U.S. patent application number 11/064977 was filed with the patent office on 2005-07-21 for annulus preserving methods and apparatus for placement of intradiscal devices.
Invention is credited to Ferree, Bret A..
Application Number | 20050159817 11/064977 |
Document ID | / |
Family ID | 29273635 |
Filed Date | 2005-07-21 |
United States Patent
Application |
20050159817 |
Kind Code |
A1 |
Ferree, Bret A. |
July 21, 2005 |
Annulus preserving methods and apparatus for placement of
intradiscal devices
Abstract
Devices such as a cylindrical bone dowel removed from a vertebra
or other human or animal bone, alive or deceased are used to fill
holes formed through a vertebral body. Synthetic nucleus
replacements or biologic tissue and/or cells may be inserted
through the hole. Single or multiple solid, gel, or liquid devices
may be placed into the disc. The material may cure in-situ. The
intradiscal device may be inserted an instrument that contains a
hollow tube. A hollow tube, including the hollow tube of an
insertion tool, may be placed into the hole drilled into the
vertebra. Cannulated drill bits may placed over guide wires to
drill the hole into the vertebra.
Inventors: |
Ferree, Bret A.;
(Cincinnati, OH) |
Correspondence
Address: |
John G. Posa
Gifford, Krass, Groh, Sprinkle,
Anderson & Citkowski, P.C.
280 N. Old Woodward Ave., Suite 400
Birmingham
MI
48009-5394
US
|
Family ID: |
29273635 |
Appl. No.: |
11/064977 |
Filed: |
February 24, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11064977 |
Feb 24, 2005 |
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10421434 |
Apr 23, 2003 |
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6878167 |
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60375185 |
Apr 24, 2002 |
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60378132 |
May 15, 2002 |
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Current U.S.
Class: |
623/17.11 |
Current CPC
Class: |
A61F 2/28 20130101; A61B
17/8085 20130101; A61F 2310/00359 20130101; A61B 17/15 20130101;
A61F 2002/4435 20130101; A61F 2/442 20130101; A61B 17/1728
20130101; A61F 2/44 20130101; A61F 2/30734 20130101; A61B 17/7059
20130101; A61B 17/1757 20130101; A61F 2220/0075 20130101; A61F
2002/30462 20130101 |
Class at
Publication: |
623/017.11 |
International
Class: |
A61B 017/56 |
Claims
I claim:
1. A method of placing an intradiscal device, comprising the steps
of: forming a hole through a vertebral body to access an
intradiscal space; placing intradiscal material into the
intradiscal space; and filling the hole formed through the
vertebral body with a plug.
2. The method of claim 1, wherein the intradiscal device includes
one or more solid, gel, or liquid devices.
3. The method of claim 1, wherein the intradiscal device cures in
situ.
4. The method of claim 1, wherein the plug is a bone dowel.
5. The method of claim 1, wherein the plug includes a central
threaded or gripping section.
6. The method of claim 1, wherein the plug includes one or more
tapered ends to conform with a vertebral endplate or other bone
surface.
7. The method of claim 1, wherein the plug is conducive to bony
ingrowth.
8. The method of claim 1, wherein the plug is hollow.
9. The method of claim 1, wherein the intradiscal material includes
a nucleus replacement.
10. The method of claim 1, wherein the intradiscal material
includes biologic tissue and/or cells.
Description
REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 10/421,434, filed Apr. 23, 2003, which claims
priority from U.S. Provisional Patent Application Ser. Nos.
60/375,185, filed Apr. 24, 2002 and 60/378,132, filed May 15, 2002;
the entire content of each being incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to spinal surgery and, in
particular, to methods and apparatus for placing intradiscal
devices.
BACKGROUND OF THE INVENTION
[0003] Intradiscal devices are often shaped to fit within the
natural concavities of the vertebral endplates that make up the
disc space. As shown in FIG. 1, the entrance into the disc space is
often narrower than the vertical space within the disc space.
Currently surgeons have three choices when inserting devices that
fit tight within the interior of the natural disc space. First,
they can insert devices that change size or shape within the disc
space. There are only a limited number of intradiscal devices that
change size or shape within the disc space. Second, surgeons can
remove a portion of the vertebrae endplate to allow the insertion
of a device that fits tightly in the tallest portion of the disc
space. Third, surgeons can distract the vertebrae to insert the
intradiscal device. However, at times, the vertebrae cannot be
distracted enough to allow the insertion of an intradiscal device
that fits tightly within the central portion of the disc space and
yet can be inserted past the periphery of the disc space.
