U.S. patent application number 12/315408 was filed with the patent office on 2010-06-03 for drill guide for cruciate ligament repair.
This patent application is currently assigned to LINVATEC CORPORATION. Invention is credited to Andrew Kam, Hugh S. West.
Application Number | 20100137872 12/315408 |
Document ID | / |
Family ID | 42223495 |
Filed Date | 2010-06-03 |
United States Patent
Application |
20100137872 |
Kind Code |
A1 |
Kam; Andrew ; et
al. |
June 3, 2010 |
Drill guide for cruciate ligament repair
Abstract
A guide that facilitates the creation of two bone tunnels for
use during a "double bundle" cruciate ligament repair. In the case
of an anterior cruciate ligament repair the guide facilitates the
formation of two tibial tunnels extending between a single aperture
on the anterior tibia and two distinct apertures on the tibial
plateau. The guide has a single angled throughbore for guiding a
drill bit on a predetermined angle relative to the anterior portion
of the tibial tunnel. In an alternative embodiment the guide has
two independent and non-intersecting bores which allow the
simultaneous placement into the tibial tunnel of two separate guide
pins to guide the formation of two tibial tunnels on the tibial
plateau.
Inventors: |
Kam; Andrew; (Odessa,
FL) ; West; Hugh S.; (Salt Lake City, UT) |
Correspondence
Address: |
GENE WARZECHA;LINVATEC CORPORATION
11311 CONCEPT BOULEVARD
LARGO
FL
33773
US
|
Assignee: |
LINVATEC CORPORATION
|
Family ID: |
42223495 |
Appl. No.: |
12/315408 |
Filed: |
December 3, 2008 |
Current U.S.
Class: |
606/96 ;
606/88 |
Current CPC
Class: |
A61B 17/1714 20130101;
A61B 17/1764 20130101 |
Class at
Publication: |
606/96 ;
606/88 |
International
Class: |
A61B 17/58 20060101
A61B017/58 |
Claims
1. A guide for guiding a drill bit into a preformed bone tunnel
having a first diameter, said guide comprising: an elongated body
having a proximal end, a distal end, a first axis and a cylindrical
portion at said distal end, said cylindrical portion coaxial with
said axis and having a predetermined outer diameter adapted to fit
within said bone tunnel; a bore extending through said cylindrical
portion, said bore having a second axis, oriented at a
predetermined angle relative to said first axis.
2. A guide according to claim 1 further comprising: a transverse,
distally facing end surface coaxially situated on said cylindrical
portion.
3. A guide according to claim 2 wherein at least a portion of said
bore intersects said end surface.
4. A guide according to claim 1 further comprising a bore having a
third axis oriented at a predetermined angle relative to said first
and second axes.
5. A guide according to claim 1 wherein, when said guide is
inserted into a bone tunnel, said bore is adapted to receive and
guide an elongated drill bit into the bone around the bone tunnel
at a predetermined angle relative to the tunnel axis.
6. A tibial guide for guiding a plurality of guide pins into a
preformed tibial bone tunnel comprising: a body having an axis and
a distal portion thereof adapted to be received in the bone tunnel;
an axial bore extending through said body; a first bore through
said distal portion for receiving a first guide pin and directing
it through said body toward a first point on the tibial plateau,
said first bore inclined at a first predetermined angle relative to
said axis; and a second bore through said distal portion for
receiving a second guide pin and directing it through said body to
a second point on the tibial plateau, the second point being spaced
a predetermined distance from said first point, said second bore
inclined at a first predetermined angle relative to said axis.
7. A tibial guide according to claim 6 wherein said first and
second bores are each inclined relative to said axis.
8. A tibial guide according to claim 6 wherein said second point is
posterior to said first point.
9. A tibial guide according to claim 7 wherein said first and
second bores do not intersect said axis.
10. A tibial guide according to claim 9 wherein said first and
second bores are each inclined relative to said axis in two
orthogonal views.
11. A tibial guide according to claim 10 wherein said orthogonal
views are lateral and anterior-posterior.
