabricate the suture anchors. Such materials are not bioabsorbable.
Additionally, the
normally curved barb of the Li system protrudes from the installation tool
during
positioning of the anchor.
Yet another suture anchor installation system is disclosed in U. S.
Patent No. 5,354,298 to Lee et al. The suture anchor installation system
comprises a
suture anchor assembly engaged with a suture anchor insertion tool. The suture
anchor assembly features a two-piece suture anchor for insertion into a pre-
drilled
2 0 hole in a bone and at least one suture having at least one surgical needle
affixed
thereto. The two-piece suture anchor has a setting pin slidably engaged within
an
engagement member having barbed legs expandable in response to proximal
movement of the setting pin. The suture anchor insertion tool includes a body
CA 02523108 1997-10-03
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portion and a distally extending shaft portion. An annular region of the
distal end of
the shaft portion engages the legs of the suture anchor engagement member. A
channel in the shaft portion aligns with a channel in the body portion to
accommodate
the suture. Needle-retaining assemblies located on the body portion of the
suture
anchor insertion tool engage the surgical needle or needles attached to the
suture.
The suture anchor installation tool of the Lee et al. 5,354,298 patent is
packaged in a preloaded condition. The package is opened in the operating room
and
the installation tool is removed from the package and used to apply the suture
anchor. Operating room conditions are not conducive to manually reloading the
Lee
et al. installation tool with a fresh suture anchor for reuse of the
installation tool. In
the event that a second suture anchor must be applied another suture anchor
installation tool package is opened and a new preloaded suture anchor
installation
system is used.
It would be advantageous to use a single installation tool during an
operation and reload it as appropriate. What is needed is a mechanism which
facilitates reloading of the suture anchor installation tool in the operating
room.
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SUMMARY
In accordance with an embodiment of the present
invention there is provided a device for releasably holding
a suture anchor, which comprises: a) a housing having a
bore; b) a collet slidably disposed within the bore for
supporting a suture anchor; c) a suture anchor mounted to
the collet, the suture anchor having a suture connected
thereto.
A suture anchor installation system is disclosed
herein. The suture anchor installation system includes a
suture anchor, the loading unit, and a suture anchor
inserter.
The suture anchor includes an elongated setting
pin at least partially mounted within a longitudinal bore of
a socket and slidably movable between a distal first
position wherein at least a portion of the setting pin is
distal to the socket and a proximal second position, the
socket having at least two proximally pointing legs which
are radially expandable in response to movement of the
setting pin to the proximal second position. Each leg of
the suture anchor preferably has at least one barb on an
exterior surface, and the setting pin has an aperture
transverse to its longitudinal orientation. A suture is
received through the aperture of the setting pin, and
optionally a surgical needle is attached to at least one end
of the suture.
As noted hereinabove, the loading unit includes a
housing and a collet movably mounted within an axial bore in
the housing. Preferably, the loading housing unit includes
spaced apart distal and medial flanges, and structure such
as a radially extending post for retaining a surgical needle
in an annular space between the distal and medial flanges.
In a preferred embodiment, the loading unit further
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comprises a cap having a back wall and a cylindrical barrel
portion, the barrel portion being engageable with the medial
flange of the housing to at least partially define an
interior space. In preferred embodiments, the collet
includes at least two arms for releasably holding the suture
anchor, each arm including a camming surface. The collet
arms are radially expandable in response to the first
tubular member of the
30
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inserter contacting the camming surface with a force sufficient to move the
collet
arms radially outward. The loading unit also preferably provides a needle park
for
holding one or more needles which are attached to the ends of the suture, and
a
space for storing coiled lengths) of the suture.
The suture anchor inserter has a first tubular member for contacting
and camming the collet and a second tubular member for releasably engaging the
socket, preferably the second tubular member of the inserter is disposed
within
the first tubular member of the inserter.
