Note: Descriptions are shown in the official language in which they were submitted.
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CABLE KNEE BRACE SYSTEM
INVENTORS
Darren Fleming
PRIORITY CLAIM
[0001] This application
claims priority from U.S. Application No. 16/436,716
filed June 10, 2019, which application is incorporated by reference in its
entirety as if
fully set forth herein.
INCORPORATION BY REFERENCE
[0002] The following
documents are incorporated by reference in their
entireties, U.S. Patent Application No. 13/867,910 filed on April 22, 2013,
U.S. Patent
Application No. 12/987,084 filed on January 8, 2011, and
U.S. Patent Application No. 11/744,213 filed on May 3, 2007.
BACKGROUND OF THE INVENTION
[0003] The human knee is a
complex mechanism that is highly vulnerable to
injury in sports like football, hockey, skiing, snowboarding, and motocross.
In these
kinds of physically demanding sports the Anterior Cruciate Ligament (ACL) and
Medial
Collateral Ligaments (MCL) are commonly injured. The ACL controls forward
movement of the tibia relative to the femur (hyper extension) and lateral
rotation of the
tibia with respect to the femur (over rotation). The MCL controls lateral
movement of the
tibia with respect to the femur. Hyper extending the leg and or laterally
rotating or
twisting or laterally bending of the leg can tear the ACL and/or MCL. The ACL
regulates
the amount of movement the tibia has with respect to the femur both in forward
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movement, and lateral rotation. When the leg reaches full extension the ACL
becomes
taut and limits the knee from hyper extending or over rotating laterally.
[0004] The MCL regulates
how much the tibia can bend laterally with respect to
the femur. The MCL becomes taut when a lateral force is applied to the leg
preventing
excessive bending. All too often in sports like motocross the leg is exposed
to forces that
exceed the ligament's ability to prevent excessive movement in the joint
sometimes
resulting in the tearing of the ACL and or MCL.
[0005] In order for a knee
brace to be effective in resisting the excessive
movement of the knee joint that tears the ACL and/or MCL, it must provide an
effective
differential force to the tibia relative to the femur. Because of the large
amount of flesh
surrounding the tibia bone and femur bone the only way to prevent the leg from
over
extending or over rotating would be to fix a rigid structure to the bones with
some sort of
mechanical means such as screws. Of course this would be impractical and
undesirable.
Not only should a knee brace be practical, it must be comfortable, and most of
all
effective at preventing knee injuries.
[0006] Most prior art
(conventional) knee brace devices for ligament protection
consist of a rigid femoral plate and tibial plate connected by hinges on
either side of the
knee. The plates are strapped to the leg tightly above and below the knee with
straps that
encircle the leg. The hinge locks as the leg reaches full extension and the
rigid frame and
straps act like a splint resisting hyperextension of the leg. There are many
variations of
the basic rigid hinged brace with differing hinge designs, strapping methods,
and
materials used. Conventional braces are limited in their effectiveness
resisting excessive
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joint movement that causes injury to the knee. The biggest reason is that the
flesh of the
leg surrounding the femur and the strapping apparatus deform allowing the leg
to
hyperextend or rotate. Even when the strapping devices are tightened to the
point of
discomfort, they have limited effect preventing excessive movement of the knee
joint
when the leg is subjected to these forces.
[0007] It is the object of
the invention to provide a knee bracing system that
bolsters the body's natural ligaments to reduce the knees proneness to injury
or re-injury.
[0008] The invention is a
cable system that acts much like the body's natural
ACL and MCL. The cables are routed around the knee joint in a way that resists
the
forces that cause excessive joint movement and injury to the ACL and or MCL.
As the
leg travels through the range of motion the cables tighten, preventing the
tibia bone from
moving forward (hyperextending) or twisting (lateral rotation) or bending
laterally with
respect to the femur.
[0009] The cable knee brace
system of this invention can be tailored or adapted
to prior art (conventional) braces increasing their effectiveness.
