U.S. patent number RE36,974 [Application Number 09/033,020] was granted by the patent office on 2000-11-28 for suture anchor.
Invention is credited to Peter M. Bonutti.
United States Patent |
RE36,974 |
Bonutti |
November 28, 2000 |
Suture anchor
Abstract
The present invention is an anchor for securing a suture in the
body. The anchor includes a tubular wall having a central axis. The
tubular wall has a proximal end and a distal end each free of
axially inwardly extending slots. The tubular wall has an inner
surface extending for the entire length of the tube and defining in
the anchor a central opening extending between the proximal end and
the distal end. The anchor has a width less than its length. A
suture may extend through the anchor within the central opening.
First and second end portions of the suture extend out of opposite
ends of the anchor and are sufficiently long to project out of the
body when the suture is secured in the body by the anchor. The
anchor has an anchoring orientation in the body achieved by
manipulation of the distal end of the anchor by pulling on the
second end portion of the suture. The anchor has a removal
orientation in the body achieved by manipulation of the proximal
end of the anchor by pulling on the first end portion of the
suture. The present invention also relates to a method of anchoring
to a bone a suture having first and second end portions.
Inventors: |
Bonutti; Peter M. (Effingham,
IL) |
Family
ID: |
22041548 |
Appl.
No.: |
09/033,020 |
Filed: |
March 2, 1998 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
344466 |
Nov 23, 1994 |
5527343 |
|
|
|
062295 |
May 14, 1993 |
5403348 |
|
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Reissue of: |
445049 |
May 19, 1995 |
05496348 |
Mar 5, 1996 |
|
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Current U.S.
Class: |
606/232; 606/323;
606/916 |
Current CPC
Class: |
A61B
17/0401 (20130101); A61B 2017/0409 (20130101); A61B
2017/0411 (20130101); A61B 2017/0414 (20130101); A61B
2017/0445 (20130101); A61B 2017/0458 (20130101); A61B
2017/0459 (20130101); A61B 2090/062 (20160201) |
Current International
Class: |
A61B
17/04 (20060101); A61B 19/00 (20060101); A61B
017/00 () |
Field of
Search: |
;606/232,72-74,104,139 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Buiz; Michael
Assistant Examiner: Trinh; Vikki
Attorney, Agent or Firm: Tarolli, Sundheim, Covell, Tummino
& Szabo L.L.P.
Parent Case Text
This application is a .Iadd.reissue of U.S. patent application Ser.
No. 08/445,049, now U.S. Pat. No. 5,496,348, which is a
.Iaddend.divisional of U.S. patent application Ser. No. 08/344,466,
filed on Nov. 23, 1994 .[.pending.]. .Iadd.now U.S. Pat. No.
5,527,343.Iaddend.. The aforementioned application Ser. No.
08/344,466 is itself a divisional of U.S. application Ser. No.
08/062,295, filed May 14, 1993 (now U.S. Pat. No. 5,403,348). The
benefit of the earlier filing dates of the aforementioned
applications Ser. Nos. 08/344,466 and 08/062,295 is hereby claimed.
Claims
I claim:
1. An apparatus comprising a suture anchor inserter, said suture
anchor inserter including an outer tube and an inner tube, said
inner tube being at least partially disposed in said outer tube and
being slidable relative to said outer tube, said inner tube having
surface means for defining a central channel, a thin elongated
member at least partially disposed in said central channel, said
thin elongated member having an end portion adapted to be disposed
in engagement with body tissue, a suture at least partially
disposed in said central channel, and an anchor, said anchor having
surface means for defining a passage through which said thin
elongated member and said suture extend, said anchor being movable
along said thin elongated member from a first position in which
said anchor is at least partially disposed within said outer tube
to a second position in which said anchor is outside of said outer
tube and is disposed in engagement with body tissue, said suture
and said thin elongated member being disposed in said passage in
said anchor throughout movement of said anchor from the first
position to the second position.
2. An apparatus as set forth in claim 1 wherein said inner tube has
surface means for applying force against said anchor to move said
anchor from the first position to the second position.