BRIEF DESCRIPTION OF THE DRAWINGS
Various embodiments are discussed below with reference to the
drawings, wherein:
FIG. 1 is a side view of a suture anchor;
FIG. 2 is a perspective view of the setting pin of the suture anchor
with a suture disposed therethrough;
FIG. 3 is an exploded view showing the suture retained by the
setting pin;
FIG. 4 is a perspective view of the suture anchor installation system
with disposable loading unit;
FIG. 5 is a cutaway partly sectional perspective view of the
disposable loading unit;
FIG. 6 is a perspective view of the loading unit and installation tool;
FIG. 7 is an exploded perspective view of the
installation tool;
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FIG. 8 is a perspective view of the interior of the handle portion of the
installation tool;
FIGS. 9 and 10 are perspective views of the distal ends of the inner
shaft and outer tube, respectively, of the installation tool;
FIG. 11 is a perspective view of the disposable loading unit with
needles and suture loaded therein;
FIG. 12 is a side view of the disposable loading unit with needles and
suture loaded therein;
FIG. 13 is an exploded perspective view of the disposable loading
umt;
FIGS. 14 and 15 are perspective views illustrating positioning of the
suture anchor within the collet;
FIG. 16 is a side sectional view of the disposable loading unit showing
retention of the suture anchor taken along line 16-16 in Fig. 6;
FIG. 17 is a sectional view of the disposable loading unit taken along
line 17-17 in FIG. 16;
FIG. 18 is an enlarged side sectional view of the disposable loading
unit showing advancement of the outer tube and inner shaft of the installation
tool;
FIG. 19 is a sectional view of the handle portion of the installation
2 0 tool;
FIG. 20 is a sectional view of the disposable loading unit showing
advancement of the outer tube and inner shaft of the installation tool;
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PIG. 21 is a sectional view of the handle portion of the installation
tool;
FIGS. 22, 23 and 24 are sectional side views showing advancement of
the collet, release of the suture anchor by the collet, and advancement of the
suture
anchor by the installation tool;
FIGS. 25 and 26 are perspective views showing retention of the
suture anchor in the installation tool, Fig. 26 being a partial cut-away view;
FIGS. 27 and 28 are perspective views illustrating the use of the
suture anchor installation system;
FIG. 29 is a sectional side view of the handle portion of the
installation tool;
FIGS. 30 to 33 are sequential sectional side views illustrating
implantation of a suture anchor; and,
FIGS. 34 and 35 are perspective views illustrating activation of the
suture anchor to expand the legs.
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DETATLED DESCRTPTTON OT' PRErERRED EMBODIMENTS
The suture anchor installation system is provided for securing a suture
to hard tissue, such as bone. The suture can be used to attach soft tissue or
a
prosthetic device to the bone. As used herein, the term "soft tissue" refers
to all of
the non-bony tissues within an organism including, but not limited to, muscle,
cartilage, skin, tendons, ligaments, etc. The term "prosthetic device" refers
to any
article implanted in the body including, but not limited to, artificial
ligaments,
muscles, joints, etc.
Moreover, the suture anchor installation system is advantageously
used in minimally invasive surgical procedures such as laparoscopic,
endoscopic, or
arthroscopic operations in which the operating instrumentation is deployed
through
narrow cannulas inserted through small incisions or openings in the patient's
body.
Alternatively, the suture anchor installation system may also be used in
standard open
surgical procedures.
The suture anchor installation system described herein comprises a
suture anchor assembly retained in a disposable loading unit, and a suture
anchor
installation tool. The suture anchor assembly features a two-piece suture
anchor for
insertion into a pre-drilled hole in bone and at least one suture having at
least one
surgical needle afftxed thereto. The two-piece suture anchor comprises a
setting pin
2 0 slidably engaged within an expandable engagement member which grips the
sides of
the hole drilled in the bone. In a preferred embodiment, this engagement
member is
an expandable socket. The expandable socket includes an apertured body portion
having at least two barbed legs extending proximally therefrom. The legs are
radially
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expandable in response to proximal movement of the setting pin. Suture anchors
suitable for use in the suture anchor installation system are described in
U.S. Patent
No. 5,354,298. The suture can be "double-armed", i.e. a needle can be attached
to
each of the two ends of the suture to facilitate knotting the suture and
securing the
soft tissue to the bone.
More particularly, referring now to FIGS. 1 to 3, a preferred two-
piece suture anchor 10 is illustrated. Preferably, the suture anchor 10 is
fabricated
from a synthetic bioabsorbable polymeric resin such as polymers of glycolide,
lactide,
caprolactone, p-dioxanone, trimethylene carbonate and physical and/or chemical
to combinations thereof The suture is preferably a size 2 suture formed of
*Dacron.
However, it is anticipated that the suture may also be formed from a synthetic
bioabsorbable polymeric resin.
