U.S. patent application number 15/184567 was filed with the patent office on 2016-10-06 for lockable implants and related methods.
The applicant listed for this patent is Kim John Chillag, Clemson University Research Foundation, University of South Carolina. Invention is credited to Kim John Chillag, John David DesJardins, Eric Montgomery Lucas, Frank Richard Voss.
Application Number | 20160287398 15/184567 |
Document ID | / |
Family ID | 49947218 |
Filed Date | 2016-10-06 |
United States Patent
Application |
20160287398 |
Kind Code |
A1 |
Lucas; Eric Montgomery ; et
al. |
October 6, 2016 |
LOCKABLE IMPLANTS AND RELATED METHODS
Abstract
Total joint replacements for implants include a first member
configured to attach to a first bone, a second member configured to
reside in an adjacent second hone and a locking mechanism. The
locking mechanism is configured to (i) lock the first and second
members in alignment for full extension or other defined stabilized
configuration and (ii) unlock to allow the first and second members
to pivot relative to each other for flexion or bending.
Inventors: |
Lucas; Eric Montgomery;
(Clemson, SC) ; DesJardins; John David; (Clemson,
SC) ; Chillag; Kim John; (Columbia, SC) ;
Voss; Frank Richard; (Columbia, SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Chillag; Kim John
Clemson University Research Foundation
University of South Carolina |
Columbia
Clemson
Columbia |
SC
SC
SC |
US
US
US |
|
|
Family ID: |
49947218 |
Appl. No.: |
15/184567 |
Filed: |
June 16, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13944606 |
Jul 17, 2013 |
9393123 |
|
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15184567 |
|
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|
61672352 |
Jul 17, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2/3804 20130101;
A61F 2002/30622 20130101; A61F 2002/30329 20130101; A61F 2002/30492
20130101; A61F 2250/0073 20130101; A61F 2/4202 20130101; A61F 2/384
20130101; A61F 2002/30079 20130101; A61F 2/30 20130101; A61F
2250/0008 20130101; A61F 2/385 20130101; A61F 2/3845 20130101; A61F
2/3836 20130101; A61F 2/32 20130101; A61F 2/4261 20130101; A61F
2002/3813 20130101; A61F 2002/30607 20130101; A61F 2002/482
20130101; A61F 2002/30668 20130101; A61F 2002/30565 20130101; A61F
2002/30632 20130101; A61F 2/42 20130101; A61F 2250/0006 20130101;
A61F 2/40 20130101 |
International
Class: |
A61F 2/38 20060101
A61F002/38; A61F 2/40 20060101 A61F002/40; A61F 2/42 20060101
A61F002/42; A61F 2/32 20060101 A61F002/32 |
Claims
1. An implant, comprising: a first member configured to attach to a
first bone; a second member in cooperating alignment with the first
member configured to reside in a second adjacent bone; and a lock
mechanism in communication with the first and/or second member
configured to (i) lock the first member to the second member for a
stabilized configuration and (ii) unlock the first and second
members to allow them to pivot relative to each other for flexion
or bending,
2. The implant of claim 1, wherein the lock mechanism is
selectively actuated by a user to lock and unlock the implant.
3. The implant of claim 1, further comprising a hinge assembly
having an axle configured to hingedly attach the first member to
the second member, wherein the hinge assembly comprises a yoke with
an axle channel that holds the axle and at least one spaced apart
second channel, wherein the lock mechanism comprises at least one
locking member that selectively slides in defined forward and
reverse directions in the at least one second channel to
respectively lock and unlock the first and second members.
4. The implant of claim 3, wherein the first member has a bearing
surface defined by a polymer insert that holds the yoke and allows
the second member to rotate in a flexion axis relative to the first
member.
5. The implant of claim 1, wherein the lock mechanism comprises a
magnet that slides to lock and or unlock in response to application
of an external magnetic field.
6. The implant of claim 1, wherein the lock mechanism is configured
to be manually selectively actuated upon a contact force associated
with a user physically pressing on an actuation member in
communication with the lock mechanism that resides under skin of
the patient with the implant.
7. The implant of claim 1, further comprising a hinge assembly that
attaches the first and second members, wherein the hinge assembly
comprises a yoke with a channel that receives first and second
laterally spaced apart first and second magnets, and wherein the
first or second member comprises spaced apart open interior spaces
that align with opposing sides of the yoke, one that receives a
first magnet and one that receives the second magnet, and wherein
the first and second magnets slide out of the yoke channel into the
respective first or second member interior spaces to unlock the
lock mechanism and the magnets slide into the yoke interior space
to lock the implant.
8. The implant of claim 1, wherein the implant is a total joint
replacement implant.
9. The implant of claim 1, wherein the implant is a total knee
replacement implant.
