U.S. patent application number 10/924240 was filed with the patent office on 2005-06-16 for kit for treating bony defects.
Invention is credited to Ahern, James W., Gertzman, Arthur, Kuslich, John E., Kuslich, Stephen D., Roche, Karen, Sunwoo, Moon Hae, Wolfe, Steven.
Application Number | 20050131417 10/924240 |
Document ID | / |
Family ID | 34656940 |
Filed Date | 2005-06-16 |
United States Patent
Application |
20050131417 |
Kind Code |
A1 |
Ahern, James W. ; et
al. |
June 16, 2005 |
Kit for treating bony defects
Abstract
The present invention is a kit and a method of using a kit for
treating bone including a fill material mixture made of
osteoconductive material, osteoinductive material and a lubricating
carrier, a porous container to receive the fill material mixture
and a tool that flowably introduces the fill material mixture into
the porous container.
Inventors: |
Ahern, James W.; (Austin,
TX) ; Gertzman, Arthur; (Flemington, NJ) ;
Roche, Karen; (Stillwater, MN) ; Sunwoo, Moon
Hae; (Old Tappan, NJ) ; Wolfe, Steven;
(Woodbury, MN) ; Kuslich, Stephen D.; (Phoenix,
AZ) ; Kuslich, John E.; (Phoenix, AZ) |
Correspondence
Address: |
PATTERSON, THUENTE, SKAAR & CHRISTENSEN, P.A.
4800 IDS CENTER
80 SOUTH 8TH STREET
MINNEAPOLIS
MN
55402-2100
US
|
Family ID: |
34656940 |
Appl. No.: |
10/924240 |
Filed: |
August 23, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60497146 |
Aug 22, 2003 |
|
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|
Current U.S.
Class: |
606/92 |
Current CPC
Class: |
A61F 2002/30062
20130101; A61F 2002/2817 20130101; A61F 2002/30677 20130101; A61F
2210/0004 20130101; A61F 2310/00293 20130101; A61F 2002/2835
20130101; A61F 2002/30011 20130101; A61B 2017/00004 20130101; A61B
17/7098 20130101; A61F 2/4601 20130101; A61F 2250/0023
20130101 |
Class at
Publication: |
606/092 |
International
Class: |
A61F 002/28; A61B
017/58 |
Claims
1. A kit for treating bone comprising: a fill material mixture
including osteoconductive material, osteoinductive material and a
lubricating carrier, the osteoconductive material having a particle
size X, the osteoinductive material having a particle size about
0.3X-0.7X; a porous container to receive the fill material mixture,
the container having pore sizes about 0.5X-2.5X; a tool that
flowably introduces the fill material mixture into the porous
container at sustained or intermittent pressures of at least 300
psi such that the fill material mixture is packed into the
container; and a halo layer of osteoinductive material at least 1
mm forms around at least a portion of an exterior surface of the
porous container.
2. The device of claim 1 wherein the ratio of the fill material
mixture is about 1 part osteoinductive material to 2 parts
osteoconductive material to 2 parts lubricating carrier;
3. The device of claim 1 wherein the osteoinductive material is
demineralized bone material.
4. The device of claim 1 wherein the osteoconductive material is
selected from the group consisting of: cortical cancellous
allograft, cortical cancellous autograft, cortico cancellous
xenograft, hydroxyapatite, tricalcium phosphate, calcium sulfate,
calcium carbonates and any combination thereof.
5. The device of claim 1 wherein the mixture is selected from a
group consisting of: demineralized bone material, morselized bone
graft, cortical cancellous allograft, cortical cancellous
autograft, cortical cancellous xenograft, hydroxyapatite,
tricalcium phosphate, calcium sulfate, calcium carbonates and any
combination thereof.
6. A method of treating bone comprising the steps of: inserting a
porous container into a bony defect; introducing the fill material
mixture into the porous container at a pressure of at least 300 psi
such that the fill material mixture is packed into the container
forming a halo layer of osteoinductive material at least 1 mm
around at least a portion of an exterior surface of the porous
container.
7. The method of claim 6 wherein the ratio of the fill material
mixture is about 1 part osteoinductive material to 2 parts
osteoconductive material to 2 parts lubricating carrier;
8. The method of claim 6 wherein the particle size of the
osteoconductive material is X, the particle size of the
osteoinductive material is about 0.3X-0.7X and the container pore
sizes are about 0.5X-2.5X.
9. The method of claim 6 wherein the osteoinductive material is
demineralized bone material.
10. The method of claim 6 wherein the osteoconductive material is
selected from the group consisting of: cortical cancellous
allograft, cortical cancellous autograft, cortico cancellous
xenograft, hydroxyapatite, tricalcium phosphate, calcium sulfate,
calcium carbonates and any combination thereof.
