Note: Descriptions are shown in the official language in which they were submitted.
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SUTURE ~NCHOR SYSTEM ~ND METHOD
~ S P F: C T F T C A T I O N
RACKGROUND OF TH~ TNV~NTTON
F1el~ of the Tnvention
This invention relates to medical equipment and in
particular to devices and methods for securing a suture to a
bone for use in maintaining a section of a ligament or soft
tissue thereto.
Pr;or A~t
Devices and methods for positioning and securing an
anchor, fastener or the like to a bone to secure a suture
thereto that is used to fasten a section of a ligament, or the
like, are well known. A number of earlier inventions of one
or both of the present inventors show several different suture
anchor arrangements and drivers. For example, one such a
driver mounting a suture anchor wherefrom a suture extends that
is for turning the anchor into a bone is shown in a U.S. Patent
to E. Marlowe Goble, No. 4,632,100. Also, other driver and
suture anchor combinations of one or both of the present
inventors, U.S. Patent No's. 5,411,506 and 5,411,523, have
provided for turning an anchor whereto a suture is connected
into a bone for use in mounting a ligament, or the like, to
that bone. Further, other patents to one of the present
inventors, U.S. Patent No.'s 4,738,255, 5,013,316 and
5,141,520, illustrate other driver and anchor combinations and
ligament mounting arrangements are shown in U.S. Patent No's
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4,772,286 and Re. 34,293, 4,870,957, 4,927,421, 4,997,433,
5,129,902, 5,352,229. Unlike these earlier suture anchor and
driver combinations, however, the present invention provides
for seating and mounting a suture directly into a hole drilled
or otherwise formed into a bone without a need to use a
separate anchor or driver.
A number of combinations of anchors, some of which include
~rrangements for capturing, maintaining and fitting sutures to
extend from seated anchors are shown in U.S. Patents issued to
others, No.'s 4,779,616; 4,946,468; 5,071,420; 5,100,417;
5,102,421; 5,139,520; 5,207,679; 5,211,650; 5,224,946;
5,236,445; and 5,258,016. None of these patents, however,
provide for a direct mounting of a suture into a bone material
that are like the arrangement of the invention that provides a
simple and easily practiced system and process for rapidly and
reliably mounting a suture to a location on or into a bone
surface.
SUM~Y OF TH~ INV~NTION
It is therefore a principal object of the present
invention in a suture anchor system and procedure to provide
for mounting a suture to a selected location in a bone cortex
for connecting a ligament, or the like, thereto.
Another object of the present invention is to provide a
suture anchor system that can be a single suture strand, or
multiple suture strands and with or without a knot formed in
the end thereof, with the suture strand or strands end for
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fitting in a hole that has been formed into a bone to receive
an adhesive to encapsulate the suture or sutures end within the
hole, mounting it therein.
Another object of the present invention is to provide a
suture anchor system that may be a single suture or multiple
sutures that are wound, braided, or otherwise maintained
together, for fitting into a hole that is formed into a bone
cortex so as to provide a hole wall area and depth relationship
to the suture or sutures cross section and length of a suture
section for fitting into and bond in which hole when the hole
is filled with a particular adhesive.
Another object of the present invention is to provide for
filling the formed hole with the adhesive that will, when
cured, encapsulate the suture or sutures therein, bonding to
the hole wall and suture or sutures to permanently mount the
suture or sutures therein, with portion or portions of the
suture or sutures extending from the bone surface for
attachment to a ligament, or the like.
Another object of the present invention is to provide a
suture anchor system that, to increase pullout strength of an
anchored suture, a single suture or plurality of sutures ends
that are for fitting into the bone hole are knotted and receive
an adhesive in that bone hole that, when dried, bonds to both
the hole wall and knotted suture or sutures, the knot or knots
to add additional pullout strength over a suture or sutures
without such knotted end.
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Still another object of the present invention is to
provide a suture anchor system where, to increase pullout
strength of an anchored suture, the bone hole is formed to have
an outwardly sloping skirt portion, increasing the hole
interior surface area.
Still another object of the present invention is to
provide a process for securing a suture or sutures to a bone
cortex where a hole is drilled into a bone material that is of
a determined width and depth to receive an end portion a suture
or sutures fitted therein and receive an adhesive to
encapsulate the suture or sutures end portion or portions and
bond thereto and to the bone hole wall surface prohibiting the
suture or sutures end portion or portions from being pulled
therefrom when an anticipated or greater tensile force is
applied to the suture or sutures.
Still another object of the present invention is to
provide a suture or sutures end portion or portions mounting
that is simple and reliable to use for mounting a suture or
sutures to a bone cortex surface, w~th the suture or sutures
then used for attaching to a ligament, or the like.