[0010] It is also
anticipated by the Applicant that this cable knee brace system
can be adapted to the elbow to prevent the arm from hyperextending. A humorous
plate
would substitute for the femoral plate 4, a radius plate would substitute for
the tibial plate
2, and bicep plate would substitute for the femoral back plate 5 creating the
differential
resistive force across the elbow joint preventing hyperextension of the arm.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 is an
outside elevation/side view of a right leg showing normal
fully extended and hyperextended (tearing ACL) views.
[0012] Figure 2 is a
top/front view of the right leg fully extended showing
normal and laterally rotated or laterally bent (tearing ACL and or MCL) views.
[0013] Figure 3 is an
outside elevation/side view of the right leg fully extended
showing the primary cable resisting hyperextension of the leg.
[0014] Figure 4 is a
top/front view of the right leg fully extended showing the
primary cable resisting lateral rotation of the leg.
[0015] Figure 5 is an
outside elevation/side view of the right leg in the flexed
position showing the primary cable knee brace system.
[0016] Figure 6 is an
exploded isometric view showing the individual parts of
the primary cable knee brace system.
[0017] Figure 7 is an
outside elevation/side view of the left leg fully extended
showing the secondary cable resisting hyper extension of the leg.
[0018] Figure 8 is a
top/front view of the right leg fully extended showing the
secondary cable resisting lateral rotation and or lateral bending of the leg.
[0019] Figure 9 is an
outside elevation/side view of the left leg in the flexed
position showing the secondary cable resisting lateral bending or lateral
rotation.
[0020] Figure 10 is an
exploded isometric view of the individual parts of the
secondary cable knee brace system.
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[0021] Figure 11 is an
inside elevation/side view of the secondary cable guide
plate that guides the secondary cable through the pivot points.
[0022] Figure 12 is an
inside elevation/side view of an alternate cable guide
plate that guides the secondary cable under and over the pivot points.
[0023] Figure 13 is an
inside elevation/side view of another alternative cable
guide plate that guides the secondary cable over and under the pivot points.
[0024] Figure 14 is a top
view of a portion of a Q-adjustable tibial shell
according to an embodiment of the present invention.
[0025] Figure 15 is a three-
quarter view of a Q-adjustable leg brace according to
an embodiment of the present invention.
[0026] Figure 16 is a top
down view of a Q-adjustable leg brace according to an
embodiment of the present invention.
[0027] Figure 17 is a top
down view of a Q-adjustable leg brace according to an
embodiment of the present invention.
DE TAILED DE S CRIP TION
[0028] To be effective
preventing injuries to the ACL 22 and or MCL 23, a knee
brace must prevent the tibia bone 26 from moving forward (hyperextending), see
Figure
1, or laterally bending and or rotating (twisting), see Figure 2, with respect
to the femur
bone 18. The patella 20 and fibula bone 24 are shown for completeness. The
knee brace
of this invention as best shown in Figures 3-17, which like references refer
to like
elements throughout the several views, introduces a novel cable system that
more
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effectively prevents hyperextension, lateral bending and or lateral rotation
of the knee
joint.
