U.S. patent application number 13/277629 was filed with the patent office on 2012-04-12 for device and method for correcting a spinal deformity.
This patent application is currently assigned to K Spine, Inc.. Invention is credited to Allen L. CARL, Dan SACHS.
Application Number | 20120089186 13/277629 |
Document ID | / |
Family ID | 35801011 |
Filed Date | 2012-04-12 |
United States Patent
Application |
20120089186 |
Kind Code |
A1 |
CARL; Allen L. ; et
al. |
April 12, 2012 |
DEVICE AND METHOD FOR CORRECTING A SPINAL DEFORMITY
Abstract
A method for correcting a spinal deformity is provided. A spinal
implant for correcting a spinal deformity includes a multipoint
connector that connects to at least one vertebra of a spine at a
plurality of locations and a force directing device that applies a
force to the vertebra through the multipoint connector. The force
directing device may include a rod which extends generally along an
axis of the spine and a force directing member which is adjustably
coupled to both the rod and the multipoint connector and which
applies a corrective force to the at least one vertebra.
Inventors: |
CARL; Allen L.;
(Slingerlands, NY) ; SACHS; Dan; (Minneapolis,
MN) |
Assignee: |
K Spine, Inc.
Minnetonka
MN
|
Family ID: |
35801011 |
Appl. No.: |
13/277629 |
Filed: |
October 20, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12645305 |
Dec 22, 2009 |
8043345 |
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13277629 |
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11196952 |
Aug 3, 2005 |
7658753 |
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12645305 |
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60598882 |
Aug 3, 2004 |
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Current U.S.
Class: |
606/249 ;
606/256; 606/257; 606/258; 606/278; 606/279 |
Current CPC
Class: |
A61B 17/7067 20130101;
A61B 17/707 20130101; A61B 2090/064 20160201; A61B 17/7064
20130101; A61B 2017/0256 20130101; A61B 17/7053 20130101; B33Y
80/00 20141201; A61B 2017/564 20130101; A61B 2017/681 20130101;
A61B 17/7004 20130101 |
Class at
Publication: |
606/249 ;
606/279; 606/278; 606/258; 606/257; 606/256 |
International
Class: |
A61B 17/70 20060101
A61B017/70; A61B 17/88 20060101 A61B017/88 |
Claims
1. A method for implanting a spine device so as to stabilize
vertebrae of a spine, the method comprising: fixing a pedicle
attachment device to a pedicle of a first vertebra; providing an
elongate member comprising a first portion and a second portion;
coupling the first portion of the elongate member to the pedicle
attachment device; and coupling the second portion of the elongate
member to a location on a spinous process of a second vertebra,
wherein the elongate member extends at an oblique angle with
respect to a median plane of the spine.
2. The method of claim 1, wherein the first vertebra is immediately
adjacent to the second vertebra.
3. The method of claim 1, wherein coupling the second portion of
the elongate member to a location on a spinous process of a second
vertebra comprises fixing the second portion to the location on the
spinous process.
4. The method of claim 1, wherein coupling the second portion of
the elongate member to a location on a spinous process of a second
vertebra comprises attaching the second portion of the elongate
member to the base of the spinous process.
5. The method of claim 1, wherein coupling the second portion of
the elongate member to a location on a spinous process of a second
vertebra comprises positioning the second portion of the elongate
member through the spinous process.
6. The method of claim 5, further comprising forming an aperture in
the spinous process.
7. The method of claim 1, further comprising reinforcing the
spinous process.
8. The method of claim 1, wherein the elongate member comprises a
rod with an adjustable length.
9. The method of claim 1, wherein the elongate member comprises a
stabilizer with limited motion.
10. The method of claim 1, wherein the elongate member comprises a
stabilizer with shock absorbing properties.
11. The method of claim 1, further comprising minimally invasively
accessing the spinous process and minimally invasively inserting
the elongate member.
12. A spinal implant system comprising: a pedicle attachment device
configured to be attached to a pedicle of a first vertebra, the
pedicle attachment device comprising a connector portion; an
elongate member having a first portion and a second portion, the
first portion being adapted to couple to the connector portion of
the pedicle attachment device, the second portion being adapted to
extend at an oblique angle with respect to a median plane of the
spine and to couple to a location on a spinous process of a second
vertebra.
13. The spinal implant system of claim 12, wherein the elongate
member has an adjustable length.
14. The spine implant system of claim 12, wherein the elongate
member comprises a dynamic element configured to permit limited
movement between the first vertebra and the second vertebra.
15. The spinal implant system of 12, wherein the elongate member
includes a shock absorber.
16. The spinal implant system of 12, wherein the elongate member
comprises a force exertion device configured to exert a force
between the pedicle of the first vertebra and the spinous process
of the second vertebra.
17. The spine implant system of claim 16, wherein the force
exertion device is configured to exert at least one of a
distracting force, a compressive force, and a derotating force
between the first vertebra and the second vertebra.
18. The spinal implant system of 12, further comprising a spinous
process reinforcement member configured to provide structural
reinforcement to the spinous process of the second vertebra.
19. The spinal implant system of 18, wherein the spinous process
reinforcement member is configured to distribute a force applied by
the elongate member onto the spinous process of the second
vertebra.
20. The spinal implant system of claim 12, wherein the connector
portion includes an aperture adapted to receive the first portion
of the elongate member.
21. The spinal implant system of claim 12, wherein the connector
portion of the pedicle attachment device is an articulating
connector.
22. The spinal implant system of claim 12, wherein the pedicle
attachment device has an adjustable length.
23. The spinal implant system of claim 12, wherein the pedicle
attachment device comprises a first articulating portion and
wherein the first portion of the elongate member comprises a second
articulating portion, wherein the first articulating portion
articulates with respect to the second articulating portion.
24. The spinal implant system of claim 23, wherein the first and
second articulating portions comprise a ball and socket.
25. The spinal implant system of claim 23, wherein at least one of
the first articulating portion and second articulating portion is
configured to slide with respect to the other of the first
articulating portion and second articulating portion.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of application
Ser. No. 12/645,305, filed Dec. 22, 2009 and entitled "Device and
Method for Correcting a Spinal Deformity," which is a divisional of
application Ser. No. 11/196,952, filed Aug. 3, 2005 and entitled
"Device and Method for Correcting a Spinal Deformity," now issued
as U.S. Pat. No. 7,658,753, which claims the benefit of U.S.
Provisional Application No. 60/598,882, filed Aug. 3, 2004 and
entitled "Spine Treatment Devices and Methods," the disclosure of
each of which is hereby incorporated by reference in its
entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to devices to treat the spine,
including but not limited to spinal stabilization devices, dynamic
stabilizers, spinal deformity correction devices, devices to treat
pain associated with the spine, and other spinal treatment
devices.
[0004] 2. Description of the Related Art
[0005] Certain spine conditions, defects, deformities (e.g.,
scoliosis) as well as injuries may lead to structural
instabilities, nerve or spinal cord damage, pain or other
manifestations. Back pain (e.g., pain associated with the spinal
column or mechanical back pain) may be caused by structural
defects, by injuries or over the course of time from the aging
process. For example, back pain is frequently caused by repetitive
and/or high stress loads on or increased motion around certain
boney or soft tissue structures. The natural course of aging leads
to degeneration of the disc, loss of disc height, and instability
of the spine among other structural manifestations at or around the
spine. With disc degeneration, the posterior elements of the spine
bear increased loads with disc height loss, and subsequently
attempt to compensate with the formation of osteophytes and
thickening of various stabilizing spinal ligaments. The facet
joints may develop pain due to arthritic changes caused by
increased loads. Furthermore, osteophytes in the neural foramina
and thickening of spinal ligaments can lead to spinal stenosis, or
impingement of nerve roots in the spinal canal or neural foramina.
