U.S. patent application number 10/245955 was filed with the patent office on 2004-03-18 for collagen-based materials and methods for augmenting intervertebral discs.
Invention is credited to Sherman, Michael C., Trieu, Hai H..
Application Number | 20040054414 10/245955 |
Document ID | / |
Family ID | 35107061 |
Filed Date | 2004-03-18 |
United States Patent
Application |
20040054414 |
Kind Code |
A1 |
Trieu, Hai H. ; et
al. |
March 18, 2004 |
Collagen-based materials and methods for augmenting intervertebral
discs
Abstract
A method of augmenting an intervertebral disc by injecting
particles of collagen-based material into the disc. The particles
may be dehydrated before implantation, and rehydrated after
implantation, or they may be implanted in a "wet" state--such as a
slurry or gel. Radiocontrast materials may be included to enhance
imaging of the injected material. Other additives may include
analgesics, antibiotics, proteoglycans, growth factors, and/or
other cells effective to promote healing and/or proper disc
function.
Inventors: |
Trieu, Hai H.; (Cordova,
TN) ; Sherman, Michael C.; (Memphis, TN) |
Correspondence
Address: |
WOODARD EMHARDT NAUGHTON MORIARTY MCNETT
Bank One Center/Tower, Suite 3700
111 Monument Circle
Indianapolis
IN
46204-5137
US
|
Family ID: |
35107061 |
Appl. No.: |
10/245955 |
Filed: |
September 18, 2002 |
Current U.S.
Class: |
623/17.16 ;
623/23.58; 623/23.63 |
Current CPC
Class: |
A61F 2/442 20130101;
A61L 31/14 20130101; A61B 17/7064 20130101; A61L 27/3856 20130101;
A61L 2430/24 20130101; A61F 2002/4627 20130101; A61F 2002/30075
20130101; A61F 2310/00365 20130101; A61B 17/7095 20130101; A61F
2/4601 20130101; A61F 2/08 20130101; A61F 2002/30224 20130101; A61F
2002/445 20130101; A61F 2250/0098 20130101; A61L 27/24 20130101;
A61F 2210/0061 20130101; A61F 2002/444 20130101; A61L 27/50
20130101; A61B 17/562 20130101; A61F 2002/30677 20130101; A61L
2430/38 20130101; A61L 31/005 20130101; A61F 2002/30588 20130101;
A61L 31/18 20130101; A61L 27/36 20130101; A61F 2002/3008 20130101;
A61B 2017/564 20130101; A61F 2230/0069 20130101 |
Class at
Publication: |
623/017.16 ;
623/023.58; 623/023.63 |
International
Class: |
A61F 002/44; A61F
002/28 |
Claims
What is claimed is:
1. A method of augmenting an intervertebral disc, said method
comprising surgically adding to an intervertebral disc a
composition comprising particulate collagen-based material.
2. The method of claim 1 wherein said surgically adding step
comprises injecting particulate collagen-based material into an
intervertebral disc.
3. The method of claim 1 wherein said collagen-based material
comprises particles ranging from 0.05 mm to 5 mm in size.
4. The method of claim 1 wherein said collagen-based material
comprises particles ranging from 0.05 mm to 3 mm in size.
5. The method of claim 1 wherein said collagen-based material
comprises particles ranging from 0.05 mm to 1 mm in size.
6. The method of claim 1 wherein said collagen-based material
comprises particles ranging from 0.25 mm to 1 mm in size.
7. The method of claim 1 wherein said collagen-based material is
injected in a dehydrated state.
8. The method of claim 1 wherein said collagen-based material is
injected in a non-dehydrated state.
9. The method of claim 8 wherein said collagen-based material is
injected as a gel.
10. The method of claim 8 wherein said collagen-based material is
injected as a solution or suspension.
11. The method of claim 1 wherein said collagen-based material is
provided as a formulation that additionally includes a
cross-linking agent to promote crosslinking of collagen
molecules.
12. The method of claim 1 wherein said collagen-based material is
provided as a formulation that additionally includes a
radiocontrast media.