[0029] Figure 3 shows the
primary cable system of this invention creating an
effective differential force to the tibia 26 relative to the femur 18 and
reinforcing the ACL
22. When the primary cable 1 of this system is properly tensioned, the brace
acts like the
body's own ACL 22 becoming taut as the leg extends resisting the forward
movement of
the tibia bone 26, with respect to the femur bone 18. Figure 4 shows the
primary cable
system of this invention resisting the lateral rotation of the tibia bone 26,
with respect to
the femur bone 18. Figure 5 shows the primary cable system of this invention
when the
leg is flexed. As shown in Fig. 3, because the tibial plate 2 moves further
away from the
femoral plate 4 as the leg extends, the primary cable 1 becomes progressively
tighter as
the leg approaches full extension. When a hyperextension force 28 is applied
to the leg as
shown in Figure 3, the tibial plate 2, patellar plate 3, and femoral plate 4
are compressed
together as the primary cable 1 comes under progressively more tension. The
tensile
force in the primary cable 1 pulls down on the tibial plate 2, and up on the
back plate 5,
creating the differential resistive force across the knee joint preventing
hyperextension of
the leg. Figure 7 shows the secondary cable system of this invention creating
an effective
differential force to the tibia 26 relative to the femur 18, and reinforcing
the ACL 22 and
MCL 23. As the leg extends the secondary cable 40 resists the forward movement
of the
tibia bone 26, with respect to the femur bone 18. Figure 8, shows the
secondary cable 40
resisting the lateral bending and or lateral rotation of the tibia bone 26,
with respect to the
femur bone 18. Figure 9 shows the secondary cable system of the invention when
the leg
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is flexed and the secondary cable 40 resisting lateral bending and lateral
rotation
throughout the leg's range of motion. As the leg extends the patellar plate 3
acts like a
hinge for the tibial plate 2 and femoral plate 4, rotating about pivot points
17a and 17b,
respectively, approximating the knees flexion-extension movement.
[0030] When a lateral
rotation force 30 is applied to the leg as shown in Figure
4 the tibial plate 2, patellar plate 3, femoral plate 4, and back plate 5 are
held rigid by the
tension developed in the primary cable 1. The tensile forces in primary cable
1 cross
behind the leg, creating cable cross over point 31 as they pass through back
plate 5,
resisting rotation and bending across the knee joint and preventing the leg
from laterally
bending or rotating. When a lateral bending or lateral rotation force is
applied to the leg
as shown in Figure 8, the tibial plate 2, patellar plate 3, and femoral plate
4 are held rigid
by the tension developed in the secondary cable 40. The tension in the
secondary cable
40 prevents the brace from bending across the knee joint preventing the leg
from laterally
bending or rotating.
[0031] This invention
comprises of a primary cable 1 and secondary cable 40
that can be made of any flexible material with a sufficiently high tensile
strength. A tibial
plate 2 that could be made of any rigid or semi-rigid material is shaped to
conform to the
tibia bone 26, beginning just below the knee and ending approximately at the
midpoint of
the tibia bone 26. The tibial plate 2 is held in position with straps lib and
11c. Foam
padding 12 is attached to the underside of the tibial plate 2 for comfort and
to provide a
firm grip on the individuals' tibia bone 26. A patellar plate 3 that could be
made of any
rigid or semi-rigid material connects the tibial plate 2 to the femoral plate
4. A femoral
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plate 4 that could be made of any rigid or semi-rigid material is located on
top of the thigh
from just above the knee to approximately mid-femur 18 and is held in position
with strap
1 la. Back plate 5 could be made of any rigid or semi-rigid material located
behind the
leg and just above the knee joint to keep the cable 1 in the proper location,
firmly holding
the femur bone 18 as the differential force of the primary cable 1 is
transmitted across the
joint. Foam padding 14 is attached to the inside of the back plate 5 to help
spread the
force of the primary cable 1 comfortably to the leg. A cable tensioner dial 6
and
locking/release button 7 with spring 8 are attached to the femoral plate 4
with retainer
screw 9. These could be made from any metal or rigid material that will
withstand the
forces required to keep the primary cable 1 locked in place during use. Other
cable
tensioning and locking mechanisms could be used, but the dial tensioning and
locking
system gives a very wide range of fine tuned cable adjustability and ease of
use.
[0032] The fundamental
element of this invention is the routing of the cables.
As best shown in Figure 6, primary cable 1 begins attached to femoral plate 4
by cable
connector 15a, crosses behind the leg through cable guide hole 13a and cable
guide hole
13b in back plate 5, and runs through a cable guide hole on the opposite side
of tibial
plate 2. The primary cable 1 then loops over the leg through a cable guide
hole and
through the cable guide hole to the other side of tibial plate 2. From the
cable guide hole
in tibial plate 2, the primary cable 1 again crosses behind the leg through
cable guide hole
13c, crossing over itself, creating cable cross over point 31, before going
through cable
guide hole 13d in back plate 5, and attaches to the opposite side of femoral
plate 4 by
second cable connector 15b.
