U.S. patent application number 11/862095 was filed with the patent office on 2008-10-16 for percutaneously deliverable orthopedic joint device.
This patent application is currently assigned to MDesign International. Invention is credited to Michael Hogendijk, Michael James Orth.
Application Number | 20080255664 11/862095 |
Document ID | / |
Family ID | 39831401 |
Filed Date | 2008-10-16 |
United States Patent
Application |
20080255664 |
Kind Code |
A1 |
Hogendijk; Michael ; et
al. |
October 16, 2008 |
PERCUTANEOUSLY DELIVERABLE ORTHOPEDIC JOINT DEVICE
Abstract
A percutaneously implantable orthopedic device is a
shape-changing joint prosthesis with a generally arcuate or
generally rectilinear configuration which is delivered through a
delivery device in a substantially straightened or slightly curved
configuration into a joint in a patient. The generally arcuate
configuration may include an open ring or spiral shape. The
generally rectilinear configuration may include a polygon or
zig-zag shape. The delivery and retrieval device can be a syringe,
hypodermic needle or cannula. The orthopedic device is moveable
into its generally arcuate or generally rectilinear configuration
in the joint by manipulation or a shape memory set. The orthopedic
device acts as a soft compliant bearing surface or cushion that
minimizes the bone-on-bone wear from articulation and loading.
Inventors: |
Hogendijk; Michael;
(Mountain View, CA) ; Orth; Michael James; (Morgan
Hill, CA) |
Correspondence
Address: |
MORRISON & FOERSTER LLP
755 PAGE MILL RD
PALO ALTO
CA
94304-1018
US
|
Assignee: |
MDesign International
Mountain View
CA
|
Family ID: |
39831401 |
Appl. No.: |
11/862095 |
Filed: |
September 26, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60911056 |
Apr 10, 2007 |
|
|
|
Current U.S.
Class: |
623/11.11 ;
606/99 |
Current CPC
Class: |
A61B 17/562 20130101;
A61F 2002/4415 20130101; A61F 2250/0058 20130101; A61F 2002/30535
20130101; A61B 2017/00004 20130101; A61F 2/30721 20130101; A61B
2017/00867 20130101 |
Class at
Publication: |
623/11.11 ;
606/99 |
International
Class: |
A61F 2/02 20060101
A61F002/02; A61B 17/68 20060101 A61B017/68 |
Claims
1. An orthopedic device suitable for minimally invasive deployment
using a tubular delivery apparatus, the orthopedic device
comprising an elongate core having a proximal end and a distal end,
the core comprising a generally arcuate configuration at
substantially body temperatures to enhance self-centering
positioning of the orthopedic device when deployed, said core being
manipulatable into a substantially straight configuration to permit
delivery.
2. The orthopedic device of claim 1, further comprising an
articular layer surrounding at least a portion of the core.
3. The orthopedic device of claim 1, wherein the core comprises
shape memory material.
4. The orthopedic device of claim 1, wherein the generally arcuate
configuration comprises a spiral shape.
5. The orthopedic device of claim 1, wherein the core, when in a
generally arcuate configuration, is substantially non-planar.
6. The orthopedic device of claim 2, wherein the device is further
configured to permit at least partial removal of at least part of
the core from the articular layer resulting in a void within the
articular layer.
7. The orthopedic device of claim 6, wherein the device is further
configured so that at least part of the void created by removal of
at least part of the core may be partially filled with a polymer
material.
8. The orthopedic device of claim 2, wherein the articular layer is
a polymeric material.
9. The orthopedic device of claim 1, further comprising a coating
of antifriction high wear material on a surface of said device.
10. The orthopedic device of claim 1, further comprising at least a
second core.
11. An orthopedic device suitable for minimally invasive deployment
using a tubular delivery apparatus, the orthopedic device
comprising an elongate core having a proximal end and a distal end,
the elongate core comprising a generally rectilinear configuration
at substantially body temperatures to enhance self-centering
positioning of the orthopedic device when deployed, said elongate
core being manipulatable into a substantially straight
configuration to permit delivery.
12. The orthopedic device of claim 11, further comprising an
articular layer surrounding at least a portion of the core.
13. The orthopedic device of claim 11, wherein the core comprises
shape memory material.
14. The orthopedic device of claim 11, wherein the core, when in a
generally rectilinear configuration, is substantially
non-planar.
15. The orthopedic device of claim 12, wherein the device is
further configured to permit at least partial removal of at least
part of the core from the articular layer resulting in a void
within the articular layer.
16. The orthopedic device of claim 15, wherein the device is
further configured so that at least part of the void created by
removal of at least part of the core may be partially filled with a
polymer material.
17. The orthopedic device of claim 12, wherein the articular layer
is a polymeric material.
18. The orthopedic device of claim 11, further comprising a coating
of antifriction high wear material on a surface of said device.
19. The orthopedic device of claim 11, further comprising at least
a second core.
20. A method of treating an orthopedic joint comprising using a
tubular delivery apparatus to minimally-invasively deploy an
orthopedic device suitable so that the device forms a substantially
non-linear pre-formed configuration in situ at substantially body
temperatures to enhance self-centering positioning of the
orthopedic device when deployed.
21. The method of treating an orthopedic joint of claim 20, further
comprising inserting an apparatus at or proximal the situs of
deployment to remove at least a portion of the device.
22. The method of treating an orthopedic joint of claim 20, further
comprising creating a gap in the orthopedic joint.
23. The method of treating an orthopedic joint of claim 20, wherein
the tubular delivery apparatus comprises a curved channel.
24. The method of treating an orthopedic joint of claim 20, further
comprising inserting an apparatus at or proximal the situs of
deployment to remove at least a portion of the core.
25. The method of treating an orthopedic joint of claim 20, wherein
the substantially non-linear pre-formed configuration is
rectilinear.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority from U.S.
Provisional No. 60/911,056 filed Apr. 10, 2007, which is
incorporated in its entirety by reference, herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] Various embodiments of the present inventions relate to the
treatment of osteoarthritis, rheumatoid arthritis, and any other
joint degenerative process with a minimally invasive implantable
device to reduce, amongst other things, bone-to-bone contact at a
joint.
[0004] 2. Related Art
[0005] Today there are an increasing number of patients with
osteoarthritis, rheumatoid arthritis, and other joint degenerative
processes. Osteoarthritis is by far the most common type of
arthritis, and the percentage of people who have it grows higher
with age. An estimated 12.1 percent of the U.S. population (nearly
21 million Americans) age 25 and older have osteoarthritis of one
form or another. Although more common in older people it usually is
the result of a joint injury, a joint malformation, or a genetic
defect in joint cartilage. Its time of occurrence differs:
osteoarthritis tends to start for men before the age of 45, and
after the age of 45 it is more common in women. It is also more
likely to occur in people who are obese or overweight and is
related to those jobs that stress particular joints.
[0006] It affects the musculoskeletal system and specifically the
joints--where two or more bones meet. It most often occurs in the
hands (particularly at the ends of the fingers and thumbs), spine
(particularly at the neck and lower back), knees, and hips. Joint
problems can include; stiffness, inflammation and damage to joint
cartilage (the tough, smooth tissue that covers the ends of the
bones, enabling them to glide against one another) and surrounding
structures. Such damage can lead to joint weakness, instability and
visible deformities that, depending on the location of joint
involvement, can interfere with the most basic daily tasks such as
walking, climbing stairs, using a computer keyboard, cutting your
food or brushing your teeth. This ultimately results in moderate to
severe pain and joint deterioration. As this is a degenerative
process of the joint it can ultimately end in total joint
replacement. Drug regimes can provide temporary relief from the
pain but do not slow down the crippling affects. The extreme result
or end point in traditional treatments is an open surgery procedure
for placing a spacer or total joint replacement with a prosthetic
device. It would be desirable as well as beneficial if there were
an intermediary step or alternative treatment before this
extreme.
[0007] Current joint replacement therapies (spacers or a total
prosthesis) require the joint capsule to be surgically opened and
the bone surfaces to be partially or totally removed. Various
spacers and or prosthetic devices can be made from a number of
biocompatible polymers such as silicone, polyurethane, Teflon etc.
Both modalities present drawbacks. For example, U.S. Pat. No.
6,007,580 to Matti Lehto et al. describes an implantable spacer
that must be fixed at one or both ends to the bone of either end of
the knuckle. It is not provided in a shape memory configuration and
must be implanted by opening of the knuckle capsule. It further
must be affixed at one or both ends to the corresponding bone
faces.
[0008] Various spacers in the art can cause inflammation and the
total joint replacement can limit the range of motion, compromise
the strength and ultimately the stability of the joint. These
surgeries are invasive and require the joint capsule to be
surgically opened. The incision itself can result in inflammation
and infection. Due to the invasiveness of the procedure and the
delicate nature of the joint it can result in joint instability
prolonged healing times.
SUMMARY OF THE INVENTION
[0009] It would be desirable to provide intermediary treatment
before deciding whether to undergo total joint replacement. Such
intermediary treatment preferably comprises providing a cushion or
improved spacer made of shape-changing, shape-memory or
shape-recovering material placed into the joint to minimize pain
and slow the deterioration process. It would further be desirable
to provide this cushion or improved articulation device in a
minimally-invasive procedure; e.g., through a hypodermic needle,
cannula or catheter that can be inserted directly into the joint
without the necessity of a surgical cut-down procedure and its
associated risks. There would be a distinct benefit to the patient
in that there would be a reduction in pain, time, and complexity in
conducting the procedure as well as decreasing healing time,
reducing post-operative pain, and slowing of deterioration in a
joint without the necessity of surgically opening the joint.