Scoliosis may also create disproportionate loading on various
elements of the spine and may require correction, stabilization or
fusion.
[0006] Pain caused by abnormal motion of the spine has long been
treated by fixation of the motion segment. Spinal fusion is one way
of stabilizing the spine to reduce pain. In general, it is believed
that anterior interbody or posterior fusion prevents movement
between one or more joints where pain is occurring from irritating
motion. Fusion typically involves removal of the native disc,
packing bone graft material into the resulting intervertebral
space, and anterior stabilization, e.g., with intervertebral fusion
cages or posterior stabilization, e.g., supporting the spinal
column with internal fixation devices such as rods and screws.
Internal fixation is typically an adjunct to attain intervertebral
fusion. Many types of spine implants are available for performing
spinal fixation, including the Harrington hook and rod, pedicle
screws and rods, interbody fusion cages, and sublaminar wires.
[0007] Spinal stenosis pain or from impingement of nerve roots in
the neural foramina has been treated by laminectomy and
foraminotomy, and sometimes reinforced with rod and screw fixation
of the posterior spine. More recently, surgeons have attempted to
relieve spinal stenosis by distracting adjacent spinous processes
with a wedge implant. Pain due to instability of the spine has also
been treated with dynamic stabilization of the posterior spine,
using elastic bands that connect pedicles of adjacent
vertebrae.
[0008] The typical techniques for fusion, distraction,
decompression, and dynamic stabilization require open surgical
procedures with removal of stabilizing muscles from the spinal
column, leading to pain, blood loss, and prolonged recovery periods
after surgery due in part to the disruption of associated body
structures or tissue during the procedures.
[0009] To reduce the invasiveness of fusion procedures, some
methods of fusion have been proposed that do not require the
extensive stripping of muscles away from the spinal column of
earlier approaches. These involve posteriorly or laterally
accessing the spine and creating spaces adjacent the spine for
posterior stabilization. Some of these procedures include fusion
via small working channels, created with dilator type devices or an
external guide to create a trajectory channel between two
ipsilateral neighboring pedicle screws. Also, placing support
structures between adjacent pedicle screws and across a joint
requires accessing and working in an area from a difficult angle
(the support structure is typically oriented somewhat perpendicular
to an angle of access and through muscle and connective tissue).
Furthermore, these stabilization devices typically involve the use
of 4 pedicle screws (each having a risk associated with it when
placed in the spine), two on each side of a motion segment, and are
not ideally suited for percutaneous stabilization required across
more than one or two segments. Accordingly, it would be desirable
to provide a less invasive or less disruptive segmental spine
stabilization procedure and implant that has a reduced risk of
damage or injury to associated tissue. It would also be desirable
to provide an implanted posterior spine system that may be used to
stabilize more than two motion segments in a less disruptive or
less invasive manner.
[0010] One method of fusing a vertebra has been proposed using
bilateral screws through the lamina using a posterior approach.
However, geometric placement of the device is difficult and the
procedure is considered dangerous because the laminar screws could
enter through anteriorly into the spinal canal and cause nerve
damage.
[0011] Accordingly, it would be desirable to provide a device that
reduces the difficulties risks of the current procedures. It would
also be desirable to provide a device that can be placed in a less
disruptive or less invasive manner than commonly used
procedures.
[0012] Unintended consequences of fixation include stress shielding
of bone, as well as transfer of load to adjacent, still dynamic
motion segments, and eventual degeneration of adjacent motion
segments. Flexible stabilization of motion segments with plastic,
rubber, super-elastic metals, fabric, and other elastic materials
has been proposed to provide a degree of dynamic stabilization of
some joints. Many of these constructs are not load bearing. Dynamic
stabilization from pedicle screw to pedicle screw along the length
of the spine has been proposed. However, this device has the
disadvantage of requiring placement of 4 pedicle screws and
associated tissue disruption.
[0013] Due to the risks, inconvenience, and recovery time required
for surgical implantation of spinal devices, some patients may
continue to prefer rigid fixation of a painful or degenerative
motion segment over dynamic stabilization of the joint. In
addition, doctors may be reluctant to recommend dynamic
stabilization for patients with back pain, because it may not
alleviate pain to a patient's satisfaction.
[0014] Furthermore, even in patients who experience good relief of
pain with dynamic stabilizers, it is anticipated that while the
onset of arthritic changes may be deferred, many patients will
still eventually proceed to develop degeneration, and require
fixation of the motion segment to obtain pain relief. Repeat spine
procedures to remove one implant and replace it with another are
associated with complications related to bleeding, surgical
adhesions, destruction of bone, and other generic risks associated
with surgical procedures. Accordingly, improved devices that
address these issues would be desirable.
[0015] A number of spinal deformities exist where the spine is
abnormally twisted and or curved. Scoliosis is typically considered
an abnormal lateral curvature of the vertebral column.
[0016] Correction of scoliosis has been attempted a number of ways.
Typically correction is followed by fusion. A Harrington rod has
been used where a compressing or distracting rod is attached above
and below a curved arch of the deformity. The spine is stretched
longitudinally to straighten the spine as the rod is lengthened.
The spine is then fused. The correction force in this device and in
similar devices is a distraction force that may have several
drawbacks including possible spinal cord damage, as well as the
high loading on the upper and lower attachment sites. Nowadays,
segmental hook and screw fixation exists for distraction and
derotation corrective forces.
[0017] A Luque device has been used where the spine is wired to a
rod at multiple fixation points along the rod and pulls the spine
to the rod. The spine is pulled to the rod with a wire and the
spine is then fused. This does not provide significant adjustment
over time and requires fusion. Once completed this does not provide
an opportunity for delayed adjustment over time. Anterior
procedures also exist in the form of fusion and newer technology
involving staples across the disc space that obviate the need for
fusion but still correct the deformity. The corrective force is
derotation with or without compression.
[0018] Accordingly it would be desirable to provide an improved
corrective device for treating scoliosis or other deformities. It
would also be desirable to provide a device that may be used
without fusion.
[0019] Spine surgeons commonly use metallic or polymeric implants
to effect or augment the biomechanics of the spine. The implants
frequently are attached or anchored to bone of the spine. Sites
typically considered appropriate for boney attachment have high
density or surface area, such as, for example, the pedicle bone,
the vertebral body or the cortical bone of the lamina. The spinous
process contains thin walls of cortical bone, and thus, has been
considered as not ideal for anchoring spinal implants as they may
not support the implants under physiologic loads, or the
intermittent high loads seen in traumatic situations. Fixation has
been attempted from spinous process to spinous process with poor
results.
[0020] A translaminar facet screw as used by some surgeons goes
through the base of spinous process to access the cancellous bone
of the lamina. A disadvantage of this device is that it is not
suitable for attaching to a pedicle screw and the depth and angle
during deployment can be very difficult to track or visualize, thus
increasing the possibility that the screw would extend into the
spinal canal. A facet screw is screwed between opposing facets of a
zygapophyseal joint.
SUMMARY OF THE INVENTION
[0021] One aspect of the present invention is directed to providing
a device and method for alleviating discomfort and or deformity
associated with the spinal column. Another aspect of the present
invention is directed to providing a minimally invasive implant and
method for alleviating discomfort associated with the spinal
column. Another aspect of the present invention provides an
anchoring device and method that requires less surrounding tissue
damage or disruption. Another aspect of the present invention
provides reinforcement of the spinous process for use in various
spinal systems. Another aspect of the invention provides a
minimally invasive, non-invasive, or remote adjustment or
lengthening of an orthopedic device. Another aspect of the
invention provides a minimally invasive, non-invasive, or remote
adjustment, lengthening or shortening of a stabilization device.