13. The method of claim 1 wherein said collagen-based material is
provided as a formulation that additionally includes an
analgesic.
14. The method of claim 1 wherein said collagen-based material is
provided as a formulation that additionally includes an
antibiotic.
15. The method of claim 1 wherein said collagen-based material is
provided as a formulation that additionally includes
proteoglycans.
16. The method of claim 1 wherein said collagen-based material is
provided as a formulation that additionally includes growth
factors.
17. The method of claim 1 wherein said collagen-based material is
provided as a formulation that additionally includes one or more
other types of cells effective to promote healing, repair,
regeneration and/or restoration of the disc, and/or to facilitate
proper disc function.
18. An intervertebral disc augmented with particulate
collagen-based material.
19. The augmented disc of claim 18 wherein said collagen-based
material comprises collagen-based material that has been injected
into the disc.
20. The augmented disc of claim 18 wherein said collagen-based
material comprises particles ranging from 0.05 mm to 5 mm in
size.
21. The augmented disc of claim 18 wherein said collagen-based
material comprises particles ranging from 0.05 mm to 3 mm in
size.
22. The augmented disc of claim 18 wherein said collagen-based
material comprises particles ranging from 0.05 mm to 1 mm in
size.
23. The augmented disc of claim 18 wherein said collagen-based
material comprises particles ranging from 0.25 mm to 1 mm in
size.
24. The augmented disc of claim 18 wherein said collagen-based
material comprises collagen-based materials that have been
reconstituted in the disc from dehydrated collagen-based
materials.
25. The augmented disc of claim 18 wherein said collagen-based
material comprises collagen-based materials that were injected into
the disc in a non-dehydrated state.
26. The augmented disc of claim 18 wherein said collagen-based
material comprises collagen-based materials that were injected into
the disc as a gel.
27. The augmented disc of claim 18 wherein said collagen-based
material comprises collagen-based materials that were injected into
the disc as a solution or suspension.
28. The augmented disc of claim 18 wherein said collagen-based
material additionally includes a cross-linking agent to promote
crosslinking of collagen molecules.
29. The augmented disc of claim 18 wherein said collagen-based
material additionally includes a radiocontrast media.
30. The augmented disc of claim 18 wherein said collagen-based
material additionally includes an analgesic.
31. The augmented disc of claim 18 wherein said collagen-based
material additionally includes an antibiotic.
32. The augmented disc of claim 18 wherein said collagen-based
material additionally includes proteoglycans.
33. The augmented disc of claim 18 wherein said collagen-based
material additionally includes growth factors.
34. The augmented disc of claim 18 wherein said collagen-based
material additionally includes one or more other types of cells
effective to promote healing, repair, regeneration and/or
restoration of the disc, and/or to facilitate proper disc function.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to materials and
methods for augmenting intervertebral discs, and more particularly
to materials and methods for augmenting intervertebral discs with
collagen-based materials.
BACKGROUND OF THE INVENTION
[0002] A healthy intervertebral disc facilitates motion between
pairs of vertebrae while absorbing and distributing shocks. The
disc is composed of two parts: a soft central core (the nucleus
pulposus) that bears the majority of the load, and a tough outer
ring (the annulus fibrosis) that holds and stabilizes the core
material.
[0003] As the natural aging process progresses, the disc may
dehydrate and degenerate, adversely affecting its ability to
adequately cushion and support the vertebral bodies. This natural
desiccation, which in its more advanced state is often referred to
as "black disc" because of the disc's dehydrated appearance on
Magnetic Resonance Imaging [MRI], can cause discomfort to the
patient as the vertebrae to come closer together compressing the
spinal nerves and causing pain.
[0004] Techniques for addressing degenerative disc disease have
heretofore relied primarily on disc replacement methods. In cases
in which a dehydrated and/or degenerating disc was augmented before
disc replacement was required, the augmentation materials have
primarily been synthetic devices that expand, are inflated, or
deploy expanding elements when implanted into the disc.
[0005] A need therefore exists for materials and methods effective
for augmenting intervertebral discs with natural materials. The
present invention addresses that need.