[0010] In various embodiments the orthopedic device is an
implantable prosthetic that has a substantially non-linear
preformed configuration (e.g. a shape that is not a substantially
straight line, such as a generally arcuate shape or a generally
rectilinear shape composed of more than a single line) which is
delivered through a hypodermic needle in a straightened
configuration and into the joint. In one embodiment the orthopedic
device is an implantable prosthetic generally arcuate open ring or
spiral which is delivered through a hypodermic needle in a
straightened configuration and into the joint. Then due to its
shape memory set, it then assumes an open ring. This ring acts as a
compliant bearing surface which minimizes the bone on bone wear
from articulation and loading. In another embodiment the orthopedic
device is an implantable prosthetic generally rectilinear polygon
or series of linear segment shape which is delivered through a
hypodermic needle in a straightened configuration and into the
joint.
[0011] In one embodiment the orthopedic device is an implantable
prosthetic with a series of discrete articulatable elements. The
elements, or segments, can be connected by one or more connectors.
In one embodiment the orthopedic device is a ratcheted linkage. In
another embodiment the orthopedic device is a series of articular
layers on a bendable elongate core. In one embodiment the
orthopedic device discrete articulatable elements can form a
generally arcuate open ring or spiral. In various embodiments the
orthopedic device may be delivered through a hypodermic needle in a
straightened configuration and into the joint. After delivery,
various embodiments of the orthopedic device can resume it
generally rectilinear or generally arcuate configuration by being
manipulated into that shape or due to a shape memory set. The
orthopedic device can act as a compliant bearing surface which
minimizes the bone on bone wear from articulation and loading.
[0012] In various embodiments, delivery or retrieval systems
include a straight or curved hypodermic needle, syringe, cannula or
catheter specially configured to implant or retrieve an orthopedic
device with a specific orientation. Certain systems can include
specially shaped plungers, needles, interlocks, removable
attachments, pinchers, lassos, tethers, hooks, threaded interfaces,
reservoirs, or cassette loading systems for interacting with or
positioning the orthopedic device. In one embodiment the orthopedic
device is an implantable prosthetic generally arcuate open ring or
spiral which is delivered through a hypodermic needle in a
straightened configuration and into the joint. Then due to its
shape memory set, it then assumes an open ring. This ring acts as a
compliant bearing surface which minimizes the bone on bone wear
from articulation and loading. In another embodiment the orthopedic
device is an implantable prosthetic generally rectilinear polygon
or series of linear segment shape which is delivered through a
hypodermic needle in a straightened configuration and into the
joint.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] These and other features, embodiments, and advantages of the
present invention will now be described in connection with
preferred embodiments of the invention, in reference to the
accompanying drawings. The illustrated embodiments, however, are
merely examples and are not intended to limit the invention.
[0014] FIG. 1A is a schematic top view of an orthopedic device
according to one embodiment of the present invention comprising a
substantially straight configuration.
[0015] FIG. 1B is a schematic top view of an orthopedic device
according to one embodiment of the present invention comprising an
open hoop arcuate configuration.
[0016] FIG. 1C is a schematic top view of an orthopedic device
according to one embodiment of the present invention comprising a
nautilus-style spiral arcuate configuration.
[0017] FIG. 2 is a schematic cross-section view perpendicular to a
longitudinal axis of an orthopedic device according to one
embodiment of the present invention comprising an elongate core and
an articular layer surrounding at least a portion of the core.
[0018] FIG. 3A is a schematic cross-section view along a plane
substantially parallel to and passing through a longitudinal axis
of an orthopedic device according to one embodiment of the present
invention comprising a substantially straight configuration, the
device comprising an elongate core and an articular layer
surrounding at least a portion of the core.
[0019] FIG. 3B is a schematic cross-section view along a plane
substantially parallel to and passing through a longitudinal axis
of an orthopedic device according to one embodiment of the present
invention comprising an open hoop arcuate configuration, the device
comprising an elongate core and an articular layer surrounding at
least a portion of the core.
[0020] FIG. 3C is a schematic cross-section view along a plane
substantially parallel to and passing through a longitudinal axis
of an orthopedic device according to one embodiment of the present
invention comprising a nautilus-style spiral arcuate configuration,
the device comprising an elongate core and an articular layer
surrounding at least a portion of the core.
[0021] FIG. 3D is a schematic cross-section view along a plane
substantially parallel to and passing through a longitudinal axis
of an orthopedic device according to one embodiment of the present
invention comprising an open hoop arcuate configuration, the device
comprising one or more elongate cores wrapped, braided or folded
along a length of the device and an articular layer surrounding at
least a portion of the core.
[0022] FIG. 3E is a schematic cross-section view along a plane
substantially parallel to and passing through a longitudinal axis
of an orthopedic device according to one embodiment of the present
invention comprising a nautilus-style spiral arcuate configuration,
the device comprising one or more elongate cores wrapped, braided
or folded along a length of the device and an articular layer
surrounding at least a portion of the core.
[0023] FIG. 4A is a schematic side view of an elongate core
according to one embodiment of the present invention comprising one
or more substantially linear or straight members.
[0024] FIG. 4B is a schematic side view of an elongate core
according to one embodiment of the present invention comprising one
or more wave, curve or zig-zag members disposed in one or more
planes.
[0025] FIG. 4C is a schematic side view of an elongate core
according to one embodiment of the present invention comprising one
or more members in a braided or weave configuration.
[0026] FIG. 5A is a schematic top view of an elongate core
according to one embodiment of the present invention comprising an
open hoop arcuate configuration and one or more end pieces.
[0027] FIG. 5B is a schematic top view of an elongate core
according to one embodiment of the present invention comprising an
open hoop arcuate configuration and one or more bends or hooks.
[0028] FIG. 5C is a schematic top view of an elongate core
according to one embodiment of the present invention comprising an
open hoop arcuate configuration and one or more features bent in or
out of the primary plane of the device.
[0029] FIGS. 6A-6K are schematic cross-section views of elongate
cores according to various embodiments of the present
invention.
[0030] FIG. 7A is a schematic perspective view of an orthopedic
device according to one embodiment of the present invention
comprising a plurality of independent or interconnectable discrete
elongate members.
[0031] FIG. 7B is a schematic perspective view of an orthopedic
device according to one embodiment of the present invention
comprising a plurality of independent or interconnectable discrete
elongate members in a "W" configuration.
[0032] FIG. 8 is a schematic perspective view of an orthopedic
device according to one embodiment of the present invention
comprising a plurality of independent or interconnectable discrete
members.
[0033] FIG. 9A is a schematic side view of an elongate core
according to one embodiment of the present invention comprising a
plurality of interconnectable discrete members in a substantially
straight configuration.
[0034] FIG. 9B is a schematic side view of one interconnectable
discrete member of FIG. 9A.
[0035] FIG. 9C is a schematic side view of an elongate core
comprising a plurality of interconnectable discrete members
according to FIG. 9A in an arcuate open loop configuration.
[0036] FIG. 10A is a schematic side view of an orthopedic device
delivery system according to one embodiment of the present
invention comprising a handle and a plunger.
[0037] FIG. 10B is a schematic side view of an orthopedic device
delivery system according to one embodiment of the present
invention comprising a substantially straight cannula or needle
with a lumen.
[0038] FIG. 10C is a schematic side view of an orthopedic device
delivery system according to one embodiment of the present
invention comprising an arcuate cannula or needle with a lumen.
[0039] FIG. 10D is a schematic side view close up of a distal end
of an orthopedic device delivery system according to one embodiment
of the present invention comprising a blunted delivery cannula.
[0040] FIG. 10E is a schematic side view of an orthopedic device
delivery system according to one embodiment of the present
invention comprising an angular tip.
[0041] FIG. 11 is a schematic side view of an orthopedic device
delivery system according to one embodiment of the present
invention comprising an implantable orthopedic device, a cannula,
and a plunger.
[0042] FIG. 12A is a schematic side cross-sectional view of an
orthopedic device delivery system according to one embodiment of
the present invention prior to implantation in a joint.
[0043] FIG. 12B is a schematic top cross-sectional view orthogonal
to FIG. 12A of two embodiments of orthopedic device delivery
systems similar to the system of FIG. 12A prior to implantation in
a joint, wherein on embodiment comprises a substantially straight
cannula and the other embodiment comprises an arcuate cannula.
[0044] FIG. 13A is a schematic side cross-sectional view of an
orthopedic device delivery system according to the embodiment of
the present invention shown in FIG. 12A upon partial insertion of
the orthopedic device into the joint.
[0045] FIG. 13B is a schematic top cross-sectional view orthogonal
to FIG. 13A of two embodiments of orthopedic device delivery
systems according to FIG. 12B upon partial insertion of the
orthopedic device into the joint.
[0046] FIG. 14A is a schematic side cross-sectional view of an
orthopedic device delivery system according to the embodiment of
the present invention shown in FIG. 12A upon deployment of the
orthopedic device into the joint.