3. An apparatus as set forth in claim 2 wherein said outer tube
includes surface means for engaging the body tissue to retain said
outer tube against movement relative to the body tissue during
movement of said anchor from the first position to the second
position.
4. An apparatus as set forth in claim 2 wherein said outer tube has
inner side surface means for defining a channel in which said inner
tube is received, said inner tube having outer side surface means
for engaging said inner side surface means on said outer tube to
guide movement of said inner tube relative to said outer tube, a
portion of said suture being disposed between said inner side
surface means on said outer tube and said outer side surface means
on said inner tube during movement of said anchor from the first
position to the second position. .Iadd.
5. An apparatus which is adapted to be at least partially received
in body tissue, said apparatus comprising an anchor having a
cylindrical outer side surface with a longitudinal central axis,
said anchor including first surface means for at least partially
defining a first passage which extends through said anchor at a
location disposed between and spaced from axially opposite ends of
said anchor, said first passage extends through said longitudinal
central axis of said anchor, said anchor including second surface
means for at least partially defining a second passage which
extends through said anchor at a location spaced from said first
passage and disposed between and spaced from axially opposite ends
of said anchor, said second passage extends through said
longitudinal central axis of said anchor at a location which is
spaced from said first passage, said anchor including third surface
means for defining a third passage which extends along said
longitudinal central axis of said anchor and intersects said first
and second passages, and suture means for extending into body
tissue, said suture means having a first portion which extends
through said first passage in said anchor, a second portion which
extends along said cylindrical side surface of said anchor between
ends of said first and second passages, and a third portion which
extends through said second passage in said
anchor..Iaddend..Iadd.6. An apparatus which is adapted to be at
least partially received in body tissue, said apparatus comprising
an anchor having a cylindrical outer side surface with a
longitudinal central axis, said anchor including first surface
means for at least partially defining a first passage which extends
through said anchor at a location disposed between and spaced from
first and second axial ends of said anchor, said first passage
extends through said longitudinal central axis of said anchor, said
anchor including second surface means for at least partially
defining a second passage which extends through said anchor at a
location spaced from said first passage and disposed between and
spaced from said first and second axial ends of said anchor, said
second passage extends through said longitudinal central axis of
said anchor at a location which is spaced from said first passage,
said anchor including third surface means disposed on said first
axial end of said anchor for receiving force to press said second
axial end of said anchor against body tissue and to urge said
anchor to rotate about an axis which extends transverse to the
longitudinal central axis of said anchor while said anchor is at
least partially enclosed by body tissue, and suture means for
extending into body tissue and for transmitting force to said
anchor to urge said anchor to rotate about the axis which extends
transverse to the longitudinal central axis of said anchor while
said anchor is at least partially enclosed by body tissue, said
suture means having a first portion which extends through said
first passage in said anchor, a second portion which extends along
said cylindrical side surface of said anchor between ends of said
first and second passages, and a third portion which extends
through said second passage in said anchor..Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to the arts of medicine and surgery,
and more particularly relates to apparatus and method for securing
a suture in body tissue.
2. Description of the Prior Art
Suture anchors have been developed for anchoring sutures during
open surgery and arthroscopic surgery with single side access. With
a suture anchored in tissue, it is possible to apply force to the
suture to hold other body tissue or implanted devices.
It is desirable that a suture anchor be as small as possible in
order to minimize damage to the tissue in which the suture is
anchored. It is also desirable that a suture anchor be easily
attached, hold the suture firmly in place, and be easily removable
without trauma. Most current suture anchors, especially those for
anchoring in bone, are not easily removable.
SUMMARY OF THE INVENTION
The present invention is an anchor for securing a suture in the
body. The suture anchors of the present invention are usable in
soft tissue as well as in bone. The anchor includes a tubular wall
having a central axis. The tubular wall has a proximal end and a
distal end each free of axially inwardly extending slots. The
tubular wall has an inner surface extending for the entire length
of the tube and defining in the anchor a central opening extending
between the proximal end and the distal end. The anchor has a width
less than its length.