12. A method of creating a pair of tibial bone tunnels, each having
a separate exit aperture on the tibial plateau, said method
comprising the steps of: forming a first bone tunnel extending from
the anterior tibia toward but not through the tibial plateau;
providing a guide for guiding a drill bit into a preformed bone
tunnel having a first diameter, said guide comprising: an elongated
body having a proximal end, a distal end, a first axis and a
cylindrical portion at said distal end, said cylindrical portion
coaxial with said axis and having a predetermined outer diameter
adapted to fit within said bone tunnel; a bore extending through
said cylindrical portion, said bore having a second axis, oriented
at a predetermined angle relative to said first axis; inserting the
cylindrical distal portion of said guide into said bone tunnel;
drilling through said distal portion of bone in said first bone
tunnel to form a second bone tunnel having a predetermined diameter
smaller than the diameter of said first bone tunnel, thereby
producing a shoulder between said first and second bone tunnels;
inserting said guide into said first bone tunnel; advancing said
guide until it abuts the shoulder at the junction of said first and
second bone tunnels; orienting said guide about its axis to align
said bore with a selected point on the tibial plateau; advancing a
drill through said bore toward said selected point on the tibial
plateau to form a third bone tunnel.
13. A method of creating a pair of bone tunnels in a bone having an
anterior surface and a posterior surface comprising the steps of:
forming a first bone tunnel extending along a first axis from a
first aperture in the anterior bone surface towards a first
predetermined point on the posterior bone surface; and forming a
second bone tunnel extending along a second axis from said first
aperture on the anterior bone surface towards a second predetermine
point on the posterior bone surface.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to drill guides for guiding drills
during surgical procedures. More particularly, this invention
relates to drill guides for positioning drills during orthopedic
surgical procedures. Still more particularly, this invention
relates to drill guides for positioning drill bits during
arthroscopic repair of anterior and posterior cruciate
ligaments.
[0003] 2. Description of the Prior Art
[0004] Drill guides for positioning drill bits during arthroscopic
surgical procedures are well known. Generally, such drill guides
comprise a generally C-shaped structure in which one end of the C
is situated at a point on the tibial plateau, representing one end
of a tibial bone tunnel, and another point at the other end of the
C representing the entry point of the tibial tunnel. (An example of
such a guide is shown in U.S. Pat. No. 5,154,720 (Trott et al.)
assigned to the assignee hereof and incorporated herein.) Guiding
structures are attached in order to enable a user to drill from one
end of the C to the other to thereby create a bone tunnel which
will ultimately be used to anchor one end of a graft replacement
ligament.
[0005] Recently, cruciate ligament repair procedures have evolved
into the use of a "double bundle" technique in order to more
accurately approximate the anatomical structure of an original ACL.
The prior art double bundle technique requires the formation of two
bone tunnels in the tibia, one for each bundle of the replacement
ligament graft, and two corresponding bone tunnels in the femur.
The present invention relates to a guide for properly locating and
forming two modified tibial bone tunnels.
[0006] It is accordingly an object of this invention to provide a
double bundle tibial guide to accurately position the exit of both
tibial bone tunnels on the tibial plateau.
[0007] It is another object of this invention to provide a guide to
accurately position the exit of two bone tunnels on a selected bone
surface.
[0008] It is yet another object of this invention to accurately
position both tunnels relative to each other.
SUMMARY OF THE INVENTION
[0009] These and other objects of this invention are achieved by
the preferred embodiment disclosed herein. In one aspect, the
invention is a guide for guiding a drill bit into a preformed bone
tunnel having a first diameter. The guide comprises an elongated
body having a proximal end, a distal end, a first axis and a
cylindrical portion at the distal end. The cylindrical portion is
coaxial with the axis and has a predetermined outer diameter
adapted to fit within the bone tunnel. The guide further comprises
a bore which extends through the cylindrical portion, the bore
having a second axis and being oriented at a predetermined angle
relative to the first axis.