[0047] FIG. 14B is a schematic top cross-sectional view orthogonal
to FIG. 14A of two embodiments of orthopedic device delivery
systems according to FIG. 12B upon deployment of the orthopedic
device into the joint.
[0048] FIG. 15A is a schematic side cross-sectional view of an
orthopedic device delivery system according to the embodiment of
the present invention shown in FIG. 12A upon deployment of the
orthopedic device into the joint and removal of the delivery
cannula.
[0049] FIG. 15B is a schematic top cross-sectional view orthogonal
to FIG. 15A of two embodiments of orthopedic device delivery
systems according to FIG. 12B upon deployment of the orthopedic
device into the joint and removal of the delivery cannula(e).
[0050] FIG. 16A is a schematic side view of an orthopedic device
according to one embodiment of the present invention comprising a
tether and a loop structure in a substantially straight
configuration.
[0051] FIG. 16B is a schematic side view of the orthopedic device
of FIG. 16A in an arcuate configuration.
[0052] FIG. 16C is a schematic side view of an orthopedic device
according to one embodiment of the present invention comprising one
or more tethers in an arcuate configuration.
[0053] FIG. 17 is a schematic side view of an orthopedic device
according to one embodiment of the present invention comprising a
looped arcuate configuration and at least one anchor.
[0054] FIG. 18 is a schematic side view of an orthopedic device
removal system according to one embodiment of the present invention
comprising an implantable orthopedic device, a cannula, and a
snare.
[0055] FIGS. 19A and 19B are schematic perspective and side views
of a portion of an interface in an orthopedic device delivery and
removal system according to one embodiment of the present invention
comprising an implantable orthopedic device and a plunger
connectable with a device interface.
[0056] FIGS. 20A-20C are schematic side views of a portion of an
interface in an orthopedic device delivery and removal system
according to another embodiment of the present invention comprising
an implantable orthopedic device and a plunger connectable with a
device interface.
[0057] FIG. 21A is a schematic side view of an orthopedic device
according to one embodiment of the present invention comprising a
multiplanar spiral configuration.
[0058] FIG. 21B is a schematic side view of an orthopedic device
according to one embodiment of the present invention comprising a
multiplanar arcuate configuration.
[0059] FIG. 21C is a schematic side view of an orthopedic device
according to one embodiment of the present invention comprising a
"W"-shaped configuration.
[0060] Throughout the figures, the same reference numerals and
characters, unless otherwise stated, are used to denote like
features, elements, components or portions of the illustrated
embodiments. In certain instances, similar names may be used to
describe similar components with different reference numerals which
have certain common or similar features. Moreover, while the
subject invention will now be described in detail with reference to
the figures, it is done so in connection with the illustrative
embodiments. It is intended that changes and modifications can be
made to the described embodiments without departing from the true
scope and spirit of the subject invention as defined by the
appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0061] As should be understood in view of the following detailed
description, this application is primarily directed to apparatuses,
systems and methods for minimally-invasive treatment of bone
joints. In various embodiments, an orthopedic device suitable for
minimally invasive deployment using a tubular delivery apparatus
with a lumen or channel, such as a cannula, hypodermic needle,
catheter, or another similar apparatus. In various embodiments the
orthopedic device is an implantable prosthetic that has a
substantially non-linear pre-formed configuration (e.g. a shape
that is not a substantially straight line, such as a generally
arcuate shape or a generally rectilinear shape composed of more
than a single line) which is delivered through a hypodermic needle
in a straightened configuration and into the joint. In one
preferred embodiment of the invention, an orthopedic device
comprises an elongate shape memory body that has a generally
arcuate configuration to enhance self-centering positioning of the
orthopedic device when deployed. In another embodiment an
orthopedic device comprises an elongate shape memory body that has
a generally rectilinear configuration to enhance self-centering
positioning of the orthopedic device when deployed. In one
embodiment an orthopedic device comprises a plurality of elongate
shape memory bodies that can be moved into a configuration to
enhance self-centering positioning of the orthopedic device when
deployed. The body can be manipulated into a substantially straight
configuration to permit delivery. In various embodiments, the
orthopedic device can be for single or multiple uses, and may be
removed from the joint.
1. Implantable Orthopedic Devices
[0062] In various embodiments the orthopedic device can have an
arcuate configuration once it is implanted in a joint. As used
herein, "arcuate" may refer to curved or rounded configurations or
shapes, but can also include generally arcuate configurations and
shapes that have some straight aspect or element with curved or
rounded configurations or shapes. As used herein, arcuate and
generally arcuate shapes can include "C", "O", "S", spiral,
nautilus, "Q" and other generally arcuate shapes. Similarly,
certain embodiments of the orthopedic device may include
rectilinear configurations, which can include polygons such as
triangles, squares, rectangles, diamonds, rhombuses, pentagons,
hexagons, octagons and other shapes with generally straight edges,
and further including shapes and configurations that are generally
rectilinear having some curved edge or comers or segments among
rectilinear shapes. As used herein, rectilinear and generally
rectilinear shapes can include "N", "M", "W", "Z", "T", "Y", "V",
"L", "X" and other generally rectilinear shapes. Various
embodiments of generally arcuate or generally rectilinear shapes
can include shapes with both rectilinear and arcuate portions, such
as a "P", "R", "B", and "U".
[0063] In order to deliver certain embodiments of the orthopedic
device to a joint, various contemplated embodiments of delivery
systems manipulate the shape of the orthopedic device into a
less-curved, or straightened configuration. In some instances, the
orthopedic device can be completely straightened, and in others the
orthopedic device may be curved in an arcuate configuration that is
less curved, or has a larger major diameter, than the device as
fully deployed in the joint. For example, FIG. 1A shows one
embodiment of an orthopedic device 100a with substantially straight
configuration. The orthopedic device 100a has a proximal end 110a
and a distal end 120a in relation to insertion into the body of a
patient, such as into a joint. In various embodiments of orthopedic
devices discussed herein, the distal end of the orthopedic device
is advanced or inserted into the body of a patient first, while the
proximal end of the orthopedic device is initially inserted
proximal to the distal end. In various embodiments, the orthopedic
device 100a has various shape configurations to permit loading from
a lumen within a needle, cannula, or other device for delivering
the orthopedic device to the site for implantation. In one
embodiment the straight configuration of orthopedic device 100a is
suited for delivery from a substantially straight needle. In other
embodiment configurations, the orthopedic device 100a is flexible
and can be bent or biased to have a curve or other shape to permit
delivery from curved or other-shaped needles or cannulae. In one
embodiment the orthopedic device 100a is delivered over a delivery
structure.
[0064] As illustrated, one embodiment of the orthopedic device has
a relatively consistent width of the elongate device. However, in
other contemplated embodiments, the width of the device body can
vary along its length. For example, the orthopedic device can have
a taper along a portion of its length, or be tapered along the
device's entire length. Width, or other dimension, can vary from
large to small or small to large, making the device thicker in some
portions than in others.
[0065] In one embodiment, the orthopedic device 100a is made of a
shape memory material. For example, the shape memory material can
be made from a heat set/shaped shape-memory material, such as
Nitinol or a shape memory plastic, polymeric, or synthetic
material, such as polycarbonate urethane. For example, one
embodiment of the orthopedic device 100a comprises a shape memory
material including a shape memory polyurethane or polyurethane-urea
polymer. One example of this type of shape memory material is
described in United States Patent Publication 2002/0161114 A1
entitled "Shape memory polyurethane or polyurethane-urea polymers"
which is incorporated in its entirety by reference herein.
Publication 2002/0161114 A1 describes a shape memory polyurethane
or polyurethane-urea polymer including a reaction product of: (A)
(a) silicon-based macrodiol, silicon-based macrodiamine and/or
polyether of the formula (I):
A--[(CH.sub.2).sub.m--O--].sub.n--(CH.sub.2).sub.m--A', wherein A
and A are endcapping groups; m is an integer of 6 or more; and n is
an integer of 1 or greater; (b) a diisocyanate; and (c) a chain
extender; or (B) (b) a diisocyanate: and (c) a chain extender, said
polymer having a glass transition temperature which enables the
polymer to be formed into a first shape at a temperature higher
than the glass transition temperature and maintained in said first
shape when the polymer is cooled to a temperature lower than the
glass transition temperature, said polymer then being capable of
resuming its original shape on heating to a temperature higher than
the glass transition temperature. Various embodiments of the
present invention relate to a shape memory polymer alone or a shape
memory composition which includes a blend of two or more of the
shape memory polyurethane or polyurethane-urea polymers defined
above or at least one shape memory polyurethane or
polyurethane-urea polymer defined above in combination with another
material. The present invention further relates to processes for
preparing materials having improved mechanical properties, clarity,
processability, biostability and/or degradation resistance and
devices or articles containing the shape memory polyurethane or
polyurethane-urea polymer and/or composition defined above.
[0066] In one embodiment the orthopedic device 100a comprises an
articular layer 105, which may also be called a blanket or a
jacket. The articular layer 105 is sized and configured to be
placed within a body, such as in a joint as a layer between bones
of the joint to provide a slideable articulation surface and/or a
cushion. In one embodiment the articular layer 105 is configured to
be compressed by loading in the joint. For example, in one
embodiment an articular layer may be compressed from a
substantially circular cross-sectional shape to an oval,
elliptical, or football shaped cross-section, which further
increases the amount of surface coverage of the articular layer
with respect to bony joint contact, resulting in reduced pressure
at the joint. In one embodiment the operating range of compression
of an orthopedic device is in the range of 0 to 50% of the cross
sectional diameter.
