U.S. patent application number 11/517694 was filed with the patent office on 2007-01-04 for osteogenic implants for soft tissue.
This patent application is currently assigned to WARSAW ORTHOPEDIC, INC.. Invention is credited to Hai H. Trieu.
Application Number | 20070003598 11/517694 |
Document ID | / |
Family ID | 34116100 |
Filed Date | 2007-01-04 |
United States Patent
Application |
20070003598 |
Kind Code |
A1 |
Trieu; Hai H. |
January 4, 2007 |
Osteogenic implants for soft tissue
Abstract
An osteogenic implant includes a degradation agent in solid form
and an osteogenerative agent in solid form. The osteogenic implant
is configured to release the degradation agent prior to releasing
the osteogenerative agent.
Inventors: |
Trieu; Hai H.; (Cordova,
TN) |
Correspondence
Address: |
LARSON NEWMAN ABEL POLANSKY & WHITE, LLP
5914 WEST COURTYARD DRIVE
SUITE 200
AUSTIN
TX
78730
US
|
Assignee: |
WARSAW ORTHOPEDIC, INC.
Warsaw
IN
|
Family ID: |
34116100 |
Appl. No.: |
11/517694 |
Filed: |
September 8, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10634798 |
Aug 6, 2003 |
|
|
|
11517694 |
Sep 8, 2006 |
|
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Current U.S.
Class: |
424/426 ;
424/94.61; 514/16.5; 514/16.7; 514/18.3; 623/16.11 |
Current CPC
Class: |
A61L 2300/45 20130101;
A61L 2300/602 20130101; A61L 2300/622 20130101; A61L 2430/38
20130101; A61L 2300/254 20130101; A61F 2002/30586 20130101; A61K
47/32 20130101; A61F 2002/30677 20130101; A61L 2300/414 20130101;
A61K 47/34 20130101; A61F 2002/444 20130101; A61L 27/54 20130101;
A61K 9/0024 20130101 |
Class at
Publication: |
424/426 ;
623/016.11; 424/094.61; 514/012 |
International
Class: |
A61F 2/28 20060101
A61F002/28; A61K 38/47 20060101 A61K038/47 |
Claims
1. An osteogenic implant comprising: a degradation agent in solid
form; and an osteogenerative agent in solid form; wherein the
osteogenic implant is configured to release the degradation agent
prior to releasing the osteogenerative agent.
2. The osteogenic implant of claim 1, wherein the osteogenerative
agent is an osteoconductive agent.
3. The osteogenic implant of claim 1, wherein the osteogenerative
agent is an osteoinductive agent.
4. (canceled)
5. The osteogenic implant of claim 1, wherein the degradation agent
includes a nucleolytic agent.
6.-7. (canceled)
8. The osteogenic implant of claim 1, wherein the degradation agent
is included in a microsphere.
9. The osteogenic implant of claim 8, wherein the microsphere is
included in a solution.
10. (canceled)
11. The osteogenic implant of claim 1, wherein the degradation
agent is included in an outer layer of the osteogenic implant
surrounding a core layer including the osteogenerative agent.
12. The osteogenic implant of claim 1, further including an outer
layer having an opening, wherein the degradation agent is included
in a first region within the outer layer and the osteogenerative
agent is included in a second region within the outer layer.
13. The osteogenic implant of claim 12, wherein the first region is
closer to the opening than the second region.
14. The osteogenic implant of claim 1, wherein the degradation
agent is included in a polymeric matrix.
15.-16. (canceled)
17. The osteogenic implant of claim 1, wherein the osteogenerative
agent is included in a polymer matrix.
18.-19. (canceled)
20. The osteogenic implant of claim 1, further comprising an
anesthetic agent or an analgesic agent.
21. The osteogenic implant of claim 20, wherein the osteogenic
implant is configured to release at least a portion of the
anesthetic agent or the analgesic agent in conjunction with the
degradation agent.
22.-24. (canceled)
25. The osteogenic implant of claim 1, wherein the osteogenic
implant includes an elongated form and a tapered end.
26. An osteogenic implant comprising: a first polymer matrix
including a degradation agent; and a second polymer matrix
including an osteogenerative agent; wherein the first polymer
matrix is configured to release at least a portion of the
degradation agent prior to time at which the second polymer matrix
is configured to release the osteogenerative agent.
27. The osteogenic implant of claim 26, wherein the osteogenerative
agent is an osteoconductive agent.
28. The osteogenic implant of claim 26, wherein the osteogenerative
agent is an osteoinductive agent.
29.-32. (canceled)
33. The osteogenic implant of claim 26, wherein the first polymeric
matrix includes a hydrogel.
34. The osteogenic implant of claim 26, wherein the first polymeric
matrix includes a bioresorbable polymer.
35.-36. (canceled)
37. The osteogenic implant of claim 26, further comprising an
anesthetic agent.
38. The osteogenic implant of claim 37, wherein the osteogenic
implant is configured to release at least a portion of the
anesthetic agent in conjunction with the degradation agent.
39.-40. (canceled)
41. A medical kit comprising: an osteogenic implant including: a
degradation agent in solid form; and an osteogenerative agent in
solid form; wherein the osteogenic implant is configured to release
the degradation agent prior to releasing the osteogenerative agent;
and a tool configured to locate the osteogenic implant proximate to
a vertebral structure.
42. The medical kit of claim 41, wherein the tool includes a lumen
and wherein the osteogenic implant is configured to fit within the
lumen.
43.-68. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. application Ser.
No. 10/634,798, entitled "METHODS AND DEVICES FOR THE TREATMENT OF
INTERVERTEBRAL DISCS," filed Aug. 6, 2003, and naming inventor Hai
H. Trieu, which is incorporated herein by reference in its
entirety.
FIELD OF THE DISCLOSURE
[0002] This disclosure, in general, relates to osteogenic implants,
and in particular, to osteogenic implants for treating spinal
ailments
BACKGROUND
[0003] In human anatomy, the spine is a generally flexible column
that can withstand tensile and compressive loads. The spine also
allows bending motion and provides a place of attachment for keels,
muscles, and ligaments. Generally, the spine is divided into four
sections: the cervical spine, the thoracic or dorsal spine, the
lumbar spine, and the pelvic spine. The pelvic spine generally
includes the sacrum and the coccyx. The sections of the spine are
made up of individual bones called vertebrae. Three joints reside
between each set of two vertebrae: a larger intervertebral disc
between the two vertebral bodies and two zygapophyseal joints or
facet joints located posteriolaterally relative to the vertebral
bodies and between opposing articular processes.
[0004] The intervertebral discs generally function as shock
absorbers and as joints. Further, the intervertebral discs can
absorb the compressive and tensile loads to which the spinal column
can be subjected. At the same time, the intervertebral discs can
allow adjacent vertebral bodies to move relative to each other,
particularly during bending or flexure of the spine. Thus, the
intervertebral discs are under constant muscular and gravitational
pressure and generally, the intervertebral discs are the first
parts of the lumbar spine to show signs of deterioration.