[0010] Another aspect of the invention is the method of creating a
pair of tibial bone tunnels, each having a separate exit aperture
on the tibial plateau. The method comprises the steps of forming a
first bone tunnel extending from the anterior tibia toward but not
through the tibial plateau, and providing a guide such as the
aforementioned guide. The method further comprises the step of
inserting the cylindrical distal portion of the guide into the bone
tunnel, drilling through the distal portion of bone in the first
bone tunnel to form a second bone tunnel having a predetermined
diameter smaller than the diameter of the first bone tunnel,
thereby producing a shoulder between the first and second bone
tunnels, inserting the guide into the first bone tunnel, advancing
the guide until it abuts the shoulder at the junction of the first
and second bone tunnels, orienting the guide about its axis to
align the bore with a selected point on the tibial plateau and
advancing a drill through the bore toward the selected point on the
tibial plateau to form a third bone tunnel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] As shown in FIG. 1, guide 100, constructed in accordance
with the principles of this invention, comprises body 102 having a
proximal end 104 and a distal end 106. Guide 100 has an axis 108
and a single inclined bore 110 having an axis 112 situated at an
angle A relative to axis 108. Bore 110 extends between an entry
point 114 on the side of body 102 and an exit point 116 coincident
with transverse end surface 120 situated at the distal end 106. The
distal end 106 is in the form of a cylinder having a diameter D and
length L adapted to fit into a bone tunnel as will be understood
below.
[0012] Bore 110 has a diameter designed to receive an elongated
drill bit 170 as seen in FIGS. 2 and 3. Drill bit 170 is slidable
within bore 110 between a retracted position as shown in FIG. 2 and
an advanced position as shown in FIG. 3.
[0013] The preferred embodiment of the device and method disclosed
herein is intended primarily for use in the tibia to prepare two
bone tunnels having spaced apart exit apertures on the tibial
plateau and a single entrance aperture on the anterior tibia.
However, it will be understood that guide 10 may be used in a
variety of procedures to create two bone tunnels, particularly two
tunnels having exit apertures spaced apart a predetermined distance
on a selected (generally posterior or distal) bone surface. The
device and method described below will facilitate the creation of a
proximal bone tunnel (starting on a generally anterior or proximal
bone surface) that splits into two distinct distal tunnels. The
proximal bone tunnel is common to both of the distal tunnels and
facilitates using a single interference screw to secure the grafts
in both tunnels to the tibia.
[0014] The operation of guide 100 and the functions of its various
features are best described in the context of an anterior cruciate
ligament repair, particularly in the context of a double bundle
repair. In a double bundle repair the surgeon prepares two tunnels
in order to provide two separate tunnel exit apertures on the
tibial plateau. Each tunnel receives a particular soft tissue graft
ligament which is in effect attached to the tibia at points
coincident with the spaced apart exit apertures.
[0015] As best seen in FIGS. 4 through 6, the double bundle
technique of this invention begins with the partial formation of a
single proximal bone tunnel in a tibia 138 utilizing a conventional
tibial guide (not shown) to create a bone tunnel 140. In the
preferred embodiment, bone tunnel 140 (sometimes referred to herein
as a first bone tunnel) is formed by using a guide pin (not shown)
in conjunction with the aforementioned prior art tibial guide (not
shown) to guide the guide pin from a point 142 on the anterior
tibia 144 toward a point 146 on the tibial plateau 147. Once the
guide pin pierces the tibial plateau a first cannulated drill bit
(not shown) having a diameter D is guided along the guide pin to
create proximal bone tunnel 140 to within a predetermined distance
D1 of the tibial plateau, such distance preferably being on the
order of 10 mm, thereby leaving a thin portion of bone 148 covering
bone tunnel 140. At this point in the procedure the first
cannulated drill bit is removed, leaving the guide pin, and a
second cannulated drill bit is selected to follow along the guide
pin to continue through the thin portion of bone 148. The second
drill bit has a diameter D2 which is less than diameter D such that
a ledge or shoulder 150 is created in bone tunnel 140 between
proximal tunnel portion 152, having a diameter D, and distal tunnel
portion 154 (sometimes referred to herein as the second bone
tunnel), having a diameter D2, best seen in FIGS. 4 and 6. Shoulder
150 provides a fixed reference point for the formation of the
second tunnel as will be understood below. Diameter D2 is equal to
the diameter of the particular bundle which will ultimately be
received within distal bone tunnel portion 154. At this point the
second drill bit and the guide pin are removed.