SUMMARY OF THE INVENTION
[0006] Briefly describing one aspect of the present invention,
there is provided a method of augmenting an intervertebral disc by
injecting particles of collagen-based material into the disc. The
particles may be implanted in a dehydrated form, and rehydrated
after implantation, or they may be implanted in a hydrated form,
such as a slurry or gel. Cross-linking agents such as
glutaraldehyde may be included in the injected material to promote
collagen crosslinking. In addition, radio-contrast materials may be
included to enhance imaging of the injected material. Similarly,
performance-enhancing additives such as analgesics and/or
antibiotics may be included to provide additional therapeutic
benefits.
[0007] Objects and advantages of the claimed invention will be
apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIGS. 1A-1D show a procedure for injecting a collagen-based
material into an intervertebral disc, according to one preferred
embodiment of the present invention.
[0009] FIGS. 2A-2F show a procedure for injecting a collagen-based
material into an intervertebral disc, according to another
preferred embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] For the purposes of promoting an understanding of the
principles of the invention, reference will now be made to certain
preferred embodiments and specific language will be used to
describe the same. It will nevertheless be understood that no
limitation of the scope of the invention is thereby intended, such
alterations and further modifications in the preferred embodiments
being contemplated as would normally occur to one skilled in the
art to which the invention relates.
[0011] As indicated above, one aspect of the present invention
relates to materials and methods for using collagen-based material
to augment an intervertebral disc. In the most preferred
embodiments the collagen-based material is injected into a disc
nucleus that is contained in a substantially sound annulus. In
other embodiments the collagen-based material is injected into a
disc nucleus that is contained in a damaged or defective
annulus.
[0012] The collagen-based material is preferably derived from
natural, collagen-rich tissue, such as intervertebral disc, fascia,
ligament, tendon, demineralized bone matrix, etc. The material may
be autogenic, allogenic, or xenogenic, or it may be of
human-recombinant origin. In alternative embodiments the
collagen-based material may be a synthetic, collagen-based
material. Examples of preferred collagen-rich tissues include disc
annulus, fascia lata, planar fascia, anterior or posterior cruciate
ligaments, patella tendon, hamstring tendons, quadriceps tendons,
Achilles tendons, skins, and other connective tissues.
[0013] The collagen-based material may be provided in any form
appropriate for introduction into a disc space. For example, the
material may be a solid, porous, woven, or non-woven material. The
material may be provided as particles or small pieces, or as a
fibrous material.
[0014] In some embodiments the material is provided in a dehydrated
state, and is "rehydrated" after implantation in the disc. In other
embodiments the material is implanted "wet." When the material is
"wet," it may be that way because it has never been dehydrated, or
it may have been dehydrated and reconstituted. When reconstituted,
the material may be reconstituted with saline or another aqueous
medium, or it may be reconstituted with a non-aqueous medium such
as ethylene glycol or another alcohol. Moreover, when provided in a
"wet" state, the material may be provided as a gel, solution,
suspension, dispersion, emulsion, paste, etc.
[0015] In the most preferred embodiments the material is a
particulate and/or fibrous material suitable for injection through
a hypodermic needle into a disc.
[0016] In the most preferred embodiments the collagen material is
provided as particles ranging between 0.05 mm and 5 mm in size.
When materials such as fascia lata or disc annulus particles are
used the particles preferably range in size from 1 mm to 5 mm. When
materials such as demineralized bone matrix are used the particles
preferably range in size from 0.5 mm to 3 mm. When small plugs of
material are used the plugs preferably range in size from 0.5 mm to
5 mm. In some embodiments larger sized pieces, such as pieces up to
20 mm in size, may be used.
[0017] The materials may be processed or fabricated using more than
one type of tissue. For example, mixtures of fascia lata and
demineralized bone matrix may be preferred in appropriate cases, as
may mixtures of DBM and annulus fibrosis material.