11. The method of claim 6 wherein the mixture is selected from a
group consisting of: demineralized bone material, morselized bone
graft, cortical cancellous allograft, cortical cancellous
autograft, cortical cancellous xenograft, hydroxyapatite,
tricalcium phosphate, calcium sulfate, calcium carbonates and any
combination thereof.
Description
FIELD OF INVENTION
[0001] The present invention relates generally to the field of
materials adapted to replace or assist a component of the skeleton
of a living body. More specifically, the present invention relates
to a system that surgeons can use for healing and supporting bony
defects.
BACKGROUND OF THE INVENTION
[0002] Bone grafts are commonly used in a wide variety of
orthopedic procedures. In particular, bone graft is often used to
aid the healing of bony defects. Such defects may arise from trauma
or a pathologic condition, or the surgeon may require graft to
support bony healing subsequent to a surgical procedure such as
joint fusion or arthrodesis.
[0003] Autogenous bone, also called autograft, is generally
considered to be the "gold standard" in terms of biological
performance. Autograft is often collected from the patient's hip.
However, collecting autograft from the patient's hip is associated
with a significant incidence of post-operative pain and the
potential for additional medical complications. In addition, the
volume of autograft material available from the patient's hip may
not be sufficient for the graft procedure.
[0004] Specially processed donor bone, or allograft, is frequently
used as an alternative to autograft. Allograft, such as morselized
granules of cortical and cancellous bone, provides an
osteoconductive material with some compressive strength, which can
be readily incorporated via the same healing process that occurs
with autogenous bone. Osteoconductivity refers to a material's
ability to provide a suitable structure or scaffold for the growth
of new blood vessels and, ultimately, bone.
[0005] Allograft which is demineralized during its processing is
commonly referred to as DBM, or demineralized bone matrix. DBM is
an osteoinductive material, meaning that it can lead to the
formation of bone by recruiting mesenchymal stem cells from the
surrounding tissues, and these cells can ultimately differentiate
into new bone.
[0006] The Optimesh.RTM. System (patented by Spineology, Inc. in
U.S. Pat. Nos. 5,549,679; 5,571,189, 6,383,188; 6,620,162;
6,620,169 and U.S. Patent Application Nos.: 09/909,667 and
10/440,036 all of which are incorporated herein by reference)
includes various tools and a porous container used to contain bone
graft or other fill material when fusing intervertebral spaces and
treating defects in intravertebral bones or other bones. While the
current Optimesh.RTM. System utilizes the concept of fill material
extrusion, it would be advantageous to capitalize on the
characteristics of both the osteoconductive and osteoinductive
materials.
SUMMARY OF THE INVENTION
[0007] To maximize the benefits of osteoinductive and
osteoconductive fill materials, there is a need for carefully
selecting and controlling the fill material flow into bony defects.
It would be a particularly useful improvement to the Optimesh.RTM.
System to fill the porous container with a fill material mixture
that is filtered, under pressure, by the container such that bone
inducing material flows out of the porous container and contacts
the surrounding tissue, while the container restrains
osteoconductive material in the container to provide support and
rigidity to the defect.
[0008] The present invention includes a method and apparatus for
healing and supporting bony defects. The method and apparatus of
the present invention combine the advantageous features of
osteoconductive and osteoinductive allograft materials. The present
invention capitalizes upon the unique properties of each component
by utilizing a mesh container placed in a bony defect. The
allograft mixture is injected into the mesh container such that the
osteoconductive material provides compressive strength to support
the bony defect and the osteoinductive material encourages bone
growth to aid in the healing of the bony defect.
[0009] The allograft mixture is formulated to be flowable, that is
the material may be discharged from a small diameter tube of length
significantly longer than the tube's diameter. The allograft
mixture is also packable such that the mixture may fill a small
mesh container or pouch so that the mesh fills to its geometric
limits as it is filled with the allograft mixture.
[0010] The allograft mixture includes non-demineralized cortical
cancellous allograft granules or other suitable osteoconductive
material, which may be fully contained by the mesh due to their
physical size, and can thereby provide some structural strength to
the bony defect. The granules provide a focus for load bearing or
load sharing just as the pebbles in concrete. The ratio of cortical
to cancellous allograft may be in the range of 25:75-100:0.