[0067] In one embodiment the articular layer is made of a shape
memory material, as described above. In certain embodiments of the
orthopedic device 100a, the body of the orthopedic device 100a
consists only of an articular layer which has shape-memory
properties. In other embodiments, as is described below, additional
structures within the articular layer may also have shape memory
characteristics. In certain embodiments, the articular layer 105
materials include but are not limited to Silicone, Teflon, Ultra
High Molecular Weight Polyurethane or and any implantable grade
material. In certain embodiments, the articular layer 105 can be
compliant and or compressible or of a non-compressible
construction. In certain embodiments, the articular layer 105 can
for instance have a variety of durometers (material hardness). In
certain embodiments, the articular layer 105 could also be infused
with air bubbles becoming much like a sponge. In certain
embodiments, the articular layer 105 can be provided in a number of
shapes and be continuous or of interrupted/individual sections. In
certain embodiments, the articular layer 105 may contain a material
or a drug to inhibit inflammation, joint deterioration etc, or a
material or drug to encourage tissue regeneration or device
encapsulation. In certain embodiments the articular layer 105
comprises a cartilage replacement material or comprises a natural
or synthetic cartilage.
[0068] In certain embodiments, the articular layer 105 is coated
with a drug such as a long lasting steroid. In certain embodiments
the articular layer is provided with wells, pockets, bubbles or
capsules for drug delivery. In one embodiment the articular layer
105 is coated with a secondary surface such as another polymer of a
different material property or an antifriction high wear material
such as Parylene or other similar materials which are known to the
art as providing for a low friction surface.
[0069] In certain embodiments, the articular layer 105 is
radiopaque, providing for visibility of the device when implanted
as viewed by X-Ray and/or other Fluoroscopic equipment. In one
embodiment the articular layer 105 radiopacity is provided by
radiopaque markers (not shown here) or by loading the articular
layer 105 with platinum, gold or other biocompatible metal.
[0070] As described above, in various embodiments the orthopedic
device can be an arcuate configuration once it is implanted in a
joint. Some non-limiting examples of arcuate configurations include
an open hoop such as is shown in the embodiment in FIG. 1B, and a
nautilus-style spiral as is shown in the embodiment in FIG. 1C.
Referring to FIG. 1B, the open hoop arcuate configuration
embodiment of the orthopedic device 100b has a proximal end 110b
and a distal end 120b in relation to insertion into the body of a
patient, such as into a joint. In certain embodiments orthopedic
device 100b has many similar attributes and characteristics of
orthopedic device 100a, such as shape memory and/or an articular
surface 105. In certain embodiments, orthopedic device 100b is an
arcuate configuration of orthopedic device 100a. In certain
embodiments the orthopedic device of 100a is biased to the
configuration as shown for orthopedic device of 100b. The bias may
be a preferred configuration for a flexible, pliable, bendable
device. In certain embodiments the orthopedic device of 100a can
change to the configuration as shown for orthopedic device of 100b
by a change in ambient or implantation site temperature or the
introduction of an activating medium or material. In certain
embodiments, the orthopedic device is reversibly configurable
between various shapes or geometries.
[0071] In one embodiment the orthopedic device 100b floats inside
the joint to better conform to the natural movement of the bones
through the range of motion of the joint. In one embodiment the
"open ring," "hoop" or "coil" configuration of orthopedic device
100b is designed to offer a mechanical advantage over that of fixed
type prosthesis as in a total joint replacement as described above
in the Background section. The design allows for the distribution
of the loading, shearing and/or compressive forces seen by the
articulation and or loading of the joint. As the orthopedic device
100b is not a closed hoop, it is not fixed in place (e.g. attached
to either end of bones in a joint) it in effect "floats" between
the ends of the bones in a joint. Thus, the orthopedic device 100b
offers little to no resistance to shape change and can spring open
or closed as force is applied to the device or to the joint, but
still maintain the purpose of providing a bearing, cushion,
slideable, or articulate surface. As there is little to no
resistance to the shape change the orthopedic device 100b in turn
allows for the distribution of the forces and/or shear as well as
resulting wear along the device more equally. In various arcuate
configurations, such as a open circle or continuous spiral,
embodiments of the orthopedic device are not closed like a complete
ring or closed circular shape would be, resulting in increased
dissipation of loading and compression though at least two
deformations in the orthopedic device. First, an open ring allows
for dynamic loading response as force that is applied to the joint
is partially dissipated by the force necessary to
radially-outwardly deform the open ring or spiral into a larger
radius profile. In one embodiment the operating range of radial
deformation of an arcuate orthopedic device is in the range of 0 to
50% of the orthopedic device profile diameter within the joint.
Second, as discussed above, the compression of the articular layer
resulting in cross-sectional deformation into a flatter shape also
dissipates force or pressure in the joint.
[0072] In one embodiment the orthopedic device 100b is sized to
snugly fit into the joint capsule itself. This fit maintains the
orthopedic device 100b center with respect to the axis of the bones
of the joint, such as in a finger or a knuckle in one non-limiting
example.
[0073] In various embodiments the orthopedic device 100b comprises
ends which are biased or bent slightly towards or away from its
center (see e.g., FIGS. 5B-5C, 21A-21B). In one embodiment the
orthopedic device, or coil, is out of plane on one or both ends,
providing a secondary shock absorbing component to the orthopedic
device as the bones in the joint are compressed axially. In one
embodiment the orthopedic device 100b is substantially flat, or
planar.
[0074] One example of a nautilus-style spiral arcuate configuration
is the embodiment of an orthopedic device 100c as shown in FIG. 1C.
The orthopedic device 100c has a proximal end 110c and a distal end
120c in relation to insertion into the body of a patient, such as
into a joint. In certain embodiments orthopedic device 100c has
many similar attributes and characteristics of orthopedic device
100a and/or 100b, such as shape memory and/or an articular surface
105. In certain embodiments, orthopedic device 100b is an arcuate
configuration of orthopedic device 100a. In certain embodiments the
orthopedic device of 100a may be altered in to a configuration as
shown for orthopedic device of 100c. The bias may be a preferred
configuration for a flexible, pliable, bendable device. In certain
embodiments the orthopedic device of 100a when unconstrained can
change to the configuration as shown for orthopedic device of 100c,
or by a change in ambient or implantation site temperature or the
introduction of an activating medium or material. In certain
embodiments, the orthopedic device is reversibly configurable
between various shapes or geometries.
[0075] The orthopedic device 100c floats inside the joint to better
conform to the natural movement of the bones through the range of
motion of the joint. The nautilus-style spiral arcuate
configuration also offers the advantages outlined by the open hoop
arcuate configuration, or hoop configuration, but provides a larger
bearing surface to the joint. With the extended length of the
spiral configuration, the orthopedic device 100c is configured to
provide more of an articulate surface, resulting in decreased
pressure on the bones by dissipating forces over a larger surface
area. The cross sectional diameter multiplied by the number of
winds in a spiral shape roughly equals the surface area coverage of
the articular surface in conformation with the bones of the joint.
For example, a small cross sectional diameter of a spiral
configuration allows for a plurality of windings in the spiral.
This plurality of spiral windings can then adjust to the general
surface area of either bone as the joint articulates.
[0076] As described thus far, certain descriptions of embodiments
of orthopedic devices have focused on the outside of the device.
However, the inside of the devices can have additional structure.
For example, in FIG. 2 an orthopedic device 200 according to one
embodiment of the present invention comprises an elongate core 240
and an articular layer 230 surrounding at least a portion of the
core 240. Referring back to FIGS. 1A-1C, various embodiments of
orthopedic devices 100a, 100b and/or 100c can either have an
elongate core or lack an elongate core. In other embodiments of
orthopedic devices 100a, 100b and/or 100c can either have an
articular layer or lack an articular layer. In other words, the
orthopedic device may consist of an elongate core, an articular
layer, or both.
[0077] As illustrated in the embodiment of at least FIG. 2 the
orthopedic device 200 includes the elongate core 240 in addition to
the articular layer 230. One preferred embodiment of the orthopedic
device 200 includes an elongate core 240 and an articular layer 230
wherein one or both the elongate core 240 and the articular layer
230 comprise a shape set memory material. In some embodiments the
articular layer 230 can surround or encapsulate the entire elongate
core 240. In other embodiments the articular layer 230 surrounds,
encapsulates, encloses or covers at least a portion of the core
240. As used herein, "surround," "encapsulate" and "enclose"
include configurations in which a core is not completely
surrounded, completely encapsulated or completely enclosed. For
example, certain embodiments of an orthopedic device contemplate an
articular layer which "surrounds" an elongate core with a
continuous or non-continuous helical band, discontinuous tabs, or
other intermittent articular layer structure.
[0078] In one embodiment the articular layer 230 is similar to any
articular layer described herein. Likewise, in various embodiments,
any articular layer may have some or all of the features of other
articular layer embodiments described herein.