[0005] The zygapophyseal joints permit movement in the vertical
direction, while limiting rotational motion of two adjoining
vertebrae. In addition, capsular ligaments surround the
zygapophyseal joints, discouraging excess extension and torsion. In
addition to intervertebral disc degradation, zygapophyseal joint
degeneration is also common because the zygapophyseal joints are in
almost constant motion with the spine. In fact, zygapophyseal joint
degeneration and disc degeneration frequently occur together.
Generally, although one can be the primary problem while the other
is a secondary problem resulting from the altered mechanics of the
spine, by the time surgical options are considered, both
zygapophyseal joint degeneration and disc degeneration typically
have occurred. For example, the altered mechanics of the
zygapophyseal joints or the intervertebral disc can cause spinal
stenosis, degenerative spondylolisthesis, and degenerative
scoliosis.
[0006] Furthermore, acute strenuous events, such as whiplash or
overextension, can damage capsular ligaments. Such damage to
capsular ligaments if untreated can lead to degradation of the
zygapophyseal joint or of the intervertebral disc.
[0007] In particular, deterioration can be manifested as a
herniated disc. Weakness in an annulus fibrosis can result in a
bulging of the nucleus pulposus or a herniation of the nucleus
pulposus through the annulus fibrosis. Ultimately, weakness of the
annulus fibrosis can result in a tear, permitting the nucleus
pulposus to leak from the intervertebral space. Loss of the nucleus
pulposus or a bulging of the nucleus pulposus can lead to pinching
of nerves, causing pain and damage to vertebrae. In addition, aging
can lead to a reduction in the hydration of the nucleus pulposus.
Such a loss in hydration can also result in pinching of nerves.
[0008] A traditional option for treating a patient includes
replacement of the intervertebral disc or the zygapophyseal joint
with an implant. Another traditional option includes fusing
adjacent vertebra using fasteners, such as traditional screws or
rods. However, such traditional methods are typically implemented
with invasive surgical procedures. In particular, some traditional
surgical procedures access the spine through the abdominal cavity,
introducing risk to major organs and often leaving large scars.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present disclosure may be better understood, and its
numerous features and advantages made apparent to those skilled in
the art by referencing the accompanying drawings.
[0010] FIG. 1 includes a lateral view of a portion of a vertebral
column.
[0011] FIG. 2 includes a lateral view of a pair of adjacent
vertebrae.
[0012] FIG. 3 includes a top plan view of a vertebra.
[0013] FIG. 4 includes a cross section view of an intervertebral
disc.
[0014] FIG. 5 includes a cross section view of a zygapophyseal
joint.
[0015] FIG. 6 includes an illustration of an exemplary osteogenic
implant.
[0016] FIG. 7 includes an illustration of exemplary
microspheres.
[0017] FIG. 8 includes a cross-sectional view illustration of an
exemplary osteogenic implant.
[0018] FIG. 9 and FIG. 10 include illustrations of an exemplary
osteogenic implant.
[0019] FIG. 11, FIG. 12, FIG. 13, and FIG. 14 include profile
illustrations of exemplary osteogenic implants.
[0020] FIG. 15 includes an illustration of an exemplary medical
kit.
[0021] FIG. 16 and FIG. 17 include illustrations of an exemplary
intervertebral space under treatment.
[0022] FIG. 18 and FIG. 19 include lateral-view illustrations of an
exemplary intervertebral space under treatment.
[0023] FIG. 20 includes an illustration of an exemplary
zygapophyseal joint under treatment.
[0024] FIG. 21 includes a block flow diagram of an exemplary method
of forming an osteogenic implant.
[0025] FIG. 22, FIG. 23, and FIG. 24 include illustrations of
exemplary agent release profiles.
[0026] The use of the same reference symbols in different drawings
indicates similar or identical items.
DESCRIPTION OF THE DRAWINGS
[0027] In a particular embodiment, an osteogenic implant includes a
degradation agent and an osteogenerative agent. In an exemplary
embodiment, the osteogenic implant is configured to release at
least a portion of the degradation agent prior to releasing at
least a portion of the osteogenerative agent. The degradation agent
can be a nucleolytic agent, such as chymopapain or chondroitinase
ABC. In an example, the osteogenerative agent can be an
osteoconductive agent or an osteoinductive agent. In a particular
example, the osteogenerative agent is an osteoinductive agent, such
as a growth factor.
[0028] In an embodiment, an osteogenic implant includes a
degradation agent in solid form and an osteogenerative agent in
solid form. The osteogenic implant is configured to release the
degradation agent prior to releasing the osteogenerative agent.
[0029] In another exemplary embodiment, an osteogenic implant
includes a first polymer matrix including a degradation agent and a
second polymer matrix including an osteogenerative agent. The first
polymer matrix is configured to release at least a portion of the
degradation agent prior to time at which the second polymer matrix
is configured to release the osteogenerative agent.
[0030] In a further exemplary embodiment, a medical kit includes an
osteogenic implant including a degradation agent in solid form and
an osteogenerative agent in solid form. The osteogenic implant is
configured to release the degradation agent prior to releasing the
osteogenerative agent. The medical kit also includes a tool
configured to locate the osteogenic implant proximate to a
vertebral structure.
[0031] In an additional exemplary embodiment, a method of forming
an osteogenic implant includes incorporating a degradation agent
into a first polymer matrix and incorporating an osteogenerative
agent into a second polymer matrix.
[0032] In a further exemplary embodiment, a method of treating a
patient includes inserting an osteogenic implant into a soft tissue
proximate to an osteal structure. The osteogenic implant includes a
degradation agent in solid form and an osteogenerative agent in
solid form. The osteogenic implant is configured to release the
degradation agent prior to releasing the osteogenerative agent.
Description of Relevant Anatomy
[0033] Referring initially to FIG. 1, a portion of a vertebral
column, designated 100, is shown. As depicted, the vertebral column
100 includes a lumbar region 102, a sacral region 104, and a
coccygeal region 106. The vertebral column 100 also includes a
cervical region and a thoracic region. For clarity and ease of
discussion, the cervical region and the thoracic region are not
illustrated.
[0034] As illustrated in FIG. 1, the lumbar region 102 includes a
first lumbar vertebra 108, a second lumbar vertebra 110, a third
lumbar vertebra 112, a fourth lumbar vertebra 114, and a fifth
lumbar vertebra 116. The sacral region 104 includes a sacrum 118.
Further, the coccygeal region 106 includes a coccyx 120.
[0035] As depicted in FIG. 1, a first intervertebral lumbar disc
122 is disposed between the first lumbar vertebra 108 and the
second lumbar vertebra 110. A second intervertebral lumbar disc 124
is disposed between the second lumbar vertebra 110 and the third
lumbar vertebra 112. A third intervertebral lumbar disc 126 is
disposed between the third lumbar vertebra 112 and the fourth
lumbar vertebra 114. Further, a fourth intervertebral lumbar disc
128 is disposed between the fourth lumbar vertebra 114 and the
fifth lumbar vertebra 116. Additionally, a fifth intervertebral
lumbar disc 130 is disposed between the fifth lumbar vertebra 116
and the sacrum 118.