SUMMARY OF THE INVENTION
[0004] The present invention involves an osteotomy of a portion of
a vertebral endplate and/or vertebral body to allow for easier
insertion of a device that fits tightly into a disc space,
especially the tallest portion(s) of the disc space. A different
aspect of the invention resides in a mechanical device to hold the
osteotomized portion of the vertebra against the vertebral body
after the intradiscal device is placed. The device may be removed
after the pieces of vertebra heal and fuse together.
[0005] Other embodiments of the invention teach devices that may be
used to fill holes drilled through a vertebra. For example, such a
device may take the form of a cylindrical bone dowel removed from a
vertebra or other human or animal bone, alive or deceased. The
dowel could be removed with a hole-cutting drill bit. The hole may
be drilled into the anterior, lateral, anterior-lateral, posterior,
or posterior-lateral portion of the vertebra. A transpsoas approach
may be used to the lateral portion of the spine. A paraspinal
approach may be used to access the posterior lateral portion of the
vertebra. The vertebrae may be distracted prior to inserting the
intradiscal device. Screws or pins could be placed into the
pedicles of the vertebrae. A distracting instrument could be placed
over the screws. Alternatively, distraction could be performed by
an instrument placed between the spinous processes.
[0006] In the preferred embodiments, synthetic nucleus replacements
or biologic tissue and/or cells are inserted through the hole
drilled into the vertebra. The material may be a solid, gel, or
liquid. Single or multiple devices may be placed into the disc. The
material that is placed into the disc may cure in-situ. The
intradiscal device may be inserted an instrument that contains a
hollow tube. A hollow tube, including the hollow tube of an
insertion tool, may be placed into the hole drilled into the
vertebra. Cannulated drill bits may placed over guide wires to
drill the hole into the vertebra.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 shows a prior art device illustrating the entrance
into the disc space;
[0008] FIG. 2A is a side-view drawing illustrating an approach
taken according to a method of the present invention;
[0009] FIG. 2B shows a portion removed from the vertebrae;
[0010] FIG. 2C shows how, with the portion removed, the intradiscal
device may be more easily inserted;
[0011] FIG. 2D shows the intradiscal device in place in an
intervertebral space;
[0012] FIG. 2E shows the replacement of an osteotomized
portion;
[0013] FIG. 2F shows anterior and lateral views illustrating a
device is used to hold the osteotomized fragment;
[0014] FIG. 2G shows anterior and lateral views of a
fragment-holding device with the lateral or side view being shown
in cross-section;
[0015] FIG. 3A shows an anterior and lateral view of a hole formed
through the vertebrae to receive a cable;
[0016] FIG. 3B is a drawing which shows the holder in place and
secured with the cable;
[0017] FIG. 4A is a view of the lateral surface of two vertebrae, a
disc, and an osteotomized piece of vertebra;
[0018] FIG. 4B is a is a view of the lateral surface of the spine
with the osteotomized bone fragment and the attached AF retracted
inferiorly;
[0019] FIG. 4C is a view of the lateral surface of the spine after
reattaching the osteotomized bone fragment;
[0020] FIG. 4D is an axial cross-section of a disc, an intradiscal
device and attached mesh;
[0021] FIG. 4E is an axial cross-section of a disc wherein a bone
fragment and attached AF have been retracted;
[0022] FIG. 4F is a coronal cross-section of the spine, an
intradiscal device, and a plate and screws;
[0023] FIG. 5A shows the view of the front of the spine and an
alternative embodiment of the invention;
[0024] FIG. 5B is a view of the anterior aspect of the spine after
removal of the bone fragments;
[0025] FIG. 5C is a sagittal cross section of the spine, an
intradiscal device, and an alternative embodiment of the plate and
screws;
[0026] FIG. 5D is a view of the anterior aspect of the spine and
the embodiment of the invention shown in FIG. 5C;
[0027] FIG. 5E is an exploded view of the front of the plates and a
screw shown in FIG. 5D;
[0028] FIG. 5F is a view of the side of bone and AF graft shown in
FIG. 5C;
[0029] FIG. 5G is a sagittal cross section of an alternative
embodiment;
[0030] FIG. 6A is a coronal cross-section of the spine, wherein a
portion of the upper vertebrae has been osteotomized;
[0031] FIG. 6B is a coronal cross-section of the spine shown in
FIG. 6A;
[0032] FIG. 7A is a sagittal cross section of the spine, an
intradiscal device, and an alterative embodiment of the plate used
to attach the bone fragment;
[0033] FIG. 7B is a view of the anterior aspect of the spine and
the embodiment of the plate shown in FIG. 7A;
[0034] FIG. 8A is a sagittal cross section through the spine and an
alternative mechanism used to attach the bone fragment;
[0035] FIG. 8B is a sagittal cross section of the spine and an
alternative embodiment of the fastening method shown in FIG.