Another aspect of the present invention also provides an implant
system and device suitable for minimally invasive, minimally
disruptive and/or percutaneous posterior deployment across a
plurality of motion segments and more than two motion segments.
Different aspects of the invention may provide distraction forces
to relieve pressure on certain structures, compression forces to
fix or stabilize motion across structures, shock absorbing
qualities to help relieve load from certain structures, and
therapeutic activity to reduce inflammation and pain. Other aspects
of the invention may supplement or bear load for degenerated,
painful, or surgically removed joints, e.g., the facet joint.
Another aspect of the invention may provide a method and system for
treating deformities such as scoliosis. Other aspects of the
invention may include sensors associated with implants or implanted
at or near the bones, soft tissue, or joints of the spine and may
provide feedback regarding the joint on an ongoing basis. The
sensors may also be part of a feedback system that alters a
property of an implant in response to sensing information. Another
aspect of the invention may provide a device or method for
delivering therapeutic substances at or near the spine.
[0022] In accordance with one aspect of the invention, a
reinforcement structure is provided for supporting the spinous
process and if desired, in addition, the lamina of a spine. The
invention further provides a method and system for forming or
implanting such structure in the spinous process or a region of
cancellous bone in the lamina of a spine. The reinforcement system
may include one or more systems of reinforcement and may be used
before, during and/or after a spinal device (e.g. a stabilization,
distraction or prosthetic device, etc.) is coupled to the spinous
process.
[0023] Various aspects of the invention are set forth in the
description and/or claims herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1A is a lateral posterior view of a vertebra with a
reinforcement structure in accordance with the invention.
[0025] FIG. 1B is a side view of the vertebra and reinforcement
structure of FIG. 1A.
[0026] FIG. 2A is a lateral posterior view of a vertebra with a
reinforcement structure in accordance with the invention.
[0027] FIG. 2B is a side view of the vertebra and reinforcement
structure of FIG. 2B.
[0028] FIG. 3A is a lateral posterior view of a vertebra with a
reinforcement structure in accordance with the invention.
[0029] FIG. 3B is a side view of the vertebra and reinforcement
structure of FIG. 3A.
[0030] FIG. 4A is a lateral posterior view of vertebrae with a
reinforcement structure and implant in accordance with the
invention.
[0031] FIG. 4B is a side view of the reinforcement structure and
implant of FIG. 4A.
[0032] FIG. 4C is a top view of a reinforcement structure and
implant in accordance with the invention.
[0033] FIG. 4D is a posterior view of the reinforcement structure
and implant of FIG. 4C.
[0034] FIG. 5 is a posterior view of a reinforcement structure and
implant in accordance with the invention.
[0035] FIG. 6 is a posterior view of a reinforcement structure and
implant in accordance with the invention
[0036] FIG. 7A is a top view of an implant implanted adjacent a
motion segment in accordance with the invention.
[0037] FIG. 7B is a posterior view of the implant as shown in FIG.
7A.
[0038] FIG. 8A is a top view of an implant implanted through the
lamina and the zygapophyseal joint in accordance with the
invention.
[0039] FIG. 8B is a posterior view of the implant as shown in FIG.
8A.
[0040] FIG. 9A is a top view of a dynamic implant in accordance
with the invention.
[0041] FIG. 9B is a posterior view of the implant as shown in FIG.
9A.
[0042] FIG. 10 is a schematic posterior portal cross sectional view
of a reinforcement device and implant in accordance with the
invention.
[0043] FIG. 11 is schematic posterior partial cross sectional view
of a reinforcement device and implant in accordance with the
invention.
[0044] FIG. 12A is an exploded perspective view of a reinforcement
device and implant in accordance with the invention.
[0045] FIG. 12B is a top view of the reinforcement device and
implant of FIG. 12A.
[0046] FIG. 13A is a schematic partial cross sectional view of an
implant in accordance with the invention in a first position.
[0047] FIG. 13B is a schematic partial cross sectional view of the
implant of FIG. 13A in a second, and implanted position.
[0048] FIG. 14A is a schematic partial cross sectional view of an
implant in accordance with the invention in a first position.
[0049] FIG. 14B is a schematic partial cross sectional view of the
implant of FIG. 14A in a second position.
[0050] FIG. 15 is a schematic side view of a connector of an
implant in accordance with the invention.
[0051] FIG. 16 is a schematic side view of a connector of an
implant in accordance with the invention.
[0052] FIG. 17 is a schematic perspective view of a connector in
accordance with the invention.
[0053] FIG. 18 is a schematic side perspective view of a dynamic
element in accordance with the invention.
[0054] FIG. 19 is a schematic side perspective view of an
adjustable implant element in accordance with the invention.
[0055] FIG. 20 is a schematic side perspective view of an
adjustable implant element in accordance with the invention.
[0056] FIG. 21 is a schematic side perspective view of an
adjustable implant element in accordance with the invention.
[0057] FIG. 22A is a schematic view of a spine deformity correction
device in accordance with the invention.
[0058] FIG. 22B is a cross section of FIG. 22A along the lines
22B-22B.
[0059] FIG. 22C is a schematic view of an adjustable pedicle
attachment device in a first position in accordance with the
invention.
[0060] FIG. 22D is a schematic view of the adjustable pedicle
attachment device of FIG. 22C in accordance with the invention.
[0061] FIG. 22E is a schematic side partial cross sectional view of
an alternative connector of the spine deformity device of FIG.
22A.
[0062] FIG. 22F is a schematic side partial cross-sectional view of
an alternative connector of the spine deformity device of FIG.
22A.
[0063] FIG. 22G is a schematic side partial cross sectional view of
an alternative connector of the spine deformity device of FIG.
22A.
[0064] FIG. 22H is a schematic side partial cross sectional view of
an alternative connector of the spine deformity device of FIG.
22A.
[0065] FIG. 23A is a schematic side view of a spine deformity
correction device in accordance with the invention.
[0066] FIG. 23B is a posterior view.
[0067] FIG. 24 is a schematic top view of an implant in accordance
with the invention.
[0068] FIG. 25 is a schematic posterior lateral perspective view of
a therapeutic substance delivery device in accordance with the
invention.
[0069] FIG. 26 is a schematic posterior lateral perspective view of
a therapeutic substance delivery device in accordance with the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0070] FIGS. 1A and 1B illustrate a reinforced posterior arch 100
of a first vertebra 91 of a spine 90, including a spinous process
101 and lamina 103. The first vertebra 100 of the spine 90 as
illustrated includes a first spinous process 101 with a superior
portion 102 having a posterior ridge 104 into which a hole 105 is
drilled. The hole 105 may be drilled with a drill, a trocar, a
large bore IV needle or similar sharp object through the external
and relatively hard cortical bone, to reach the internal cancellous
bone within the spinous process 101 and adjacent the lamina
103.
[0071] Once the cancellous bone is accessed, optionally, a tool
such as a balloon tamp, or other expandable member or small
crushing or drilling member is used to create a cavity 107 or
cavities within the cancellous bone by compressing, crushing or
drilling out the bone material. X-rays may be used to determine how
far to drill into the bone. The cavity 107 may be in the spinous
process, through to the base of the spinous process, or through the
spinous process and into the lamina. In one embodiment the cavity
is cone shaped or widens as it moves anteriorly towards the
lamina.