10. The implant of claim 1, wherein the implant is a total joint
replacement implant of an elbow.
11. A method of operating an implant in a patient, comprising:
selectively unlocking a lock of an implant having first and second
members that can move relative to each other using an implantable
lock onboard the implant; and selectively locking the lock to lock
the first member and the second member together in a fixed
configuration for structural stability using the onboard lock.
12. The method of claim 11, wherein the lock comprises at least one
magnet that slides, and wherein the selectively locking and
unlocking are carried out by passing an external magnetic field
over the at least one magnet.
13. The method of claim 11, wherein the selectively locking is
manually carried, out by physically pressing on an actuation member
in communication with the lock that resides under skin of the
patient with the implant.
14. A lockable implant, comprising: a first member configured to
attach to a first bone; a second member in cooperating alignment
with the first member configured to reside in a second adjacent
bone; and a lock mechanism in communication with the first and
second members configured to (i) lock the first member to the
second member for a stabilized configuration and (ii) unlock the
first and second members to allow them to pivot relative to each
other for flexion or bending, wherein the implant first and second
members have a cooperating ball and socket configuration and the
lock mechanism comprises at least one locking member that can slide
through a locking channel to enter and exit a defined interior
space of the first and/or second member to lock and unlock the
implant.
15. The implant of claim 14, wherein the lock mechanism is
selectively actuated by a user to lock and unlock the implant.
16. The implant of claim 14, wherein the lock mechanism comprises
at least one magnet that slides to lock and/or unlock in response
to application of an external magnetic field.
17. The implant of claim 14, wherein the lock mechanism is
configured to be manually selectively actuated upon a contact force
associated with a user physically pressing on an actuation member
in communication with the lock mechanism that resides under skin of
the patient with the implant.
18. A lockable implant, comprising: a first member configured to
attach to a first bone; a second member in cooperating alignment
with the first member configured to reside in as second adjacent
hone; and a lock mechanism in communication with the first and
second members configured to (i) lock the first member to the
second member for a stabilized configuration and (ii) unlock the
first and second members to allow them to pivot relative to each
other for flexion or bending, wherein the implant is a total hip
replacement implant.
19. The implant of claim 18, wherein the lock mechanism is
selectively actuated by a user to lock and unlock the implant.
20. The implant of claim 18, wherein the lock mechanism comprises
at least one magnet that slides to lock and/or unlock in response
to application of an external magnetic field or the look mechanism
is configured to be manually selectively actuated upon a contact
force associated with a user physically pressing on an actuation
member in communication with the lock mechanism that resides under
skin of the patient with the implant.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 13/944,606, filed Jul. 17, 2013, which claims the benefit
of and priority to U.S. Provisional Application Ser. No.
61/672,352, filed Jul. 17, 2012, the contents of which are hereby
incorporated by reference as if recited in full herein.
FIELD OF THE INVENTION
[0002] The present invention relates to surgical implants and is
particularly suitable for implants used in articulating joints
and/or in the presence of muscular deficiency,
BACKGROUND
[0003] Knee arthrodesis, indicated in the presence of inadequate
muscular control or soft tissue stability, allows for patients to
successfully ambulate. This surgery results in a rigidly extended
lower limb that cannot he flexed or reduced in length. The extended
position requires greater muscular strength and endurance to
control, even when not mobile, which can lead to secondary joint
pain and muscular fatigue. The permanence of this rigid extension
can also prevent patient participation in many normal daily living
activities such as bathing, tying shoes, or sitting, in close
quarter spaces such as a cars, airplanes and theaters.
[0004] Total knee replacement (TKR) is a surgical procedure to
relieve pain, correct deformity, and restore knee function using
artificial materials to restore the load bearing and movement
functions of the knee. If primary treatment fails, a revision
procedure is required. As the number of knee replacement procedures
increases, so does the incidence of revision surgeries. With each
surgery more native anatomy is lost and the risk of secondary
damage to musculature, nerves and bone increases. Multiple surgical
interventions can compound these risks and negative complications,
and can lead to terminal knee dysfunction.
[0005] Other joints that may be suitable for implants can have
similar or other issues.
SUMMARY OF EMBODIMENTS OF THE INVENTION
[0006] Embodiments of the present invention provide lockable
implants that allow for flexion when desired by the patient., and
that lock into a fixed or semi-rigid configuration for structurally
stable alternative configurations.
[0007] The lockable implants can be selectively locked and/or
unlocked by a user.
[0008] The lockable implants can have mechanical or
electromechanical locks to lock and unlock the implant, and this
the associated lower anatomical member, into a specific
orientation.
[0009] The lockable implants can include a magnetically operated
lock that cooperates with an externally applied magnetic field to
lock and unlock the implant.