[0036] In a particular embodiment, if one of the intervertebral
lumbar discs 122, 124, 126, 128, 130 is diseased, degenerated, or
damaged or if one of the zygapophyseal joints is diseased,
degenerated or damaged, that disc or joint can be at least
partially treated with an osteogenic implant according to one or
more of the embodiments described herein. In a particular
embodiment, an osteogenic implant can be inserted into the
intervertebral lumbar disc 122, 124, 126, 128, 130 or a
zygapophyseal joint.
[0037] FIG. 2 depicts a detailed lateral view of two adjacent
vertebrae, e.g., two of the lumbar vertebrae 108, 110, 112, 114,
116 illustrated in FIG. 1. FIG. 2 illustrates a superior vertebra
200 and an inferior vertebra 202. As illustrated, each vertebra
200, 202 includes a vertebral body 204, a superior articular
process 206, a transverse process 208, a spinous process 210 and an
inferior articular process 212. FIG. 2 further depicts an
intervertebral disc 214 between the superior vertebra 200 and the
inferior vertebra 202. A zygapophyseal joint 216 is located between
the inferior articular process 212 of the superior vertebra 200 and
the superior articular process 206 of the inferior vertebra 202. As
described in greater detail below, an osteogenic implant according
to one or more of the embodiments described herein can be installed
within or in proximity to the intervertebral disc 214 between the
superior vertebra 200 and the inferior vertebra 202 or within or in
proximity to the zygapophyseal joint 216.
[0038] Referring to FIG. 3, a vertebra, e.g., the inferior vertebra
202 (FIG. 2), is illustrated. As shown, the vertebral body 204 of
the inferior vertebra 202 includes a cortical rim 302 composed of
cortical bone. Also, the vertebral body 204 includes cancellous
bone 304 within the cortical rim 302. The cortical rim 302 is often
referred to as the apophyseal rim or apophyseal ring. Further, the
cancellous bone 304 is generally softer than the cortical bone of
the cortical rim 302.
[0039] As illustrated in FIG. 3, the inferior vertebra 202 further
includes a first pedicle 306, a second pedicle 308, a first lamina
310, and a second lamina 312. Further, a vertebral foramen 314 is
established within the inferior vertebra 202. A spinal cord 316
passes through the vertebral foramen 314. Moreover, a first nerve
root 318 and a second nerve root 320 extend from the spinal cord
316.
[0040] The vertebrae that make up the vertebral column have
slightly different appearances as they range from the cervical
region to the lumbar region of the vertebral column. However, all
of the vertebrae, except the first and second cervical vertebrae,
have the same basic structures, e.g., those structures described
above in conjunction with FIG. 2 and FIG. 3. The first and second
cervical vertebrae are structurally different than the rest of the
vertebrae in order to support a skull.
[0041] Referring now to FIG. 4, an intervertebral disc is shown and
is generally designated 400. The intervertebral disc 400 is made up
of two components: an annulus fibrosis 402 and a nucleus pulposus
404. The annulus fibrosis 402 is the outer portion of the
intervertebral disc 400, and the annulus fibrosis 402 includes a
plurality of lamellae 406. The lamellae 406 are layers of collagen
and proteins. Each lamella 406 includes fibers that slant at
30-degree angles, and the fibers of each lamella 406 run in a
direction opposite the adjacent layers. Accordingly, the annulus
fibrosis 402 is a structure that is exceptionally strong, yet
extremely flexible.
[0042] The nucleus pulposus 404 is an inner gel material that is
surrounded by the annulus fibrosis 402. It makes up about forty
percent (40%) of the intervertebral disc 400 by weight. Moreover,
the nucleus pulposus 404 can be considered a ball-like gel that is
contained within the lamellae 406. The nucleus pulposus 404
includes loose collagen fibers, water, and proteins. The water
content of the nucleus pulposus 404 is about ninety percent (90%)
by weight at birth and decreases to about seventy percent by weight
(70%) by the fifth decade.
[0043] Injury or aging of the annulus fibrosis 402 can allow the
nucleus pulposus 404 to be squeezed through the annulus fibers
either partially, causing the disc to bulge, or completely,
allowing disc material to escape the intervertebral disc 400. The
bulging disc or nucleus material can compress the nerves or spinal
cord, causing pain. Accordingly, the nucleus pulposus 404 can be
treated with an osteogenic implant to treat ailments associated
with the intervertebral disc 400.
[0044] FIG. 5 includes a cross-sectional view of the spine
illustrating a portion of a superior vertebra 504 and a portion of
an inferior vertebra 502. The inferior vertebra 502 includes
superior articular processes 506 and 508 and the superior vertebra
504 includes inferior articular processes 510 and 512. Between the
superior articular process 506 and the inferior articular process
510 is a zygapophyseal joint or facet 514 and between the superior
articular process 508 and the inferior articular process 512 is a
zygapophyseal joint or facet 516.
[0045] When damaged or degraded, the zygapophyseal joints 514 and
516 can be treated. For example, an osteogenic implant can be
inserted into or in proximity to the zygapophyseal joints 514 and
516. In particular, such an osteogenic implant can be configured to
fuse the inferior articular process (506 or 508) to the superior
articular process (510 or 512).
Description of Agents
[0046] In an exemplary embodiment, a device to be implanted at
least partially in the nucleus pulposus of an intervertebral disc
or in a zygapophyseal joint can include at least one agent in solid
or semi-solid form. The agent can generally affect a condition of
the nucleus pulposus or affect bone growth. For example, the agent
can decrease the hydration level of the nucleus pulposus or can
cause a degeneration of the nucleus pulposus that leads to a
reduction in hydration level, to a reduction in pressure, or to a
reduction in size of the nucleus pulposus within the intervertebral
disc. An agent causing a degeneration of the disc or reduction in
hydration level is herein termed a "degradation agent." In another
example, an agent (e.g., an osteogenerative agent) can affect bone
growth in proximity to the intervertebral disc or the zygapophyseal
joint. For example, an osteogenerative agent can be an
osteoinductive agent, an osteoconductive agent, or any combination
thereof.
[0047] An exemplary degradation agent can reduce hydration levels
in the nucleus pulposus or can degrade the nucleus pulposus,
resulting in a reduction in hydration level or in pressure within
the intervertebral disc. For example, the degradation agent can be
a nucleolytic agent that acts on portions of the nucleus pulposus.
In an example, the nucleolytic agent is proteolytic, breaking down
proteins.
[0048] An exemplary nucleolytic agent includes a chemonucleolysis
agent, such as chymopapain, collagenase, chondroitinase,
keratanase, human proteolytic enzymes, papaya proteinase, or any
combination thereof. An exemplary chondroitinase can include
chondroitinase ABC, chondroitinase AC, chondroitinase ACII,
chondroitinase ACIII, chondroitinase B, chondroitinase C, or the
like, or any combination thereof. In another example, a keratanase
can include endo-.beta.-galactosidase derived from Escherichia
freundii, endo-.beta.-galactosidase derived from Pseudomonas sp.
