U.S. patent application number 12/578327 was filed with the patent office on 2010-04-15 for variable tension post fixation.
This patent application is currently assigned to ROCKFORD ORTHOPAEDIC SPORTS MEDICINE SERVICES, LLC. Invention is credited to Scott Trenhaile.
Application Number | 20100094355 12/578327 |
Document ID | / |
Family ID | 42099587 |
Filed Date | 2010-04-15 |
United States Patent
Application |
20100094355 |
Kind Code |
A1 |
Trenhaile; Scott |
April 15, 2010 |
VARIABLE TENSION POST FIXATION
Abstract
A variable tension post fixation device includes an outer screw
including a head configured to receive a driver, a conical tip, a
threaded shaft extending between the head and the tip, and an
incompletely cannulated core, and an inner screw including a
proximal end, a distal end, and at least one suture hole, wherein
the inner screw is configured to be insertably coupled with the
outer screw.
Inventors: |
Trenhaile; Scott;
(Belvidere, IL) |
Correspondence
Address: |
DICKE, BILLIG & CZAJA
FIFTH STREET TOWERS, 100 SOUTH FIFTH STREET, SUITE 2250
MINNEAPOLIS
MN
55402
US
|
Assignee: |
ROCKFORD ORTHOPAEDIC SPORTS
MEDICINE SERVICES, LLC
Belvidere
IL
|
Family ID: |
42099587 |
Appl. No.: |
12/578327 |
Filed: |
October 13, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61104881 |
Oct 13, 2008 |
|
|
|
Current U.S.
Class: |
606/304 ;
606/232; 606/316 |
Current CPC
Class: |
A61B 2017/0448 20130101;
A61B 2017/0453 20130101; A61B 17/0401 20130101; A61B 2017/044
20130101 |
Class at
Publication: |
606/304 ;
606/316; 606/232 |
International
Class: |
A61B 17/86 20060101
A61B017/86; A61B 17/04 20060101 A61B017/04 |
Claims
1. A variable tension post fixation device comprising: an outer
screw comprising a head configured to receive a driver, a conical
tip, a threaded shaft extending between the head and the tip, and
an incompletely cannulated core; and an inner screw comprising a
proximal end, a distal end, and at least one suture hole, wherein
the inner screw is configured to be insertably coupled with the
outer screw.
2. The device of claim 1, wherein the outer screw includes at least
two side channels configured to receive at least two mating
expansion tabs of the driver.
3. The device of claim 1, wherein the outer screw includes at least
one external eyelet provided on the shaft proximal to the head.
4. The device of claim 1, wherein the incompletely cannulated core
is at least partially threaded.
5. The device of claim 4, wherein the inner screw includes a
partially threaded portion configured to mate with the at least
partially threaded core.
6. The device of claim 1, wherein the inner screw is configured to
mate with the driver independent of the outer screw.
7. The device of claim 1, wherein an outer diameter of the inner
screw is constricted for a length between the proximal end and the
at least one suture hole.
8. The device of claim 1, wherein when the inner screw is assembled
with the outer screw, the assembly is rotatable in a unified
manner.
9. The device of claim 2, wherein the at least two side channels
are configured to accommodate sutures extending from an interior to
an exterior of the outer screw.
10. A device for variable tension suture fixation, comprising: a
cylindrical outer screw including a conical tip, a threaded shaft,
a belled head, at least one external eyelet, and a partially
cannulated threaded core; and an elongated inner body including a
central lumen, a threaded head, an opposing tip, and a shaft
disposed between the head and the tip, wherein the inner body is
configured to be removably secured within the partially cannulated
threaded core, and wherein the inner body cooperates with the outer
screw to provide for variable tension fixation of at least two
sutures.
11. The device of claim 10, wherein the inner body is configured to
secure and tension a first set of sutures and the outer screw is
configured to secure and tension a second set of sutures.
12. The device of claim 11, wherein the first set of sutures extend
from the central lumen of the inner body and exit the outer screw
through at least one side channel when fully assembled.
13. The device of claim 10, wherein the belled head includes at
least one side channel configured to mate with a driver.
14. The device of claim 10, wherein the threaded head is configured
to mate with a driver.
15. The device of claim 10, wherein the inner body is rotatable
within the partially cannulated threaded core to a locked
position.
16. The device of claim 10, wherein the shaft of the inner body is
narrowed for a length between the central lumen and the threaded
head.