The suture anchor 10 includes a socket 11 for insertion distally into a
pre-drilled hole in bone or hard tissue. The socket has a body portion 12
terminating
in an annular distal end surface 13 which acts as a stop surface as discussed
below, an
axially extending aperture 14, and at least two (preferably four) legs 15
extending
proximally from the body portion 12. Legs 15 are normally radially expandable
in
response to movement of a SettlIlg plI1 20 slidably disposed within the
axially
extending aperture 14 as explained more fully below with reference to Figs. 34
and
35: The setting pin 20 has a suture attachment feature and is movable between
a
distal position with respect to socket 11 wherein socket legs 15 are not
expanded,
and a proximal position with respect to the socket 11 wherein socket legs l S
are
urged to a radially spread-out configuration.
*trade-mark
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More particularly, setting pin 20 includes a shaft portion 22, a tapered
tip 23 with preferably a substantially frustoconical shape and a proximal
facing
abutment surface 26, and a transverse aperture 21 near the distal end for
receiving a
suture 30. Proximal end 25 is rounded and acts as a camming surface. The
setting
pin 20 also includes two longitudinal notches 24 extending along shaft portion
22
along which suture 30 is disposed.
Proximally extending legs 15 of the socket 11 include barbs 16 on
their outer surface and an inwardly inclined inner surface 17. When setting
pin 20 is
moved proximally from its initial distal-most position (i.e. by pulling suture
30), the
rounded proximal end 25 of the shaft portion cams against the inner surface 17
and
thereby urges legs 1 S to expand radially outward. At the most proximal
position of
the setting pin 20, the abutment surface 26 of tapered tip 23 contacts distal
end
surface 13 of the socket. Setting pin 20 is thereby stopped from further
proximal
movement. A matching non-circular cross section of the pin and socket aperture
may
be employed to prevent suture interference with the setting action by
preventing free
rotation of the setting pin within the axial aperture of the socket and by
locating the
suture between the legs 15 of the socket.
Referring now to FIG. 4, the suture anchor installation system
includes a disposable loading unit 100 and an installation tool 200. The
disposable
loading unit 100 is removably engageable within installation tool 200 by
mounting
onto the distal operating portion 201.
Referring now to FIGS. 4, and 6-10, the installation tool 200 includes
a distal elongated operating portion 201 and a proximal handle portion 202.
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The operating portion 201 includes an outer tube 210 which extends
longitudinally from trigger portion 220 and is movably mounted thereto. Outer
tube
210 includes an axial bore for receiving inner shaft 230, discussed below. At
the
distal end opening 211 of the bore there are two lengthwise extending slots
212 (see,
FIG. 10) which divide the distal end portion of the outer tube 210 in two
partitions.
The outer tube terminates in distal edges 2I3 which provide a camming function
discussed below. Lengthwise notches 215 for receiving a length of suture
extend
from proximal end surface 214 of the outer tube to the proximal edges of slots
212.
The inner shaft 230 is disposed within the bore of outer tube 210 and
1o includes a mouth 231 having partitions 231a and 231b defined by
longitudinal slots
232 (See, Fig. 9). The inner shaft 230 is fixedly attached to the handle
portion 240
by means of notch 233. Mouth 231 of the inner shaft is adapted to engage the
proximal end portion of the legs 15 of socket 11, and to hold the suture
anchor 10
temporarily until the suture anchor 10 is inserted into the bone site.
The handle portion 202 includes a trigger portion 220 and a handle
240 having an outer gripping surface 247.
Referring to FIGS. 7 and 8, trigger 220 includes a frame having a
finger rest 221 and a substantially rectangular body portion 222. The
rectangular
body 222 is adapted to be slidably received into distal inner chamber 241 of
handle
2 0 240. Tubular section 223 extends along body 222 and is adapted to fit
within
cylindrical bore 242 of handle 240. An axial bore 224 extends longitudinally
through
trigger 220 and receives outer tube 210. Ribs 225 extending longitudinally on
the
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inside surface of bore 224 engage notches 215 to prevent rotation of outer
tube 210
relative to trigger 220.
The proximal end 214 of the outer tube is fixedly mounted to the
distal portion 256 of collar 255 (see, FIG. 7). Collar 255 also includes a
flange 257
and a proximal portion 258. Distal portion 256 is slidably disposed within
axial bore
224, but flange 257 provides a stop surface and limits further distal entry of
collar
255 into bore 224. Proximal portion 258 is received into the center of helical
compression spring 250.
Collar 255 is at least partially disposed within middle chamber 243 of
1 o handle 240. Spring 250 extends into proximal chamber 244 of the handle.
The
proximal end of spring 250 abuts a surface at the proximal end of chamber 244.
the
distal end of spring 250 abuts flange 257 of the collar and thereby exerts a
distally
directed biasing force on the collar 255 and outer tube 210 when in a
compressed
state.