[0079] In one embodiment the elongate core 240 comprises a shape
memory material. For example, the elongate core 240 can comprise a
shape memory material can made from a heat set/shaped shape-memory
material, such as Nitinol or a shape memory plastic, polymeric,
synthetic material. For example, one embodiment of the elongate
core 240 comprises a shape memory material including a shape memory
polyurethane or polyurethane-urea polymer, as is described above.
In one embodiment the elongate core 240 comprises a metal "open"
ring such as Nitinol encapsulated by an articular layer 230, or
outer blanket, comprising silicone. In one embodiment the elongate
core 240 comprises a hardened polymer. In one embodiment the
elongate core 240 is configured such that a heat set Nitinol with
an arcuate configuration, such as an open ring configuration, a
horseshoe configuration, or a spiral configuration, can be
straightened for delivery through cooling or plastic deformation,
then recovered to its original heat-set shape once released from a
delivery system, such as one embodiment using a properly sized
hypodermic needle. In one embodiment the elongate core 240
comprises a non-shape memory material which can be bent or
deformed.
[0080] In certain embodiments, the elongate core 240 is coated or
impregnated with a drug such as a long lasting steroid. In one
embodiment the elongate core 240 is coated with a secondary surface
such as another polymer of a different material property or an
antifriction high wear material such as Parylene or other similar
materials which are known to the art as providing for a low
friction surface.
[0081] In one embodiment an orthopedic device comprises a removable
elongate core and an articular layer. The removable elongate core
can be any among the various elongate cores described herein. The
orthopedic device would be inserted with an elongate core within
the orthopedic device to keep the orthopedic device in a rigid
substantially-straight or arcuate shape configuration. When placed
in a target site such as a joint in a patient, the removable
elongate core could be removed leaving the articular layer in place
at the target site. In one embodiment the lumen left in the
articular layer by the removal of the elongate core remains hollow
allowing for compression, deformation, or cushioning of the joint
by the orthopedic device's articular layer (see discussion relating
to FIG. 18 below). This lumen, or center, could also be filled with
a lumen material such as a liquid, polymer, collagen, or drug etc.
The orthopedic device could be provided with a port or a valve at
one or both ends to contain the lumen material. In one embodiment
the lumen material is a liquid that can be configured, organized or
hardened by the application of energy, radio frequency, laser,
heat, cold, etc.
[0082] The cross-section of some embodiments of orthopedic devices
including an elongate core can have various non-limiting options,
as are shown in FIGS. 3A-3E. FIG. 3A is a schematic cross-section
of an orthopedic device 300a comprising a substantially straight
configuration. In this embodiment the device comprises an elongate
core 340a and an articular layer 330a surrounding at least a
portion of the core 340a. The articular layer 330a has a proximal
end 331a and a distal end 332a. The elongate core 340a has a
proximal end 341a and a distal end 342a342a. In one embodiment the
orthopedic device 300a is similar to the orthopedic device 100a
described above. FIG. 3B shows a device an elongate core 340b and
an articular layer 330b surrounding at least a portion of the core
340b in an open hoop arcuate configuration. The articular layer
330b has a proximal end 331b and a distal end 332b. The elongate
core 340b has a proximal end 341b and a distal end 342b. In one
embodiment the orthopedic device 300b is similar to the orthopedic
device 100b described above. Certain embodiments of a spiral shaped
device, such as is shown in FIG. 3C can have a single elongate
core. For example, orthopedic device 300c comprises a
nautilus-style spiral arcuate configuration, the device comprising
an elongate core 340c and an articular layer 330c surrounding at
least a portion of the core 340c. The articular layer 330c has a
proximal end 331c and a distal end 332c. The elongate core 340c has
a proximal end 341c and a distal end 342c. In one embodiment the
orthopedic device 300c is similar to the orthopedic device 100c
described above.
[0083] In some embodiments, the elongate core can wrap around on
itself or consist of a number of pieces, such as is shown in FIGS.
3D and 3E. FIG. 3D shows an orthopedic device 300d with an open
hoop arcuate configuration. The device 300d comprises one or more
elongate cores 340d wrapped, braided or folded along a length of
the device and an articular layer 330d surrounding at least a
portion of the core(s) 340d. The articular layer 330d has a
proximal end 331d and a distal end 332d. The elongate core 340d has
a proximal end 341d and a distal end 342d. In one embodiment the
orthopedic device 300d is similar to the orthopedic device 100b
described above. In the illustrated embodiment in FIG. 3D, the
elongate core 340d is a unitary body. In other embodiments, two or
more elongate cores 340d are situated in a roughly parallel or
co-linear orientation, which can be twisted or braided or
interlocked. Other embodiments of the orthopedic device need not be
limited to a single elongate core or backbone, but could have a
plurality of cores or backbones including a braided configuration,
continuous overlaps, etc. FIG. 3E shows an orthopedic device 300e
with a nautilus-style spiral arcuate configuration. The device 300e
comprises one or more elongate cores 340e wrapped or folded along a
length of the device and an articular layer 330e surrounding at
least a portion of the core(s) 340e. In the illustrated embodiment
in FIG. 3E, the elongate core 340e is a unitary body. In other
embodiments, two or more elongate cores 340e are situated in a
roughly parallel or co-linear orientation, which can be twisted or
braided or interlocked. Other embodiments of the orthopedic device
need not be limited to a single elongate core or backbone, but
could have a plurality of cores or backbones including a braided
configuration, continuous overlaps, etc.
[0084] The shape of the elongate core can vary, as is shown in
embodiments in FIGS. 4A-4C. FIG. 4A shows an elongate core 440a
with one or more substantially linear or straight members. FIG. 4B
shows an elongate core 440b with one or more wave, curve or zig-zag
members that may be in one or more planes at any angle with respect
to one another. FIG. 4C shows an elongate core 440c with one or
more members in a braided or weave configuration. Any of these
patterns can be used with any of the elongate cores disclosed
herein.
[0085] Various embodiments of elongate cores can have different
features along the length or ends of the core, as is shown in FIGS.
5A-5C. An elongate core 540a with an open hoop arcuate
configuration can have one or more end segments, as is shown in
FIG. 5A. Such end segments can include proximal end segment 561a
and/or distal end segment 562a. In various embodiments, the
elongate core or cores 540a can have zero, one, two or more end
segments. In one embodiment the end segment 561a or 562a is
radiopaque or can be used as a marker for visualization of the ends
of the orthopedic device. The elongate core 540a has a proximal end
541a and a distal end 542a. In one embodiment the end segments 561a
and 562a are spherical bodies. In another embodiment, the end
segments 561a and 562a are loops. In one embodiment the end
segments 561a and 562a extend from the same material as the length
of the elongate core 540a. In one embodiment the end segments 561a
and 562a are separate elements made of the same or different
material as the length of the elongate core 540a and which are
bonded, fused, welded, glued, or otherwise attached to the proximal
end 541 a and a distal end 542a, respectively. Although not
illustrated, it is contemplated that an elongate core 540a has one
or more medial segments anywhere along the length of the elongate
core 540a. In various embodiments, elongate core 540a has end
segments or medial segments to help improve stability of an
articular layer or outer blanket, and need not be flat or planar,
but can be biased out of the primary plane of the device at one end
or both ends.
[0086] One elongate core 540b embodiment includes one or more
bends, such as proximal bend 541b and/or distal bend 542b as shown
in FIG. 5B. In various embodiments, the bends can also be called
hooks. In various embodiments, the bends or hooks can be closed off
to form a loop, as with certain embodiments of elongate core 540a.
Alternately, elongate core 540c has one or more segments bent in or
out of the primary plane of the device as shown in FIG. 5C. In one
embodiment proximal segment 541c is bent radially inward from the
curvature of the elongate core 540c. In one embodiment distal
segment 542c is bent radially outward from the curvature of the
elongate core 540c. In other embodiments, proximal segment 541c
and/or distal segment 542c are bent radially inward, radially
outward, and/or up or down from the primary plane of the elongate
core 540c.
[0087] Elongate cores can have any of a variety of cross-sectional
structures or profiles. For example, some embodiments of elongate
cores cross-sections are shown in FIGS. 6A-6K. The illustrated
embodiments are not limiting, but merely examples of various
possible cross-sectional profiles of any of the embodiments of
elongate cores or orthopedic devices described herein. The
illustrated embodiments shows a variety of possible cross-sectional
shapes for embodiments of the device or the core of the device,
including a square, ellipse, triangular, etc., and wherein the
elongate core can be modified by twisting, abrading, pitting and
zigzagging, etc.
[0088] FIG. 6A illustrates a cross-sectional view of an embodiment
of a circular profile elongate core 640a, which can be rotated
along a longitudinal axis of the core 640a. In various embodiments
the elongate core 640a is at least partially surrounded by an
articular layer, wherein the elongate core 640a and/or the
articular layer actuate between a straight or slightly curved
configuration to a more curved or arcuate configuration. During
this change in configuration, elongate core 640a and the articular
layer may rotate with respect to each other. In one embodiment the
elongate core 640a and the articular layer has some frictional
engagement, which may interfere with rotation between the elements,
resulting in some level of deformation. Furthermore, in one
embodiment both the elongate core 640a and the articular layer will
have different material properties which are dependent on
stiffness, durometer and other aspects of the respective materials.
Depending on the desired orientation of an orthopedic device during
delivery to a joint, the orientation of the elongate core 640a
and/or the articular layer may be controlled by the configuration
of the delivery device being used.