A suture may extend through the anchor within the central opening.
First and second end portions of the suture extend out of opposite
ends of the anchor and are sufficiently long to project out of the
body when the suture is secured in the body by the anchor.
The anchor has an anchoring orientation in the body achieved by
manipulation of the distal end of the anchor by pulling on the
second end portion of the suture. The anchor has a removal
orientation in the body achieved by manipulation of the proximal
end of the anchor by pulling on the first end portion of the
suture.
The present invention also relates to a method of anchoring to a
bone a suture having first and second end portions. The method
includes the steps of:
threading the suture through an anchor having proximal and distal
end portions so that the suture extends completely through the
anchor, the first end portion of the suture extends in a first
direction out of the proximal end portion of the anchor, and the
second end portion of the suture extends in a second direction out
of the distal end portion of the anchor;
inserting the suture and the anchor distally into the bone in an
insertion/release orientation in which (a) the first end portion of
the suture extends proximally from the proximal end portion of the
anchor to a location outside of the bone, and (b) the second end
portion of the suture extends distally into the bone from the
second end portion of the anchor and wraps proximally back around
the anchor and extends proximally past the outside of the anchor to
the location outside of the bone, the anchor and the first and
second end portions of the suture being generally parallel with
each other when the anchor and the suture are in the
insertion/release orientation; and
causing the anchor to pivot within the bone to an anchoring
orientation different from the insertion/release orientation by
pulling at the location outside of the bone on the second end
portion of the suture.
The invention also relates to a method of anchoring a suture to a
bone having a harder outer layer and a softer inner layer. The
method includes the steps of: providing an opening extending from a
location outside of the bone through the harder outer layer of bone
into the softer inner layer of bone; connecting a suture with a
suture anchor; inserting the suture anchor with the suture
connected thereto through the opening into the softer inner layer
of bone; and pulling on the suture to change the orientation of the
anchor within the softer inner layer of bone to block movement of
the anchor out of the opening.
The invention also relates to a method of anchoring a suture in
soft tissue .
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other features of the present invention will
become apparent to one skilled in the art to which the present
invention relates upon consideration of the following description
of the invention with reference to the accompanying drawings,
wherein:
FIG. 1 is a perspective view of a suture anchor in accordance with
the present invention;
FIG. 2 is a longitudinal sectional view of the suture anchor of
FIG. 1;
FIG. 3 is an end view of the suture anchor of FIG. 1 taken along
line 3--3 of Pig. 2;
FIG. 4 is a perspective view showing a suture threaded through the
suture anchor of FIG. 1;
FIGS. 5-9 illustrate schematically the insertion of the suture
anchor of FIG. 1 in bone with the aid of an inserter in accordance
with the present invention;
FIGS. 10A-10B illustrate schematically the use of the suture anchor
for anchoring different objects to body tissue;
FIGS. 11-16 illustrate schematically the removal of the suture
anchor;
FIGS. 17-20 illustrate alternative anchor constructions;
FIGS. 21 and 22 illustrate an alternative inserter
constructions;
FIGS. 23-25 illustrate the forming of an anchoring opening in bone
with a cannulated drill and a K-wire;
FIG. 26 is a pictorial view of an alternative anchor construction;
and
FIG. 27 is a longitudinal sectional view of the anchor of FIG.
26.
DESCRIPTION OF PREFERRED EMBODIMENT
The present invention relates to a suture anchor and particularly
to an anchor for anchoring a suture to body tissue such as bone and
to a method for such anchoring and removal. The present invention
is applicable to various anchor constructions. As representative of
the present invention, FIG. 1 illustrates a suture anchor 10. The
anchor 10 is a cylindrical member with a tubular wall 12 extending
about a longitudinal axis 14 of the anchor. The wall 12 has a
cylindrical outer surface 16 and a cylindrical inner surface 18.
The inner surface 18 of the anchor 10 defines a cylindrical central
channel 20 extending longitudinally through the anchor 10.