Inner shaft 230 extends through outer tube 210, through the axial bore
of collar 255, and into and through chambers 243 and 244 of handle 240.
Projections
245 in the handle are adapted to engage notches 233 to secure the inner shaft
230 to
the handle 240.
The outer tube 210 is formed from clear polycarbonate to permit the
2 0 surgeon to see the suture anchor 10 through the outer tube 210, and inner
shaft 230
is preferably fabricated from a biocompatible metal such as stainless steel or
titanium.
Handle 240 and trigger 220 may be fabricated by, for example, injection
molding
from polymeric resin having the mechanical properties suitable for the use
described
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herein. Suitable polymers include acrylics, and/or polycarbonates, for
example.
Handle 240 and trigger 220 are preferably fabricated in two parts which are
then
assembled and fastened together by adhesive bonding, or rivets, screws or
other such
fastening means.
Referring now to FIGS. 5, 11, 12, and 13, the disposable loading unit
100, shown in combination with the suture anchor 10, suture 30 and needles 50,
includes a housing 110, a removable cap 150, and a spring biased collet 160
for
releasably holding the suture anchor 10.
Housing I 10 includes a body 111 having a distal flange I 12. The
distal flange 112 includes a distal surface 113 corresponding to the distal
end 12S of
housing 110, a proximal surface 114, and lateral slots 128 which include
angled
portions 128a to retain the suture 30. Medial flange 115 includes distal
surface 116,
proximal surface I 17, and snap fit ridges I 18 extending at least partially
around the
circumferential outer edge of the flange I 1 S. Medial flange 115 also
includes
I5 flattened surfaces 127 around its circumferential rim, surfaces 127 being
adapted to
engage corresponding flattened surfaces 1 S7 in the cap to inhibit relative
rotation
between the cap ISO and housing 1 I0. A distal chamber 102 is at least
partially
defined by proximal surface 114 of the distal flange, and distal surface 116
of the
medial flange, and provides a space for the storage of curved needles 50, one
needle
being attached to each end of suture 30. A proximal chamber 104 is at least
partially
defined by proximal surface I 17 of the medial flange, and provides space for
the
storage of suture 30. Radial slots I 19 in medial flange 115 provide access
for the
suture 30 to extend from the distal chamber 102 to the proximal chamber 104.
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Housing I 10 also includes an axial bore I35 extending from the distal end 125
to the
proximal end 126 of housing 110. Buttress plates 137 extend distally from the
medial
flame 115 and provide support therefor.
The body 111 of housing 110 includes a central tubular portion 141
having an inner wall defining the axial bore 135. Also included as part of the
body
11 I are upper shelf 142, middle shelf 143, and lower shelf 144. The terms
"upper"
and "lower" are used relative to each other herein with reference to the
drawings
(See, e.g. Fig. 12), and not to any external frame of reference. The upper and
lower
shelves 142, 144 each include, on opposite sides, a proximal cut-away portion
145 to
accommodate the butt end of the surgical needle 50, and a medial cut away
portion
146 to accommodate the pointed tip of the curved surgical needle S0. The
proximal
cut away portions 145 are in the vicinity of respective radial slots I 19 to
allow the
suture 30 attached to the butt end of the needle to extend through radial slot
l 19 into
the proximal chamber 104. Upper and lower shelves 142, 144 occupy the distal
chamber 102. The middle shelf 143 extends to the proximal end 126 of housing
110.
Suture 30 follows a path, for example, extending from the butt end of
one needle 50 mounted in needle park 130 on upper shelf 142, through one of
the
radial slots 119 in the medial flange, and into proximal chamber 104 where
part of its
length is stored as a coil above middle shelf 143. Suture 30 then extends back
out
through radial slot I 19 across distal chamber 102 around lateral posts 136
and
through one lateral slot 128 in the distal flange 112 whereupon it extends
across
collet 160 and into and through suture anchor 10. From the suture anchor 10,
suture
follows a reverse path on the other side of the housing 1 I0, extending
through
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lateral slot 128 on the other side of distal flange 112, around the lateral
posts 136 on
the other side (not shown) of the housing, across distal chamber 102, through
the
opposite side radial slot 119, and into proximal chamber 104 where a length of
suture
30 is stored below middle shelf 143. Thereafter, suture 30 returns through the
opposite side radial slot 119 and is attached to the butt end of the second
needle 50
mounted to a needle park 130 on the lower shelf 144.