[0072] A reinforcing material is then delivered into the cancellous
bone or cavity 107 of the spinous process 101 and/or within the
lamina 103. The material is selected to provide reinforcing
properties to the spinous process 101 and/or lamina 103 sufficient
to support (whether alone or in combination with other support
elements) a spine support structure, a prosthesis, or other device
attached to the spinous process and or supported lamina. The
material may be a bone cement or polymer with strength and hardness
properties selected to provide sufficient reinforcement to the
region so that the spinous process may be used at least in part, to
support an implant structure for attaching to and manipulating the
biomechanics of the spine. Examples include but are not limited to
polymers such as acrylic cement developed for use in vertebroplasty
procedures. The material may be a flowable polymer material that
cures within the cavity. Suitable materials may be readily selected
by one of ordinary skill in the art.
[0073] Reinforcement structures may be placed within the cavity
prior to, during or after injection of flowable material for
further strength properties. As illustrated, an additional support
structure 106 is provided within the cavity. The support structure
106 may be inserted through a cannula and released to expand as a
spring-like or self-expanding member, into the cavity. The support
structure 106 provides further support of the spinous process
and/or lamina. Alternatively, or additionally, one or more posts or
struts may be provided within the cavity or extending out of the
spinous process or lamina from the area of cancellous bone, to
supplement the support of the spinous process or lamina in
combination with the polymer or other curable material. The
reinforcement structures may be formed of a number of different
materials such as, e.g., a metal or biocompatible polymer. Such
reinforcement structures may also be used in other bony areas of
the spine including the vertebra, the pedicles, facets, the
transverse process, etc.
[0074] As shown in FIGS. 2A and 2B, an inferior portion 109 of a
spinous process 108 may also be reinforced. Similarly a hole 110 is
drilled in the inferior portion of the spinous process 108 and a
cavity 111 is formed. The cavity 111 is similarly filled with a
curable polymer and is reinforced by reinforcing elements 112
positioned within the cavity.
[0075] The reinforcement structure may be used in a number of
applications including increasing the strength of healthy bone to
support the load and fixation of orthopedic implants, as well as
increasing the strength of bone weakened by osteoporosis, chronic
steroid use, avascular necrosis, weakened by injury and cancer
involving the bone. According to one aspect, the reinforcement
structure comprises a material that provides sufficient strength
including but not limited to suitable polymers, e.g. PEAK,
titanium, steel and carbon fiber.
[0076] The stabilizing and/or distracting devices described herein
may be formed of a material that provides sufficient column
strength including but not limited to suitable polymers, e.g. PEAK,
titanium, steel, and carbon fiber.
[0077] Referring to FIGS. 3A and 3B, an alternative support
structure 120 is illustrated. The support structure 120 allows the
anchoring of implants under physiologic loads on the spinous
process 101 while shielding underlying bone from loads that would
normally cause the bone to fracture. (The implants may
alternatively or in addition be anchored or attached to the lamina
103, e.g., with addition of small screws, barbs or adhesive that
engage with the lamina while avoiding injuring the spinal cord
surrounded by the lamina.) The support structure 120 comprises a
hood like element positioned over the posterior arch 100, i.e., the
spinous process 101 and lamina 103 of a spine 90. The support
structure 120 may be made of a moldable or malleable material (e.g.
putty, formable ceramic, clay-like material, or a moldable polymer
or malleable alloy or metal) that cures into or forms a solid,
strong structure. Heat, light, catalysts, precursors, or local
pressure and force, for example, may be used to make the hood
moldable or firm. The support structure of filling material to
support the spinous process may be constructed or formed of
moldable composites that can cure into hard material such as, e.g.,
ground glass powder or glass fiber fillers mixed into an acrylic
matrix and activated with light or other biophysical modalities.
Other cements or other curable materials may be suitable as well.
The support structure 120 further comprises openings 121 to guide
drill bits and/or for the placement of screws, reinforcement posts,
or other instruments or supplemental support structures. The guide
may insure accurate positioning of the implant. The support
structure 120 may be anchored on the posterior arch by mold bending
or forming the structure about the anatomy. The support structure
120 may be anchored into the lamina or spinous process by anchoring
elements, such as, e.g., screws or barbs. The support structure 120
may also be anchored via screws or posts. Alternatively, the
support structure 120 could be a preformed implant with contours
that fit the anatomy of the posterior arch 100 or that are
malleable or moldable to the anatomy. Also, the support structure
20 may be anchored into the pedicles 122 with screws, into the
underlying bone with barbs, screws, bone anchors, or adhesives,
over the edges of structures with hooks, or may be constructed of a
plurality of pieces that may be assembled into one piece around the
bone. Wings 120a of support structure may be placed over the lamina
to spread the force of any device attached to the support structure
120
[0078] As illustrated in FIGS. 3A and 3B, a sensor 120b is
positioned on the support structure 120. The sensor 120b may be
embedded in the material. The sensor may sense stress on the
support structure 120 from implants secured to it, or may sense
other information that may be desirable to monitor. The sensor may
include a communication element configured to communicate sensed
information to an external device, e.g., when interrogated.
[0079] Referring to FIGS. 4A-4D, a support structure 130 is
illustrated positioned over a posterior portion 132 of a spinous
process 131 with wings 130a over the lamina 103 including small
screws 130b into lamina 103. Wings 130a may help spread the force
from any devices attached or coupled to the support structure 130.
Pedicle screws 135 are anchored into pedicles 136 and are further
anchored into the spinous process 131 through screws 134 positioned
through holes 133 in the support structure 130. As shown in FIG.
4C, the screw 134 includes a sensor 134a that may be used to sense
loads on the device. Use of such sensors is described further
herein. The pedicle screw 135 includes a screw capture device 135a
for receiving a screw or rod of a spinous process screw or other
rod. The capture device 135a may be a polyaxial head of a pedicle
screw it may include a hole, a threaded screw hole with a washer or
cap. Cross bar 135b is positioned across the spine between heads of
pedicle screws 135 to prevent pedical screws from creeping
laterally. A wedge shaped nut 134d between the head 134c of the
screw 134 and the support structure. Another nut 134b may be
positioned between support structure 120 and pedicle screw, and
secure against the support structure 120. These features may be
used in a similar manner in the embodiments described herein.
[0080] FIG. 5 illustrates the spinous process screws 134 coupled to
a spinous process 101 of a first vertebra 91 through a hood or
support structure 130 in a manner similar to that described above
with respect to FIGS. 4A-4D. The screws 134 extend bilaterally
across the posterior of a second vertebra 92 and are anchored to
capture elements 135a of pedicle screws 135 anchored into pedicles
93a of a third vertebra 93.
[0081] FIG. 6 illustrates a device for stabilizing or distracting
the spine with pedicle screws 135 and cross bar 135b positioned as
in FIG. 4D. Hood structure 132 includes openings for receiving
screws 132b coupled to the hood 132 on one end and to the heads
135a of pedicle screws 135 and on the other end. The screws 132b do
not penetrate the spinous process. Obliquely threaded nuts secure
the screws 132b against the hood 132.
[0082] The reinforcement or supporting devices described herein may
be used in conjunction with a number of different spine devices,
including, for example, the various distraction, fusing or dynamic
stabilizing devices described herein. The hoods or reinforcement
devices herein may also be customized, for example by using
stereolithography. The hoods or reinforcement devices may be used
for example with a brace. The pedicle screw may be telescoping as
described with respect to FIGS. 22C and 22D.
[0083] The devices described herein may be coupled to the spinous
process using minimally invasive techniques. These techniques may
include percutaneously accessing the spinous process and/or using
dilators to access the spinous process at an oblique angle with
respect to median plane m and/or horizontal plane h through the
spine of the patient.