The anchor 10 has a first end portion indicated generally at 30, a
second end portion indicated at 32, and an intermediate portion
indicated generally at 34. The present description assumes that the
first end portion 30 will be inserted into the body tissue as the
leading end portion of the anchor 10. For purposes of the present
description, the anchor first end portion 30 will therefore be
described as a distal end portion of the anchor, and the second end
portion 32 will be described as a proximal end portion. The anchor
10 as illustrated in FIG. 1 is uniform and symmetrical in its
construction, and accordingly either end of the anchor 10 can serve
as the leading or distal end portion of the anchor upon
insertion.
The anchor proximal end portion 32 has an annular end face 36
extending radially between an inner periphery 38 and an outer
periphery 40. The inner periphery 38 is the proximal end of the
cylindrical inner surface 18 and of the central channel 20 of the
anchor 10. The distal end portion 30 of the anchor 10 includes an
annular end face 42 extending radially between an inner periphery
44 and an outer periphery 46. The inner periphery 44 terminates the
distal end of the cylindrical inner surface 18 and of the central
channel 20 of the anchor 10.
The anchor 10 is made of a biocompatible material. Suitable
materials include stainless steel or titanium (presently
preferred), cobalt chrome and other biocompatible metals. Plastic
can also by used, suitable materials including polyethylene; and
biodegradable materials such as PLA and PGA when the anchor is to
be left in the body.
The anchor 10 is longer than it is wide. That is, the length of the
anchor 10, between its distal end face 42 and its proximal end face
36, is greater than the outer diameter of the anchor 10. The anchor
10 must be long enough, relative to its width, so that when rotated
it does not accidentally back out of an opening through which it is
inserted into body tissue such as bone. More specifically, the
anchor must be longer than the diameter of the opening through
which it is inserted into body tissue such as bone. However, the
anchor 10 should not be longer than necessary, so as to avoid
unnecessary tissue damage.
Applicants have found that a suitable range of dimensions is from
about length equals 1.5 times width to about length equals four
times width. It is preferred that the length to width ratio be
about three to two for an anchor in bone, and longer (possibly four
to one) for a soft tissue anchor. One anchor that has been
constructed is about two millimeters long, about one millimeter in
diameter, and has a central channel with a diameter of about
one-half millimeter. This central channel diameter is suitable for
receiving a number two suture therethrough. Other anchors which
have been constructed and tested range in length from three
millimeters to four millimeters.
The anchor 10 is for use in anchoring a suture such as a suture 50
(FIG. 4) in body tissue such as bone. The suture 50 is threaded
completely through the central channel 20 of the anchor 10. A
distal portion 52 of the suture 50, including a suture distal end
54, extends from the distal end portion 30 of the anchor 10. A
proximal portion 56 of the suture 50, including a suture proximal
end 58, extends from the proximal end portion 32 of the anchor 10.
An intermediate portion 60 of the suture 50 is disposed within the
anchor central channel 20, inside the wall 12 of the anchor 10.
The inner diameter of the anchor 10, i.e., the cross sectional
width of the central channel 20 as defined by the anchor inner
surface 18, is preferably greater than the width or diameter of the
suture 50. Thus, the suture 50 can pass freely through the anchor
10. The anchor inner surface 18 guides movement of the suture 50
within the anchor 10. There are no knots holding the suture to the
anchor 10. Knots tend to weaken the system. Also, there are no
axially extending slots in the anchor 10 into which the suture 50
can enter.
When the suture 50 extends through the anchor 10, the suture is
engageable with the proximal and distal end portions 32 and 30,
respectively, of the anchor. The anchor proximal end portion 32,
including the end face 36 and the inner edge 38, directs movement
of the suture 50 into and out of the anchor 10 through the proximal
end portion 32. The anchor distal end portion 30, including the
annular end face 42 with its edges 44 and 46, directs movement of
the suture 50 into and relative to the distal end portion 30 of the
anchor 10.