[0018] Cross-linking agents may be added to the formulation to
promote cross-linking of the collagen material. For example,
glutaraldehyde or other protein cross-linking agents may be
included in the formulation. The cross-linking agents may promote
covalent or non-covalent crosslinks between collagen molecules.
Similarly, agents to inhibit protein denaturization may also be
included. Crosslinking agents that would be appropriate for use in
the claimed invention are known to persons skilled in the art, and
may be selected without undue experimentation.
[0019] When the material is to be used as a slurry or gel,
additives to promote slurry or gel formation may also be included.
These additives may promote protein folding, water binding,
protein-protein interactions, and water immobilization.
[0020] In addition, a radiocontrast media, such as barium sulfate,
or a radiocontrast dye, such as HYPAQUE.RTM., may be included to
aid the surgeon in tracking the movement and/or location of the
injected material. Radiocontrast materials appropriate for use in
discography are known to persons skilled in the art, and may be
selected for use in the present invention without undue
experimentation.
[0021] Finally, other additives to provide benefits to the injected
collagen-based material may also be included. Such additives
include anesthetics, to reduce pain caused by the procedure, and
antibiotics, to minimize the potential for bacterial infection.
[0022] Proteoglycans may also be included to attract and/or bind
water to keep the nucleus hydrated. Similarly, growth factors
and/or other cells (e.g., intervertebral disc cells, stem cells,
etc.) to promote healing, repair, regeneration and/or restoration
of the disc, and/or to facilitate proper disc function, may also be
included. Additives appropriate for use in the claimed invention
are known to persons skilled in the art, and may be selected
without undue experimentation.
[0023] In some embodiments the collagen material is dehydrated
before injection into the disc space, where it is rehydrated by
absorbing fluid from the disc space. In other embodiments the
collagen material is provided as a gel, slurry, or other hydrated
formulation before implantation.
[0024] The collagen-based material is "surgically added" to the
disc space. That is, the material is added by the intervention of
medical personnel, as distinguished from being "added" by the
body's natural growth or regeneration processes. The surgical
procedure preferably includes injection through a hypodermic
needle, although other surgical methods of introducing the
collagen-based material into the disc may be used. For example, the
material may be introduced into a disc by extrusion through a
dilated annular opening, infusion through a catheter, insertion
through an opening created by trauma or surgical incision, or by
other means of invasive or minimally invasive deposition of the
materials into the disc space.
[0025] Referring now to the drawings, FIGS. 1A-1D show one method
of injecting a collagen-based material into a disc. In FIG. 1A,
dehydrated particulate fascia lata or annulus fibrosis material 11
is provided in a syringe 12 (in a sterile package). The material is
rehydrated and/or dispersed in a suspension medium as shown in FIG.
1B, to provide a wet dispersion 13 of collagen-based material. A
hypodermic needle 14 is attached to syringe 12, and the syringe is
inserted into a nucleus pulposus 15 contained within a disc annulus
16 (FIG. 1C). The needle/syringe may be moved around within the
disc space, sweeping from side to side and back and forth, to
ensure uniform distribution of the collagen-based material 13
within the disc space, as shown in FIG. 1D. It is preferred,
however, that the tip of the needle be maintained near the center
of the disc to ensure deposition of the material within the nuclear
disc space, and to minimize potential leakage.
[0026] Alternatively, small collagen plugs 21 may be inserted into
the disc space as shown in FIGS. 2A-2F. The collagen plugs 21 may
be compressed before or by insertion into a small diameter tube 22,
and are provided in a delivery cannula 23 (FIGS. 2A-2C). The
delivery cannula 23 is attached to a dilator 24.
[0027] The compressed plugs are inserted into a disc nucleus 25
having a substantially intact annulus 26 by penetrating the annulus
with a guide needle 27 (FIG. 2D). Dilator 24, preferably with
delivery cannula 23 already attached, is inserted through the
annulus over guide needle 27 (FIG. 2E). The collagen plugs 21 are
then ready for injection (or extrusion) into the disc space.
[0028] The collagen plugs are deposited into the disc space. As
with the wet particulate/fibrous material, the cannula may be moved
up and back, and/or side to side, to ensure even distribution of
the plugs (FIG. 2F) a plunger 28 may be used to push the plugs from
the cannula.