17. A single fixation device for variably tensioning ACL bundles,
comprising: means for securing and tensioning a plurality of
sutures to allow a first ACL bundle to be variably tensioned
independent of a second ACL bundle.
18. The device of claim 17, wherein the means comprises a rotatable
outer body, wherein tension of a first pair of the plurality of
sutures is adjusted with rotation of the outer body.
19. The device of claim 18, wherein the means further comprises an
inner body rotatably coupled within the outer body, wherein a
second pair of the plurality of sutures is independently adjusted
through rotation of the inner body within the outer body.
20. The device of claim 19, wherein the means further comprises the
inner body in a locked position within the outer body whereby the
inner body and the outer body are rotated in combination to provide
tension to the plurality of sutures.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C.
.sctn.119(e) to U.S. Provisional Patent Application Ser. No.
61/104,881 filed on Oct. 13, 2008, and incorporated herein by
reference. This application is related to U.S. Non-Provisional
patent application Ser. No. ______, filed on even date herewith,
having attorney docket number R615.103.102, and incorporated herein
by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a medical device
that facilitates orthopaedic procedures requiring tensioning and
fixation of sutures to bone. With this device, variable tension may
be applied independently to one or more different sets of sutures.
For example, during anterior cruciate ligament (ACL)
reconstruction, the device may be used as primary or secondary
fixation of an ACL graft on the tibial side of the reconstruction
construct. With the device, variable tension may be applied
independently to the sutures, such as those found with single or
double bundle ACL reconstruction.
BACKGROUND OF THE INVENTION
[0003] Anterior cruciate ligament (ACL) reconstruction is one of
the most commonly performed procedures on the human knee. Primary
surgical goals during ACL reconstruction include restoring
translational and rotational stability of the knee. These goals are
often achieved by utilizing a soft tissue graft that is fixated on
the femoral and tibial sides of the joint. A common cause of graft
failure within the first 6 weeks is loss of fixation strength. This
loss of fixation strength is more commonly found on the tibial side
rather than the femoral attachment of the ACL graft.
[0004] To alleviate the loss of fixation strength, surgeons often
use a screw and washer on the tibial side of the joint to create a
backup fixation whereby the suture tails of the ACL graft are tied
around the screw as a post. A simple limitation with this type of
backup fixation, however, is that the sutures tied around the screw
can not be tensioned once they are tied. Furthermore, with the
advent of double bundle ACL reconstruction, a need for independent
tensioning of each ACL bundle has evolved. Unfortunately, the
simple screw and washer configuration does not allow for
independent tensioning of the four suture tails on the two
independent bundle limbs.
[0005] The ability to attach sutures around a post and then be able
to further tension those sutures to a desired tension after they
have been tied would be beneficial, for example, during ACL
reconstruction. Also, a desirable device would allow for
independent tensioning of two sets of suture tails on a single
tibial post, including tensioning of suture tails often found on
the tibial side of the joint when performing a double bundle ACL
graft.
[0006] For these and other reasons, there is a need for the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIGS. 1a through 1i illustrate an embodiment of a variable
tension post fixation device.
[0008] FIGS. 2a through 2g illustrate an embodiment of a variable
tension post fixation device.
[0009] FIGS. 3a through 3h illustrate an embodiment of a variable
tension post fixation device.
[0010] FIGS. 4a through 4b illustrate an embodiment of a variable
tension post fixation device.
[0011] FIG. 5 illustrates one technique of performing ACL
reconstruction using a variable tension post fixation device as
described herein.
DETAILED DESCRIPTION
[0012] A desirable fixation device would provide orthopaedic
surgeons performing single or double bundle ACL reconstruction with
the ability to tension suture tails after the suture tails are
attached to the fixation device. The device would allow the surgeon
to tension each strand of the suture tails to a desired tension,
and then tension the entire construct one last time in a combined
fashion if desired.
Techniques
[0013] With reference to FIG. 5, one technique of performing single
or double bundle ACL reconstruction is described. The tunnels are
drilled, the graft(s) are passed through their respective tunnels,
and the femoral fixation is placed. In double bundle
reconstruction, each bundle is pulled out of their respective
tibial tunnel. For fixation of each bundle, the surgeon may use
interference screws in each tunnel as a primary fixation. Secondary
fixation may include variable tensioning with separate fixation
devices, as described herein, positioned distal to the exit of each
tibial tunnel or may include combining the four strands of the
sutures from the two bundles of the double bundle ACL and providing
variable tensioning with a single fixation device, as described
herein. The disclosed fixation device would allow each ACL bundle
(2 suture tails per bundle) to be variably tensioned independent of
the other on a single post.