8A;
[0036] FIG. 9A is a coronal cross section of the spine, a drill and
osteotomy guide, and an osteotome;
[0037] FIG. 9B is a coronal cross section of the spine and the
embodiment of the invention shown in FIG. 9A;
[0038] FIG. 9C is a view of the lateral side of the spine and the
guide shown in FIG. 9A;
[0039] FIG. 9D is a view of the lateral side of the spine and an
alternative embodiment of a cutting guide;
[0040] FIG. 1OA is a coronal cross section of the spine and an
embodiment of the invention with bone fragments having an
alternative shape;
[0041] FIG. 10B is a view of the lateral aspect of the spine shown
in FIG. 1OA;
[0042] FIG. 11A is a coronal cross section of the spine;
[0043] FIG. 11B is a coronal cross section of the spine drawn
during the insertion of an intradiscal device;
[0044] FIG. 11C is a coronal cross section of the spine drawn in
FIG. 11B, after the insertion of an intradiscal device;
[0045] FIG. 11D is a view of the lateral surface of the spine drawn
in FIG. 11A;
[0046] FIG. 12A is a drawing that shows an alternative approach
according to the invention;
[0047] FIG. 12B shows the use of a plate and screws following the
procedure of FIG. 12A;
[0048] FIG. 13A is a lateral view of a device that may used to fill
the hole drilled into the vertebra;
[0049] FIG. 13B is a view of the end of a device according to the
invention;
[0050] FIG. 13C is a coronal cross section of the spine and an
anterior view of the invention drawn in FIG. 13A;
[0051] FIG. 13D is an anterior view of an alternative embodiment of
the invention which has holes 1310, 1312 that extend to chambers
within the device;
[0052] FIG. 14A is an anterior view of an alternative embodiment of
the invention wherein the tip of the device rotates relative to the
body of the device;
[0053] FIG. 14B is an anterior view of the embodiment of the
invention drawn in FIG. 14A;
[0054] FIG. 15A is an anterior view of a vertebra and an alignment
guide;
[0055] FIG. 15B is an anterior view of a vertebra and an
alternative embodiment of the invention wherein the guide has
components that fit against the vertebral endplates;
[0056] FIG. 16A is a coronal cross section of the spine and an
alternative embodiment of the invention;
[0057] FIG. 16B is a coronal cross section of the spine and the
embodiment of the invention drawn in FIG. 16A, and wherein
polymethylmethacrylate (PMMA) has been injected into the hole in
the vertebra;
[0058] FIG. 17 is an axial cross section of a disc;
[0059] FIG. 18A is an anterior view of a distraction device;
and
[0060] FIG. 18B is an anterior view of the embodiment of the
invention drawn in FIG. 18A and the cross section of the pedicles
of two vertebrae.
DETAILED DESCRIPTION OF THE INVENTION
[0061] FIG. 2A is a side-view drawing illustrating an approach
taken according to a method of the invention. In particular, a tool
such as an osteotome 202 is used to remove or truncate a lower
anterior portion of the upper vertebrae 206. FIG. 2B shows the
portion removed from the vertebrae. FIG. 2C shows how, with the
portion removed, the intradiscal device may be more easily
inserted. FIG. 2D shows the intradiscal device in place in the
intervertebral space. FIG. 2E shows the replacement of the
osteotomized portion. Note that the piece of bone itself may be
drilled and/or tapped if necessary, preferably before the
osteotomy, to assist with reattachment.
[0062] FIG. 2F provides an anterior and lateral view showing the
way in which the device is used to hold the osteotomized fragment.
FIG. 2G is an anterior and lateral view of the preferred
fragment-holding device, with the lateral or side view being shown
in cross-section. As an alternative to a plate and fasteners, a
cable system may be used to hold the osteotomized portion in place.
FIG. 3A shows an anterior and lateral view of a hole formed through
the vertebrae to receive a cable, and FIG. 3B is a drawing which
shows the holder in place and secured with the cable.