[0010] The lockable implants can be self-locking, responsive to
applying a force at or above a defined force or load.
[0011] The lockable implants can include buttons, latches or
flexible surfaces on the implant that are accessible by the user
(through palpation or the like) either manually or with a tool,
that can be used to activate the locking or unlocking ability of
the implant.
[0012] Embodiments of the invention are directed to implants that
include: (a) a first member configured to attach to a first bone;
(b) a second member in cooperating alignment with the first member
configured to reside in a second adjacent bone; and (c) a lock
mechanism in communication with the first and/or second members
configured to (i) lock the first member to the second member for a
stabilized configuration and (ii) unlock the first and second
members to allow them to pivot relative to each other for flexion
or bending.
[0013] The lock mechanism can be selectively actuated by a user to
lock and unlock the implant.
[0014] The implant may include a hinge assembly having an axle
configured to hingedly attach the first member to the second
member. The hinge assembly can include a yoke with an axle channel
that holds the axle and at least one spaced apart second channel.
The lock mechanism can include at least one locking member that
selectively slides in defined forward and reverse directions in the
at least one second channel to respectively lock and unlock the
first and second members.
[0015] The implant can include a hinge assembly having an axle
configured to hinged y attach the first member to the second
member. The hinge assembly can include a yoke that resides between
the first and second members and has a laterally extending yoke
axle channel and at least one spaced apart laterally extending
second channel that is spaced apart from the axle channel. The
second member can include outer laterally extending locking
channels that reside on opposing ends of and can align with the at
least one second laterally extending second channel. The lock
mechanism can include at least one locking member that can slide,
side-to-side through the second member locking channels to enter
and exit a defined interior space of the at least one second
channel of the yoke to lock and unlock the implant.
[0016] The second member can include spaced apart laterally
extending axle channels that reside on opposing ends of and can
align with the laterally extending axle channel so that the axle
resides in the second member axle channels and the yoke axle
channel.
[0017] The first member can have a bearing surface defined by a
polymer insert that holds the yoke and allows the second member to
rotate in a flexion axis relative to the first member.
[0018] The lock mechanism can include a magnet that slides to lock
and/or unlock, in response to application of an external magnetic
field.
[0019] The lock mechanism can be configured to be manually
selectively actuated upon a contact force associated with a user
physically pressing on an actuation member in communication with
the lock mechanism that resides under skin of the patient with the
implant.
[0020] The implant can include a hinge assembly that attaches the
first and second members. The hinge assembly can include a yoke
with a channel that receives first and second laterally spaced
apart first and second magnets. The first or second member can
include spaced apart open interior spaces that align with opposing
sides of the yoke, one that receives a first magnet and one that
receives the second magnet. The first and second magnets can slide
out of the yoke channel into the respective first or second member
interior spaces to unlock the lock mechanism and the magnets can
slide into the yoke interior space to lock the implant.
[0021] The lock mechanism can be self-engaging in response to
application of a load introduced by the patient when the first and
second members are in a substantially aligned orientation.
[0022] The implant can he a total joint replacement implant.
[0023] The implant can be a total knee replacement implant.
[0024] The implant can be a total joint replacement implant of an
elbow.
[0025] Other embodiments are directed to methods of operating an
implant in a patient. The methods include: (a) selectively
unlocking a lock of an implant having first and second members
using an implantable lock onboard the implant; and (b) selectively
locking the lock to lock the first member and the second member
together in a fixed configuration for structural stability using
the onboard lock.
[0026] The lock can include at least one magnet that slides and the
selectively locking and unlocking can be carried out by passing an
external magnetic field over the at least one magnet.
[0027] The selectively locking can be manually carried out by
physically pressing on an actuation member in communication with
the lock that resides under skin of the patient with the
implant.
[0028] Other embodiments are directed to lockable implants. The
implants include a first member configured to attach to a first
bone; a second member in cooperating alignment with the first
member configured to reside in a second adjacent bone; and a lock
mechanism in communication with the first and second members
configured to (i) lock the first member to the second member for a
stabilized configuration and (ii) unlock the first and second
members to allow them to pivot relative to each other for flexion
or bending.
[0029] The lock mechanism can be selectively actuated by a user to
lock and unlock the implant.
[0030] The lock mechanism can include at least one magnet that
slides to lock and/or unlock in response to application of an
external magnetic field.
[0031] The lock mechanism can be configured to be manually
selectively actuated upon a contact force associated with a user
physically pressing on an actuation member in communication with
the lock mechanism that resides under skin of the patient with the
implant.
[0032] The implant first and second members can have a cooperating
ball and socket configuration and the lock mechanism can include at
least one locking member that can slide through a locking channel
to enter and exit a defined interior space of the first and/or
second member to lock and unlock the implant.