[0084] FIG. 7A is a side view of a joint of the spine with a
fixation device percutaneously implanted to fuse adjacent vertebrae
by fixation of the facet joints. Pedicle screw 146 in the pedicle
143 of the adjacent vertebral members 141, 142. As illustrated in
FIG. 7B, the pedicle screw 146 has a polyaxial screw head 147 for
receiving a spinous process screw 148 having a tapered tip. The
spinous process screw 148 is screwed from the contralateral side of
the spinous process, through the spinous process 140 of vertebral
member 141, adjacent the facet joint 149 between the vertebral
member 141 and vertebral member 142, and then captured or placed
into the head 147 of the pedicle screw 146.
[0085] When implanted, the pedicle screws are positioned in the
pedicles in a generally known manner. The facet joint or facet
joints between the spinal members that are to be fused, are
debrided and grafted. A flank stab wound is made to expose the base
of the spinous process. The spinous process screw is then inserted
and navigated through the wound to the spinous process and/or soft
tissue. Tissue dilators or retractors may be used to facilitate
insertion of the spinous process screw through soft tissue. The
spinous process screw 148 is then placed through the spinous
process 140, and into and captured by the head 147 of the pedicle
screw 146. Compression across and the facet joint 149 may be
provided using a nut placet in the polyaxial head of the pedicle
screw. Alternatively, external compression may be used prior to
placement of the oblique rod of the spinous process screw. A
similar screw may also be placed from the spinous process 140 to
the contralateral pedicle. The spinous process 140 may be
reinforced prior to or after placing the screw 148.
[0086] Referring to FIG. 8A, a similar fusion system as illustrated
with respect to FIGS. 7A and 7B. Pedicle screw 156 is positioned in
the pedicle 153 of the adjacent vertebral members 151, 152. The
pedicle screw 156 has a polyaxial screw head 157 for receiving a
spinous process screw 158 having a tapered tip. The spinous process
screw 158 is screwed from the contralateral side of the spinous
process 150, through the spinous process 150 of vertebral member
151, through the facet joint 159 between the vertebral member 151
and vertebral member 152 and then into the head 157 of the pedicle
screw 156.
[0087] An oblique skin stab wound is made to navigate to the base
of the spinous process 150, which may be exposed under direct
vision. The spinous process screw 158 (or other device) is then
placed through the spinous process 150, across (adjacent or
through) the facet joint 159, and into the head 157 of the pedicle
screw 156 (or otherwise attached to a pedicle attachment device for
attaching devices to the pedicle), immobilizing the facet joint
159. A similar screw may also be placed from the spinous process
150 to the contralateral pedicle. The spinous process may be
reinforced prior to or after placing the screw or other device. The
other devices attached or coupled to the spinous process as
described herein may be similarly deployed.
[0088] The devices described herein may be coupled to the spinous
process using minimally invasive techniques. These techniques may
include percutaneously accessing the spinous process and/or using
dilators to access the spinous process at an oblique angle with
respect to median plane and/or horizontal plane through the spine
of the patient.
[0089] Referring to FIGS. 9A and 9B, a spine is illustrated with a
spinal fusion system in place. A spinous process screw 168 is
placed from the contralateral side of the spinous process 160,
through the spinous process 160 of a first vertebra 161 and across
the facet joint 169 between the first vertebra 161 and an adjacent
second vertebra 162, and into the pedicle 164 of the second
vertebra 162.
[0090] Another feature of the spinous process screw of FIGS. 9A-9B
is that it may be configured to exert flexible, stabilizing,
nonfusion forces to the motion segment. For example, this may be
used in the event that patient suffers from pain due to laxity or
other dysfunction of the spinal structures (e.g. degenerative
spondylolisthesis). In other words, the looseness or other
dysfunction of the joint and surrounding tissue may cause pain. The
present invention provides a device and method for dynamically
stabilizing (or reducing) such a joint while allowing some
flexibility and movement. The device and method provide such
stabilization on an oblique angle with respect to the rotational
axis of the spine, i.e. at an oblique angle with respect to the
median and horizontal planes of the spine. The spinous process and
a pedicle could also be used to anchor a device exerting a
stabilizing or compression or contractile force between the two
anchors on an oblique angle. Devices that may be used to exert such
a contractile force may include, for example, polymeric materials,
super elastic metals, and fabrics. The spinous process screw 168
includes a sensor 165a that may be used to sense motion of the
distraction device. The forces or stresses on the device may be
monitored and used to determine if it is necessary to convert the
device to a fusion type device or to otherwise reduce or alter
motion. The sensor may also be used as a diagnostic device to
measure the amount of joint motion upon insertion of the implant or
over time.
[0091] The system illustrated in FIGS. 9A and 9B may also be used
for the treatment of spondylolysis, to attain stability across the
pars interarticularis.
[0092] The spinous processes 140, 150, 160 may be reinforced in a
manner as described herein. The various rods or screws through the
spinous processes 140, 150, 160 may also be positioned through a
posterior arch reinforcing member as described herein.
[0093] FIG. 10 illustrates a spinous process rod or screw 60 in
accordance with the invention. The spinous process rod or screw 60
comprises an elongate portion 61 configured to extend through the
reinforcement hood 51 (for example, as described in further detail
herein with reference to FIGS. 3A-4D positioned around spinous
process 50 and into an adjacent element such as, e.g. a pedicle
screw. The spinous process rod or screw 60 may include threaded
portions. The distal end 62 of the rod may be threaded or otherwise
configured to engage an adjacent element. The spinous process screw
or rod 60 further comprises a proximal securing element 65 located
on the proximal portion 64 of the spinous process screw or rod 60.
The proximal securing element 65 is configured to engage a first
wall 52 portion of the spinous process 60 or reinforcement hood 51.
("Engage" as used herein means to either directly or indirectly
engage.) As illustrated, the distal securing element 63 comprises
an obliquely threaded nut that is configured to receive screw 61
which is coupled to the hood 51 at an oblique angle with respect to
the wall 53. The oblique threaded nut may be used in other
applications where a screw is oblique with respect to the abject to
which is engaged, coupled or attached. The obliquely threaded nut
may have a predetermined angle at which it directs the screw with
respect to the hood to guide the desired angle or directions of the
screw placement. This may be predetermined base on imaging of a
particular patient's anatomy. A distal securing element 63 is
provided more distal of the proximal securing element 65. The
distal securing element is configured to engage a second wall
portion 53 generally opposite the first wall portion 52 so that the
spinous process element is secured or fixed to the hood and spinous
process. (The term "fix" as used herein means either directly or
indirectly fix to and may include dynamic elements.)
[0094] FIG. 11 illustrates a spinous process rod or screw 80 in
accordance with the invention. The spinous process rod or screw 80
comprises an elongate portion 81 configured to extend through the
reinforcement hood 71 (for example, as described in further detail
herein with reference to FIGS. 3A-4D) positioned around spinous
process 70 and into an adjacent element such as, e.g. a pedicle
screw. The spinous process rod or screw 80 may include threaded
portions. The distal end 82 of the rod may be threaded or otherwise
configured to engage an adjacent element, e.g. with a connecting
member, including but not limited to connecting members described
herein. The spinous process screw or rod 80 further comprises a
proximal securing element 85 located on the proximal portion 84 of
the spinous process screw or rod 80. The proximal securing element
85 is configured to engage a first wall 72 portion of the spinous
process 70 or reinforcement hood 71. ("Engage" as is used herein to
mean either directly or indirectly engage.) A hollow space or
chamber 74 is formed in the reinforcement hood 71 so that the
hollow chamber may engageably receive one or more securing
elements, e.g. first and second securing elements 86, 87 therein.
The securing elements 86, 87 may be positioned on either or both
sides of the spinous process 70 through which the screw or rod 80
is positioned. As illustrated in FIG. 11, securing element 86 is
positioned on the proximal portion 84 of the screw 80 while
securing portion 87 is positioned on the distal portion 82 of the
screw 80. Securing elements 86, 87 may be obliquely threaded nuts,
for example, as described with respect to nut 80b in FIG. 3E.