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[0033] In additional
embodiments, primary cable 1 begins attached to femoral
plate 4 by first cable connector 15a, crosses behind the leg through first
cable guide hole
13a and second cable guide hole 13b in back plate 5, creating cable cross over
point 31,
and attaches to the opposite side of tibial plate 2 with clamping screw 10a.
The primary
cable 1 then loops over the leg attaching to the other side of tibial plate 2
with clamping
screw 10b. From clamping screw 10b, the primary cable 1 again crosses behind
the leg
through third cable guide hole 13c and fourth cable guide hole 13d in back
plate 5, and
attaches to the opposite side of femoral plate 4 by the second cable connector
15b.
[0034] As best shown in
Figure 10, secondary cable 40 begins attached to the
outside, or collateral side, of the femoral plate 4 by the femoral cable
connector 42a and
runs through the femoral cable guide hole 44a. The secondary cable 40 crosses
femoral
pivot point 17a and tibial pivot point 17b through cable guide plate 48. From
there, the
secondary cable 40 runs through tibial plate guide hole 44b and attaches to
the outside, or
lateral side, of the tibial plate 2 by the tibial cable connector 42b,
completing the route.
[0035] In some embodiments,
a single cable is used as it passes through the
various guides. In alternative embodiments, the cable could be made up of
individual
segments connected together to form the completed routing. For example, first
primary
cable segment la and second primary cable segment lb can be formed by a single
cable,
or can be two separate cables connected together with tibial plate 2 to
complete the loop.
First primary cable segment la begins attached to femoral plate 4 by first
cable connector
15a, crosses behind the leg through the cable guide hole 13a and cable guide
hole 13b in
back plate 5 and attaches to the opposite side of tibial plate 2 with clamping
screw 10a.
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Without having to loop over the leg, the second primary cable segment lb is
attached to
the opposite side of tibial plate 2 with clamping screw 10b. From clamping
screw 10b the
second primary cable segment lb crosses behind the leg through the cable guide
hole 13c,
and crossing over itself, creating cross over point 31, before going through
cable guide
hole 13d in back plate 5 and completes the loop by attaching to the opposite
side of
femoral plate 4 with cable connector 15b.
[0036] The segments of the
cable extending from the cable cross over point 31
to the tibial plate portion of the brace and returning to the cable cross over
point 31 form
the tibial control loop portion 32 of the cable. The segments of cable
extending from the
cable cross over point 31 to the femoral plate portion of the brace and
returning to the
cable cross over point 31 form the femoral control loop portion 33 of the
cable. Fig. 6, for
example, illustrates these control loop portions 32 and 33. During use, for
example when
the knee is extended toward hyperextension, the tibial control loop will
lengthen, causing
an inverse tightening of the femoral control loop.
[0037] The primary cable 1
is adjusted by turning the cable tensioner dial 6
taking up the excess primary cable 1 length. The primary cable 1 is
automatically locked
into place by the ratcheting gears 16 on the cable tensioning dial 6 and
spring 8 actuated
locking/release button 7. The button 7 is also used to release the tension in
primary cable
1 for installation and removal of the brace.
[0038] While an infinite
number of secondary cable routings across the pivot
points are possible, directly through the pivot points as shown in 46a is most
desirable to
achieve optimum tension on the secondary cable 40 throughout the leg's full
range of
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motion. Figure 11 shows a cable guide plate which guides the cable directly
through the
pivot points, secondary cable routing 46a, as described above. Alternate
secondary cable
guide plate configurations as shown in Figures 12 and 13 could be used guide
the
secondary cable around the pivot points. For example, alternate secondary
cable routing
46b could be achieved using the cable guide plate shown in Figure 13 which
guides the
secondary cable 40 over, or to the fore of, femoral pivot point 17a and under,
or to the aft
of, tibial pivot point 17b.