IFO-13309 strain, endo-.beta.-galactosidase produced by Pseudomonas
reptilivora, endo-.beta.-N-acetylglucosaminidase derived from
Bacillus sp. Ks36, endo-.beta.-N-acetylglucosaminidase derived from
Bacillus circulans KsT202, or the like, or any combination thereof.
In a particular example, the degradation agent includes
chymopapain. In another example, the degradation agent includes
chondroitinase ABC.
[0049] An osteogenerative agent, for example, can encourage the
formation of new bone ("osteogenesis"), such as through inducing
bone growth ("osteoinductivity") or by providing a structure onto
which bone can grow ("osteoconductivity"). Generally,
osteoconductivity refers to structures supporting the attachment of
new osteoblasts and osteoprogenitor cells. As such, the agent can
form an interconnected structure through which new cells can
migrate and new vessels can form. Osteoinductivity typically refers
to the ability of the agent or a surface or a portion thereof to
induce nondifferentiated stem cells or osteoprogenitor cells to
differentiate into osteoblasts.
[0050] In an example, an osteoconductive agent can provide a
favorable scaffolding for vascular ingress, cellular infiltration
and attachment, cartilage formation, calcified tissue deposition,
or any combination thereof. An exemplary osteoconductive agent can
include collagen; a calcium phosphate, such as hydroxyapatite,
tricalcium phosphate, or fluorapatite; demineralized bone matrix;
or any combination thereof.
[0051] In another example, an osteoinductive agent can include bone
morphogenetic proteins (BMP, e.g., rhBMP-2); demineralized bone
matrix; transforming growth factors (TGF, e.g., TGF-.beta.);
osteoblast cells, growth and differentiation factor (GDF), LIM
mineralized protein (LMP), platelet derived growth factor (PDGF),
insulin-like growth factor (ILGF), fibroblast growth factor (FGF),
platelet derived growth factor (PDGF), members of the hedgehog
family of proteins, iriterleukins (Ils), colony stimulating factors
(CSF), cartilage derived growth factors (CDGF), cartilage derived
morphogenic proteins (CDMP), or any combination thereof. In a
further example, an osteoinductive agent can include HMG-CoA
reductase inhibitors, such as a member of the statin family, such
as lovastatin, simvastatin, pravastatin, fluvastatin, atorvastatin,
cerivastatin, mevastatin, pharmaceutically acceptable salts esters
or lactones thereof, or any combination thereof. With regard to
lovastatin, the substance can be either the acid form or the
lactone form or a combination of both. In a particular example, the
osteoinductive agent includes a growth factor. In addition,
osteoconductive and osteoinductive properties can be provided by
bone marrow, blood plasma, or morselized bone of the patient, or
other commercially available materials.
[0052] In addition, the implantable device can include an
anti-inflammatory agent. An exemplary anti-inflammatory agent can
include a soluble tumor necrosis factor .alpha.-receptor, a
pegylated soluble tumor necrosis factor .alpha.-receptor, a
monoclonal antibody, a polyclonal antibody, an antibody fragment, a
COX-2 inhibitor, a metalloprotease inhibitor, a glutamate
antagonist, a glial cell derived neurotrophic factor, a B2 receptor
antagonist, a substance P receptor (NK1) antagonist, a downstream
regulatory element antagonistic modulator (DREAM), iNOS, an
inhibitor of tetrodotoxin (TTX)-resistant Na+-channel receptor
subtypes PN3 and SNS2, an inhibitor of interleukin, a TNF binding
protein, a dominant-negative TNF variant, Nanobodies.TM., a kinase
inhibitor, or any combination thereof. Another exemplary
anti-inflammatory agent can include Adalimumab, Infliximab,
Etanercept, Pegsunercept (PEG sTNF-R1), Onercept, Kineret.RTM.,
sTNF-R1, CDP-870, CDP-571, CNI-1493, RDP58, ISIS 104838,
1.fwdarw.3-.beta.-D-glucan, Lenercept, PEG-sTNFRII Fc Mutein, D2E7,
Afelimomab, AMG 108, 6-methoxy-2-napthylacetic acid or
betamethasone, capsaiein, civanide, TNFRc, ISIS2302 and GI 129471,
integrin antagonist, alpha-4 beta-7 integrin antagonist, cell
adhesion inhibitor, interferon gamma antagonist, CTLA4-Ig
agonist/antagonist (BMS-188667), CD40 ligand antagonist, Humanized
anti-IL-6 mAb (MRA, Tocilizumab, Chugai), HMGB-1 mAb (Critical
Therapeutics Inc.), anti-IL2R antibody (daclizumab, basilicimab),
ABX (anti IL-8 antibody), recombinant human IL-10, HuMax IL-15
(anti-IL 15 antibody), or any combination thereof.
[0053] In addition, other agents can be incorporated, such as an
antibiotic, an analgesic, an anesthetic, a radio-contrast agent, or
any combination thereof. For example, a pain medication can be
incorporated in a matrix material in which another agent is
incorporated or in a separate matrix material. An exemplary pain
medication includes codeine, propoxyphene, hydrocodone, oxycodone,
or any combination thereof. In a further example, an antiseptic
agent can be incorporated within a matrix material. For example,
the antiseptic agent can include an antibiotic agent. In an
additional example, a radio-contrast agent can be incorporated into
a reservoir, such as an agent responsive to x-rays.
[0054] Each of the agents or a combination of agents can be
maintained in solid or semi-solid form. For example, solid forms
can include powder, granules, microspheres, miniature rods, or
embedded in a matrix or binder material, or any combination
thereof. In an example, fluids or water from surrounding tissues
can be absorbed by the device and placed in contact with an agent
in solid form prior to release. Further, a stabilizer or a
preservative can be included with the agent to prolong activity of
the agent.
[0055] In particular, one or more agents can be incorporated into a
polymeric matrix, such as a hydrogel, a non-bioresorbable polymer,
a bioresorbable polymer, a natural polymer, or a recombinant
polymer. An exemplary hydrogel can include polyacrylamide (PAAM),
poly-N-isopropylacrylamine (PNIPAM), polyvinyl methylether (PVM),
polyvinyl alcohol (PVA), polyethyl hydroxyethyl cellulose, poly
(2-ethyl) oxazoline, polyethyleneoxide (PEO), polyethylglycol
(PEG), polyacrylacid (PAA), polyacrylonitrile (PAN),
polyvinylacrylate (PVA), polyvinylpyrrolidone (PVP), or any
combination thereof. A non-bioresorbable polymer can include a
hydrogel and can include polyurethane, silicone,
polymethylmethacrylate (PMMA), polyethylene, poly vinyl alcohol,
poly vinyl pyrrolidon, poly(2-hydroxy ethyl methacrylate),
poly(acrylic acid), ethylene vinyl acetate, poly(ethylene glycol),
poly(methacrylic acid), polyacrylamide, or any combination thereof.