[0089] In various embodiments, an elongate core may be configured
to limit deformation and/or rotation in various orientations during
a change in configuration between straightened and curved profiles.
FIG. 6B illustrates a cross-sectional view of an embodiment of a
triangular profile elongate core 640b, which can limit rotation of
an articular layer along a longitudinal axis of the core 640b. FIG.
6C illustrates a cross-sectional view of an embodiment of a
rectangular profile elongate core 640c, which can limit rotation of
an articular layer a longitudinal axis of the core 640c. FIG. 6D
illustrates a cross-sectional view of an embodiment of a
trapezoidal profile elongate core 640d, which can limit rotation of
an articular layer along a longitudinal axis of the core 640d. FIG.
6E illustrates a cross-sectional view of an embodiment of an oval
or elliptical profile elongate core 640e, which can limit rotation
of an articular layer along a longitudinal axis of the core 640e.
FIG. 6F illustrates a cross-sectional view of an embodiment of a
ridged profile elongate core 640f, which can limit rotation of an
articular layer along a longitudinal axis of the core 640f. FIG. 6G
illustrates a cross-sectional view of an embodiment of a
non-symmetric profile elongate core 640g, which can limit rotation
of an articular layer along a longitudinal axis of the core 640g.
FIG. 6H illustrates a cross-sectional view of an embodiment of a
cross or X-profile elongate core 640h, which can limit rotation of
an articular layer along a longitudinal axis of the core 640h. FIG.
6I illustrates a cross-sectional view of an embodiment of a lumen
profile elongate core 640i, which can limit rotation of an
articular layer along a longitudinal axis of the core 640i. FIG. 6J
illustrates a cross-sectional view of an embodiment of a pentagon
profile elongate core 640j, which can limit rotation of an
articular layer along a longitudinal axis of the core 640j. FIG. 6K
illustrates a cross-sectional view of an embodiment of a hexagon
profile elongate core 640k, which can limit rotation of an
articular layer along a longitudinal axis of the core 640k.
[0090] Some embodiments of an elongate core include a plurality of
interconnectable discrete elongate members, such as is shown in
FIGS. 7-9C. In various embodiments, two or more discrete elongate
members may be connected along a single core wire, a series of core
wires, or connectors. In one embodiment one or more discrete
elongate members can rotate or spin about the connector or core
wire. In another embodiment one or more discrete elongate members
are affixed to the connectors or core wire in a manner to reduce or
prevent rotation of the elongate members with respect to connector
or core wire. As illustrated in FIG. 7A one embodiment of an
orthopedic device 740a comprising a plurality of interconnectable
discrete elongate members has elongate members 742, 744 and 746
which are linked by connector 760. In various embodiments the
connector 760 can be a single core member extending between all the
discrete elongate members, or it can be any number of discrete
connecting members between the elongate members. In one embodiment,
an orthopedic device 740b with a plurality of independent or
interconnectable discrete elongate members can have a "W"-shaped
generally rectilinear configuration. The connectors 760 can be
configured to orient the elongate members such as 742, 744, 746 and
748 in any number of orientations or angles. In various embodiments
the connectors 760 can have shape memory configurations or biases
for particular orientations depending on the doctor's preference or
the device selected. The overall shape of an orthopedic device can
have any number of configurations: for example, at least a "C", "O"
and "W" shape have been mentioned, but the device and/or articular
layer and/or elongate core can be in any shape or configuration.
The device is not limited to the "C"-shape or a spiral shape.
[0091] An elongate core may comprise a plurality of discrete
members of one of various shapes and sizes, wherein the discrete
members may be interconnected to function as an elongate core or a
backbone as set forth herein. Likewise, FIG. 8 shows orthopedic
device 840 with interconnected members 841, 842, and 843 which are
linked by an extendable connector 860.
[0092] One embodiment of an elongate core 940a with a plurality of
interconnectable discrete members, or links 950a, in a
substantially straight configuration is shown in FIG. 9A. Elongate
core 940a may be described as a multi-link elongate core,
multi-link core, multi-link orthopedic device, or multi-link
orthopedic implant. In one embodiment of a multi-link orthopedic
device a series of rigid or flexible links are configured to
translate the multi-link core from a straight or slightly curved
configuration into a curved orientation or configuration. The
diameter of curvature of the device could be adjustable by the
ratcheting features provided on each link 950a. In one embodiment
the links 950a are made of a material that can undergo some level
of elastic deformation. In another embodiment, the links 950a are
made of a more rigid material. With embodiments of the device,
core, or link that are made from a super elastic material such as
Nitinol, the implant can be straightened from its curved, deployed
or implanted configuration and placed in a needle or cannula.
However, a less elastic material such as stainless steel or certain
plastics might yield or break if straightened that much. Using a
curved delivery system, such as one shown in FIG. 10C below, would
allow a more-rigid arcuate implant to be slightly straightened
enough for insertion, but not enough to cause yielding.
[0093] Looking closer at a link, FIG. 9B shows a side view of one
link 950b. In one embodiment link 950b is a link 950a of FIG. 9A.
In one embodiment link 950b comprises a first end 951 and a second
end 952. Various links 950b are interconnectable between the second
end 952 of a first link 950b and the first end 951 of a second link
950b', and in one embodiment the interconnection is a hinged
connection between a first link interface 990 and a second link
interface 980. In one embodiment the first link interface 990 is a
post and the second link interface 980 is a channel in which the
post is captured to allow rotation. In another embodiment, the
second link interface 980 is a post and the first link interface
990 is a channel in which the post is captured to allow rotation.
In various other embodiments, other link interfaces allowing some
rotation including snap fits, connectors, or other similar
interfaces may be used. In the illustrated embodiment, the link
950b comprises a ratchet prong 960 and ratchet teeth 970. The
ratchet teeth 970 of one link 950b interact with the ratchet prong
960 of a second link 950b' to allow rotation with respect to links
950b and 950b' while restricting or limiting rotation in the
opposite direction.
[0094] Various link embodiments can be configured to an arcuate
configuration, as in FIG. 9C showing an elongate core 940c with
links according to FIG. 9A in an arcuate open loop configuration.
In one embodiment the elongate core 940c is actuated and locked
into an arcuate configuration by the ratcheting mechanism as
described above. In one embodiment the ratchet locking is
configured to be disengageable such that the prong is releasable
from the teeth to allow the elongate core 940c to rotate in a
straight or less-curved configuration.
2. Method and Apparatus for Delivering Implantable Orthopedic
Devices
[0095] In various embodiments of orthopedic devices described
herein, the orthopedic devices are configured to have an arcuate
shape in a joint. In certain embodiments, the orthopedic device can
be straightened into a substantially straight or less-curved
configuration for implantation with an orthopedic device delivery
system. For example, in one embodiment an arcuate orthopedic device
can be straightened by cooling or chilling a shape-memory material
in the orthopedic device and then inserting the orthopedic device
into a tube, cannula, or hypodermic needle of specific design shape
and cross section. The pre-loaded hypodermic needle is then
attached to a handle through a coupling or interface such as a luer
lock standard to the industry or any other attachment means. The
physician then straightens the finger by applying force providing
for a space or gap to occur in the joint. For example, the force
can be provided by using his hands, or a tool, to pull, stretch or
spread the desired joint. In one embodiment a sharp tool such as a
scalpel or trocar can be used to pierce the joint tissue. In
another embodiment, the deliver device needle can pierce the joint
tissue. The needle is positioned mid-point between the posterior
and anterior surfaces of the joint. The tip of the needle is
advanced into the joint, completely within the joint capsule. Once
inserted the physician releases the device by advancing it out of
the needle using an advancing mechanism, such as a handle and
plunger. Once deployed the needle and handle can be removed from
the joint. If more than one joint, such as a knuckle, is treated
the deployed needle can be removed via the luer type connector and
a second attached to the same handle, repeating the procedure as
needed.
[0096] One orthopedic device delivery system 1000 comprising a
handle 1010 and a plunger 1020 that is suitable for delivering the
orthopedic device implant is shown in FIG. 10A. In various
embodiments, the orthopedic device delivery system 1000 can be
provided in a number of mechanical configurations. One objective of
the orthopedic device delivery system 1000 is to completely advance
the orthopedic device out of a channel, cannula, lumen, or needle,
with non-limiting examples illustrated in FIGS. 10B and 10C. In
various embodiments, the orthopedic device delivery system 1000 is
actuated by advancing the orthopedic device by a simple ram type
piston or hypodermic needle configuration, or through the use of a
lead screw, or through the use of a pneumatic or hydraulic type
mechanism. In the illustrated embodiment, the handle 1010 comprises
a distal handle region 1012 and a proximal handle region 1011 and
the plunger 1020 comprises a distal plunger region 1022 and a
proximal plunger region 1021. In one embodiment the distal handle
region 1012 comprises a cannula interface 1015, such as a luer
connector.
[0097] Embodiments of a cannula or needle can be straight or
curved, as in FIGS. 10B and 10C respectively. A substantially
straight cannula 1030b or needle with a lumen 1035b is suitable for
delivering the orthopedic device implant described herein in
conjunction with the orthopedic device delivery system 1000 of FIG.