Referring also now to FIG. 16, the distal flange 112 includes a rim
portion I20 extending circumferentially around the distal opening of axial
bore 135
and having a bevelled distal surface 121, and a radially inward extending lip
122
having a proximally facing annular surface 123. Housing 110 preferably
includes
needle parks 130 extending radially outward from the body portion 111 between
the
distal and medial flanges 112 and 115, respectively, so as to retain a curved
needle SO
on the upper and lower shelves 142 and 144, respectively within the distal
annular
space 102.
each needle park 130 comprises a distal upright post I31 having a
needle supporting projection 132, and a proximal upright post 133 having a
needle
retaining projection 134. The posts 131, 133 are resilient and allow the
needle SO to
snap fit into the space between the projections I32, 134 for convenient
removal by
the surgeon.
2 0 Referring to FIGS. 13 and 16, cap 150 is removably attachable to
housing 110 and includes a cylindrical barrel portion 151 and a circular back
wall
154. The distal edge of the barrel portion 1 S 1 includes a bevelled inner
surface 153
to facilitate engagement of the barrel portion 151 with medial flange 11 S,
and notches
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I 52 which engage and receive snap fit ridges 1 I 8 to removably secure the
cap 1 SO to
the housing 110. Back wall 154 includes a central aperture 155 defined by
bevelled
proximal rim 156. A portion of the bevelled rim 156 extends partially across
the
proximal opening of axial bore 135 so as to present a distal facing surface
158 across
bore 135 to retain the collet 160. Cap 150 includes flattened inner surfaces
157
corresponding to flattened surfaces 127 of the medial flange I 15 (See, Fig.
13).
Upper and Iower ridges 159 facilitate manual grasping and holding of the cap
by the
surgeon.
Referring now to FIGS. 13-16, the collet 160 is slidably mounted in
1o axial bore 135 and has a generally cylindrical body portion 161 and at
least two, and
preferably four, arms 164 extending distally therefrom. The body portion 161
has a
planar surface 169, which, in conjunction with a corresponding planar surface
in bore
135 of the housing, inhibits rotation of the collet I 60 relative to the
housing 110.
Arms 164 are separated from each other by longitudinally extending slots 165.
Bore
168 extends axially through the collet 160. At the proximal opening of bore
168 the
body portion 161 includes a bevelled rim 163 which aligns with bevelled rim
156 of
the cap when collet 160 is in its most proximal position within the bore 135.
Collet
160 is resiliently biased to this most proximal position by helical
compression spring
140 which surrounds arms 164. Spring I40 is positioned within the space
between
2 o the outer surface of arms 164 and the inner surface of the axial bore 13
5. Distal
surface 162 of the collet body portion 161 and proximal surface 123 of the
housing
distal flange 112 provide stop surfaces between which spring 140 is disposed.
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Collet arms 164 include a suture anchor holding portion 166, which is
adapted to engage the setting pin shaft 22 between proximal surface 26 of the
tapered
tip 23 and the distal end surface 13 of the socket when the setting pin 20 is
in its
distal-most position with respect to the socket I 1.
The collet 160 is slidably movable from its initial proximal-most
position against the biasing force of spring 140 to a distal position wherein
the arms
164 are at least partially disposed outside of axial bore 13 S. Arms 164 can
be radially
spread apart when collet 160 has been moved to its distal-most position. Each
arm
164 of the collet includes an interior bevelled rim 167 which serves as a
camming
surface. Rim 167 is contacted by the distal edge 213 of the outer tubular
member
2I0 of the suture anchor installation tool 200. As will be illustrated below,
as the
inserter 200 is moved distally, collet 160 and suture anchor 10 are pushed
distally
forward until distal surface 162 completely compresses spring 140 and is
thereby
stopped from moving distally further. At this configuration arms 164 of the
collet are
outside the housing 110 and beyond rim 121 of the distal flange I 12. Further
force
distally exerted upon bevelled camming rim 167 will tend to cause arms 164 to
splay,
or expand radially outward. Expansion of arms 164 in such a manner thereby
releases the suture anchor 10 gripped by the distal holding portion 166 of the
arms.
Referring now to FIGS. 16, and 17, the disposable loading unit 100
2 0 with suture anchor 10 mounted therein is shown in its initial
configuration. The
suture anchor 10 is held by collet 160, which is biased to its most proximal
position
relative to the housing 110 by means of spring 140. As can be seen from Fig.
17, the
housing can include longitudinal ridges 135a spaced apart around the interior
of bore
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135. These ridges provide friction between the collet and the housing 110.
Likewise, bore 168 can include ridges 168a to position outer tube 210 of the
installation tool more precisely.