Securing elements may be attached a variety of ways, for example as
illustrated in FIGS. 12A-12B and 13A-13B. FIGS. 12A-12B illustrate
manual insertion of securing elements in accordance with the
invention. Spinous process screw 80a is placed through both wings
of the hood 71 while passing through holes 1000 as shown. Securing
elements 86a and 87a are inserted into receiving holes 1001 within
the hood 71 and receiving holes 1002 within the spinous process
screw 80a. Securing elements 86a, 87a prevent movement of the
spinous process screw 80a. FIGS. 13A-13B illustrate automatic
deployment of securing elements in accordance with the invention.
The securing elements 86b and 87b could be positioned in recesses
1004 in the spinous process screw 80b and spring loaded with
springs 1003 attached inside of the recesses 1004. An external
sheath 1005 is positioned around the spinous process screw 80b. The
screw 80b is positioned through a spinous process and a hood. The
securing elements are then deployed upon removal of an external
sheath 1005. The securing element 86,86a, or 86b is configured to
engage the first wall portion of the spinous process (or hood) from
within the hood 71. The securing element 87, 87a, or 87b is
configured to engage a second wall portion 73 generally opposite
the first wall portion 72 so that the spinous process element is
secured to the hood and spinous process.
[0095] FIGS. 14A and 14B illustrate a spinous process rod or screw
54 in accordance with the invention. The spinous process rod or
screw 54 comprises an elongate outer tube portion 55 and an inner
rod portion 56. The inner rod portion 56 is configured to move
longitudinally within the tube portion 55 to lengthen or shorten
the spinous process screw or rod 54. The inner wall of the tube
portion 55 may include a threaded inner wall that mates with a
threaded outer wall of the rod 54 so that the rod may be screwed to
advance the rod 56 and thereby lengthen or shorten the spinous
process screw or rod 54. Once the outer rod 55 and screw 56 are
positioned within a spinous process or hood 51 the spinous process
screw or rod 54 may then be lengthened as shown in FIG. 14B to
extend through the reinforcement hood 51. The lengthened spinous
process screw may be used to distract the spinal segment or
segments as well.
[0096] The pedicle attachment devices herein may include a sensor
that may be used to sensor one or more parameters e.g., strain,
pressure, motion, position change, that provides information about
possible screw failure. The sensor may communicate the information
to an external device, e.g. telemetrically, and may be passively
powered by an external device.
[0097] According to another aspect of the invention a rod is
provided that is anchored to with pedicle screws with screw heads
made of or attached to swivel collars, polyaxial heads, or other
movable fasteners to allow for near physiologic levels of motion of
the spinal motion segment. Angular movement may be provided where a
distracting element attaches on either side of a motion segment so
that when distracting or lengthening the device, there is
accommodation in the device for the change of angle that
occurs.
[0098] FIG. 15 illustrates an enlarged portion of a spinal
prosthesis. The prosthesis 280 may provide support of the load on
the spine where a facet has been removed or may provide other
support or distraction. The prosthesis 280 comprises a distraction
bar 281 used to distract a motion segment of the spine in a number
of manners including the distraction devices described herein. A
pedicle screw 283 is screwed into a pedicle of the spine or other
anatomical location. The distraction bar 281 includes and
articulating cup 282 having an inner surface 282a. The pedicle
screw 283 has a ball 284 received by and coupled to the cup 282 of
the distraction bar 281. In addition to shock absorbing
capabilities described in various embodiments herein, the
distraction bar 281 also articulates with a portion of the spine to
which the pedicle screw 283 is attached.
[0099] FIG. 16 illustrates a variation of the prosthesis 280
described with respect to FIG. 15. The prosthesis 285 comprises a
distraction bar 286 and an articulating ball 287 configured to
engage and couple with an articulation cup 289 of a pedicle screw
288. The prosthesis 285 operates in a similar manner as prosthesis
280.
[0100] FIG. 17 illustrates a variation of the prostheses 280, 285
described herein respectively with respect to FIGS. 15 and 16. The
prosthesis 290 comprises a distraction bar 291 having an end 292
with a lumen 293 for slidably receiving the end 296 of a pedicle
screw 295. The end 296 of the pedicle screw 295 comprises a ball
portion 297 attached to a neck 298. The ball 297 portion is
configured to slide within the lumen 293 of the distraction bar 291
which contains the ball portion 297. The neck 298 of the pedicle
screw 295 extends out of the distraction bar 291 through a
longitudinal slit 294 that slidably receives the narrower neck
portion 298 of the pedicle screw 295.
[0101] One embodiment of the invention is a rod anchored at each
end across a motion segment that can be "switched" between dynamic
stabilization and rigid fixation in a minimally invasive,
percutaneous, or non-invasive fashion. One way for this to occur is
injection of a flowable material within the lumen of the device,
which would cure, and immobilize the components which allow for
motion. Electrical current, heat, mechanical energy, or other
techniques could also be used to render movable components fixed.
Another method is insertion of a rigid implant axially along the
length of the dynamic implant. This method of rendering a flexible
prosthesis rigid may be applied to the design of other combination
motion/fixation prostheses, including disc, facet hip, knee,
fingers shoulder, elbows, and ankle prostheses, etc.
[0102] FIGS. 18-21 illustrate convertible or adjustable dynamic
stabilization devices for joints. The stiffness or flexibility of
the device may be altered or titrated after implantation to adapt
the stiffness to a particular patient, and/or to adjust the
stiffness over time, for example when laxity of the joint increases
with age. Referring to FIG. 18 illustrates a dynamic stabilization
prosthesis 350. The prosthesis comprises a flexible coil 352
contained in a tube member 351 comprising telescoping tubes. The
prosthesis 350 may be used in a number of manners affixed across a
joint motion segment to dynamically stabilize the joint. The coil
352 may be energy absorbing. The coil 352 may also be configured to
exert a distracting force on the joint when implanted. FIG. 19
illustrates the dynamic stabilization prosthesis 350 of FIG. 18
converted to a rigid or more rigid prosthesis. The prosthesis 350
includes a slit 353 for receiving a rigid wire member 354. In FIG.
19 the rigid wire member 354 is inserted into the slit 353 to form
the prosthesis from a dynamic prosthesis into a rigid prosthesis.
As an alternative to a rigid wire member, a flexible coil of a
selected stiffness may be inserted to change the stiffness of the
dynamic prosthesis. The tube may alternatively comprise a
ferromagnetic material contained therein and an electromagnetic
field is applied that causes the prosthesis to become stiffer. The
field may be varied to provide a variety of gradients in stiffness.
The device may also include a sensor that operates as sensor 170a
described herein. Feedback may be provided and the stiffness of the
prosthesis adjusted accordingly. The stiffness may be varied when
implanted using patient feedback so that the implant is more or
less flexible depending upon an individual patient's needs. In
addition the stiffness may be changed at different times during the
course of the implants lifetime. For example, the stiffness may be
increased when an increased amount of stabilization is
required.
[0103] FIG. 20 illustrates an alternative prosthesis 360 also
comprising a flexible coil 362 contained in a tube member 361. The
tube member is configured to receive a fluid material such as a
curable polymer 364 that cures in the tubular member to create a
rigid prosthesis. As illustrated in FIG. 20 a rigid prosthesis is
formed from a dynamic prosthesis by injecting the polymer material
364 into the tubular member 361. The flexibility/stiffness
properties of the prosthesis may be selected by selecting such
properties of the polymer to be injected.