The suture anchor 10 can be used to anchor the suture 50 in body
tissue such as a piece of bone indicated schematically at 60 in
FIG. 5. The bone 60 has an outer surface 61, a harder outer layer
62 of cortical bone and a softer inner layer 64 of cancellous bone
or marrow. A more or less well defined boundary 66 separates the
outer layer 62 from the inner layer 64.
An opening 70 is provided in the bone 60 to receive the anchor 10
to secure the suture 50 to the bone 60. The opening 70 may be a
pre-existing opening or may be operatively provided as by drilling.
The opening 70 preferably extends completely through the layer of
cortical bone 62, as it is much more difficult to drive an anchor
or suture through the hard cortical bone. It may be desirable to
extend the opening 70 at least part way into the softer layer of
bone 64, as illustrated in the drawings, to initially provide some
room for the anchor 10 to change its orientation within the bone
60. It may not, however, be necessary to extend the opening 70 into
the softer bone layer 64 as shown. The layer 64 may be soft enough
to receive the anchor 10 directly.
The width of the opening 70 should be about the same size as or
slightly larger than the width of the anchor 10. This will allow
room for the anchor 10 to be satisfactorily driven into the bone
60, while minimizing the possibility of the anchor 10 accidentally
backing out of the bone 60 through the opening 70. The opening 70
is preferably formed with a cannulated drill 99 (FIGS. 23-25) over
the K-wire 98. The K-wire 98 is first inserted into the bone 60
(FIG. 23), through the cortical bone 62 into the cancellous bone
64. The cannulated drill 99 (FIG. 24) is then placed over the
K-wire 98 and used to form the opening (FIG. 25) in the bone
60.
After the suture 50 is threaded through the anchor 10 as
illustrated in FIG. 4, the anchor is set in the bone 60 with the
aid of an inserter 80 (FIG. 5.). The inserter 80 is a cannulated
inserter (having the suture extending through it). The inserter 80
includes a pusher 82 and a guide 84. The pusher 82 is a cannulated
or tubular member having a widened proximal end portion 86 and a
tapering conical distal end portion 88. A central channel 90
extends through the length of the pusher 82. The pusher 82 is
slidingly received in a central channel 96 of the tubular guide 84.
The guide 84 has a widened proximal end portion 92 and a flanged
distal end portion 94.
The inserter 80, the suture 50, and the anchor 10 are placed in the
relative positions shown in FIG. 5 over a K-wire (indicated
schematically at 98) extending through the central channel 90 of
the pusher 82. The inserter guide flange portion 94 is placed
against the outer surface 61 of the bone 60. The proximal end face
36 of the anchor 10 is in abutting engagement with the distal end
portion 88 of the pusher 86. The proximal portion 56 of the suture
50 extends through the central channel 90 of the 92, and the
proximal end 58 of the suture extends out of the inserter 80 to a
location outside the bone 60. The distal portion 52 of the suture
50 wraps back around the anchor 10 proximally, and the distal end
54 of the suture extends out of the guide channel 96 to a location
outside the bone 60.
The pusher 82 is then moved (FIG. 6) along the central channel 96
of the guide 84, toward the bone 60, until the anchor 10 is in the
desired position in the opening 70 in the bone 60. The K-wire 98 is
then removed to allow manipulation of the anchor 10.
When the anchor 10 is in the insertion condition shown in FIG. 6,
the intermediate portion 60 of the suture 50 is disposed within the
anchor 10. The suture portion 52 extends distally out of the distal
end portion 30 of the anchor 10. The suture portion 52 extends
around the annular distal end face 42 of the anchor 10 and wraps
back around the anchor 10 in a proximal direction. The suture
portion 52 extends proximally along or past the outside of the
anchor 10 to the proximal end portion 32 of the anchor 10 and
thence proximally such that the distal end portion 54 of the suture
50 extends to a location outside the bone 60. Thus, when the anchor
10 is in position to be anchored in the bone 60, the suture 50 is
threaded completely through the anchor 10 and both ends 54 and 58
of the suture project out of the opening 70 to a location outside
of the bone 60.