10A. In one embodiment the cannula 1030b comprises a distal cannula
region 1032b and a proximal cannula region 1031b. In one embodiment
the delivery cannula 1030b can be attached to a handle 1010 in an
orthopedic device delivery system such as orthopedic device
delivery system 1000 with any of a number of attachment means such
as a standard luer type coupler, bayonet, a luer mount, or a thread
type means for attachment to the delivery handle 1010. In one
embodiment proximal cannula region 1031b comprises a flange 1038b
and a luer connector 1037b. The needle or deployment cannula 1030b
can be provided in many shapes and cross sections. In one
embodiment the cannula 1030b is sized and configured to interface
with the orthopedic device in a specific orientation for delivery
into a joint. This interface may be a key-slot, or other mechanical
interface. In one embodiment the distal cannula region 1032b is
provided at its distal end with an insertion feature such as a
point, knife edge or blunt atraumatic edge.
[0098] Another embodiment of orthopedic device delivery system
comprising an arcuate cannula 1030c or curved needle is shown in
FIG. 10C. It has a lumen 1035c is suitable for delivering the
orthopedic device implant described herein in conjunction with the
orthopedic device delivery system 1000 of FIG. 10A. In various
embodiments, arcuate cannula 1030c is similar to substantially
straight cannula 1030b, except that arcuate cannula 1030c is more
curved. In one embodiment the cannula 1030c comprises a distal
cannula region 1032c and a proximal cannula region 1031c. In one
embodiment the delivery cannula 1030c can be attached to a handle
1010 in an orthopedic device delivery system such as orthopedic
device delivery system 1000 with any of a number of attachment
means such as a standard luer type coupler, bayonet, a luer mount,
or a thread type means for attachment to the delivery handle 1010.
In one embodiment proximal cannula region 1031c comprises a flange
1038c and a luer connector 1037c. The needle or deployment cannula
1030c can be provided in many shapes and cross sections. In one
embodiment the cannula 1030c is sized and configured to interface
with the orthopedic device in a specific orientation for delivery
into a joint. This interface may be a key-slot, or other mechanical
interface. In one embodiment the distal cannula region 1032c is
provided at its distal end with an insertion feature such as a
point, knife edge or blunt atraumatic edge.
[0099] In some embodiments the process or method of inserting an
orthopedic device into a joint is preferably atraumatic. In one
embodiment a fluoroscopically placed stab incision is followed by a
cannula insertion for orthopedic device delivery. The stab incision
would by its nature provide a path for a delivery needle or cannula
to follow. The stab incision could or would remove the necessity
for the cannula tip to be sharp. For example, In one embodiment a
joint such as a knuckle can be physically identified for orthopedic
device placement. The device can be fluoroscopically placed or
inserted without fluoroscopy. A cannula is inserted into the stab
incision and the orthopedic device is delivered through the cannula
in the incision to the joint.
[0100] Looking more closely at the tip of a needle or cannula,
FIGS. 10D and 10E illustrate two potential options. A blunted
delivery cannula 1030d with a lumen 1035d is shown in FIG. 10D. In
certain embodiments, the blunted delivery cannula 1030d is used in
conjunction with a joint piercing tool (not illustrated here) such
as a knife, scalpel, spike, trocar, or other sharp instrument for
piercing tissue surrounding a joint in order to create an access
hole or port through which a cannula can be inserted to provide the
orthopedic device access to a joint. An angular tip 1030e with a
lumen 1035e is shown in FIG. 10E. In one embodiment the angular tip
1030e is sharp enough to pierce tissue surrounding a joint in order
to create an access hole or port through which a cannula can be
inserted to provide the orthopedic device access to a joint. In
another embodiment, the angular tip 1030e is atraumatic and is used
to guide the delivery device in a previously opened incision or
natural opening in tissue. Minimally or atraumatic distal cannula
regions 1032b, 1032c corresponding to any cannula, such as cannula
1030b-E are intended to be slid through the stab incision, such as
made by a scalpel, thereby spreading the tissue which makes up the
knuckle capsule as it goes in.
[0101] As described above, in various embodiments an elongate core
is at least partially surrounded by an articular layer, wherein the
elongate core and/or the articular layer actuate between a straight
or slightly curved configuration to a more curved or arcuate
configuration. During this change in configuration, elongate core
and the articular layer may rotate with respect to each other. In
one embodiment the elongate core and the articular layer has some
frictional engagement, which may interfere with rotation between
the elements, resulting in some level of deformation. Furthermore,
in one embodiment both the elongate core and the articular layer
will have different material properties which are dependent on
stiffness, durometer and other aspects of the respective materials.
Depending on the desired orientation of an orthopedic device during
delivery to a joint, the orientation of the elongate core and/or
the articular layer may be controlled by the configuration of the
delivery device being used. In various embodiments, the shape,
curvature, or tip of the cannula, needle, or lumen can be
configured to control the specific orientation of the orthopedic
device as it is being implanted. For instance, the point of a
needle, trocar, or angle-tipped cannula such as an orthopedic
device delivery system with an angular tip 1030e could be used to
define the relationship of the orthopedic device and its
orientation in a joint.
[0102] One way of delivering embodiments of the orthopedic device
is shown in FIG. 11, where an implantable orthopedic device 1100 is
advanced through a cannula 1110 by a plunger 1120. The orthopedic
device 1100 comprises a distal end 1102 and a proximal end 1101,
and is similar to the embodiments of orthopedic devices described
herein. The cannula 1110 has a distal end 1112 which is configured
to present the orthopedic device 1100 into the implant delivery
site in a joint in the proper orientation. The plunger 1120 has a
distal end 1122 which advances the orthopedic device 1100 out of
the cannula 1110 and into the joint. In the illustrated embodiment,
the distal end 1122 of the plunger 1120 pushes the proximal end
1101 of the orthopedic device 1100. In one embodiment the plunger
is sized to match the cross sectional diameter of the proximal end
of the device and can also be provided with features to engage the
device in a specific fashion. In other embodiments (not
illustrated) the plunger is configured to attach to a distal or
medial portion of the orthopedic device to pull or advance the
device out of the cannula. In one embodiment the orthopedic device
delivery system is configured to deliver the orthopedic device 1100
in an orientation within a plane ("primary plane") roughly
corresponding to a plane of bony or cartilaginous articulation
within a joint, which is roughly orthogonal to a longitudinal axis
of at least one bone comprising part of the joint. As an orthopedic
device is delivered into a joint, such as a knuckle, the tissue
surrounding the knuckle including a joint capsule and various
ligaments helps maintain the orientation of the orthopedic device
in or near the primary plane within the joint by containing the
orthopedic device around its outer periphery. In one embodiment an
angular tip at the distal end 1112 of the cannula 1110 helps
maintain the proper orientation of the orthopedic device 1100
within or near the primary plane and avoiding undesired bias or
deformation of the orthopedic device 1100.
[0103] Some of the steps in delivering an orthopedic device 1200 in
a joint with an orthopedic device delivery system are illustrated
in FIGS. 12A-15B. In these figures a joint comprises a first bone
1201, a second bone 1202, and tissue 1203 surrounding the joint,
such as a joint capsule and/or a ligament. The "A" figures
illustrate a side view of the joint and the "B" figures illustrate
a cross-sectional view orthogonal to the side view in "A." The
primary plane of the orthopedic device roughly corresponds to the
plane of the "B" when bones 1201 and 1202 are roughly linear. When
the bones 1201 and 1202 actuate with respect to each other, the
primary plane may actuate as well to roughly correspond to a plane
normal to a point of contact between the bones 1201 and 1202 with
the orthopedic device 1200. A cannula 1230 with a distal end 1232
and a lumen 1235 is shown in both views. In the illustrated
embodiment, the distal end 1232 of the cannula 1230 comprises a
feature which helps maintain the proper orientation of the
orthopedic device during delivery. As shown, one embodiment of the
distal end 1232 feature is an angled tip. In each of FIGS. 12B,
13B, 14B and 15B, two embodiments of a cannula 1230b and 1230c are
illustrated. One would be used at a time, but both are illustrated
(with cannula 1230b in solid lines and 1230c in dotted lines) to
demonstrate that a straight or curved cannula, respectively, can be
used to deliver the orthopedic device as described with respect to
FIGS. 10B and 10C above. A plunger 1250 advances the orthopedic
device 1200 into the joint using any of the advancing mechanisms
described herein.
[0104] A step showing the device prior to implantation is shown in
FIGS. 12A-12B. This illustration shows both a substantially
straight cannula 1230b and another embodiment comprising an arcuate
cannula 1230c. A step illustrating at least partial insertion of
the orthopedic device 1200 into the joint is shown in FIGS.
13A-13B. In one embodiment a tool (not illustrated) is used to
pierce the tissue 1203 with a stab incision prior to insertion of
the cannula 1230. In another embodiment, the cannula 1230 pierces
the tissue 1203. The plunger 1250 advances the orthopedic device
1200 into the joint. Deployment of the device into the joint is
shown in FIGS. 14A-14B. The orthopedic device 1200 is shown in an
arcuate configuration. The deployment of the orthopedic device 1200
into the joint and removal of the delivery cannula(e) 1230b or
1230c is illustrated in FIGS. 15A-15B.