An exemplary bioresorbable polymer can include polylactide (PLA),
polyglycolide (PGA), poly(lactide-co-glycolide) (PLGA),
polyanhydride, polyorthoester, or any combination thereof. An
exemplary natural polymer or a recombinant polymer can include a
polysaccharide, collagen, silk, elastin, keratin, albumin, fibrin,
starch, chitosans, gelatin, alginates, dextrans, or any combination
thereof. Other exemplary polymers include poly(alpha-hydroxy
acids), conjugates of poly(alpha-hydroxy acids), polyaspirins,
polyphosphagenes, PVA-g-PLGA, PEGT-PBT copolymer (polyactive),
PEO-PPO-PEO (pluronics), PEO-PPO-PAA copolymers, PLGA-PEO-PLGA,
polyphosphoesters, polyester-anhydrides, polyamino acids,
polyurethane-esters, polyphosphazines, polycaprolactones,
polytrimethylene carbonates, polydioxanones, polyamide-esters,
polyketals, polyacetals, glycosaminoglycans, hyaluronic acid,
hyaluronic acid esters, polyethylene-vinyl acetates, silicones,
polyurethanes, polypropylene fumarates, polydesaminotyrosine
carbonates, polydesaminotyrosine arylates, polydesaminotyrosine
ester carbonates, polydesamnotyrosine ester arylates, polyethylene
oxides, polyorthocarbonates, polycarbonates, or copolymers or
physical blends thereof or combinations thereof.
[0056] In a particular example, a hydrogel can hydrate to release
an agent. In a further example, a non-bioresorbable polymer can be
configured to break apart or disintegrate as a result of hydration,
mechanical stress, or vibration. In another example, a
bioresorbable polymer can dissolve or can be absorbed, releasing an
agent incorporated therein. In a further example, a natural polymer
can act as a hydrogel, a bioresorbable polymer, or a
non-bioresorbable polymer and release an agent as a result of
hydration, dissolution, or disintegration.
Description of a Device
[0057] In an exemplary embodiment illustrated in FIG. 6, an
osteogenic implant 600 includes a degradation agent and an
osteogenerative agent. In an example, the degradation agent can be
included in a first matrix material 602 and the osteogenerative
agent can be included in a second matrix material 604. In
particular, the osteogenic implant 600 is configured to release at
least a portion of the degradation agent prior to releasing at
least a portion of the osteogenerative agent. For simplicity,
releasing an agent is used herein to mean releasing at least a
portion of the agent unless explicitly stated otherwise. For
example, the osteogenic implant 600 can release the degradation
agent prior to releasing the osteogenerative agent. Alternatively,
the osteogenic implant 600 can be configured to release
substantially all of the degradation agent prior to releasing the
osteogenerative agent.
[0058] For example, FIG. 22, FIG. 23, and FIG. 24 include
illustrations of exemplary agent release profiles. As illustrated
in FIG. 22, the degradation agent release profile 2202 can reach a
peak concentration prior to the osteogenerative agent release
profile 2204. As depicted, the release profiles 2202 and 2204 can
overlap. Further, the degradation agent release profile can begin
close to the time 2206 of implanting or can be delayed in time from
the time 2206. As illustrated in FIG. 23, the osteogenerative agent
release profile 2304 can begin after the degradation agent release
profile 2302 subsides. For example, the beginning of the
osteogenerative agent release profile 2304 can be delayed from the
cessation of the degradation agent release profile 2302 by a period
of time 2308. Further, the release profiles can be different, for
example, having different peak concentrations and length of
release. As illustrated in FIG. 24, the degradation release profile
2402 can have a higher peak and quicker release than the
osteogenerative agent release profile 2404. In particular, the
osteogenerative agent release profile 2404 can provide a lower dose
for a longer period of time.
[0059] Returning to FIG. 6, the first matrix material 602 and the
second matrix material 604 can be relatively located in the
osteogenic implant 600 in positions that, in operation, results in
the release of the degradation agent prior to the osteogenerative
agent. For example, the first matrix material 602 can be located
around the second matrix material 604. In another example, the
first matrix material 602 can be located closer to an opening of
the osteogenic implant 600 than the second matrix material 604,
resulting in dissolution or hydration of the first matrix material
602 prior to the second matrix material 604.
[0060] In another exemplary embodiment, the first matrix material
602 can have a composition that results in faster release of the
degradation agent when in operation and the second matrix material
604 can have a composition that results in slow release or delayed
release of the osteogenerative agent. In a particular example, the
first matrix material 602 can include a first polymer material and
the second matrix material 604 can include a second polymer
material. For example, the first matrix material 602 can include
starch or another material that degrades relatively quickly and the
second matrix material 604 can include a hydrogel or degradable
polymer, such as PEO or PGA, that hydrates or degrades to release
an agent relatively slower. In addition, one or both of the matrix
materials 602 and 604 can include radio-contrast media.
[0061] In a particular example, the matrix material (602 or 604)
can include a biocompatible injectable polymer or polymer
precursor. In an example, the polymer can be a hydrogel, a soft
gel, an elastic material, or any combination thereof that can
immobilize the agent or agents. In particular, the matrix material
(602 or 604) can include a polymer precursor that can react in vivo
to form a polymer. For example, the matrix material (602 or 604)
can react to form a hydrogel, a soft gel, an elastomer, a rigid
material, or any combination thereof. In a particular example, the
matrix material (602 or 604) can react to form a rigid load-bearing
component. In an example, the matrix material (602 or 604) can form
a fusion cage or other structure. In a further example, the polymer
formed from the injectable material can be degradable or resorbable
in vivo.
[0062] Further, the matrix materials 602 and 604 can be
incorporated into more than one osteogenic implant. For example,
the matrix materials 602 and 604 can be incorporated into separate
osteogenic implants. Alternatively, the matrix materials 602 and
604 can be incorporated together in more than one osteogenic
implant to be inserted.
[0063] In addition, the osteogenic implant 600 can include a third
agent, such as an antibiotic, an analgesic, an anesthetic, a
radio-contrast agent, an anti-inflammatory agent, or any
combination thereof. The third agent can be incorporated in one or
both of the first matrix material 602 or the second matrix material
604. For example, the first matrix material 602 can include an
anti-inflammatory agent. In another example, the second matrix
material 604 can include an anesthetic agent. In a further example,
the second matrix material 604 can include a radio-contrast agent.
As such, dispersion of the radio-contrast agent can be detected by
a radiographic technique and can indicate the onset of release of
the osteogenerative agent.
[0064] FIG. 7 includes an exemplary osteogenic implant 700
including sets of microspheres (704 and 706) in a solution 702. For
example, a set of microspheres 704 can include a degradation agent
and a set of microspheres 706 can include an osteogenerative
agent.
[0065] In an example, the solution 702 can be a biocompatible
fluid, gel, paste, slurry, or any combination thereof. In an
example, the solution 702 is configured to prevent release of the
agents from the microspheres prior to implant. For example, the
solution 702 can be a saline solution, an alcohol solution, a
glycerol solution, an oil-based solution, a polymer, or any
combination thereof. In particular, the solution 702 can include an
injectable polymer that is configured to react in vivo to form a
hydrogel, a soft gel, an elastomer, a rigid polymer, or any
combination thereof. The solution 702 also can include a
radio-contrast agent. In another example, the solution 702 can be a
gel, such as a high viscosity gel. Alternatively, the sets of
microspheres (704 and 706) can be included in separate
solutions.