The orientation of the anchor 10 within the bone 60 is then changed
to a blocking orientation as seen in FIGS. 7-9 to block removal of
the anchor from the bone. The distal end 54 (FIG. 7) of the suture
50 is pulled proximally, as indicated by the arrow 100. This
pulling force is transmitted through the suture portion 52 to the
distal end portion 30 of the anchor 10. Because the suture portion
52 wraps around the distal end portion 30 of the anchor 10, tensile
force on the suture portion 52 in the direction indicated by the
arrow 100 imparts a pivoting or rotational moment to the anchor 10.
The anchor 10 rotates or pivots in the direction indicated by the
arrow 102 from the insertion condition shown in FIG. 6, through
intermediate positions shown in FIGS. 7 and 8, to the blocking
position or condition shown in FIG. 9. The tapered surface of the
plunger end portion 88 aids in pivoting the anchor 10 as desired.
The anchor 10 pivots relatively freely in the softer inner layer of
bone 64.
To set the anchor firmly, both ends of the suture 50 are pulled
outward to set the anchor 10 firmly against the outer layer of bone
62. In this position, the anchor 10 lies generally parallel to the
surface of the bone 60 and generally perpendicular to the insertion
direction of the opening 70. The distal suture portion 52 is
clamped against the undersurface 66 of the cortical bone layer 62
by the outer surface 16 of the anchor 10 at the distal end portion
30 of the anchor. The proximal suture portion 56 is clamped against
the undersurface 66 of the cortical bone layer 62 by the anchor
outer surface 16 at the proximal end 32 of the anchor 10. Thus, the
suture 50 is secured in the bone 60.
When the anchor 10 is in the blocking condition, the anchor is
oriented in the bone 60 across the opening 70 in the outer bone
layer 62. Because the anchor 10 is longer than it is wide, and
because the opening 70 in the outer bone layer 62 is only large
enough to accept the width of the anchor 10 and not the length of
the anchor 10, the anchor cannot move through the opening in the
outer bone layer when the anchor is in the blocking orientation or
condition. The suture 50 may then be used to attach muscle or
ligament or other tissue to the bone 60. The suture 50 may also be
used to attach implants or other devices to the bone 60.
FIGS. 10A and 10B illustrate schematically several uses for the
suture anchor 10. In FIG. 10A, the suture anchor 10 and the suture
50 are shown securing an implant or splint 130 to the bone 60. In
FIG. 10B, the suture anchor 10 and the suture 50 are shown securing
soft tissue such as a muscle 140 to the bone 60 with a knot 142.
The suture anchor 10 can be used in any manner as needed for
anchoring a suture to bone, soft tissue, etc.
To aid in placement of the anchor 10 in the bone 50, a K-wire such
as the K-wire 98 (FIGS. 5 and 6) is used. The K-wire is inserted
into the bone 60 as shown in FIG. 23, preferably into the inner
bone layer 64 past (deeper than) the point where the anchor will
be. Next, a cannulated drill 99 (FIG. ) is placed over the K-wire
98 and rotated to make the opening 70 in the bone 60. FIG. 25
illustrates the opening 70 after drilling and removal of the drill
99. Note that the opening 70 is not as deep as the K-wire 98 is
driven. The anchor is then inserted into the bone as discussed
previously.
The suture anchor 10 is easily removable from the bone 60 without
causing trauma to the bone. FIGS. 11-16 illustrate sequentially the
removal process.
In FIG. 11, the anchor 10 is shown in its anchoring or blocking
position lying parallel to the bone surface 61 and transverse to
the opening 70. The inserter 80 is placed over the opening 70. One
end 58 of the suture 50 is threaded up through the central opening
90 in the inserter pusher 84. The other end 54 of the suture 50 is
threaded up between the pusher 84 and the guide 82 in the central
channel 96 of the guide.