[0011] The granules may be mixed with DBM or other suitable
osteoinductive material, which is a fine particulate, and a
lubricating carrier. As the mesh is filled with the cortical
cancellous allograft granules, some of the particulate DBM may be
retained within the filled mesh, but a portion of it may be free to
flow out through the pores of the mesh. This results in a
surrounding "halo" of osteoinductive material at the margins of the
filled mesh, in direct apposition with the surrounding host tissue
where it can initiate recruitment of the stem cells, thus
encouraging bone growth to heal the bony defect.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] The allograft mixture may generally be comprised of three
components: non-demineralized cortical cancellous allograft
granules or other suitable osteoconductive material, demineralized
bone matrix ("DBM") or other suitable osteoinductive material and
sodium hyaluronan (HA), or other suitable lubricating carrier. The
non-demineralized cortical cancellous allograft granules may
generally be 200-2000 microns in size and may have an aspect ratio
of about 1.5 longer than wide. The DBM may generally be 100-1000
microns in size and tends to be more uniform and rounded in shape.
The lubricating carrier may generally be a viscous liquid, for
example, sodium hyaluronan in varying molecular weights, alginate,
dextran, gelatin, collagen and others. The DBM is more likely than
the non-demineralized granules to be suspended in the lubricating
carrier due to the geometric and size difference between the DBM
and the non-demineralized granules.
[0013] Ceramic materials may be added as alternatives to the
cortical cancellous granules. The ceramics are also load bearing,
load sharing, and osteoconductive. The ceramic material formulation
may include, for example, calcium hydroxyapatite, tricalcium
phosphate and calcium sulfate among others. Calcium hydroxyapatite
resorbs very slowly, over a period of years. Tricalcium phosphate
resorbs slowly, in about 3-6 months. Calcium sulfate resorbs more
quickly, in less than 3 months.
[0014] As shown in FIG. 1, the tendency for the DBM to flow with
the carrier is particularly noticeable when the mixture is
delivered and packed into the mesh container 10. The DBM particles
flow through the mesh pores under the force applied by the emptying
of the filled tube into the confined mesh container. The smaller of
the DBM particles flow through the mesh pores into the bony defect.
These DBM particles are the sole osteoinductive elements in the
mixture. As the DBM is forced through the mesh pores, the DBM makes
intimate contact with the irregular surfaces of the bony defect and
consequently causes new bone to grow precisely at the surfaces
where bony fusion is intended.
[0015] The mesh pores, generally about 250-5000 microns, may act as
a sieve or filter that preferentially retains the non-demineralized
granules. This filtering feature may allow the larger, irregularly
shaped granules to pack tightly together within the mesh while the
fluid component, also carrying the particles of DBM, may fill the
interstices of the packed granules and flow through the pores of
the mesh.
[0016] The relationship between the sizes of the DBM, the mesh
pores and the granules may generally be described as follows: If
the granules have a size equal to X, then the DBM size may
generally be in the range of 0.3-0.7.times. and the pore size may
generally be in the range of 0.5-2.5X.
[0017] The formulation of the mixture may generally be in the range
of about 2 parts DBM, 8 parts non-demineralized allograft granules
and 8 parts lubricating carrier.
[0018] The non-demineralized granules are primarily osteoconductive
(supporting bone growth on the surface, but not strongly inducing
growth), while the DBM is both osteoconductive and osteoinductive
(encourages bone to grow). Because the DBM is osteoinductive, as
the DBM flows out of the mesh pores in the fluid carrier, the DBM
creates an increased potential for bone growth surrounding the mesh
container, at the host-mesh interface, which may help to speed bony
healing, or incorporation of the mesh and graft into the host bone
structure.
[0019] As shown in FIG. 2, a single mesh container 10 may have
varying pore sizes, resulting in a differential porosity. That is,
where the pores are larger, more fill material will flow out of the
pores and where the pores are smaller less fill material will flow
out of the pores. This differential porosity allows the surgeon to
direct the flow of material out of the mesh pores and thus optimize
the placement of the osteoinductive DBM more precisely to promote
bony growth at the defect site.
[0020] FIG. 3 shows a preferred tool 20, patented as U.S. Pat. No.
6,620,169 to Spineology, Inc, that may be used to process and
inject the fill material mixture. In a preferred embodiment, the
tool 20 shown in FIG. 3 is used to process the fill material
mixture and inject the mixture into fill tubes. FIG. 4 shows the
preferred embodiment where the fill material mixture is extruded
from a fill tube 30 having at least one opening to direct the flow
of the fill material mixture into the porous container 10 for
optimal fill material placement.
[0021] Additional components, for example, bone morphogenic
protein, vascular endothelial growth factor, platelet derived
growth factor, insulin-like growth factor, chondrocyte growth
factor, fibroblast growth factor, antiviral agents, antibiotic
agents and others may be added to the formulation.
* * * * *