[0066] The sets of microspheres (704 or 706) can be incorporated
into the solution 702 during manufacture or prior to implantation.
For example, the sets of microspheres (704 or 706) can be
incorporated in the solution 702 at the time of manufacture. In
another example, the sets of microspheres (704 or 706) can be mixed
with the solution prior to surgery or implantation.
[0067] In particular, the sets of microspheres (704 or 706) can be
configured to release agents at different times or at different
rates. For example, the set of microspheres 704 can be configured
to release a degradation agent at a fast rate or following
implantation. The set of microspheres 706 can be configured to
release an osteogenerative agent at a slower rate or at a delayed
time. For example the set of microspheres 706 can include a coating
that results in delayed release of the osteogenerative agent.
Alternatively, the composition of the set of microspheres 706 can
be configured to hydrate or dissolve at a slower rate than the set
of microspheres 704.
[0068] The microspheres in the set of microspheres (704 or 706) can
have an average diameter in a range of approximately 1.0 micron to
approximately 4.0 mm. For example, the average diameter can be
approximately 10 microns to approximately 2.0 mm, such as
approximately 100 microns to 1.0 mm.
[0069] In general, the osteogenic implant 700 can be implanted
using a syringe. The syringe can be inserted through the epidermis
and into a soft tissue region proximate to an osteal structure,
such as an intervertebral space. In an example, the location of the
tip of the syringe can be determined by radioscope. In a particular
example, the tip of the syringe can be located in an intervertebral
space, such as within a nucleus pulposus. The solution and the sets
of microspheres (704 and 706) can be released into the soft tissue,
such as the nucleus pulposus. As a result, the sets of microspheres
(704 and 706) can hydrate or dissolve at different rates, resulting
in release of the respective agents at different rates or at
different times. In addition, one or more of the solution 702, and
the sets of microspheres (704 and 706) can include radio-contrast
agents. Alternatively, the degradation and osteogenerative agents
can be incorporated in powder from into different polymers or
polymer precursors that result in release of the agents at
different rates once implanted in vivo.
[0070] In another exemplary embodiment illustrated in FIG. 8, the
osteogenic implant 800 can be configured in a multilayer structure.
For example, the osteogenic implant 800 can be configured as a
sphere, a cylinder, or a polygon. In particular, a first matrix
material 802 can be coated over a second matrix material 804.
Alternatively, additional layers of matrix material can be
included. For example, the first matrix material 802 can form a
coating layer over a core layer formed of the second matrix
material 804. The first matrix material 802 can include a
degradation agent and the second matrix material 804 can include an
osteogenerative agent.
[0071] Once implanted, the osteogenic implant 800, for example, can
dissolve or hydrate. In an example, the first matrix material 802
can hydrate, dissolve, or disintegrate to release the degradation
agent prior to the second matrix material 804 hydrating,
dissolving, or disintegrating to release the osteogenerative agent.
In a further exemplary embodiment, layers can be located outside of
the first matrix material 802, intermediate to the first and second
matrix materials 802 and 804, or underlying the second matrix
material 804. For example, an additional coating external to the
first matrix material 802 can delay exposure of the first matrix
material 802 and provide protection for the first matrix material
802 during transport or implanting. A layer located between the
first and second matrix materials (802 and 804) can delay exposure
of the second matrix material 804 until after the first matrix
material 802 hydrates, dissolves, or disintegrates. Further, a
layer located internal to and surrounded by the second matrix
material 804 can alter its dose and rate of release based on a
change in surface area, volume, or the ratio thereof of the second
matrix material 804.
[0072] While the cross-sectional view illustrated in FIG. 8 depicts
a cylinder or a sphere, the osteogenic implant 800 can be a sheet
material or a polygonal material. In particular, the osteogenic
implant 800 can be configured based on the desired functionality of
the osteogenic implant 800 and techniques for implanting such an
osteogenic implant 800.
[0073] In a particular embodiment, the osteogenic implant can form
a cylinder. Such a form is conducive to implantation using a
cannula/trocar assembly, and can be directed through connective
tissue. For example, a soft tissue can be pierced by a
cannula/trocar assembly. The trocar can be removed and the
osteogenic implant inserted into a lumen of the cannula. A stylet
can be used to push the osteogenic implant through the lumen of the
cannula and into the soft tissue.
[0074] For example, FIG. 9 includes an illustration of an exemplary
osteogenic implant 900, which includes a coating 902 and an opening
908. The coating 902 can include a polymer, ceramic, metallic
material, or any combination thereof In a particular example, the
coating 902 can include an osteoconductive material.
[0075] In another example, the coating can include a fluid
impermeable material to limit access to materials surrounded by the
coating 902. Materials incorporating agents can be surrounded by
the coating 902 and can be accessible through the opening 908. For
example, a first material 904 can be located closer to the opening
908 than a second material 906. As such, the first material 904 can
be exposed to fluids of soft tissue in which the osteogenic implant
900 is to be implanted before the second material 906 can be
exposed.
[0076] In a particular example, the first material 904 can include
a degradation agent and the second material 906 can include an
osteogenerative agent. As such, the first material 904 can hydrate,
dissolve, or disintegrate prior to the second material 906,
releasing the degradation agent prior to releasing the
osteogenerative agent.
[0077] Alternatively, the osteogenic implant 900 can include more
than one opening 908 and can be formed into additional shapes. For
example, the osteogenic implant can form a sphere, a polygon, a
cone, a cylinder, or any combination thereof.
[0078] In an additional embodiment, FIG. 10 includes an
illustration of an osteogenic implant 1000 that includes a coating
1002 and more than one opening 1010 through the coating 1002. In
addition, the osteogenic implant 1000 includes materials 1004,
1006, and 1008. In particular, the material 1004 is located closer
to an opening 1010 than the material 1006, and the material 1006 is
located closer to an opening 1010 than the material 1008.
[0079] In an exemplary embodiment, the material 1004 can be free of
a degradation agent or an osteogenerative agent. In an example, the
material 1004 can hydrate, dissolve, or disintegrate to expose the
material 1006. The material 1006 can include a degradation agent
and the material 1008 can include an osteogenerative agent. As a
result, the material 1006 can hydrate, dissolve, or disintegrate
prior to the material 1008, resulting in the release of the
degradation agent prior to the release of the osteogenerative
agent.
[0080] In another exemplary embodiment, the material 1004 can
include a degradation agent, the material 1006 can be free of a
degradation agent or an osteogenerative agent, and the material
1008 can include an osteogenerative agent. As a result, the
material 1004 can hydrate, dissolve, or disintegrate prior to the
material 1006, resulting in the release of the degradation agent.
The material 1006 can hydrate, dissolve, or disintegrate prior to
the material 1008, resulting in a delay in the release of the
osteogenerative agent.