[0016] For a double bundle procedure, of the two tunnels required
one is anterior on the tibial surface and the other is generally
posterior thereto. Both tunnels may have different diameters
corresponding to the size of the particular graft ligament bundle
to be received in its respective tunnel. Distal tunnel portion 154
is the anterior one in this explanation. Guide 100 is now used to
create the posterior tunnel.
[0017] When the diameter of the posterior graft ligament bundle is
determined, a third drill bit 170 having a diameter D3 equal to
that of the posterior bundle is inserted into bore 110 of guide 100
in retrograde fashion as best seen in FIG. 3. That is, in the
preferred embodiment the diameter of the shaft of drill bit 170 is
smaller than the diameter of its head 172 and the diameter of bore
110 within body 102 is sized to accommodate the shaft. This enables
tighter control over drill 170. By assembling drill 170 into guide
100 in retrograde fashion (in direction R) the drill head 172 will
ultimately abut the exit point (shoulder) 176 of bore 110. From
point 176 distally toward the end 120 of guide 100 bore 110 has a
diameter equal to or slightly greater than diameter D3, in order to
accommodate head 172. Drill bit 170 and guide 100 are assembled so
that the head 172 of drill bit 170 is retracted into bore 110 such
that no portion of the head 172 extends beyond the lateral extent
177 of body 102 at point 176 where it intersects with the exit of
bore 110. This last point enables the assembled drill bit and drill
guide to be inserted into proximal bone tunnel 140 through the
single anterior aperture 142 as shown in FIG. 4.
[0018] The cylindrical distal end 106 of drill guide 100 is
inserted into bone tunnel 140 until its distal end surface 120
abuts against the shoulder 150 at the juncture of proximal tunnel
portion 152 and distal tunnel portion 154. Guide 100 is then
oriented in a selected rotary position around axis 8 in order to
aim axis 112 at a suitable exit point 160 on the tibial plateau. An
index mark is situated on the surface of body 102 to facilitate
aiming axis 112. Point 160 is intended to be generally posterior of
point 146 and is intended to be the exit aperture for the second of
the two tunnels to be formed. Drill bit 170 is cannulated, allowing
a guide pin (not shown) to be drilled through the cannulation of
drill bit 170 to point 160. Should the location need to be changed,
the pin may be removed and the guide may be repositioned before
posterior tunnel 180 (sometimes referred to herein as the third
tunnel) is formed. Once the proper guide orientation is selected,
the drill bit 170 may simply follow the guide pin to exit the
tibial plateau at the selected point.
[0019] It is preferable during this procedure to use a drill bit
170 having a monofluted, circumferentially asymmetric head 172
similar to that manufactured by ConMed Linvatec under the trademark
SENTINEL.RTM.. Alternatively, depending upon the chosen dimensions
of the drill bit head and the guide bore 110, a conventional drill
bit with a circumferentially symmetric head may be used. Once both
anterior and posterior tunnels 154 and 180 have been formed, the
guide pin drill bit and guide may all be removed to allow the
procedure to continue.
[0020] Bone tunnel 140 comprises a proximal tunnel portion 152
which is a single cylindrical tunnel having a single axis and
intersecting the anterior tibia at a single aperture 142. Bone
tunnel 140 also comprises an anterior distal tunnel portion 154 and
a posterior distal tunnel 180, each tunnel intersecting the tibial
plateau 147 at their distal-most exit apertures 182 and 184,
respectively. Tunnel exit apertures 182 and 184 are aligned with
their axes 186 and 188, respectively, in a common plane extending
generally anterior to posterior.
[0021] It will be understood that the axes 186 and 188 are spaced
apart along the tibial plateau by a predetermined distance
sufficient to effect the purposes of the double bundle techniques.
Each distal tunnel section 154 and 180 receives a particular bundle
of a graft ligament, and both handles are together received in the
common proximal tunnel section 152. The spacing along the tibial
plateau may be selected by using a guide 100 that is dimensioned,
primarily by variation in the angle A between axes 108 and 112, to
produce a different spacing.
[0022] It is noted that length L of distal end 106 is sufficiently
long to enable bore 110 to receive a drill bit such that the
proximal end is accessible from a point outside the anterior tibia
without interference from the tibial tunnel wall.