[0029] The plugs expand upon exiting the dilator, and may further
expand as they rehydrate in the disc space.
[0030] As to the benefits of the inventive materials and methods,
augmentation of the intervertebral disc may restore or improve the
natural condition and/or performance of the disc. In addition,
augmentation may retard or reverse the progressive degeneration of
a dehydrated disc.
[0031] Reference will now be made to specific examples using the
processes described above. It is to be understood that the examples
are provided to more completely describe preferred embodiments, and
that no limitation to the scope of the invention is intended
thereby.
EXAMPLE 1A
Hydrated Particulate Fascia Lata
[0032] A suspension of particulate or fibrous (autologous or
allogenic) fascia lata is prepared in a biocompatible medium such
as saline or ethylene glycol. The particle size ranges from 0.1 mm
to 5 mm, with most particles being between 0.25 and 2 mm.
[0033] The suspension is injected directly into the nuclear disc
space through an intact annulus using a hypodermic needle, and is
contained within the disc space following injection. The medium
subsequently diffuses out of the disc space and leaves the fascia
lata material behind.
[0034] Inspection of the disc reveals that an appropriate level of
augmentation may be obtained with a single injection of material.
Alternatively, several smaller doses/injections may be used to
achieve comparable results.
EXAMPLE 1B
Hydrated Particulate Fascia Lata with Crosslinking Agent
[0035] A suspension of particulate or fibrous (autologous or
allogenic) fascia lata is prepared in a biocompatible medium such
as saline or ethylene glycol. The particle size ranges from 0.1 mm
to 5 mm, with most particles being between 0.25 mm and 2 mm. A
glutaraldehyde crosslinking agent is added to promote collagen
crosslinking.
[0036] The suspension is injected directly into the nuclear disc
space through an intact annulus using a hypodermic needle, and is
contained within the disc space following injection. The medium
subsequently diffuses out of the disc space and leaves the fascia
lata material behind.
[0037] Inspection of the disc reveals that an appropriate level of
augmentation may be obtained through either a single injection of
material, or by multiple injections.
EXAMPLE 1C
Dehydrated Particulate Fascia Lata
[0038] Dehydrated fascia lata material is provided in particulate
form. Particle sizes range between 0.05 mm and 3 mm, with most
particles being between 0.10 mm and 1 mm. The dehydrated material
is loaded in a specially designed syringe for delivery of solid
materials.
[0039] The material is extruded into the nuclear disc space of the
treated disc through a small dilated annular opening. The material
remains inside the disc space after the needle is removed. It
subsequently absorbs moisture or body fluids and swells up in
vivo.
[0040] Inspection of the disc reveals that an appropriate level of
augmentation may be obtained through either a single injection of
material, or by multiple injections.
EXAMPLE 2A
Hydrated Particulate Disc Annulus Material
[0041] A suspension of particulate or fibrous allogenic annulus
fibrosis is prepared in a biocompatible medium such as saline or
ethylene glycol. The particle size ranges from 0.1 mm to 5 mm, with
most particles being between 0.25 and 2 mm.
[0042] The suspension is injected directly into the nuclear disc
space through an intact annulus using a hypodermic needle. The
suspension is contained within the disc space following injection.
The medium subsequently diffuses out of the disc space and leaves
the annulus fibrosis material behind.
[0043] Inspection of the disc reveals that an appropriate level of
augmentation may be obtained through either a single injection of
material, or by multiple injections.
EXAMPLE 2B
Hydrated Particulate Disc Annulus Material with Crosslinking
Agent
[0044] A suspension of particulate or fibrous allogenic annulus
fibrosis is prepared in a biocompatible medium such as saline or
ethylene glycol. The particle size ranges from 0.1 mm to 5 mm, with
most particles being between 0.25 and 2 mm. A glutaraldehyde
crosslinking agent is added to promote collagen crosslinking.