In accordance with the above objects, the present
invention is in a suture anchor system and process for mounting
a suture or sutures into, so as to extend from, a bone material
surface for attachment to a ligament, or the like. The system
includes a single suture or a number of sutures that may be
wound, braided, or otherwise maintained together, with an end
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portion or portions of the suture or sutures ~or fitting into
a hole that has been formed through a bone cortex surface and
into the bone material. The hole is formed to have a diameter
and depth such that, with the suture or sutures end portion or
portions fitted therein, and with an introduction of an
adhesive or resin therein, and after adhesive or resin drying,
curing or polymerizing, the ~uL~e end portion or portions will
be secured within the hole, resisting withdrawal when a tensile
stress is applied thereto. The suture or sutures end portion
or portions can be knotted and fitted within the prepared hole
to increase suture surface area, producing a greater purchase.
In practice, a bone hole diameter and depth are selected
for the material of the bone whereto the suture or sutures are
to be attached, taking into account the suture or sutures
portion or portions length as will be fitted in the hole and
thickness and whether the suture or sutures end portion or
portions are knotted, and considering the adhesive to be used.
In practice, an adhesive known as polymethlymethacrylate
(PMMA), similar to that manufactured by Howmedica, Richards or
Zimmer USA, that will dry within approximately one to twenty
minutes has been used. Further, a light activate resin as
commonly used by dentists can be used as the adhesive for this
invention.
The pullout strength or purchase of the mounted suture or
sutures that is the resistance to the suture or sutures being
pulled out of the mount can be increased when the suture or
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sutures end or ends has been knotted. A hole of the invention
formed into a bone mass should have a hole wall surface area
that is at least equal to the suture or sutures thickness and
length of the suture portion that is for positioning in the
hole. In practice, this purchase should be the tensile
strength of the suture or sutures mounted in the hole.
With the single suture or plurality of sutures end or ends
adhesively mounted within the bone hole, the 8uture or sutures
can be used to tie a ligament, or the like, onto that bone
surface.
RRI~F ~CRTPTTON OF TH~ DRAWINGS
These and other objects and features of the invention will
become more fully apparent from the following description, in
which the invention is described in detail in conjunction with
the accompanying drawings. In which drawings:
Fig. 1 is a side elevation view of a section of bone
showing straight holes formed into the bone cortex utilizing an
awl or k-wire, twist drill and twist drill with a
countersinking collar;
Fig. 2 is a view like that of Fig. 1, with the formed
holes shown as receiving a tool fitted therein whereover are
positioned single suture, plurality of sutures and a plurality
of sutures knotted together;
Fig. 3 is a view like that of Fig 2, showing the formed
holes with the tools removed and an adhesive filling the
individual holes;
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Fig. 4 is a side elevation view of a section of bone
material with a shallow broad hole formed therein that a
knotted section or portion of a pair of sutures has been fitted
into, with the hole shown filled with an adhesive;
Fig. 5 is a side elevation view of a section of bone
material showing a deep narrow hole formed therein wherein a
knotted end portion of a single suture has been positioned and
showing the hole filled with an adhesive;
Fig. 6 is a side elevation view of a section of bone
material wherein a narrow hole has been formed that is deeper
than the hole of Fig. 5, and contains a straight end section or
portion of a single suture fitted therein and showing the hole
filled with an adhesive;
Fig. 7A is a side elevation view of a scissoring twist
drill shown drilling a straight hole into a section of bone
material;
Fig. 7B is a view like that of Fig. 7A except a collar
portion of the scissoring twist drill is shown as having
traveled upwardly along a drill shaft with the upper ends of
reaming arms of the drill shown scissoring outwardly and skirt
cutting elements of the drill shown extending outwardly to form
a hole in the bone material that has an outwardly flared
interior wall;
Fig. 7C is a view like that of Fig. 7B with the collar
shown returned to the attitude shown in Fig. 7A, closing the
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reaming arms showing the scissoring twist drill being pulled
out of the formed hole; and
Fig. 8 is a view of the hole formed in the bone material
utilizing the scissoring twist drill of Figs. 7A, 7B and 7C,
~howing a knotted end of a single suture positioned therein and
showing the hole filled with an adhesive.