[0105] Other embodiments of orthopedic devices can have additional
features which can control the extent to which a device is open or
closed. For example, one orthopedic device 1600 comprising a tether
1610 and a loop structure 1620 is shown in a substantially straight
configuration in FIG. 16A. In one embodiment, the orthopedic device
1600 exhibits similar characteristics as the previously described
devices discussed herein. For example, the straight configuration
of the device 1600 may correspond to a configuration used for
device delivery. In a normal state, the device 1600 may be an open
ring, arcuate shape, or other configuration or shape when it is not
being straightened for delivery or removal. The orthopedic device
1600 comprises a proximal end 1601 and a distal end 1602. The
proximal end 1601 comprises the tether 1610 and a distal end 1602
comprises the loop structure 1620. The tether 1610 can be a
lanyard, suture, wire, or other structure which in one embodiment
is unitary with the orthopedic device 1600. In one embodiment the
tether 1610 is unitary with an elongate core in the orthopedic
device 1600. The tether 1610 passes through the loop structure
1620. After the orthopedic device 1600 is deployed in a joint it
assumes an arcuate configuration as shown in FIG. 16B. In one
embodiment the tether 1610b is pulled tight to bring the proximal
end 1601 and distal end 1602 of the orthopedic device 1600 toward
each other and the tether 1610b is tied into a knot, plug,
mechanical fastener or other securing mechanism 1630b to form a
substantially closed ring configuration for the orthopedic device
1600b. Depending on the degree of desired openness in the arcuate
configuration of the orthopedic device 1600, the tether 1610b can
be pulled and locked at different lengths to create a desired hoop
or device size. Once the desired size is attained, the securing
mechanism 1630b is locked. The tether 1600b can then be cut
proximate to the proximal side of the securing mechanism 1630b. The
tether 1600b can also be cut for retrieval of the device from the
joint. In another embodiment an orthopedic device 1600c comprises
one or more tethers, such as tethers 1610c and 1612c as shown in
FIG. 16C. In one embodiment the tethers 1610c and 1612c are secured
to each other with a securing mechanism 1630c such as is described
with respect to securing mechanism 1630b. The tethers 1610c and
1612c can then be cut proximate to the proximal side of the
securing mechanism 1630c. The tether 1610c and/or 1612c can also be
cut for retrieval of the device from the joint.
[0106] Another embodiment of an orthopedic device 1700 includes a
looped arcuate configuration 1710 and at least one anchor, as is
shown in FIG. 17. The orthopedic device 1700 has a proximal end
1701 and a distal end 1702. In one embodiment the proximal end 1701
and distal end 1702 are crossing ends on substantially the same
axis. In one embodiment the orthopedic device 1700 has a proximal
anchor 1720 at the proximal end 1701 and a distal anchor 1730 the
distal end 1702. Orthopedic device 1700 has a substantially
straight or less-curved configuration (not illustrated) for
delivery. Once the orthopedic device 1700 is delivered to the
joint, it reverts to its looped arcuate configuration 1710. In
various embodiments, the anchors 1720 and 1730 are unitary and
formed with an elongate core in the orthopedic device 1700, are
unitary and formed with the an articular layer in the orthopedic
device 1700, or are formed of separate elements and attached to the
orthopedic device 1700. In various embodiments the anchors 1720
and/or 1730 are threaded, tapered, cylindrical, barbed, hooks,
ribs, dissolvable, drug eluting and/or non-symmetric. In one
embodiment the anchors 1720 and/or 1730 are roughly cylindrical and
configured to be releasably attachable with a tool or plunger. In
one embodiment the anchors 1720 and/or 1730 are impregnated with a
bonding material. In one embodiment the anchors 1720 and/or 1730
are secured in to tissue surrounding or in the joint, such as bone,
cartilage, a capsule or ligaments. In one embodiment the anchors
1720 and/or 1730 are bio-absorbable into surrounding tissue.
[0107] Retrieval of orthopedic devices is also contemplated. For
example, one orthopedic device delivery and retrieval system 1801
can grab an implantable orthopedic device 1800 and pull it through
a cannula 1830 using a snare 1850, as is illustrated in FIG. 18.
Orthopedic device delivery and retrieval system 1801 is configured
to deploy and/or retrieve the implantable orthopedic device 1800.
In one embodiment the cannula 1830 is part of a separate retrieval
system with a lumen sufficiently sized and configured to recapture
and retrieve a deployed orthopedic device 1800. In various
embodiments the orthopedic device 1800 has end segments or medial
segments along the orthopedic device 1800 articulate layer and/or
elongate core, such as is illustrated in FIGS. 5A-5C. In one
embodiment the orthopedic device 1800 comprises one or more snare
interface points such as end segments 561a and 562a described with
respect to FIGS. 5A-5B above. For example, end segments 561a and
562a can be a ball, sphere, bead, hook, loop or other feature which
can be ensnared by a tightened snare 1850 to pull the orthopedic
device 1800 out of the joint. In one embodiment the snare interface
point is radiopaque or has markers for fluoroscopic visualization
during the retrieval procedure. In one embodiment the snare 1850 is
attached (not illustrated) to a handle or control device proximal
to the cannula 1830. For example in one embodiment the snare 1850
is attached to a handle or plunger with can be withdrawn or pulled
with respect to the cannula 1830 to tighten the snare 1850 and pull
the orthopedic device out of the joint and out of the patient's
body.
[0108] In one embodiment of an orthopedic device retrieval system
1801 the distal end of the cannula 1830 comprises a hook (not
illustrated) which can be used to grab or retrieve an orthopedic
device. In one embodiment the cannula hook is actuatable by the
doctor by pressing a button to extend or rotate the hook into the
joint, which then connects or grabs a part of the orthopedic device
for retrieval. In an additional embodiment, the button can be
released to pull the hook back into place to lock on to the
orthopedic device to be recaptured. In one embodiment of an
orthopedic device retrieval system 1801 only an elongate core is
retrieved, leaving the articular layer in the joint in a manner
similar to that discussed above regarding FIG. 2.
[0109] Another orthopedic device retrieval system 1901 can retrieve
an implantable orthopedic device 1900 with a plunger 1950
connectable with a device interface 1910, as is shown in FIGS.
19A-19B. In one embodiment the device interface 1910 is a junction
with a male threaded section 1911 on the distal end of the plunger
1950 and a female threaded section 1912 on the proximal end of the
orthopedic device 1900. In one non-illustrated embodiment the
device interface 1910 is a junction with a female threaded section
1912 on the distal end of the plunger 1950 and a male threaded
section 1911 on the proximal end of the orthopedic device 1900. In
one embodiment the minor diameter of the threads of the male
threaded section 1911 is roughly the same as the outer diameter of
the plunger or orthopedic device. In one embodiment the major
diameter of the threads of the male threaded section 1911b is less
than the outer diameter of the plunger or orthopedic device
resulting in a step at 1911b to provide uniform contact with the
orthopedic device 1900.
[0110] Another orthopedic device retrieval system can remove an
implantable orthopedic device 2000 using a plunger 2050 connectable
with a device interface 2010, as is shown in FIGS. 20A-20C. In one
embodiment the device interface 2010 is a junction with closed jaws
2052a at a distal end of the plunger 2050 and a jaw interface 2002
on the proximal end of the orthopedic device 2000. In one
embodiment the jaw interface 2002 comprises a step 2005 for
grasping or locking on to the jaw interface 2002. The step 2005 can
be a linear, circumferential, or other feature for grasping with
the jaws. In various embodiments the jaw interface 2002 comprises a
portion of an articular layer 2003, a portion of an elongate core
2004, or, as illustrated in FIG. 20C, both a portion of an
articular layer 2003 and a portion of an elongate core 2004
according to various embodiments of elongate cores and articular
layers described herein. In one embodiment with the jaw interface
2002 comprising a portion of the elongate core 2004, the elongate
core 2004 is exposed at the jaw interface 2002. The closed jaws
2052a can be actuated into open jaws 2052b to release the
orthopedic device 2000 into a joint. Conversely, the open jaws
2052b can be actuated into a closed configuration as closed jaws
2052a to recapture the orthopedic device 2000 from the joint. In
one embodiment jaws 2052a and 2052b are spring loaded. In
alternative embodiments, the device interface 2010 comprises a
solenoid, linkage, ring mechanism, push-pin, snap-fit, and
ball-detent interface. In one embodiment the device interface 2010
is an electrolyte junction whereby the application of energy, such
as electricity, causes the junction to dissolve thereby breaking
the junction between the plunger 2050 and the orthopedic device
2000.
[0111] FIGS. 21A-21C illustrate non-limiting embodiments of
orthopedic devices which may exhibit similar characteristics of
other orthopedic devices described above. FIGS. 21A and 21B
illustrate orthopedic devices 2100a and 2100b, respectively, which
have a multi-planar configuration which may be similar to the
devices illustrated in FIGS. 1C and 1B or FIG. 3C or 3B. Here, the
devices show a characteristic demonstrating that the devices do not
have to be constrained in a single plane. FIG. 21C is a schematic
side view of an orthopedic device 2100c according to one embodiment
of the present invention comprising a "W"-shaped generally
rectilinear configuration. This embodiment further demonstrates
devices that are not limited to arcuate configurations.
[0112] It will be understood that the foregoing is only
illustrative of the principles of the invention, and that various
modifications, alterations, and combinations can be made by those
skilled in the art without departing from the scope and spirit of
the invention. Accordingly, it is not intended that the invention
be limited, except as by the appended claims.
* * * * *