Referring now to FIGS. 18 and 19, outer tube 210 is inserted through
bore 135 of housing 110 until the distal edge 213 of the outer tube contacts
caroming
surface 167 in the collet. The handle portion 202 of the installation tool is
in the
configuration illustrated in FIG. 19 at this stage of operation.
Referring now to FIGS. 20 and 21, additional distal force is applied to
the installation tool 200 by the surgeon, which advances the inner shaft 230
until the
distal end opening 231 engages the proximal end portion of legs 15 of the
suture
anchor I 0. The handle portion 202 of the installation tool is in the
configuration
illustrated in FIG. 21 at this stage. As one can see from FIG. 21, the outer
tube 210
and connector 255 are pushed back in the proximal direction against the
biasing force
of spring 250, which compresses in response thereto.
Referring now to FIG. 22, further distal force applied by the surgeon
moves the collet 1 GO out of the housing I 10 against the biasing force of
spring 140,
which compresses.
Referring now to FIG. 23, when spring 140 reaches full compression
and the collet 1 GO has reached its furthest distal extension beyond the
distal extension
beyond the distal surface 113 of flange 112, collet arms 164 are biased into
an open
configuration by the caroming action of distal edge 213 on caroming surface
167 as
the outer tube continues to advance. Collet arms I 64 release the suture
anchor 10,
which is held by the inner shaft 230.
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Referring now to FIGS. 24-26, once the outer tube 210 has pushed
past the collet 1G0, it springs forward relative to the inner shaft 230 in
response to
the biasing action of spring 250, thereby at least partially enclosing the
suture anchor
10. Suture 30 is positioned in notch 215 of the outer tube, while the proximal
end of
suture anchor 10 remains engaged within the distal opening 231 of inner shaft
230.
Referring now to FIG. 27, the installation tool 200 and loading unit
100 are shown in use in conjunction with a cannula 270 inserted through an
opening
281 in body tissue 280. The cannula 270 includes a narrow endoscopic tube 271
and
a non-endoscopic cap 272 to which the tube 271 is attached.
1 o Referring to FIGS. 28-30, in accordance with a preferred method, an
opening 281 is made in soft tissue 280 by creating an incision in the skin.
Cannula
tube 271 is inserted into the incision. Then, an obturator disposed through a
drill
guide (not shown) is deployed through the cannula tube 271 to create a soft
tissue
opening 281, thereby gaining access to the drilling site on the bone. The
obturator is
removed, and a drill bit inserted through the drill guide (not shown) is
employed to
drill an appropriately sized hole 283 in the bone 282. Next, the drill bit is
removed
and outer tube 210 is inserted through the drill guide, which remains disposed
through cannula 270 and soft tissue opening 281. The outer tube 210 is
positioned in
alignment with hole 283 in bone mass 282. Trigger portion 220 of the
installation
2 0 tool is then pressed, which moves outer tube 210 proximally, while distal
force
applied to the handle advances the inner shaft 230 and suture anchor 10 toward
the
bone, thereby inserting the suture anchor 10 into hole 283 in the bone, as can
be seen
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in FIG. 31. The handle permits partial retraction of outer tube 210 to permit
the
surgeon to visualize the suture anchor 10 prior to its insertion into the
bone.
Referring to FIG. 32, the trigger portion 220 is released and the
installation tool 200 is withdrawn from cannula 270 with suture 30 left
extending
through cannula tube 271.
Referring to FIG. 33, suture 30 is then pulled proximally to engage
the setting pin 20 in socket I I . Referring also now to Figs. 34 and 35, in
the initial
configuration of the suture anchor 10, setting pin 20 is extended distally
from the
socket 11, as seen in FIG. 34. Upon pulling the suture 30, however, setting
pin 20 is
l0 pulled back into socket 11 and legs 15 are thereby radially expanded as
shown in
PIG. 36. This expansion of legs 15 locks the suture anchor 10 firmly into hole
283 in
the bone 282.
Once the suture anchor I O is securely installed the surgeon can
remove the needles 50 and suture 30 from the disposable loading unit 100. Soft
tissue 280 can be secured to the bone mass 282 by tying down the tissue with
knots
in the suture 30 in accordance with known surgical procedures.
It will be understood that various modifications may be made to the
embodiments disclosed herein. The above description should IlOt be construed
as
limiting, but merely as exemplifications of preferred embodiments. Those
skilled in
2 o the art will envision other modifications within the scope and spirit of
the claims
appended hereto.