[0033] The implant first and second members can be attached with a
hinge having an axle in an axle channel.
[0034] The implant can be a total hip replacement implant.
[0035] The lock mechanism can be self-engaging in response to
application of a load introduced by the patient when the first and
second members are in a substantially aligned and/or defined
orientation.
[0036] The implant can be a total knee replacement implant.
[0037] The implant can be a total joint replacement implant.
[0038] The implant can be a total joint replacement implant of a
wrist.
[0039] The implant can be a total joint replacement implant of a
hip.
[0040] The implant can be a fatal joint replacement implant of a
shoulder.
[0041] The implant can be a total joint replacement implant of an
elbow.
[0042] The implant can be a total joint replacement implant of an
ankle.
[0043] The selectively locking can be manually carried out by
physically pressing on an actuation member in communication with
the lock that resides under skin of the patient with the
implant.
[0044] It is noted that aspects of the invention described with
respect to one embodiment, may be incorporated in a different
embodiment although not specifically described relative thereto.
That is, all embodiments and/or features of any embodiment can be
combined in any way and/or combination. Applicant reserves the
right to change any originally filed claim or file any new claim
accordingly, including the right to be able to amend any originally
filed claim to depend from and/or incorporate any feature of any
other claim although not originally claimed in that manner. These
and other objects and/or aspects of the present invention are
explained in detail in the specification set forth below.
[0045] Other systems and/or methods according to embodiments of the
invention will be or become apparent to one with skill in the art
upon review of the following drawings and detailed description. It
is intended that all such additional systems, methods, and/or
devices he included within this description, be within the scope of
the present invention, and be protected by the accompanying
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] Other features of the present invention will be more readily
understood from the following detailed description of exemplary
embodiments thereof when read in conjunction with the accompanying
drawings.
[0047] FIG. 1 is an isometric perspective view of a knee implant
according to embodiments of the present invention. The device is
unlocked and partially flexed.
[0048] FIG. 2 is an exploded view of the device shown in FIG.
1.
[0049] FIG. 3 is a side view of the device shown in FIG. 1. The
device may be locked in this position.
[0050] FIG. 4 is a side view of the device shown in FIG. 1 in a
partially flexed orientation. The device is unlocked.
[0051] FIG. 5 is a side view of the device shown in FIG. 1 and FIG.
3, with components of the locking mechanism removed.
[0052] FIG. 6 is a side view of the device shown in FIG. 1 and FIG.
4 in a partially flexed orientation, with components of the locking
mechanism removed.
[0053] FIG. 7 is a sectioned midplane side view of the device shown
in FIG. 1. The device may be locked or unlocked, in this
position.
[0054] FIG. 8 is a sectioned midplane side view of the device shown
in Figure in a partially flexed orientation. The device is
unlocked.
[0055] FIG. 9 is an isometric view of the device shown in FIG. 1,
and aligned/rotated about its flexion axis as shown in FIG. 3, FIG.
5, and FIG. 7. The device is in an unlocked state, and the femoral
component is removed for visibility,
[0056] FIG. 10 is an isometric view of the device shown in FIG. 1,
and aligned/rotated about its flexion axis as shown in FIG. 3, FIG.
5, FIG. 7, and FIG. 9. The device is in a locked state, and the
femoral component is removed for visibility.
[0057] FIG. 11 is a rear view of the device shown in FIG. 1,
sectioned in a frontal plane across the center of the locking
mechanism. The device is in an unlocked state.
[0058] FIG. 12 is a rear view of the device shown in FIG. 1,
sectioned in a frontal plane across the center of the locking
mechanism, as shown in FIG. 11. The device is in a locked
state.
[0059] FIG. 13 is an isometric view of the device shown in FIG. 1,
and rotated about its flexion axis as shown in FIG. 1, FIG. 2, FIG.
4, FIG. 6, and FIG. 8. The femoral component is removed for
visibility. The device is unlocked.
[0060] FIG. 14 is an example of a knee implant system in position
relative to the femur "F" and tibia "T".
[0061] FIG. 15 an example of an embodiment of the device with a
mechanical pushbutton for the locking mechanism according to
embodiments of the present invention,
[0062] FIG. 16 is front view of the embodiment of the device seen
in FIG. 15.
[0063] FIG. 17 is an embodiment of the device where the lock can
occur vertically through the stem of the femoral and tibial
components according to embodiments of the present invention, shown
in the locked position.
[0064] FIG. 18 is a view of the embodiment shown in FIG. 17, in a
flexed and unlocked position.
[0065] FIG. 19 is an embodiment of the device with another lock
mechanism that is configured with a latch that engages when the
device moved into full extension and/or a walking stable
configuration according to yet other embodiments of the present
invention.