[0104] As illustrated in FIG. 21 a flexible prosthesis 365 is
illustrated. The flexibility of the prosthesis 365 is adjustable by
injecting a polymer material into one or more of the columnar
cavities 367, 368, 369. The polymer may be injected into each
cavity at a different time so the stiffness of the prosthesis may
be increased gradually over time. The stiffness/flexibility
properties of the polymer injected may also be selected according
to a desired stiffness/flexibility of the implant.
[0105] According to an embodiment of the invention, the dynamic
stabilizer may comprise a shock absorber that has both energy
absorbing and energy dissipating properties. The tension band
effect of the posterior columns may also offload the pressures
borne by anterior column of the spine. So in addition to helping to
protect the facet joints, other aspects of the invention would help
slow the progression of degenerative disc disease, annular
degradation, disc herniation, and vertebral compression
fractures.
[0106] Another aspect of the invention is to supplement implants or
repair procedures of the anterior column with a posterior shock
absorber device (rod, screw, plate). Examples of these implants or
procedures include total disc replacements, annular repair,
artificial nucleus, and vertebroplasty/kyphoplasty.
[0107] Another aspect of the invention is to supplement implants or
repair procedures of the posterior column with a shock absorber
rod. Examples of these implants or procedures include interspinous
distraction wedges, facet joint replacements, and posterior arch
replacements.
[0108] Another aspect of the invention provides a posterior support
implants with shock absorbing properties, to decrease or remove the
load experienced by the facets. Implant components may include
springs, coils, hydraulic or fluid filled piston chambers, or
elastic materials. Each end of the device could be anchored in such
a fashion so the rod bridges the facet joint, reducing the loads
borne by the joint. This is believed to reduce wear of the facets
and resulting pain and altered spinal biomechanics
[0109] An improved device is provided that utilizes the spinous
process, the pedicle, adjacent ribs and/or a transverse process or
a combination including one or more of these anatomical structures,
to correct or stabilize a deformed spine. The device may be used to
correct scoliosis using one or more of these anatomical structures
and multiple points at a plurality of spine segments. The
correction may be made incrementally over time and may or may not
include a fusion process.
[0110] In one embodiment, a percutaneously and obliquely placed
rigid or dynamic stabilizer is provided. Stabilizer segments are
anchored to base of spinous process at one end and a pedicle screw
at the other end, as a unilateral temporary stabilizer. The dynamic
stabilizers described herein may be adjusted over time to gradually
bring the spine in alignment. The stabilizer may be used to
derotate (untorque) and correct the spine. A stabilizer placed
across a motion segment, i.e., not at the same vertebral level may
be used to create overgrowth where desired, i.e. on the
non-instrumented side of the motion segment. Such overgrowth may
help stabilization or correction of the spine.
[0111] FIGS. 22A-24 illustrate an explantable, temporary scoliosis
stabilization device. The system is configured to be manipulable
once it is installed. The systems illustrated are configured to
alter the orientation of a vertebral body and in particular to
untorque the spine about the axis of the spinal column as well as
applying a corrective straightening or translation force with
respect to a vertical rod. According to one aspect of the
invention, a device for correcting deformities of the spine is
provided where the device may be adjusted over time to direct the
corrective forces as needed over time. According to another aspect,
a multipoint stabilizing device is coupled to the posterior
portions of the spine.
[0112] The systems illustrated in FIGS. 22A-24 comprise a
multipoint anchoring mechanism that provides for multidimensional
correction of the spinal or spinal segments by positioning the
anchor at a plurality of locations on a spine. As illustrated for
example in FIGS. 22A-22H, the multiple locations include the
spinous process and pedicle of a particular vertebra. A bar is
attached between the spinous process and pedicle. A force directing
device couples the bar to a vertical rod. As illustrated in FIGS.
23A-23B, the multiple locations include the spinous process of one
level and the pedicle of another level (e.g. an adjacent level). As
illustrated in FIG. 24, the multiple locations include the spinous
process, through a transverse process 605 into a costal aspect of a
rib 606. The vertical rod in these figures is attached or coupled
to the spine at neutral and balanced vertebra, typically only at
the most upper and most lower positions.
[0113] The device comprises a telescoping rod (or plate) 536 to
which various segments of the spinal column are to be fixed. The
rod 536 telescopes to adjust the height to accommodate particular
segments or a height of the spine. As illustrated in FIG. 22A a
portion 500 of the spine comprises a plurality of adjacent segments
501, 502, 503, 504, 505, (additional adjacent segments may also be
corrected). The portion 500 of the spine exhibits a concave
curvature between segments 501 and 505. Pedicle screws 506, 507,
508, 509, 510 are attached to pedicles of segments 501, 502, 503,
504, 505, respectively. Dynamic stabilizers 516, 517, 518, 519, 520
are attached to pedicle screws 506, 507, 508, 509, 510 and to
spinous processes 521, 522, 523, 524, 525 respectively of segments
501, 502, 503, 504, 505. Wires 526, 527, 528, 529, 530 attached to
the rod 536 via hooks 531, 532, 533, 534, 535 attached to the rod
536. The wires 526, 527, 528, 529, 530 are used to tension the
portion of the spine 500 to pull on the concavity. If the portion
has a convexity, rods may be used in place of wires to push on the
convexity to straighten the spine.
[0114] FIG. 22B is a cross section of FIG. 22A along the lines
22B-22B. The pedicle screw 508 includes a screw capture device 508a
for receiving a screw head or rod of a dynamic stabilizer, in this
case, a spinous process screw 518. The capture device may be a
hole, a threaded screw hole with a washer or cap. The pedicle screw
508 may be configured to telescope outwards or inwards to be
positioned to receive the screw head or rod of a dynamic stabilizer
518 as shown in FIGS. 22C and 22D. The spinous process screw 518 is
shown in 22C where, given the trajectory of the spinous process
screw 518, its end does not intercept the capture device 508a of
the pedicle screw 508. As shown in FIG. 22D the pedicle screw's
trunk 508b is lengthened with a telescoping or other similar
lengthening mechanism so that the end of the spinous process screw
518 may be positioned in the capture device 508a.
[0115] The spinous process screw 518 is anchored through the
reinforced spinous process 523 (having a reinforcement hood 523a or
is otherwise reinforced as described herein. Note that the
reinforcement hood may have a single lamina wing where a single
screw is attached as opposed to bilateral screws.) with a head
portion 518a engaging the pedicle screw 508 and a rod portion 518b
extending through a reinforced spinous process 523. The dynamic
stabilizer 518 includes a loop connector end 518c for receiving a
hook 518d of a wire (or a telescoping rod) 528 that is attached to
the rod 536 with a ratcheted connector 533. The wire may also be a
rod, spring, elastic band or other force-directing device. The loop
connector end 518c may also be a poly axial connector that allows
translation in a variety of directions or places, i.e., so that an
oblique angle rod can be captured (for example, similar to pedicle
screw 508 and capture device 508a). The wire 528 may be adjusted or
tightened at various times with the ratcheted connector 533, e.g.,
during a period of time where the spine is being corrected. As the
spine is straightened, excess wire may be trimmed off. This
procedure may be done percutaneously, e.g. by accessing wire near
the skin. Each dynamic stabilizer is similarly constructed.
[0116] FIGS. 22E-22H illustrate various dynamic stabilizers that
may be used to correct spinal deformity. Dynamic stabilizers 518e,
518i, and 518m are coupled by coupling mechanisms 541a-c to the
telescoping rod 536. The coupling mechanisms 541a-c may be
positioned on or through the plate or telescoping rod 536. Dynamic
stabilizer 518e includes rod 518f that will extend through a
reinforced spinous process and is coupled by a coupling mechanism
518g to rod 518h in an end-to-end fashion. Rod 518h slidably
extends through opening in coupling mechanism 541a attached to the
telescoping rod 536. The rod 518h is adjustable within the coupling
mechanism 541a to lengthen or shorten the distance of the dynamic
stabilizer 518e between the spinous process and the telescoping rod
536. The coupling mechanism 541a is configured to clamp down on the
rod 518h to secure it in place once the distance has been adjusted.