[0045] The suspension is injected directly into the nuclear disc
space through an intact annulus using a hypodermic needle. The
suspension is contained within the disc space following injection.
The medium subsequently diffuses out of the disc space and leaves
the annulus fibrosis material behind.
[0046] Inspection of the disc reveals that an appropriate level of
augmentation may be obtained through either a single injection of
material, or by multiple injections.
EXAMPLES 3A-3C
Dehydrated Annulus Fibrosis
[0047] Dehydrated annulus fibrosis is provided in granule,
particulate and powder form, for example 3A-3C respectively.
Particle sizes range between 0.05 mm and 3 mm, with most particles
being between 0.10 mm and 1 mm. The dehydrated material is loaded
in a specially designed syringe for delivery of solid
materials.
[0048] The material is extruded into the nuclear disc space of the
treated disc through a small dilated annular opening. The material
remains inside the disc space after the needle is removed. It
subsequently absorbs moisture or body fluids and swells up in
vivo.
[0049] Inspection of the disc reveals that an appropriate level of
augmentation may be obtained through either a single injection of
material, or by multiple injections.
EXAMPLES 4A-4B
Demineralized Bone Matrix (DBM) Gel
[0050] Demineralized bone matrix (DBM) gel is provided with and
without glutaraldehyde as a cross-linker additive (examples 4A and
4B, respectively). In both cases the material is warmed up to an
appropriate temperature for melting or thinning out the gel, and is
injected directly into the nuclear disc space through an intact
annulus using a hypodermic needle. The DBM gel becomes solidified
in the disc space after injection.
[0051] Inspection of the disc reveals that an appropriate level of
augmentation may be obtained through either a single injection of
material, or by multiple injections.
EXAMPLES 4C
Dehydrated Demineralized Bone Matrix (DBM)
[0052] Dehydrated DBM is provided in granule, particulate and
powder form. Particle sizes range between 0.05 mm and 3 mm, with
most particles being between 0.10 mm and 1 mm. The dehydrated
material is loaded in a specially designed syringe for delivery of
solid materials.
[0053] The material is extruded into the nuclear disc space of the
treated disc through a small dilated annular opening. The material
remains inside the disc space after the needle is removed. It
subsequently absorbs moisture or body fluids and swells up in
vivo.
[0054] Inspection of the disc reveals that an appropriate level of
augmentation may be obtained through either a single injection of
material, or by multiple injections.
EXAMPLE 5A-5D
Mixtures of Annulus Fibrosis and Demineralized Bone Matrix
[0055] Mixtures of particulate and fibrous allogenic annulus
fibrosis and demineralized bone matrix (DBM) gel, with and without
additives and/or cross-linkers, are provided. The materials are
warmed up to an appropriate temperature for melting or thinning out
the gel mixture, and are injected directly into the nuclear disc
space through an intact annulus using a hypodermic needle. The gel
mixture becomes solidified in the disc space after injection.
[0056] Inspection of the disc reveals that an appropriate level of
augmentation may be obtained through either a single injection of
material, or by multiple injections.
EXAMPLE 6
[0057] Elongated cylindrical plugs (0.5 mm to 5 mm in diameter,
preferably 1 mm to 2 mm) of solid, porous, or fibrous collagen are
provided in a dehydrated state. The plugs are compressed in the
radial direction and are inserted into delivery cannula for
delivery into disc space.
[0058] A guide wire or needle is used to penetrate the disc space
through an intact annulus. A dilator is subsequently inserted into
the disc space over the guide wire/needle, and the guide
wire/needle is removed. The delivery cannula containing a collagen
plug is attached to the dilator prior to extrusion of the plug into
the disc space. As the plugs absorb moisture after entering the
disc space, they become more compliant, flexible and expanded.
[0059] The level of disc augmentation achieved depends on the
number of plugs inserted, and/or on the total plug volume deposited
in the disc space.
EXAMPLE 7
[0060] Cylindrical plugs or rolls (2 mm-20 mm in diameter,
preferably 10-15 mm) of solid, porous, or fibrous collagen are
provided in a dehydrated state. The dehydrated plugs are typically
more rigid than those in hydrated state, and thus, can be easily
inserted into the disc space through an annular opening created by
trauma or surgical incision.