[0066] FIG. 20 is a side section view of the embodiment in FIG.
19.
[0067] FIG. 21 is a schematic illustration of an exemplary lockable
implant in an elbow joint according to embodiments of the present
invention.
[0068] FIG. 22 is a schematic illustration of an exemplary lockable
total replacement hip implant according to embodiments of the
present invention.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0069] The present invention now is described more fully
hereinafter with reference to the accompanying drawings, in which
embodiments of the invention are shown. This invention may,
however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein; rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art.
[0070] Like numbers refer to like elements throughout. In the
figures, the thickness of certain lines, layers, components,
elements or features may be exaggerated for clarity. Broken lines
illustrate optional features or operations unless specified
otherwise. One or more features shown and discussed with respect to
one embodiment may be included in another embodiment even if not
explicitly described or shown with another embodiment.
[0071] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof As
used herein, the term "and/or" includes any and all combinations of
one or more of the associated listed items. As used herein, phrases
such as "between X and V" and "between about X and Y" should be
interpreted to include X and Y. As used herein, phrases such as
"between about X and Y" mean "between about X and about Y." As used
herein, phrases such as "from about X to Y" mean "from about X to
about Y."
[0072] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the specification and relevant art and
should not be interpreted in an idealized or overly formal sense
unless expressly so defined herein. Well-known functions or
constructions may not be described in detail for brevity and/or
clarity.
[0073] It will be understood that when an element is referred to as
being "on", "attached" to, "connected" to, "coupled" with
"contacting", etc,, another element, it can be directly on.,
attached to, connected to, coupled with or contacting the other
element or intervening elements may also be present. In contrast,
when an element is referred to as being, for example, "directly
on", "directly attached" to, "directly connected" to, "directly
coupled" with or "directly contacting" another element, there are
no intervening elements present. It will also be appreciated by
those of skill in the art that references to a structure or feature
that is disposed "adjacent" another feature may have portions that
overlap or underlie the adjacent feature.
[0074] Spatially relative terms, such as "under", "below", "lower",
"over", "upper" and the like, may be used herein for ease of
description to describe one element or feature's relationship to
another element(s) or feature(s) as illustrated in the figures. It
will be understood that the spatially relative terms are intended
to encompass different orientations of the device in use or
operation in addition to the orientation depicted in the figures.
For example, if the device in the figures is inverted, elements
described as "under" or "beneath" other elements or features would
then be oriented "over" the other elements or features. Thus, the
exemplary term "under" can encompass both an orientation of over
and under. The device may be otherwise oriented (rotated 90 degrees
or at other orientations) and the spatially relative descriptors
used herein interpreted accordingly. Similarly, the terms
"upwardly", "downwardly", "vertical", "horizontal" and the like are
used herein for the purpose of explanation only unless specifically
indicated otherwise.
[0075] It will be understood that, although the terms first,
second, etc. may be used herein to describe various elements,
components, regions, layers and/or sections, these elements,
components, regions, layers and/or sections should not be limited
by these terms. These terms are only used to distinguish one
element, component, region, layer or section from another region,
layer or section. Thus, a first element, component, region, layer
or section discussed below could be termed a second element,
component, region, layer or section without departing from the
teachings of the present invention. The sequence of operations (or
steps) is not limited to the order presented in the claims or
figures unless specifically indicated otherwise.
[0076] The term "about" means that the recited number or value can
vary by +/-20%.
[0077] The term "sterile" means that the noted device or material
meets or exceeds defined medical guidelines of cleanliness and is
substantially (if not totally) without contaminants so as to be
suitable for medical uses.
[0078] Turning now to the figures, FIG. 1 illustrates an example of
a lockable implant 10 that is a total knee replacement (TKR)
implant 10 according to embodiments of the present invention.
Although primarily described as a TKR, the implant 10 can be used
in other joints, particularly articulating joints such as, for
example, ankles, hips, shoulders, elbows, wrists and the like (see,
e.g., FIG. 21). Although, the knee implant 10 can lock into place
at about 0 and about 180 degrees, other implants can have other or
additional locking orientations. For example, the elbow implant 10
(FIG. 21) can be configured to "lock" in place at about 90
degrees.
[0079] Although the implant 10 is shown primarily herein as
including a hinge to allow pivoting movement between two attached
cooperating members 20, 30, other attachment configurations for
other movement of a particular joint can he used, such as a ball
and socket type configuration (FIG. 22).