[0063] It will be appreciated, that although, in the preferred
embodiment, only a portion of the upper vertebrae is osteotomized,
an anterior portion of the lower vertebrae or both the upper and
lower vertebrae may be modified according to the invention,
depending upon the area of the spine, patient's physiology and
other factors. Indeed, if both the upper and lower vertebrae are
osteotomized, the angle of approach may be reduced.
[0064] Additionally, the anterior, lateral, and/or posterior
portions of the vertebrae may be osteotomized according to the
invention, and the osteotomized bone fragment(s) may include
attached Annulus Fibrosus (AF). Although the osteotomy may be
limited to either the vertebra above or below the disc,
alternatively osteotomies can be performed on the vertebra above
and below the disc. An allograft bone and AF component, or an
allograft bone and tendon/ligament component, may be used to
reconstruct the AF.
[0065] FIG. 4A is a view of the lateral surface of two vertebrae
402, 404, a disc 406, and an osteotomized piece of vertebra 408.
The dotted area of the drawing represents the osteotomized bone
fragment. The bone fragment and vertebra can be drilled and tapped
prior to the osteotomy. A guide as shown in FIGS. 9A and 9B can be
used to drill, tap, and cut the vertebra. The Annulus Fibrosus (AF,
410) is cut.
[0066] A portion of the AF that is attached to the bone fragment is
separated from the remainder of the AF. FIG. 4B is a view of the
lateral surface of the spine with the osteotomized bone fragment
408 and the attached AF 410 retracted inferiorly, to allow entry
into the disc space. The area outlined by the dotted lines in the
superior vertebra represents the cut surface of the superior
vertebra.
[0067] FIG. 4C is a view of the lateral surface of the spine after
reattaching the osteotomized bone fragment. A plate 412 and screws
414 can be used to hold the bone fragment in position. The plate in
this case is limited to a single vertebra (area of the drawing with
horizontal lines), and does not project beyond the vertebral
endplate. The plate may further include a mechanism that prevents
the screws from backing out of the plate. For example, C-rings that
snap shut after the screws pass by the C-rings can be incorporated
into the plate. The screws can pass through the bone fragment
and/or portion of the vertebra above the fragment.
[0068] FIG. 4C shows screws passing through the bone fragment and
screws that do not pass through the bone fragment. Mesh, as
described in my U.S. Pat. No. 6,371,990 is shown attached to the
cut and uncut portions of the AF. The mesh is represented by the
portion of the drawing with vertical and horizontal lines. FIG. 4D
is an axial cross section of a disc, an intradiscal device, and the
attached mesh. The intradiscal device is represented by the dotted
area of the drawing. Pieces of mesh (area of the drawing with
horizontal lines) are shown on the inner and outer surfaces of the
AF. Sutures pass through both pieces of mesh and the interposed
AF.
[0069] FIG. 4E is an axial cross section of a disc wherein a bone
fragment and attached AF have been retracted to allow entry into
the disc space. FIG. 4F is a coronal cross section of the spine, an
intradiscal device 430, and the plate and screws 432, 434 used to
hold the bone fragment 436 in position.
[0070] FIG. 5A is the view of the front of the spine and an
alternative embodiment of the invention wherein the vertebrae above
and below the disc are osteotomized. A portion of the AF (AF'),
attached to both bone fragments, is separated from the remaining
AF. FIG. 5B is a view of the anterior aspect of the spine after
removal of the bone fragments and the portion of the AF that
connects the bone fragments. The separated bone fragments and the
AF that connects the bone fragments are on the right side of the
drawing.
[0071] FIG. 5C is a sagittal cross section of the spine, an
intradiscal device 502, and an alternative embodiment of the plate
and screws 504, 506. A flexible material 510 preferably connects
the plates. The screws may converge or diverge to increase pull-out
strength. FIG. 5D is a view of the anterior aspect of the spine and
the embodiment of the invention drawn in FIG. 5C.
[0072] FIG. 5E is an exploded view of the front of the plates and a
screw drawn in FIG. 5D. The screws can be threaded into the plates,
which helps prevent the screws from backing out of the vertebrae.
Two or more threads can be used in the portion of the screw that
attaches to the plate. The flexible material is shown at 510. FIG.
5F is a view of the side of bone and AF graft drawn in FIG. 5C. The
graft may be an autograft or an allograft.
[0073] FIG. 5G is a sagittal cross section of an alternative
embodiment of the bone and AF graft 262. The graft 262 is
preferably held into holes drilled into the vertebrae by
interference screws 264. The graft can be autograft or allograft.
Allografts could be made from tissues other than vertebrae and AF.