[0014] Although the disclosed fixation device is described for use
in performing single or double bundle ACL reconstruction, it is
understood and within the scope of the present invention for the
disclosed fixation device to be used in other procedures where
tensioning of sutures is desired.
Variable Tension Posts
[0015] FIGS. 1a through 1i illustrate one embodiment of a variable
tension post fixation device. The variable tension post fixation
device of FIG. 1a through 1f includes an outer screw (or sleeve)
and an inner key configured to fit within the outer screw (or
sleeve). The outer screw and inner key cooperate to provide for
variable tension fixation of sutures, as described below.
[0016] In one embodiment of use, a drill guide is placed distal to
the exit point of the most distal tibial tunnel, and a pilot hole
is drilled in the bone (see FIG. 5). After the pilot hole is
drilled, the outer screw of the variable tension post fixation
device is placed in the pilot hole.
[0017] In one embodiment, the outer screw is fully threaded and
headless, and includes a series of concentric channels or bores (t,
x, y, z) (FIG. 1a). In one embodiment, the outer screw is inserted
nearly flush with the cortex of the bone (FIG. 1b), and provides a
recipient sight for the inner key (see FIGS. 1d, 1e). In one
embodiment, the inner key includes a key tip, a key shaft, and a
key head, with the key head being approximately the same diameter
as the outer screw (FIG. 1c, 1d, 1e).
[0018] The concentric bores or channels of the outer screw allow
for insertion of the outer screw into the pilot hole in the bone,
and locking of the inner key within the outer screw. In one
embodiment, the outer screw is secured in the pilot hole with a
driver by engaging the driver in the channel or bore t (FIG. 1b).
After the outer screw is anchored in the bone, the driver is
removed and the suture tails are fed through and/or attached to the
inner key (FIG. 1c).
[0019] In one embodiment, the key head of the inner key has 2 holes
through which sutures are fed. In one embodiment, suture tails 1
and 2 are fed through the key head from the bottom up and then tied
to each other (FIGS. 1c, 1f). This helps to keep the twisted
sutures under the key head and around the key shaft. In one
embodiment, suture tails 3 and 4 are fed through a central hole in
the key shaft and tied to each other (FIG. 1c). The key tip is then
inserted into the outer screw channel or bore z, and the inner key
is rotated in order to tension the sutures (FIG. 1d). In one
embodiment, the inner key is rotated using the same size driver
used for the outer screw. In one embodiment, a collar is provided
around the key head to help prevent the suture tails 1 and 2 from
slipping onto the driver during rotation of the inner key.
[0020] Once the desired tension on the sutures has been obtained,
the driver is used to rotate the inner key and advance the key tip
through the channel or bore x until the key tip reaches the channel
or bore y (FIG. 1e). In one embodiment, the sutures are slightly
over-tensioned as the key tip is advanced through the channel or
bore x and into the locking channel or bore y. Slightly over
tensioning the sutures will allow for the inner key to "unwind"
within the locking channel or bore y, as the key tip rotates to the
lock position (FIG. 1a).
[0021] In one embodiment, locking pin slots are provided in the key
head, and locking pins are inserted into the slots to prevent the
inner key from rotating relative to the outer screw when the inner
key is in the "locked" position (FIGS. 1e, 1f). In one embodiment,
the locking pins extend along the key shaft through the key shaft
channel or bore x and into the locking channel or bore y next to
the key tip (FIGS. 1e, 1a). As such, the key tip of the inner key
and, therefore, the inner key itself is prevented from rotating
within the locking channel or bore y.
[0022] In one embodiment, if the ACL bundles need to be further
tensioned, the entire construct (inner key and outer screw) can be
advanced farther into the pilot hole by inserting the driver into
the key head and turning the entire construct clockwise. Because
the outer diameters of the outer screw and the inner key are
essentially the same, the entire construct can be advanced as a
unit even beyond the cortex of the tibial bone posteriorly.