[0080] As shown, the implant 10 includes a first member 20, e.g.,
lower (tibial) member a second member 30, e.g., upper (femoral)
member 30 with a lock, or locking mechanism 40 (also called a
latch). The lower member 20 can be attached to the tibia ("T") and
the upper member 30 can be attached to the femur ("F") via
respective stems 25, 35. The lower and upper members 20, 30 can be
connected via a hinge yoke 22. The locking mechanism 40 can be
incorporated into the hinge that is attached to the rotating
platform area using the hinge yoke 22.
[0081] The hinge yoke 22 can include a laterally extending channel
or aperture 122.sub.2 that is aligned with channel 130.sub.1 in the
upper member 30 to hold an axle 50, typically inside an axle
bearing 51, so as to allow the upper member 30 to pivot with
respect to the lower member 20 via the axle 50. The hinge yoke 22
can include a second channel or laterally extending aperture
122.sub.1 that holds a moveable locking member 52, shown as a pin
or bolt, that can selectively slide to engage or disengage a
channel 130.sub.2 in the upper member 30 to (i) lock into a full
stabilization walking configuration (e.g., full extension) to allow
an arthrodesis gait without requiring normal muscular strength
and/or control and (ii) unlock to allow the members 29, 30 to pivot
relative to each other for flexion or bending when not ambulating.
FIG. 14 illustrates an exemplary implant 10 in position relative to
the femur "F" and the tibia "T".
[0082] In some embodiments, the hinge yoke 22 can include first and
second spaced apart, laterally extending apertures or channels
122.sub.1, 122.sub.2 (FIGS. 7, 9), one of which hold the axle 50 as
discussed above and the other holding at least one slidable locking
member 52. As shown, the axle 50 may be larger than the locking
member(s) 52, but the reverse configuration may also be used. The
axle 50 can reside behind the locking member(s) 52 as shown. In
other embodiments, the axle 50 resides in front of the locking
member(s) 52.
[0083] In the embodiment shown, at least one slidable locking
member 52 includes two locking members, one on each side of the
implant 10. The locking members 52 can slide inward and outward
substantially in concert, or be separately deployable.
[0084] The hinge yoke locking member(s) channel 122.sub.1 can be
configured as a single channel with a constant diameter or with
different diameters. Where more than one locking member 52 is used,
the different locking members 52 can have different sizes (e.g.,
diameters) and/or configurations or may have the same
configurations and sizes. In the embodiment shown, the hinge yoke
22 includes a forward channel 122.sub.1 with a reduced diameter or
inner extending lip 57 at a medial section thereof 57 (FIGS. 11,
12) or with two aligned laterally extending closed channels (not
shown), one for each of the two locking members 52 (where two are
used). Although shown as two locking members 52 a single locking
member 52 or more than two may be used.
[0085] In some embodiments, the implant 10 can include a polymer
insert 21 forming part of the hinge/rotating platform 121 as in
conventional implants 10. The locking mechanism 40 can be
incorporated into conventional or novel hinge/rotating platform
systems.
[0086] In some embodiments, the insert 21 and/or hinge yoke 22 can
be provided in multiple configurations that can be selected by a
doctor for a particular patient so that the doctor can choose one
that locks the patient's leg 5-10 degrees short of "full extension"
for a stable walking configuration.
[0087] The implants 10 can be modular, interfacing with other
implantable components of a knee replacement system, allowing for
adjustment of limb length and fixation angle. The implants 10 can
be suitable for patients who could undergo revision, but are at
risk, of complications that could compromise its success. The
implants 10 can be used for patients with poorly performing
revision implants, but who do not desire permanent fusion (or
amputation). The implants 10 can be used for patients that
otherwise would require fusion or amputation. The implants 10 can
be used with patients having existing fusions who can "take-down"
to the lockable knee implant to provide them with increased
mobility or quality of life. The implants 10 may also be used as a
primary implant for a first TKR surgery irrespective of whether a
patient may have the compromised tissue or bone structure as a
precaution.
[0088] The implants 10 can have a hinge/rotating platform 121 and
provide industry standard stability. The locking configurations can
be configured to fit modular revision TKRs. The interfacing
configurations of modular revision TKR implants can allow mix and
match of components to custom it to individual patients. The
implant 10 can restore the knee joint function using a rotating
hinge-like function with two axis of articulation, including
articulating members 21, 30, which rotate about axle 50, and
articulating members 20 and 21, 22 which rotate about the stem 23
(FIG. 7) of the hinge yoke 22, to allow the joint to function in a
more normal fashion. In some embodiments, the implant 10 can
include a mobile, bearing-type sliding component that supports the
yoke 22 and may allow for some Anterior/Posterior (AP) motion (not
shown). For descriptions of conventional TKR designs, including
rotating, hinged designs, see, e.g., U.S. Pat. No. 5,358,527, U.S.
Pat. No. 5,800,552, U.S. Pat. No. 7,572292, U.S. Pat. No.