[0081] In a further exemplary embodiment, the material 1004 can
include a degradation agent, the material 1006 can including both a
degradation agent and an osteogenerative agent, and the material
1008 can include an osteogenerative agent. As a result, the
material 1004 can hydrate, dissolve, or disintegrate to release the
degradation agent. Subsequently, the material 1006 can hydrate,
dissolve, or disintegrate to release both the degradation agent and
the osteogenerative agent, and finally, the material 1008 can
hydrate, dissolve, or disintegrate to release additional
osteogenerative agent. Alternatively, the device can be configured
with a gradient of agent concentration. Further, while the
materials 1004, 1006, and 1008 are discussed in relation to
degradation agents and osteogenerative agents, the materials 1004,
1006, and 1008 also can include other agents, such as an
anti-inflammatory agent, an antibiotic, an analgesic, an
anesthetic, a radio-contrast agent, or any combination thereof.
[0082] In addition, the osteogenic implant can include surface
configurations to assist with implanting. In particular, the
osteogenic implant can include terminal ends that are configured to
engage a tool or move through tissue and can include surface
features that engage tissue. For example, a cylindrical osteogenic
implant can have a tapered terminal end configured to more easily
move through soft tissue. In an example illustrated in FIG. 11, the
terminal end 1102 of an osteogenic implant 1100 can have a round
shape. In another example illustrated in FIG. 12, the terminal end
1202 of an osteogenic implant 1200 can have a cone shape, a
pyramidal shape, or a blade shape.
[0083] In another exemplary embodiment, the osteogenic implant can
have a terminal end configured to engage a tool, for example,
during implanting. For example, FIG. 13 includes an illustration of
an osteogenic implant 1300 including a tapered end 1302 and an
engagement end 1304. The engagement end 1304 can be configured to
engage a tool, such as a stylet. As illustrated, the engagement end
1304 can have a rounded indentation to engage a rounded end of a
stylet. In another example, the engagement end 1304 can include a
conical, a cross-shaped, a pyramidal, a triangular, a rectangular,
or a cylindrical indentation, or any combination thereof.
[0084] In addition, the external surface of the osteogenic implant
can include serrations, threads, barbs, or any combination thereof.
As illustrated in FIG. 14, an osteogenic implant 1400 can include a
tapered terminal end 1402 and a shaped surface 1404. For example,
the shaped surface 1404 can form threads. Such threads can be used
to further motivate the osteogenic implant 1400 through soft tissue
or to control insertion depth. In another example, serrations or
barbs can be used to secure the osteogenic implant within the soft
tissue, or can be used to agitate a surface of an osteal structure,
such as a vertebral end plate.
Medical Kit
[0085] In an exemplary embodiment, the osteogenic implant can be
included in a medical kit. For example, FIG. 15 includes an
illustration of a medical kit 1500 that includes one or more
osteogenic implants 1502. Alternatively or in addition, the medical
kit 1500 can include at least one set of microspheres, either in
dry form or in solution.
[0086] In addition, the medical kit 1500 can include a scalpel 1504
or another tool for making incisions. Further, the medical kit 1500
can include a suture or thread 1506.
[0087] Further, the medical kit 1500 can include a tool for
implanting the osteogenic implants 1502. For example, the medical
kit 1500 can include a cannula 1512 and can include a trocar 1508
or a stylet 1510 to engage the cannula 1512. In a particular
example, the osteogenic implants 1502 can be implanted by locating
the tip of the cannula 1512 and trocar 1508 at a desired location
within a soft tissue. The trocar 1508 can be removed from the
cannula 1512 and the osteogenic implants 1502 placed in the lumen
of the cannula 1512. The stylet 1510 can be used to motivate the
osteogenic implants 1502 through the lumen of the cannula 1512 and
into the soft tissue.
[0088] In addition, the medical kit 1500 can include a container
1516 with a ceramic material, bone cement, tissue sealant, or any
combination thereof and a syringe 1514 for injecting the ceramic
material, bone cement, or tissue sealant into the tissue. In
particular, when the osteogenic implants 1502 are implanted in a
nucleus pulposus through the annulus fibrosis, the syringe 1514 can
be used to inject tissue sealant to seal the annulus fibrosis and
prevent the nucleus pulposus from herniating.
[0089] In addition, the medical kit 1500 can include written
instructions 1518 indicating methods of using the various
components of the medical kit 1500. The instructions 1518 can
direct the use of the osteogenic implant 1502, the assembly of the
osteogenic implant 1502, counter-indications for use of such
implants, warnings and caveats, or any combination thereof.
[0090] In an example, the medical kit 1500 can be included in a
single container and sealed. Alternatively, the medical kit 1500
can be an assembly of various containers including various
components of the medical kit 1500.
Osteogenic Implant Implantation
[0091] The osteogenic implant can be inserted into the nucleus
pulposus of an intervertebral disc of a patient or into a
zygapophyseal joint of a patient. For example, the osteogenic
implant can be implanted as a whole within the nucleus pulposus or
within the zygapophyseal joint. In another example, the osteogenic
implant can be place in proximity to the zygapophyseal joint.
[0092] FIG. 16 and FIG. 17 include illustrations of an osteogenic
implant 1604 implanted within the nucleus pulposus 1602 of an
intervertebral disc 1600. The osteogenic implant 1604 can be
inserted through a passage 1606 in the annulus fibrosis 1608 of the
intervertebral disc 1600. In an example, the passage 1606 is formed
and a cannula or an instrument having a lumen therethrough can be
used to guide the osteogenic implant 1604 through the passage 1606.
Once the osteogenic implant 1604 is inserted into the nucleus
pulposus 1602, the passage 1606 in the annulus fibrosis 1608 can be
sealed using a tissue sealant, scaffold plug, or any combination
thereof. In a particular example, the tissue sealant or scaffold
plug includes regenerative agents, such as growth factors. A
similar method can be used to insert an osteogenic implant into a
zygapophyseal joint.
[0093] Once the osteogenic implant 1604 is located within the
nucleus pulposus, matrices within the osteogenic implant 1604 can
hydrate, dissolve, or disintegrate to release agents. For example,
a matrix material can hydrate to release a degradation agent. As a
result, a treatment region 1710 of the nucleus pulposus 1602 can
degrade. Subsequently, another matrix material of the osteogenic
implant 1604 can release an osteogenerative agent to initiate bone
growth.
[0094] In an alternative embodiment illustrated in FIG. 18, the
osteogenic implant 1808 can be inserted into the nucleus pulposus
of an intervertebral disc 1810 through one of a superior vertebra
1802 or an inferior vertebra 1806. As illustrated in FIG. 18, the
osteogenic implant 1808 can be inserted through the vertebral body
and the end plate of the superior vertebra 1802. For example, an
access 1814 can be drilled through the vertebral body and the end
plate of the superior vertebra 1802. The osteogenic implant 1808
can be guided through the access 1814 into a nucleus pulposus of
the intervertebral disc 1810. The access 1814 can be sealed with a
ceramic material, bone cement, tissue sealant, or any combination
thereof.
[0095] In an exemplary embodiment, one or more materials of the
osteogenic implant 1808 can hydrate, dissolve, or disintegrate to
release one or more agents. For example, a matrix material can
release a degradation agent, resulting in the degradation of the
nucleus pulposus within a treatment region 1804. The treatment
region 1804, for example, can include a portion of the nucleus
pulposus and the cartilaginous end plate of the superior and
inferior vertebrae 1802 and 1806.