The pusher 84 is moved distally (down) into contact with the anchor
10 (FIG. 11). The pusher 84 (FIG. 12) is then moved further down
into the bone 60 to move the anchor 10 away from the outer bone
layer 62 and allow room for the anchor to rotate within the inner
bone layer 64. The surgeon then pulls in the direction indicated by
the arrow 110 (FIG. 13) on the suture end 58 which projects out of
the central channel 90 of the pusher 84. The tensile force on the
suture end 58 causes the anchor 10 to rotate within the bone 60 in
the direction indicated by the arrow 112. The tapered pusher end
portion 88 assists in initiating and controlling rotation of the
anchor 10. The anchor 10 rotates within the bone 60 until it is
disposed transverse to the bone surface 61 and parallel to the
opening 70, as illustrated in Pig. 14. The anchor 10 is then in a
release condition which is effectively the same as its insertion
condition (FIG. 6). The anchor 10 and the pusher 84 are then
removed distally from the bone 60 as illustrated in FIGS. 15 and
16.
This removal technique has been shown to work in 42 of 42 clinical
trials.
There are several features of the anchors of the present invention
which contribute to their ease of use, especially in removal. They
do not anchor themselves by digging into tissue as does a screw or
an anchor with a pointed end. Instead, they rely on not being able
to fit back through the hole they went in. Because they do not have
axially inwardly extending slots or other non-uniform
configurations at their ends, they can be turned within the
cancellous bone to a vertical position (parallel to and aligned
with the insertion opening) and thus made removable simply by
pulling on the appropriate suture end. The non-oblique ends of the
anchors, i.e., 90.degree. end faces or curved or tapered end faces,
do not bite into the bone and thus do not inhibit removability;
rather, they allow easy rocking for change of orientation between
insertion/removal and anchoring. The lack of knots avoids stress
risers in the suture. There are no slots in the anchor to cut the
suture.
FIGS. 17-20 illustrate schematically several alternative anchor
configurations. An anchor 150 (FIG. 17) which is symmetrical
end-to-end has a cylindrical outer surface 152 and two tapered end
surfaces 154 (only one of which is shown). The tapered end surface
154 extends between an annular end face 156 and the cylindrical
outer surface 152. An anchor 160 (FIG. 18) has a cylindrical outer
surface 162 and a curved end surface 164. The curved end surface
164 extends between an annular end face 166 and the cylindrical
outer surface 162. An anchor 170 (FIG. 19) has a cylindrical outer
surface 172 and at each end a curved end surface 174. The curved
end surfaces 174 extend between annular end faces 176 and the
cylindrical outer surface 172. A tapered (non-90.degree.) anchor
end is not for the purpose of biting into the tissue to lock the
anchor in place. It is for the purpose of the anchor pushing its
way through intermediate tissue to get to the anchoring location.
Then, the cocking (pivoting) of the anchor holds it in place. A
sharp device can migrate within the body, which is highly
undesirable.
An anchor 180 (FIG. 20) is similar to the anchor 10 (FIG. 1) but
has four side openings through which a suture 82 enters and exits
the anchor 180. The suture 182 extends into the anchor 180 through
an opening 184 and passes out the opposite side through an opening
186. The suture 182 loops around at 188, extends back into the
anchor 180 through an opening 190 and passes out the opposite side
through an opening 192. With this anchor construction, also,
pulling on one or the other of the projecting suture ends causes
cocking or rotation of the anchor to change its orientation between
an insertion or release condition to a blocking condition.
In the embodiments of FIGS. 1-17, 19 and 20, the anchors are
uniform and have the same shape at each end. Thus, for example, the
distance (i) from any first point on the end face 36 of the anchor
10 (FIG. 2) measured along a line extending parallel to the central
axis 14 to a second point on the opposite end face 42, is the same
as (ii) the distance from any third (other) point on the end face
36 measured along a line extending parallel to the central axis 14
to a fourth point on the opposite end face 42. Similarly, with the
anchor 170 (FIG. 19), the distance (i) from any first point on one
of the curved end surfaces 174 measured along a line extending
parallel to the central axis of the anchor to a second point on the
opposite curved end surface 174, is the same as (ii) the distance
from any third (other) point on the first end surface 174 measured
along a line extending parallel to the anchor central axis to a
fourth point on the opposite curved end surface 174, is the third
point is disposed on the anchor at the same distance from the
axially outermost point of the first end of the anchor as is the
first point.