D~TATT~ D~CRTPTTON
Figs. 1, 2 and 3 show a side elevation view of a section
of bone material lo wherein, as shown in Fig. 1, holes are
formed into the bone material as by utilizing an awl or k-wire
11, turning a twist drill 12 and twist drill with
countersinking collar 13, forming straight holes 14, 15 and 16,
respectively. Fig. 2 shows the holes 14, 15 and 16 as having
received, respectively, a straight suture 17, a pair of sutures
18 twisted together and a pair of sutures 19 that have a knot
20 tied therein. The single and twisted pair of sutures 17 and
18, respectively, are shown fitted into the respective holes 14
and 15 by folding forward sections of each over an end of a
straight insertion rod 21. Which insertion rod includes
parallel forward end sections 22 with a space or gap 23
therebetween wherein the suture or sutures are maintained.
After, the insertion rod 21 is withdrawn, the folds of the
suture 17 and sutures 18 remain in the holes 14 and 15, as
shown in Fig. 3. Shown in Fig. 2 the sutures 19 are folded
back upon themselves at knot 20, providing sufficient rigidity
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I
to allow the suture knot to be slid by an operator into the
hole 16.
With the respective suture 17, eutures 18 and knot 20 of
sutures 19 fitted into the prepared holes 14, 15 and 16, ~hown
in Fig. 2, and after removal of insertion rod 21, the holes 14,
15 and 16 are filled with an adhesive 24, as shown in Fig. 3.
The adhesive is selected to provide, after curing, for
maintaining the suture or sutures in the holes 14, 15 and 16,
respectively, to withstand a tensile stress as it is
anticipated will be exerted thereon. Which tensile stress is
at least a stress as would be exerted on the mounting when the
suture or sutures are used to connect a ligament, tendon or
soft ti ~11~ onto the bone surface, or a like use. In practice,
to provide which desired pullout strength or purchase, adhesive
24 is selected to be both easily applied and quick curing. An
adhesive known as polymethlymethacrylate (PMMA), has been used
successively for practicing this procedure, though, it should
be understood, the invention is not limited to use of such
material and any adhesive material as is suitable for
implantation in a human body, such as a grout filling, other
adhesive, bone paste, bone plug, light activated resin as used
in dental procedures, or the like, can be so used within the
scope of this disclosure.
Figs. 7A, 7B and 7C show a scissoring twist drill 30 as an
example of a device for use for forming an inwardly flared or
skirt shaped hole 31 in a bone material 29, as shown in Fig. 8.
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The hole 31, like the above described holes 14, 15 and 16, is
to receive a suture or sutures, shown as a single suture 32 in
Fig. 8. The suture 32 can, but is not required to have, a knot
33 tied in an end thereof, or the like, and is fitted in the
hole 31 to receive an adhesive 34 therearound that fills hole
31 and, when cured, secures the suture 32 in the bone material
29.
The scissoring twist drill 30, shown in use in Figs. 7A,
7B and 7C, as set out herein, is an example of a drill type
device ~or forming an inverted counter bore or skirt shaped
hole 31 for use as set out above. It should, however, be
understood that other arrangements for forming a hole like hole
31 into bone material 29 could be so used within the scope of
this disclosure. To provide for drilling the hole 31 the
scissoring twist drill 30 is for fitting in and being turned by
a conventional drill, or the like.
As shown, the scissoring twist drill 30 includes a
straight center shaft 35 therethrough that ends in a twist
drill end 35a and is for turning, as shown, into bone material
29. Above the twist drill end 35a, a pair of scissor blades
36a and 36b are mounted to the straight center shaft 35 at
pivot 37 to scissor apart. In which blade scissoring, lower
cutting ends 38a and 38b and upper camming ends 39a and 39b of
the respective scissor blades 36a and 36b spread apart and
extend out from and are to be retracted back into the straight
center shaft 35. Which scissoring action provides for moving
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the cutting ends 38a and 38b outwardly to the attitude shown in
Fig. 7B. The extended cutting ends of the turning drill 30
ream the hole 31 walls of to the shape shown in Figs. 7B, 7C
and 8, when the camming ends 39a and 39b are spread apart.
With, when the CA ing blades are moved together, as shown in
Figs. 7A and 7C, the cutting ends 38a and 38b are retracted
into the straight shaft 35. To provide for which ~A~i ng
blades travel, the camming blades each include an outwardly
slopping surface 40a and 40b, respectively, from a narrow
rounded top end 4la and 4lb, to an inwardly stepped section,
respectively. The CA ing blades top ends 41a and 41b maintain
the scissoring blades in a retracted attitude shown in Figs 7A
and 7C, so long as a first sleeve 42 is fitted thereover. The
sleeve 42 is preferably biased by a spring, not shown, to
resist positioning over the c~ ing blade top ends. To extend
or outwardly pivot the scissoring blades cutting ends 38a and
38b, to the altitude shown in Fig. 7B, a second sleeve 43 is
journaled to the straight shaft to remain stationary as the
straight shaft is turned and, engages the first sleeve 42 that
moves over the cA~ing blade top ends 4la and 4lb, as shown in
Figs. 7A and 7C. To control which second sleeve 43, a handle
44 is fitted to extend out from the second sleeve surface to be
held by an operator, who manually retracts the first sleeve 42
telescoping into the second sleeve 43, allowing the camming
ends 38a and 38b to spread apart as shown in Fig. 7B.