For example, the graft could be made of bone from the patella and
the tibia with patellar tendon connecting the pieces of bone.
[0074] FIG. 6A is a coronal cross section of the spine wherein
portion of the upper vertebrae has been osteotomized. FIG. 6B is a
coronal cross section of the spine drawn in FIG. 6A, after
inserting an intradiscal device. The invention allows distraction
of the disc space to insert the intradiscal device. The bone
fragment can be advanced along the side of the vertebra, after
distraction of the disc space.
[0075] FIG. 7A is a sagittal cross section of the spine, an
intradiscal device, and an alterative embodiment of the plate 702
used to attach the bone fragment. One or more arms 704 from the
bottom of the plate extend under the bone fragment. The arms of the
plate also extend through a portion of the AF. FIG. 7B is a view of
the anterior aspect of the spine and the embodiment of the plate
drawn in FIG. 7A.
[0076] FIG. 8A is a sagittal cross section through the spine and an
alternative mechanism used to attach the bone fragment. The
mechanism includes a screw with member 802 that is threaded into
the vertebra and a second component 804 that extends through one or
more holes in the bone fragment connects the bone fragment to the
vertebra. The drawing illustrates the use of a flexible, suture or
cable like component that is tightened over the bone fragment. A
nut that threads to a threaded projection through the bone fragment
could also be used to attach the bone fragment.
[0077] FIG. 8B is a sagittal cross section of the spine and an
alternative embodiment of the fastening method drawn in FIG. 8A.
The fastener may be crimped to a cable extending through the bone
fragment, after the bone fragment is placed against the
vertebra.
[0078] FIG. 9A is a coronal cross section of the spine, a drill and
osteotomy guide 902, and an osteotome 904. FIG. 9B is a coronal
cross section of the spine and the embodiment of the invention
drawn in FIG. 9A. The osteotome is drawn extending through the
guide and into the vertebra. The guide can also be used to
pre-drill and pre-tap holes 910, 912 in the vertebrae and/or the
bone fragment. FIG. 9C is a view of the lateral side of the spine
and the guide drawn in FIG. 9A. The dotted area of the drawing
represents holes in the guide for drilling and tapping the
vertebra. The area of the drawing with closely spaced diagonal
lines represents the slot for inserting an instrument to cut the
vertebra. FIG. 9D is a view of the lateral side of the spine and an
alternative embodiment of the cutting guide. The guide drawn in
FIG. 9D does not have a component that extends into the disc space.
The guide can be held against the vertebra by pins, screws, or taps
placed through the holes in the guide.
[0079] FIG. 1OA is a coronal cross section of the spine and an
embodiment of the invention with bone fragments 1002 having an
alternative shape. The bone fragments area represented by the
dotted area of the drawing. FIG. 10B is a view of the lateral
aspect of the spine drawn in FIG. 10A.
[0080] FIG. 11A is a coronal cross section of the spine. The AF is
shown at 1102. The osteotomy extends inside the AF ring. FIG. 11B
is a coronal cross section of the spine drawn during the insertion
of an intradiscal device. The bone fragment has been removed from
the vertebra. The intradiscal device 1104 is inserted into the AF
ring. A portion of the nucleus pulposus may be removed to allow
room for the intradiscal device. The AF is not cut. The bone
fragment may also remain attached to the AF.
[0081] FIG. 11C is a coronal cross section of the spine drawn in
FIG. 11B, after the insertion of an intradiscal device. FIG. 11D is
a view of the lateral surface of the spine drawn in FIG. 11A. In
this case the AF has not been cut.
[0082] FIG. 12A is a drawing that shows an alternative approach
according to the invention, wherein a plug 1202 is removed from one
of the vertebral bodies using a hole saw, for example, to gain
access to the intradiscal space 1206 without having to cut the
annulus. After some form of natural or synthetic disc augmentation
or replacement material 1204 is inserted into the disc space, the
plug 1202 or autograft/allograft may be inserted and optionally
secured with a plate 1220 and screws. FIG. 12B shows the use of a
plate and screws following the procedure of FIG. 12A. Note that
this `trans-vertebral` route could be located relative to the
pedicle of a vertebra. The hole could pass through the pedicle,
through a portion of the pedicle, through the base of the pedicle,
or near the pedicle.