[0039] Fig. 15 depicts an
alternative tibial shell arrangement. When configured
in this manner, the tibial shell 2B mounts to the tibial shell 2A at point 51,
forming the
axis of rotation. The shell 2B is secured to the tibial shell 2A using tibial
adjustment
locking screw 52. The tibial shell 2B rotates about axis 51 in order to
establish the desired
Q-angle, as depicted in Fig. 16. The relative rotation of the tibial shell 2B
about axis 51 is
controlled using screws 53A-B on either side of the tibial shell 2B, as
depicted in Fig. 14.
By lengthening or shortening the adjustment screws, which push against
corresponding
bearing surface 55A-B, the tibial shell pivots accordingly about the axis 51.
[0040] Figure 14 best
depicts the adjustment mechanism showing adjustment
screws 53 A-B threaded through retention nuts 54 A-B in tibial shell 2B. As
best shown
in Figure 16, after loosening adjustment locking screw 52 and then shortening
adjustment
screw 53A, lengthening adjustment screw 53B pushes against bearing surface 55B
on
tibial shell 2A, forcing tibial shell 2B to rotate clockwise about axis 51
until adjustment
screw 53A contacts bearing surface 55A on tibial shell 2A before tightening
adjustment
locking screw 52.
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[0041] Cable guides accept
the cable, the cable being comprised of one or more
segments, which transfers energy to control knee movement and prevent
hyperextension
of the knee joint in the same manner as the other embodiments described above,
for
example, Figs. 2-6. In the same manner as the embodiments described above, the
cable
may be composed of one or multiple portions. While the routing of the cable is
not
depicted, in a preferred embodiment, the cable beginning from cross over point
31,
extends to a first side of tibial shell 2A passing through one or more cable
guide holes,
then extends over tibial shell 2B through one or more cable guide holes, and
then extends
back down the opposite side of tibial shell 2A through one or more cable guide
holes and
then extends back to cable cross over point 31, forming the tibial control
loop 32.
[0042] When the knee of the
user extends, the cable portion extending from a
cross over point 31 around the tibial shell 2B and returning to the cross over
point, the
tibial control loop 32, lengthens accordingly. This produces a direct response
in the
portion of the cable which extends from the cross over point 31 over and
around the
femoral plate, the femoral control loop. That portion of the cable tightens,
bringing the
femoral plate and the back plate 5 into the leg and behind the knee joint
respectively, and
stopping further extension of the knee by controlling the length of the tibial
control loop.
[0043] Fig. 15 depicts both
the femoral shell 4 and tibial shells 2A and 2B of a
knee brace according to an embodiment of the present invention. Notably, the
back plate,
straps, and cable routing are absent in order to more clearly depict the
arrangement of the
adjustable tibial shell 2B. As depicted, the invention according to this
alternative
embodiment maintains many of the features described in alternative embodiments
herein,
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including: 4, 6, 17C and 17D. Fig. 15 depicts the tibial shell 2B of Fig. 14
as well as its
mounting surface 56 on tibial shell 2A. The axis of rotation 51 is clearly
depicted as
running through the point at which the tibial shells 2A-B are connected.
[0044] Foam padding may be
strategically placed at various points on the inside
portions of the brace depicted in Fig. 15. For example, on the sides near
hinge point 17C
and 17D, and underneath tibial shells 2A and 2B as well as femoral shell 4.
This foam
provides increased comfort to the user.
[0045] Fig 16 depicts the
adjustability of the tibial shell 2B which creates a
chosen Q-angle 57. The angle between the tibia and the femur forms the
quadriceps
angle, herein referred to as the Q-angle 57. This angle varies depending on
the physiology
of the user. The tibial shell 2B is adjustable in order to customize the Q-
angle 57 to
accommodate each user. By turning the adjustment screws 53A-B, the Q-angle 57
may be
changed as the tibial shell 2B pivots 58. The Q-angle is adjustable in either
direction. In
preferred embodiments, the Q-angle 57 is adjustable up to 4 degrees in either
direction,
AQ. A Q-angle of less than average, is defined as Varus. In this embodiment,
the Q-angle
57 may be referred to as negative, for example, the brace may be adjusted -4
degrees from
average, AQ, forming a more acute Q-angle 57. A Q-angle greater than normal is
referred
to as Valgus, and may be formed by adjusting the brace to increase the Q-
angle, for
example +4 degrees from average. The depicted arrangement in Fig. 16 shows,
for
example, a Valgus arrangement, where the Q-angle of the brace, Q2, is greater
than an
average angle, Ql. In order to achieve this, the tibial plate 2B has been
adjusted toward
the outside of the user's leg (right side knee brace). Once the user is happy
with their
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customized Q-angle, they can lock the brace using locking screw 52. This
prevents the Q-
angle from changing while the user is wearing the device.