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In practice, for forming hole 31, an operator holding the
handle 44 in one hand and the sleeve 42 in their other, as
shown in Fig. 7A and drills into the bone material 29. At a
desired depth, the operator holding on the handle 44, pulls the
first sleeve 42 into the second sleeve 43 allowing the
scissoring blades camming ends 39a and 39b to move outwardly
that also pivot the scissoring blade cutting ends 38a and 38b
outwardly. The cutting ends are thereby moved the attitude
shown in Fig. 7B, reaming out the hole 31 to have an inverted
counterbore or skirted top portion, as shown best in Fig. 8.
Thereafter, to remove the twist drill after hole 31 is formed,
holding handle 44, the first sleeve 42 is moved out of the
second sleeve 43, traveling over the scissor blade camming ends
39a and 39b, to pivot the scissoring blades 36a and 36b back
into the straight shaft 35. With the scissoring blades
retracted, as shown in Fig. 7C, the twist drill 30 drill end
35a can be pulled out of the formed hole 31. Which hole 31
then receives, as set out above, a suture end portion and an
adhesive to mount that suture end portion in the hole 31 in
bone material 29.
Figs. 4, 5 and 6 are here provided to illustrate a
relationship between suture configuration and hole dimensions
for providing a required purchase of the suture that is mounted
to the bone material of the invention. In practice, where a
suture is to be used for securing a tendon, ligament, or the
like, onto a bone surface, a pull out strength greater than the
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yield strength of the suture is preferred. Which purchase is
a function of the adhesive properties of a selected adhesive
52, the surface area of the wall of a hole formed into the bone
~,
and the surface area of the portion of a suture or sutures
fitted in the hole that is covered by the adhesive after
curing. Fig. 4 illustrates how a shallow hole 51 formed into
bone material 50 can provide a required purchase to a plurality
of sutures that have been tied into a knot that is arranged in
the hole 51. For the suture mounting of Fig. 4, an adhesive
material 52, like that set out above as adhesive 24 known as
polymethlymethacrylate or crnoacralate, light activated re5in,
or the like, can be used. To compute the purchase as will be
obtained for this adhesive 52 the hole 51 is formed to have a
diameter, shown as d, and height h, to provide a wall area (Aw)
having a surface area that is greater than or equal to the
suture surface area (As) of the portion of the suture that is
in the hole. To provide a required and greater purchase or
pullout strength. For Fig. 4, the suture surface area (As) is
the combined thickness of utures 53 and further includes, at
least the surface area of a knot 54 (Ak) computed utilizing the
knot 54 diameter Kd. Which knot 54 has been tied in the
sutures 53. The knot 54, in practice, effects a column of the
cured adhesive 52 and thereby is believed to further increases
purchase over the purchase obtained considering the suture and
knot surface areas alone.
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To further illustrate a relationship between the hole
dimensions and suture or sutures, Fig. 5 shows a single suture
56 positioned in a hole 55 that is narrower, shown as diameter
d, with a greater height, shown as h, than the hole 51 of Fig.
4. A knot 57 is shown tied in the suture 56 end for further
increasing purchase. For calculating purchase of the suture 56
in the hole 55, after curing of adhesive 52 therein, the hole
area in relation to the suture and knot surface areas are
considered, as set out above, with the presence of knot 57
increasing purchase.
The relationship of hole wall surface area and the suture
surface area, as set out above, is taken into consideration to
provide at least a required purchase using an adhesive 52, as
shown in Fig. 6. Shown therein, a narrow hole 58, shown as
having a diameter d, and has a greater height, h, than the
height of holes 51 and 55 of Figs. 4 and 5, is provided for
mounting a single suture 59 therein. Which suture 59, as
shown, does not have a knot, or the like, formed in the end
thereof. So arranged, as the suture 59 lacks a knot,
additional purchase as such knot would provide is not
available, and the purchase is calculated from the relationship
of the hole wall area and suture surface area only.
While preferred embodiments of the present invention in a
suture mounting system and process have been shown and
described herein, it should be apparent that this disclosure is
made by way of example only and that variations to both the
14
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suture mountings and proc~C-c~c are possible within the scope of
this disclosure without departing from the subject matter
coming within the scope of the following claims and a
reasonable equivalency thereof, which claims we regard as our
invention.