7,753,960, U.S. Pat. No. 7,799,084, and US PUB 2010/0131070, the
contents of which are hereby incorporated by reference as if
recited in full herein.
[0089] FIGS. 1 and 4 illustrate the implant 10 with the upper
member 30 partially pivoted relative to the lower member 20
allowing flexion. FIG. 3 illustrates the implant 10 in a locked
upright configuration for stable, weight-bearing walking.
[0090] The device 10 can be locked via mechanical or
electromechanical locking mechanism 40 that engages the hinge
comprising the hinge yoke 22. The lock or locking mechanism 40 is
typically =powered, but may be passively powered (e.g., inductively
powered) without requiring an on board power source. The lock can
be selectively activated and/or deactivated by a user. The locking
mechanism 40 can be manually or electronically activated and/or
deactivated. The locking mechanism 40 can be manually actuated.
[0091] A user can activate and/or deactivate the locking mechanism
from one state to the other. The device 10 can maintain its current
status until the user intervenes.
[0092] The locking mechanism 40 may be self-activating in response
to a large load, such as a load-bearing weight, being applied, to
the members 20, 30, when the members 20, 30 are aligned in a
substantially straight or other stable (walking) orientation (such
that the pivot shaft of the two components 20, 30, e.g., femoral
and tibial components, are substantially in-line so that the limb
is substantially straight). This activation can be while a patient
is prone on a bed or sofa by pushing against a foot board, for
example, but is typically in response to standing upright. The
activation can be induced by a jolt, mall jump or other movement to
cause the mechanical lock to move to the lock orientation.
[0093] When members 22 and 30 are aligned as shown in FIG. 3, FIG.
5, FIG. 7, FIG. 9, FIG. 10, FIG. 11, and FIG. 12, each locking
member 52 can translate axially within interior spaces 53, 54 of
channels 122.sub.1 and 130 to lock and unlock the device 10. The
lock is disengaged, as shown. In FIGS. 9 and 11, when the locking
members 52 reside entirely within the respective internal space 54
of channel 130.sub.2 of member 30. The lock is engaged, as shown in
FIGS. 10 and 12, when one or both locking members 52 are in
communication with the interior space 53 of channel 122.sub.1 of
hinge yoke 22, blocking rotation of member 30 with respect to
member 22, and thus preventing flexion.
[0094] In some particular embodiments, an interruption 57 in the
interior channel 122.sub.1 that divides internal spaces 53 can take
the form of a reduced diameter, and can keep locking members 52
from physically contacting either other, or from traveling beyond a
pre-determined distance.
[0095] When the device 10 is rotated about axle 50, interference
geometry 60 of the hinge yoke 22 blocks access of channel 122.sub.1
and can serve to keep locking members 52 from leaving interior
space 54.
[0096] In some embodiments, as shown for example in FIG. 2, the
locking mechanism 40 can include a magnetic material 55, which can
be a physical "permanent" magnet, that is embedded in, assembled,
attached and/or connected to the locking member 52. A cap 56 can be
used to seal off the magnetic material 55 from bodily fluid. As
shown in FIG. 2, the locking member 52 includes a receiving space
that holds the magnetic material 55 therein and cooperates with the
cap 56 to seal the magnetic material therein.
[0097] With the use of an internal magnetic material 55, attractive
or repulsive axial (side-to-side relative to the implant body)
force can be applied to the bolts 52 with a user interface device
155 which can apply an external magnetic field (physical or
electrical magnet via a user probe, control or other user interface
input device), causing the locking member(s) 52 to translate
laterally with respect to the implant body 10.
[0098] In some embodiments, the polar axis of magnetic material 55
can be in-line with the axis of the lock, and external magnets in
the same polar axis can be passed over either side of the device
10, pulling the bolts medially and into an unlocked configuration
as shown in FIG. 10 and FIG. 12. By reversing the external magnets
to the opposite polar direction, the user can pass the external
magnets 155m over either side of the device 10 to move the locking
members 52 medially to unlock the device 10 as shown in FIG. 9 and
FIG. 11.
[0099] FIG. 14 illustrates that a tattoo or other externally
visible marker 255 can be applied to the skin of a patient over the
locking mechanism 10 to provide alignment information for
directional reference for "lock" and "unlock" actions (which can be
icons or other suitable visible indicia).
[0100] In some particular embodiments, the magnetic material 55 can
be a rare earth magnet, which is typically much stronger than
ferrous magnets. There are two conventional types of rare earth
magnets, neodymium magnets (e.g., neodymium-iron-boron) and
samarium-cobalt magnets.
[0101] In some embodiments, the polar magnetic axis of magnetic
material 55 within locking members 52 can be aligned in such a way
that the natural state of the implant is to remain locked until
user intervention.