[0083] FIG. 13A is a lateral view of a device that may used to fill
the hole drilled into the vertebra. The device 1302 is inserted
after insertion of the intradiscal device. The device is threaded
at 1304. The ends 1306, 1308 of the device are preferably tapered
to match the plane of the vertebral endplate and the plane of the
periphery of the vertebra. The threads do not extend to the tip of
the device, allowing the device to be pushed or impacted into
position before the device is screwed into the vertebra. The
threads of the device are preferably self-tapping. The device is
preferably made of a material that allows bone in-growth. For
example, the device may be made of bone, titanium, or tantalum.
Alternatively, the device may be made of other materials such as
ceramic, chrome cobalt, stainless steel, plastic, or other
material. The outer surface of the device may be treated with a
material that promotes bone in-growth. For example, the device may
be plasma sprayed with titanium, covered with small beads, covered
with hydroxy appetite, or other material. One end of the device may
configured to except the tip of a screwdriver. The portion of the
device that contacts the intradiscal device may be flat, spherical
or other appropriate shape.
[0084] FIG. 13B is a view of the end of the device 1302. FIG. 13C
is a coronal cross section of the spine and an anterior view of the
invention drawn in FIG. 13A. The area of the drawing with vertical
lines represents an intradiscal device such as a nucleus
replacement.
[0085] FIG. 13D is an anterior view of an alternative embodiment of
the invention which has holes 1310, 1312 that extend to chambers
within the device. The chambers in the device may be filled with a
material that promotes the growth of bone into the device. For
example, the device may be filled with bone, including bone removed
while drilling a hole in the vertebra. Alternatively, the holes
within the device could allow fluids to pass into and/or out of the
disc. My patent U.S. Pat. No. 6,685,696, the entire content of
which is incorporated herein by reference, teaches hollow devices
that pass through the vertebral endplates and into the vertebral
body. The method and devices taught in this application teach
insertion of a hollow device obliquely through the vertebral body
and into the disc space. The hollow chambers may or may not be
filled with bone.
[0086] FIG. 13E is a cross section of the embodiment of the
invention drawn in FIG. 13D. In an alternative embodiment the
lateral end of the device may be closed to help prevent tissue from
growing into the device. Tissue within the device could impede the
flow of fluids into and out of the device.
[0087] FIG. 14A is an anterior view of an alternative embodiment of
the invention wherein the tip of the device (1402) rotates relative
to the body of the device. The tip of the device is free to rotate
to match the alignment of the vertebral endplates. FIG. 14B is an
anterior view of the embodiment of the invention drawn in FIG. 14A.
A C-ring 1410 has been passed through a hole in the body of the
device. The C-ring clips over the shaft of the rotating member. The
shaft of the rotating member passes through a hole in the body of
the device. The C-ring connects the two components.
[0088] FIG. 15A is an anterior view of a vertebra and an alignment
guide 1504. The alignment guide is placed against the surface of a
vertebra 1506. A guide wire 1508 has been passed through the guide
and into the vertebra. A cannulated drill bit may be placed over
the guide wire to create the hole in the vertebra. FIG. 15B is an
anterior view of a vertebra and an alternative embodiment of the
invention wherein the guide has components that fit against the
vertebral endplates.
[0089] FIG. 16A is a coronal cross section of the spine and an
alternative embodiment of the invention. The disc is depicted with
the area of the drawing having vertical lines. A small device 1602
has been inserted into a hole drilled into the vertebra. The device
seals one end of the hole. The device may be threaded or press fit
into the position shown in the Figure. The device is placed into
the hole after placing the intradiscal device into the disc
space.
[0090] FIG. 16B is a coronal cross section of the spine and the
embodiment of the invention drawn in FIG. 16A, and wherein
polymethylmethacrylate (PMMA, 1606) has been injected into the hole
in the vertebra. The PMMA and the device hold the intradiscal
device in the disc space. Other in-situ curing or expanding
materials may be used to replace the device or the PMMA.
[0091] FIG. 17 is an axial cross section of a disc. My co-pending
U.S. patent application Ser. No. 10/412,434, incorporated herein by
reference, teaches osteotomy of the lateral portion of the
vertebra. The technique may be used on any portion of the vertebra.
For example, as illustrated in this figure, the vertebra could be
osteotomized at the posterior-lateral portion of the vertebra
(1702).
[0092] FIG. 18A is an anterior view of a distraction device. The
two end components 1802, 1804 may be forced apart. A clip 1806 is
used to hold the components in an extended position. The clip
cooperates with the teeth 1808 of the superior component. FIG. 18B
is an anterior view of the embodiment of the invention drawn in
FIG. 18A and the cross section of the pedicles of two vertebrae.
The saddle-shaped end components 1802, 1804 straddle the
pedicles.
* * * * *