[0023] The variable tension post fixation device of FIGS. 1g
through 1i is similar to the variable tension post fixation device
of FIGS. 1a through 1f, however, the inner key of the variable
tension post fixation device of FIGS. 1g through 1i has a larger
diameter head than the outer screw (FIG. 1g, 1i). The larger
diameter head provides more room to bring all four suture tails
from the bottom up through their own hole (FIG. 1h). In one
embodiment, suture tails 1 and 2 are fed up through the key head
and tied to each other, as are suture tails 3 and 4. In one
embodiment, as described above, a collar is provided around the key
head to help keep the sutures from becoming entangled with the
driver. In one embodiment, in addition to the holes for sutures in
the key head, a central hole is provided in the key shaft for
additional sutures (FIG. 1i).
[0024] The inner key of the variable tension post fixation device
of FIGS. 1g through 1i is "locked" in the locking channel or bore y
of the outer screw in a manner similar to that described above. In
one embodiment, however, the key head of the inner screw is still
spaced or offset from the top of the outer screw when the inner key
is in the "locked" position (FIG. 1i). This slight offset allows
for further advancement of the entire construct once the inner key
is locked to the outer screw whereby further tensioning of the
sutures at the conclusion of the procedure is possible.
[0025] FIGS. 2a through 2g illustrate another embodiment of a
variable tension post fixation device. In one embodiment, as
outlined above, a drill is used to create a pilot hole in the tibia
distal to the most distal exiting tibial ACL bundle (see FIG. 5).
The variable tension post fixation device of FIGS. 2a through 2g
includes an outer screw and an inner screw. In one embodiment, the
outer screw is a fully threaded headless screw that is inserted
flush to the cortex of the tibial bone (FIG. 2a). In one
embodiment, the outer screw is incompletely cannulated and includes
side channels that are cut partially along the sides to receive a
driver (FIGS. 2a, 2b). In one embodiment, the driver is cylindrical
and includes expansion keys or tabs that correspond to the side
channels of the outer screw to provide ease of insertion and
stability when anchoring the outer screw in the bone (FIG. 2c).
[0026] In one embodiment, the inner portion of the outer screw of
the variable tension post fixation device of FIGS. 2a through 2g
has threads that extend to the bottom of the cannulation portion of
the screw (FIG. 2d). In addition, the inner screw is threaded and
also partially cannulated to receive a driver (FIGS. 2d, 2e). In
one embodiment, the inner screw has 4 holes formed axially
therethrough to accommodate sutures (FIG. 2e). In one embodiment,
suture tails 1 and 2 are each fed through respective holes in the
inner screw and tied to each other, as are suture tails 3 and 4
(FIG. 2e). The inner screw is then placed into the threaded
cannulation of the outer screw and advanced with the driver until
the desired tension is achieved on the sutures (FIG. 2d).
[0027] The variable tension post fixation device of FIGS. 2f
through 2g is similar to the variable tension post fixation device
of FIGS. 2a through 2e, however, the inner screw of the variable
tension post fixation device of FIGS. 2f through 2g has a
fenestrated end. In one embodiment, suture tails 1 and 2 are fed
through the openings in the fenestrated end and tied to each other,
as are suture tails 3 and 4 (FIG. 2f). In one embodiment, a pronged
driver is used to engage the fenestrations and advance the inner
screw into the outer sleeve to achieve the desired tension on the
sutures (FIG. 2g).
[0028] FIGS. 3a through 3h illustrate another embodiment of a
variable tension post fixation device. In one embodiment, as
outlined above, a drill is used to create a pilot hole in the tibia
distal to the most distal exiting tibial ACL bundle (see FIG. 5).
The variable tension post fixation device of FIGS. 3a through 3h
includes an outer screw and an inner screw. In one embodiment, the
outer screw is a fully threaded headed screw that is inserted flush
to the cortex of the tibial bone (FIG. 3a). In one embodiment, the
pilot hole is cored out to accommodate the head of the outer
screw.
[0029] In one embodiment, the outer screw is incompletely
cannulated and includes side channels that are cut partially along
the sides to receive mating expansion keys or tabs of a cylindrical
driver (FIGS. 3a, 3b). In one embodiment, external suture eyelets
are provided beneath the head of the outer screw such that before
completely sinking the outer screw head flush with the cortex of
the tibial bone, suture tails 1 and 2 are fed through the external
eyelets and tied to each other (FIG. 3a, 3b). The outer screw head
is then sunk flush with the cortex of the tibial bone whereby
suture tails 1 and 2 are tensioned (FIG. 3d).