[0046] Fig. 17 depicts an
embodiment of the present invention with the femoral
back plate 5 installed. As depicted, the back plate is positioned just above
the knee joint,
behind the user's knee. The back plate 5 guides the portions of the cable 1 to
a cross over
point 31, not shown, located on its back side. Each portion of the cable 1, is
then guided
back up toward the upper portion of the brace, for example to either side of
the femoral
plate 4, and the first tibial plate 2A. Cable guide holes along the perimeter
of tibial plate
2A are also shown, these guide holes receive the cable from the femoral back
plate 5, and
guide the cable 1 along tibial plate 2A toward and to tibial plate 2B where
the cable 1
enters another guide hole in tibial plate 2B before crossing over to the other
side of tibial
plate 2B and returning along the same path on the opposite side of the brace.
This portion
of the cable's path, from the cross over point 31 to the tibial plate 2B and
back forming
the tibial control loop 32. A similar path occurs where the cable 1 extends
from the cross
over point 31 on the femoral back plate 5 up to cable guides on either side of
the femoral
plate 4, connecting to the adjustment mechanism 6.
[0047] In additional
embodiments of the present invention, the tibial plate may
include additional portions which increase the hold on the wearer's tibia.
Increased tibia
control offers additional protection from hyperextension. As there is little
tissue between
the tibia and the external portion of the leg, this area is ideal for control
of the leg. In
some embodiments, the underside of the tibia plate, closest to the user's leg,
may include
an additional semi-ridged portion. As the cable system is tightened, for
example, this
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semi-ridged portion conforms to the shape of the user's tibia. This provides
an increased
hold on the tibia.
[0048] In additional
embodiments of the present invention, the tibia plate may
be constructed such that the plate has varying flexibility across itself For
example, this
varying flexibility would allow the tibia plate to conform to the shape of the
user's leg,
while also providing the necessary rigidity. In this example, a second semi-
ridged portion
may not be required, or, alternatively, may be offered in addition to the
second semi-
ridged portion.
[0049] In additional
embodiments of the present invention, the user may, of
course, use the brace as a preventative device, before any damage occurs, as
opposed to
after. In such a case, additional protection may be required. For example,
user's engaged
in extreme sports may require supplemental protection from impacts.
Embodiments of the
present invention may, therefore, include knee caps which protect the knee
from strike
forces. In some embodiments, the knee cap portion is disposed between the
tibial and
femoral plates such that when the plates pivot away from one another, the knee
cap
remains in place. In such an example, the tibial and femoral plates glide over
or beneath
the knee cap portion so as to allow necessary flexibility. Further, additional
padding at the
front of the knee may be added in order to both support the knee and protect
it from strike
forces.
[0050] While the invention
has been described and illustrated with regard to the
particular embodiment, changes and modifications may readily be made, and it
is
intended that the claims cover any changes, modifications, or adaptations that
fall within
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the spirit and scope of the invention. Changes and modifications can readily
be made to
adapt this tibial shell Q angle adjustment invention to conventional knee
braces. It is also
anticipated that this invention can be adapted to an elbow brace by
substituting the
adjustable tibial shell with an adjustable radius shell. This allows a
symmetrical elbow
brace to be adjusted to fit the angle between the humerus and radius of the
user's arm, and
can be adjusted to fit a right or left arm.
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