[0023] An alternative embodiment of the tibial guide of this
invention comprises guide 10, best seen in FIG. 7. Guide 10 is used
with a single tibial tunnel similar to tunnel 140 shown in FIG. 6.
Guide 10 comprises a body 12 having a proximal end 14, a distal end
16 and an axis 18. An axial bore 19 extends along the length of
body 12. Guide 10 is used to guide two guide pins 50 and 52, best
seen in FIGS. 8 and 9.
[0024] Guide 10 has a handle 42 and a tunnel engaging cylindrical
distal portion 44. Distal portion 44 is inserted into a single
tibial tunnel following an axially aligned guide pin (not shown)
after the tunnel has been formed by conventional means as discussed
above. Once the single tunnel (like tunnel 140 of FIG. 6) has been
formed by drilling over the guide pin, the drill is removed so
guide 10 can be placed on the guide pin via bore 19. Two
diametrically opposed indicia 17 on handle 42 indicate how guide 10
should be aligned to assure anterior-posterior positioning of guide
pins 50 and 52 ultimately used to form the "double bundle" tunnels.
Each indicia 17 shows the orientation of a respective guide pin
bore at the distal end of guide 10.
[0025] In order to form the "double bundle" tunnels, guide 10
comprises two independent, non-intersecting bores 60 and 62 best
seen in FIGS. 10-13. Each of these bores has an entrance aperture
60A and 62A, respectively, on the surface of body 12 at points
proximal to tunnel engaging distal portion 44. This enables guide
pins 50, 52 to be inserted into bores 60 and 62, respectively,
while distal portion 44 is in the tibial tunnel. Bores 60 and 62
are both situated within body 12, however, for clarity, only a
single bore is shown in each of FIGS. 10-13. As shown in FIG. 14,
each bore 60 and 62 has an exit aperture 60B and 62B, respectively,
on the distally facing surface 66 of distal end 16. The exit
apertures are aligned in a generally anterior-posterior plane. (It
will be understood that FIG. 14 also includes an axial aperture,
representing the distal end of bore 19, although this has been
omitted for clarity.)
[0026] It will be understood that the inclination of guide pins 50
and 52 relative to axis 18 will cause the pins to be separated by a
distance D4 (lateral view) that is greater than the diameter D5 of
distal portion 44. Thus, the spacing of the exit apertures of the
two tunnels on the tibial plateau depends on the distance of the
tibial plateau from the distal end of the single tibial tunnel
(and, therefore, it depends on the thickness of the thin bone layer
148 of FIG. 6).
[0027] After the guide pins 50, 52 are set in the bone distal to
the single tibial tunnel, the guide 10 may simply be pulled out of
the tunnel (in part because of the flexibility of the pins),
leaving the guide pins in place to guide drill bits to form each of
the "double-bundle" tunnels.
[0028] As shown in FIGS. 8 and 9, the guide pin cannulations 60 and
62 are inclined relative to the axis 18 of the guide 10. When seen
in an anterior-posterior view (FIG. 9) the cannulations 60 and 62
do not intersect the axis of the guide and are angled relative to
each other by an angle on the order of 6.degree.. In this A/P view
the guide pins passing through these cannulations are aligned in
planes which are angled relative to axis 18 by an angle on the
order of 3.degree.. When viewed in the lateral view (FIG. 8), the
guide pin cannulations are aligned in planes angled relative to
axis 18 by an angle on the order of 5.degree. and angled relative
to each other by an angle on the order of 10.degree..
[0029] The intent of guide 10 is to produce two tunnel exit
apertures on the surface of the tibial plateau in such a way that
the two exit apertures are aligned within the same plane as the
axis of the guide. Furthermore, the goal is to produce these two
exit apertures with one instrument (the guide) which does not need
to be moved until the formation of both tunnels is complete. In
addition, the formation of the tunnels does not need to begin until
the locations of both tunnels are identified so the surgeon does
not need to commit to the location of any tunnel until he or she is
satisfied with the location of both tunnels. To accomplish this,
guide 10 enables the alignment of two graft pins, one for each
tunnel, simultaneously through the same guide body.
[0030] It will be understood by those skilled in the art that
numerous improvements and modifications may be made to the
preferred embodiment of the invention disclosed herein without
departing from the spirit and scope thereof.
* * * * *