[0030] In one embodiment, the shaft of the inner screw includes a
central hole through which suture tails 3 and 4 are fed and then
tied to each other (FIG. 3c, 3d). In one embodiment, the inner
screw includes a partially threaded portion that is thread into the
outer screw whereby the inner screw is pressed into the outer screw
until the threads of the inner screw engage the locking threads of
the outer screw cannulation (FIG. 3c, 3d). As such, the inner screw
is rotated until the desired tension is achieved on the suture
tails 3 and 4. With the inner screw thread into the outer screw,
the inner screw and the outer screw are now a single construct. If
further tension on the sutures is desired, the driver may be
introduced into the inner screw and the whole construct can be
further rotated and advanced.
[0031] In one embodiment, the shaft of the inner screw narrows
under the head to accommodate the suture tails 3 and 4 as the inner
screw is rotated within the outer screw. In addition, in one
embodiment, to avoid entanglement of suture tails 3 and 4 in the
locking threads between the inner screw and the outer screw, the
sutures are fed through side channels provided in the outer screw
before the locking threads are engaged.
[0032] The variable tension post fixation device of FIGS. 3e
through 3h is similar to the variable tension post fixation device
of FIGS. 3a through 3d, however, the outer screw of the variable
tension post fixation device of FIGS. 3e through 3h has a concave
outer portion (FIGS. 3e, 3g). In addition, the inner screw is free
of threads (FIGS. 3f, 3g).
[0033] In one embodiment, suture tails 1 and 2 are fed through the
suture eyelets provided on the outer screw, and the outer screw is
thread into the pilot hole as described above (FIG. 3g). In
addition, sutures tails 3 and 4 are fed through the central hole of
the shaft of the inner screw and then tied to each other.
Thereafter, the inner screw is press fit into the outer screw to
tension suture tails 3 and 4 (FIG. 3g).
[0034] In one embodiment, prior to tensioning suture tails 3 and 4,
a cap that engages the inner screw with its own hex head is placed
on the inner screw. As such, the cap and the inner screw are
rotated to achieve the desired tension on sutures 3 and 4. Once the
desired tension is achieved, the inner screw is press fit into the
outer screw and the cap is crimped onto the outer screw. The outer
screw, the inner screw, and the cap are now a single unit (FIG.
3h). Thus, further tensioning can be achieved with the crimping
device on the cap by rotating the entire construct.
[0035] FIGS. 4a through 4b illustrate another embodiment of a
variable tension post fixation device. In one embodiment, as
outlined above, a drill is used to create a pilot hole in the tibia
distal to the most distal exiting tibial ACL bundle (see FIG. 5).
The variable tension post fixation device of FIGS. 4a through 4b
includes an outer screw and an inner screw. In one embodiment, the
outer screw is a fully threaded headed screw that is inserted flush
to the cortex of the tibial bone (FIG. 4a).
[0036] In one embodiment, the outer screw is incompletely
cannulated and includes side channels that are cut partially along
the sides to receive mating expansion keys or tabs of a cylindrical
driver, as described above. In one embodiment, external suture
eyelets are provided beneath the head of the outer screw such that
before completely sinking the outer screw head flush with the
cortex of the tibial bone, suture tails 1 and 2 are fed through the
external eyelets and tied to each other (FIG. 4a). The outer screw
head is then sunk flush with the cortex of the tibial bone whereby
suture tails 1 and 2 are fully tensioned (FIG. 4a).
[0037] In one embodiment, the inner screw is free of threads and
includes a shaft that fits inside the outer screw (FIG. 4a). In one
embodiment, the head of the inner screw is domed and includes four
holes through which suture tails 3 and 4 are fed and then tied
together (FIGS. 4a, 4b). In one embodiment, the head of the inner
screw also includes two additional holes positioned peripherally
which are used to rotate the inner screw and develop the desired
tension on suture tails 3 and 4. In one embodiment, once the
desired tension is achieved, two anchoring screws or pins are
inserted through the additional holes in the head of the inner
screw and into the tibia (FIG. 4a). The anchoring screws or pins
fix the head of the inner screw to the bone and secure the tension
on suture tails 3 and 4.
[0038] The embodiments of a variable tension post fixation device
described herein provide orthopaedic surgeons with the option of
using a single tibial post for fixation and the ability to provide
variable tension independently to more than one suture stand.
[0039] Although the invention herein has been described with
reference to particular embodiments, it is to be understood that
these embodiments are merely illustrative of the principles and
applications of the present invention. It is therefore to be
understood that numerous modifications may be made to the
illustrative embodiments and that other arrangements may be devised
without departing from the spirit and scope of the present
invention as defined by the appended claims.
* * * * *