[0096] In addition, a matrix material of the osteogenic implant
1808 can hydrate, dissolve, or disintegrate to release an
osteogenerative agent. The osteogenerative agent can influence
growth of bone between the superior and inferior vertebrae 1802 and
1806. For example, the osteogenerative agent can encourage fusion
of the two vertebrae 1802 and 1806 through the formation of an
osteal bridge structure 1912, as illustrated in FIG. 19.
[0097] In a further exemplary embodiment illustrated in FIG. 20, an
osteogenic implant 2012 is inserted into a zygapophyseal joint or
facet joint 2010 through an articular process, such as a superior
articular process 2006 of an inferior vertebra 2002. Alternatively,
the osteogenic implant 2012 can be inserted through the inferior
articular process 2008 of the superior vertebra 2004. In an
exemplary embodiment, the osteogenic implant 2012 is inserted
through an access 2014 drilled into an articular process. The
osteogenic implant 2012 can engage one or both of the articular
processes 2006 or 2008. Alternatively, the osteogenic implant 2012
can be positioned within the zygapophyseal joint to not engage the
articular processes 2006 or 2008. The access 2014 can be sealed
with a ceramic material, bone cement, tissue sealant, or any
combination thereof.
[0098] While the embodiments illustrated in FIG. 16, FIG. 17, FIG.
18, and FIG. 20 illustrate a single osteogenic implant, one or more
osteogenic implants can be implanted in an intervertebral space or
a joint. For example, two, three or more osteogenic implants can be
placed within an intervertebral space.
[0099] In a particular embodiment, osteogenic implants can be
inserted into the intervertebral disc and the two articular
processes associated with two adjacent vertebrae. As such, the
implanted devices can influence bone growth to fuse the two
adjacent vertebrae together at three locations: between the
vertebral bodies, between the left articular processes, and between
the right articular processes.
Patient Treatment Using an Implantable Device
[0100] Typically, the embodiments of the osteogenic implant
described above can be used to treat conditions associated with an
intervertebral disc. For example, a patient can have undergone a
prior discectomy or can have experienced a herniated disc. In
another example, a scan of the patient, such as a computed
tomography (CT) scan or a magnetic resonance imaging (MRI) scan,
can indicate a problem in a particular intervertebral disc. In such
a case, a device can be implanted in the patient.
[0101] In an exemplary embodiment, a healthcare provider can
monitor the osteogenic implant, such as through using radiographic
techniques. For example, the osteogenic implant can include
radio-contrast agents within one or more matrix materials of the
osteogenic implant. Each of the radio-contrast agents in the matrix
materials can be release with other agents with in the matrix
material and can degrade or be removed from the area through
biological or diffusion processes. Alternatively, a radio-contrast
agent can be injected separately and can degrade or diffuse. In a
particular example, a matrix material including an osteogenerative
agent can include a radio-contrast agent that is released when the
matrix material is hydrated, dissolved, or disintegrated. As such,
a healthcare provider can observe release of the osteogenerative
agent based on the coincidental release of the radio-contrast
agent. In another example, different radio-contrast agents can be
included in different matrix materials. Each radio-contrast agent
can be separately detectable to indicate release of different
agents.
[0102] Based on the data received from radiographic techniques, the
healthcare provider can adjust treatment of the patient, such as
injecting an additional agent. For example, once osteogeneration
has been initiated, the healthcare provider can inject or implant
additional osteogenerative material. For example, the healthcare
provider can inject an osteoconductive gel or additional cellular
material, such as stem cells. In particular, a surgeon can inject
stem cells that respond to the osteogenerative agent being release
from the implanted device as indicated by the coincidental release
of a radio-contrast agent.
[0103] In addition, the device can be used in conjunction with
other devices such as mechanical supports, such as an
intervertebral body spacer, an interspinous spacer, a fusion cage,
pedicle screw and rod systems (e.g., a percutaneous rod device), a
screw, a rigid polymer formed from an injectable polymer precursor,
an interior plate,or any combination thereof. For example, the
device can be used in conjunction with a SEXTANT.RTM. system
available from Medtronic Sofamor Danek.
Formation of an Osteogenic Implant
[0104] In an exemplary embodiment, the osteogenic implant can be
formed in accordance with an exemplary method 2100 illustrated in
FIG. 21. For example, a degradation agent can be incorporated in a
first matrix material, as illustrated at 2102. In a particular
example, a degradation agent, such as chymopapain or chondroitinase
ABC, can be incorporated into the first matrix material. The first
matrix material can be a polymeric material, such as a hydrogel or
a bioresorbable material. In particular, the first matrix material
can release the degradation agent through a hydration mechanism or
a dissolving mechanism.
[0105] In addition, an osteogenerative agent can be incorporated in
a second matrix material, as illustrated at 2104. In a particular
example, an osteogenerative agent, such as an osteoconductive or an
osteoinductive agent, can be incorporated into the second matrix
material. In particular, an osteoinductive agent can include a
growth factor, such as bone morphogenic protein. The second matrix
material can be a polymeric material, such as a hydrogel or a
bioresorbable material. In particular, the second matrix material
can release the osteogenerative agent through a hydration mechanism
or a dissolving mechanism.
[0106] Further, the first and second matrix materials can be
incorporated into an osteogenic implant, as illustrated at 2106.
For example, the osteogenic implant can be formed through molding
the first and second matrix materials. In an example, the second
matrix material can be molded into a sphere and the first matrix
material can be molded around the second matrix material as a
coating. In another example, the first and second matrix materials
can be formed into separate sets of microspheres and incorporated
into a solution. In a further example, the first and second matrix
materials can be inserted into a hollow device. In an additional
example, the first and second matrix materials can be formed as
separate cylinders, placed in a row, and coated with an exterior
coating material.
[0107] In addition, other agents, such as an anti-inflammatory
agent, an antibiotic, an analgesic, an anesthetic, a radio-contrast
agent, or any combination thereof, can be incorporated into the
first or second matrix materials. In another example, the other
agent can be included in a third matrix material. One or more
additional matrix materials can be used to form the osteogenic
implant.
Conclusion
[0108] With the implanted device described above, osteal structures
can be fused or bone growth can be effected. In particular, such
devices can be implanted using laparoscopic techniques. Such
devices can further reduce the likelihood that a more invasive disc
replacement implant will be used.
[0109] The above-disclosed subject matter is to be considered
illustrative, and not restrictive, and the appended claims are
intended to cover all such modifications, enhancements, and other
embodiments that fall within the true scope of the present
invention. For example, it is noted that the components in the
exemplary embodiments described herein as having a particular
function or as being located in a particular location are
illustrative and it is noted that such components can perform
additional functions or be located in different configurations.
Thus, to the maximum extent allowed by law, the scope of the
present invention is to be determined by the broadest permissible
interpretation of the following claims and their equivalents, and
shall not be restricted or limited by the foregoing detailed
description.
* * * * *