[0102] Magnetic material can be extremely brittle and can also be
vulnerable to corrosion (such as from the digestive acids in the
body). The magnetic material can be sealed within the locking
member 52 and cap 56. The magnetic material 55 can he alternatively
or additionally plated or coated with a biocompatible material such
as polyethylene to protect them from breaking, chipping and/or for
corrosion resistance. Particular examples of rare earth magnets
include Nd.sub.2Fe.sub.14B, SmCo.sub.5 and Sin(Co,Fe,Cu,Zr).
[0103] The magnetic material 55 can include a material that moves
or changes viscosity in response to exposure to a magnetic field
such as a magnetorheological fluid (also known as an MR fluid,
available from Lord Corporation, Erie, Pa.) or a ferrofluid. The
fluids change viscosity when subjected to a magnetic field.
[0104] The lock 40 can also or alternatively be a mechanical lock
58, as seen in FIG. 15, that can be manually pushed by a user to
engage and/or disengage the locking members 52. For example, a user
can push against skin on one side of the implant 10 to slide a pin
in a defined direction, e.g., inward or up or down, a distance
sufficient to disengage a lock feature that engages or disengages
the locking members 52. FIGS. 15 and 16 illustrate an exemplary
manually deployable push button 58 that a user can use to engage or
disengage the locking mechanism 40, e.g., to slide locking members
52.
[0105] In some embodiments, the hinge yoke 22 can include a set of
stacked dome or belleview washers, springs or other biasing members
that can bias the movement in one direction (to the unlocked or
locked position).
[0106] The locking mechanism 40 can be self-activating in response
to application of load bearing weights as noted above.
[0107] The locking mechanism 40 can be a mechanical assembly that
includes a set of stacked dome or belleview washers, springs or
other biasing members that compress when a defined load is applied
and allow a locking member to translate in a defined direction,
e.g., sideways or up or down to engage a mechanical lock retention
feature associated with the hinge yoke 22.
[0108] As shown in FIGS. 17 and 18, the locking mechanism 40 can be
configured so that locking can occur with a vertical lock member
52, which resides in a channel 330 within the femoral component 30.
When the user moves the leg into full extension, locking member 52'
can slide down into an aligned channel 230 of tibial component 20.
When locking member 52' is in simultaneous communication with both
channels 230, 330 flexion cannot occur and the device 10 is thus
locked, allowing for ambulation. When the user wishes to unlock the
device, the user can lift the leg so that the tibial member is
above the femoral member, and the locking member 52' will return
entirely to the shaft 330 of femoral member 30, thus unlocking the
device and allowing for flexion.
[0109] In some embodiments of the device 10, the locking mechanism
40 is configured so that locking can occur in response to when the
device is moved into full extension., as shown in FIG. 19 and FIG.
20. The lock or locking mechanism 40 can include an upwardly
projecting member 45 that is in communication with a spring or
other resilient member 46 to bias the member in one position, e.g.,
the member 45 can be spring-loaded. The upper femoral component 30
includes an interior wall 30w. The upwardly projecting member 45
has a lip 47 or other shaped feature with a geometry shaped to
interface with and secure with a defined depression in the femoral
component 30 interior wall 30w. In this embodiment, the locking
mechanism 40 can be disengaged through the previously described
method of magnetic operation and/or a mechanical push actuation,
e.g., via a push button a or other input.
[0110] In other embodiments, the locking mechanism can be activated
using an inductively powered circuit/switch based on an externally
applied inductive power source.
[0111] FIG. 21 shows the implant 10 can be for an elbow that can
lock into place at about 60-120 degrees, e.g., about 90 degrees,
from the long or substantially axially aligned configuration of the
stem members 25, 35.
[0112] FIG. 22 shows an alternate implant 10' with a lock mechanism
40 that can lock a ball and socket configuration as the two
cooperating members 20', 30' of a total replacement hip joint. The
lock mechanism 40 can include at least one locking member 52 (e.g.,
a magnet or other configuration such as one or more of the
components/configurations described above) that slides into an
interior cavity 10c of the first or second member 20, 30 to latch
or lock the two members together in a defined stable configuration.
The at least one locking member 52 can also slide further in the
same direction or in an opposing direction to unlatch or unlock the
implant (the two members 20, 30) and allow bending and/or
flexion.
[0113] While the foregoing written description of the invention
enables one of ordinary skill to make and use what is considered
presently to be the best mode thereof, those of ordinary skill will
understand and appreciate the existence of variations,
combinations, and equivalents of the specific embodiment, method,
and examples herein. The invention should therefore not be limited
by the above described embodiment, method, and examples, but by all
embodiments and methods within the scope and spirit of the
invention as claimed.
* * * * *