[0061] Nucleotomy is necessary before the plug can be inserted. As
the plugs absorb moisture after entering the disc space, they
become more compliant, flexible and expanded.
[0062] The level of disc augmentation/replacement achieved depends
on the size and number of plugs inserted into the disc space.
EXAMPLE 8
[0063] Particulate fascia used for cosmetic procedure
(FASCIAN.RTM.) was modified to include a radiocontrast media. A
small quantity of barium sulfate powder was blended with 80 mg of
>0.5 mm Gastrocemius Fascia for visualization under fluoroscopic
imaging. About 1-1.5 cc of water was added to the blend in the
syringe for hydration.
[0064] After hydration for 5-10 minutes, the material
(Fascian/Barium Sulfate/Water or F.B.W.) was injected into the
nuclear disc space of a harvested porcine intervertebral disc.
X-ray images of the disc were obtained before and after
injection.
[0065] A small increase in disc height was noticed after injection.
Also, manual compression indicated that the disc was stiffer after
injection. The injected disc was also tested under compression up
to 5000N. There was no gross leakage observed during the
compression test. Only a slight oozing of a small amount of
injected material was observed at the injection site, but it
stopped quickly.
[0066] The disc was cut in the horizontal plane to confirm the
location of the injected material. F.B.W. was found contained
within the disc annulus and mixed in with nucleus pulposus.
EXAMPLE 9
[0067] Particulate fascia used for cosmetic procedures
(FASCIAN.RTM.) was modified before experimentation to include a
radiocontrast material. A small quantity of radiocontrast dye or
barium sulfate powder was blended with about 200 mg of 0.25-1.0 mm
Gastrocemius Fascia for visualization under fluoroscopic imaging.
About 1.5-3 cc of saline was added to the blend in the syringe for
hydration.
[0068] After hydration for about 30 minutes, the material
(Fascian/Dye or Barium Sulfate/Water) was injected into the nuclear
disc space of cadaveric intervertebral discs (L2-3 and L3-4). X-ray
images of the discs were obtained before and after injection. A
small increase in disc height was noticed radiographically after
injection. There was no gross leakage observed at the injection
site. In the case of L3-4 injection, the needle tip was maintained
approximately at the center of the disc, which resulted in material
deposition mainly within the nucleus pulposus.
EXAMPLE 10
[0069] Particulate fascia (FASCIAN.RTM.) having particle sizes of
0.25 mm and 0.5 mm was purchased from Fascia BioSystems. Collagen
solutions were prepared, with each solution consisting of
approximately 80 mg of particulate fascia, 0.75 ml of saline, and
0.25 ml HYPAQUE.RTM. radiocontrast solution.
[0070] Thoracic and lumbar discs in two pigs were subjected to
stabbing injury. The injured discs were then injected with 1-2 ml
of collagen solution at 4 weeks after injury. The injections were
performed using a 3 ml syringe, a 20 gauge hypodermic needle and a
graft placement device. Confirming X-ray was taken using C-arm
fluoroscopy.
[0071] The injured discs appeared to have somewhat reduced heights
at four weeks after injury. Of approximately 12 injected discs,
there was only one leakage observed. The amount of leakage was
visually estimated to be less than 20% of the total volume
injected. The low incidence of leakage indicates that the annulus
is capable of self-sealing when a small gauge needle is used for
injection.
[0072] The disc height increased upon collagen injection depending
on the injected volume. In particular, an approximately 46%
increase in disc height was achieved with 2 ml injection. In some
cases the disc height gain was reduced after injection as
radio-contrast dye and water molecules diffused out of the disc
under intra-discal pressure.
[0073] While the invention has been illustrated and described in
detail in the drawings and foregoing description, the same is to be
considered as illustrative and not restrictive in character, it
being understood that only the preferred embodiment has been shown
and described and that all changes and modifications that come
within the spirit of the invention are desired to be protected.
* * * * *