FIGS. 21 and 22 illustrate an alternative inserter construction.
The inserter 200 (FIG. 21) includes a pusher 202 having a
cylindrical wall 204. The wall 204 has a cylindrical inner surface
206 defining a central passage 208. The wall 204 has a handle 210
at its proximal end and a tapered distal end portion 212.
The inserter 200 includes a depth gauge 220 connected with the
pusher 202 for movement with the pusher 202. The depth gauge 220 is
a cylindrical member having an internal surface 222 defining a
central passage 224 through the depth gauge. The depth gauge 220
has a threaded portion 226 threadedly received in the central
passage 208 of the pusher 202. The depth gauge 220 has an indicator
portion 228 projecting outwardly from the central passage 208 of
the pusher 202. The indicator portion 228 has a distal end surface
230 and depth markings 232. The depth gauge 220 is rotatable within
and relative to the pusher 202 to have a particular depth marking
adjacent the distal end portion 212 of the pusher 202.
In use, the depth gauge 220 is set so that a particular depth
marking is showing adjacent the distal end portion 212 of the
pusher 202, corresponding to the estimated thickness of the
cortical bone portion 62 at the location of anchor insertion. An
anchor such as the anchor 10 is then placed on the distal end 230
of the depth gauge with a suture such as the suture 50 threaded
through in the same manner as described above. The proximal end 58
of the suture 50 extends through the central passage 224 of the
depth gauge 220 and through the central passage 208 of the pusher
202 to a location outside the body. The distal end 54 of the suture
50 extends through the opening 70 around the outside of the depth
gauge indicator portion 228 and past the tapered end portion 212 of
the pusher 202 to a location outside the body.
The assembly is moved into the opening 70 as shown in FIG. 22,
possibly over a K-wire 98. When the distal end portion 212 of the
pusher 202 engages the outer surface 61 of the bone 60, the anchor
10 is in its proper position. The inserter 200 and the K-wire 98
may then be removed. The anchor 10 is then rotated within the
softer inner layer 64 of the bone 60 to an anchoring position as
shown in FIG. 9.
The methods and principles involved in soft tissue anchoring are
similar to those involved in anchoring in bone. In joining soft
tissue to soft tissue, it is preferable to insert the anchor
directly through the soft tissue, not into an opening in the
tissue. Thus, the anchor may have a slightly sharpened or pointed
distal end (tip) to push through the tissue layers. Also, both the
anchor and the insertion tool may be made curved, or may be made of
an elastic material, in order to be able to be pushed over a curved
K-wire.
In bone it is necessary to drill a hole to get the anchor into
position. Unlike bone, soft tissue is highly visco-elastic. In soft
tissue, one can simply push the tissue away from the intended
location of the anchor. As the anchor is pushed through a certain
location by the insertion tool, the tissue is pushed from that
location. Once the anchor is pushed through a position by the
insertion tool, the tissue pushed away will collapse back over the
suture and not allow the anchor to be pulled out easily.
In soft tissue applications, the needle goes in to the tissue
first. It can be straight or curved. The curved needle may be
enough to cut the way into the soft tissue, like a knife cutting a
slot for a meat thermometer in a roast. A tapered or bullet shaped
anchor pushes the tissue out of its way as it proceeds along the
needle/guide wire.
FIGS. 26 and 27 illustrate an alternate anchor construction. The
anchor 240 is of a generally cylindrical construction like the
anchor 10. The anchor 240 has end portions 242 and 244 which flare
radially outwardly. This can minimize cutting of a suture passing
through the anchor 240, such as the suture 246. In any of these
anchor constructions, it is desirable to avoid sharp edges, and so
the ends may be rounded or polished or de-burred.
From the above description of the invention, those skilled in the
art will perceive improvements, changes and modifications in the
invention. Such improvements, changes and modifications within the
skill of the art are intended to be covered by the appended
claims.
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