The coupling mechanisms 541a-c may include a screw, cam or clamp
mechanism to clamp or lockably engage rods 518h, l, and p as
described in use herein.
[0117] Similarly, dynamic stabilizer 518i includes rod 518j that
will extend through a reinforced spinous process and is coupled by
a coupling mechanism 518k to rod 518l in an end to side fashion.
Rod 518l slidably extends through opening in coupling mechanism
541b attached to the telescoping rod 536. The rod 518l is
adjustable within the coupling mechanism 541b to lengthen or
shorten the distance of the dynamic stabilizer 518i between the
spinous process and the telescoping rod 536. The coupling mechanism
541b is configured to clamp down on the rod 518l to secure it in
place once the distance has been adjusted.
[0118] Dynamic stabilizer 518m includes a rod 518n that will extend
through a reinforced spinous process and is coupled by a threaded
coupling 518o to rod 518p. The rod 518p is slidably and rotatably
positioned within a cylindrical hole in coupling mechanism 541c
attached to the telescoping rod 536. The rod 518p may be rotated,
i.e., screwed or unscrewed so that the stabilizer lengthens or
shortens at the threaded coupling 518o. The rotation or screwing
may be actuated at or near the skin where the rod 518p is
positioned in the coupling mechanism 541c.
[0119] Dynamic stabilizer 518q includes a rod 518r that will extend
through a reinforced spinous process and is coupled by a multiaxial
coupling 518s similar to a multiaxial screw head type coupling, to
rod 518t. The rod 518t is a telescoping rod and is coupled by
coupling mechanism 541d to the vertical rod 536.
[0120] Each of the dynamic stabilizers may include sensors located
thereon to sense data corresponding to a parameter of the dynamic
stabilization device or the spine. FIG. 22E-22H illustrate sensors
542a-542d located on the dynamic stabilizer. The sensors may
comprise, e.g., a strain, stress, pressure, position or motion
sensor. Such sensors may include a variety of sensors that are
generally know. For example, strain gauges, accelerometers or piezo
electric sensors may be employed to sense parameters that
correspond, e.g., to the position of the spine, a vertebra, a
dynamic stabilizer, as well as the parameters relating to the
forces or mechanical loads that are effecting the device. Each of
the sensors may individually sense information or information
relative to each of the other sensors may be sensed and compared.
The information may be used to set tension on the device, to
identify when repositioning is necessary or to otherwise provide
information as to the status of the device or portions thereof, or
status of the spine that is being treated. The sensors may include
some level or circuitry including, e.g. a telemetry circuit that
transmits information concerning the sensors to an external device.
The sensors may be battery powered or may use passive circuits that
are powered by an external device. The information may be used to
identify when one of the stabilizers no longer has tension
associated with the stabilizer thus identifying when the tension
needs to be modified in the device. Accordingly, each segment may
be moved separately, monitored separately and adjusted separately
form the other segments. Each segment may be moved to a different
degree and in different directions or at different angles with
varying forces.
[0121] FIG. 23A illustrates an alternative configuration of the
correction device according to the invention. A portion 550 of the
spine comprises a plurality of adjacent segments 551, 552, 553,
554, 555, 555a (additional adjacent segments may also be
corrected). The portion 550 of the spine exhibits a concave
curvature between segments 551 and 555a. Pedicle screws 556, 557,
558, 559, 560 are attached to pedicles of segments 551, 552, 553,
554, 555, respectively. Dynamic stabilizers 566, 567, 568, 569, 570
are attached to pedicle screws 556, 557, 558, 559, 560 and through
spinous processes, 572, 573, 574, 575, 576 respectively of adjacent
segments 555a, 551, 552, 553, 554. Thus, the dynamic stabilizers
are positioned across the motion segments between the corresponding
adjacent segments. The dynamic stabilizers 566, 567, 568, 569, 570
attached to the telescoping rod 576 in one or more manners such as,
for example, the dynamic stabilizers 518, 518e, 518i, 518m, 518q as
illustrated in FIGS. 22A-22H, herein. The dynamic stabilizers 566,
567, 568, 569, 570 are used to tension the portion of the spine 500
to pull on the concavity, or if the portion has a convexity, to
push, pull on, or translate the convexity to straighten the spine.
Thus each of the dynamic stabilizers are attached a plurality of
locations on the spine and operate to stabilize adjacent segments
with respect to each other.
[0122] FIG. 23B illustrates a pedicle screw and dynamic stabilizer
in greater detail. The pedicle screw 558 is screwed into pedicle
563 of vertebra 553. The pedicle screw 558 includes a screw hole
558a for receiving a screw head or rod of a dynamic stabilizer 568.
A screw capture device 558b such as a nut or a threaded portion of
the pedicle screw is configured to capture and receive the dynamic
stabilizer screw or head portion 568a. The capture device 558b of
the stabilizer engages the pedicle screw 558 and a rod portion 568b
extends through a reinforced spinous process 574. The dynamic
stabilizer 568 includes a connector end 580 for receiving a wire or
a hook of a telescoping rod that is attached to a telescoping rod
576. The dynamic stabilizer 568 is anchored through the reinforced
spinous process 574 of an adjacent vertebra 552 (FIG. 23A) thus
immobilizing or stabilizing the motion segment between the vertebra
552, 553. This device may also be used in fusion, i.e. to fuse the
motion segments across vertebra of a multipoint connector. The
device may also be used to encourage overgrowth at certain
locations. In particular it may encourage overgrowth on the
non-fused lateral side of a vertebra (opposing the fused lateral
side) stabilized with the multipoint connector between two
vertebrae.
[0123] FIG. 24 illustrates a device for treating a deformity such
as scoliosis. The device includes a dynamic stabilizer 600
comprising a spinous process screw 601 and a pedicle screw 602
including a spinous process screw capture device 603. The spinous
process screw is configured to be positioned through a reinforced
spinous process 604 and through a transverse process 605 into a
costal aspect of a rib 606. The dynamic stabilizer 600 includes a
connector portion 607 configured to be connected to a telescoping
rod as described herein with reference to FIGS. 22A-H and 23A-23B.
Similar to FIGS. 22A-H and 23A-23B, a plurality of segments may be
secured to a telescoping rod with a plurality of dynamic
stabilizers. The pedicle screw in this and all other embodiments
described in this application may include a telescoping portion
that can adjust the length of the screw head from the anchoring
point where the pedicle screw is anchored into the bone. The
pedicle screw 602 also includes a sensor located thereon (or
incorporated therewith). The sensor may comprise, for example, a
motion detector, a position detector, a pressure sensor, a strain
gauge, and ultrasonic transducer/sensor. The sensor may sense a
change in strain on the screw that may be due to loosening or
repositioning of the screw. The sensor may also sense a change in
position of the screw that indicates a change in alignment and
corresponding loosening or repositioning of the screw. The sensor
may also sense a change in pressure due to loosening or
repositioning of the screw. The sensor may also include an
ultrasonic transducer and transmitter that can determine change in
positioning of the screw, e.g. loosening of the screw indicated by
a change in interfaces of materials or characteristic property
change indicating screw loosening or repositioning. The sensor may
include some electronics such as a telemetry circuit that allows it
to communicate with an external device. The sensor may also be
powered by an external device e.g., in a manner generally known in
the art.
[0124] The various embodiments of the invention described herein
may include sensors integrated with or provided on a structural
spinal implant. A number of factors may be detected as described
herein. Additional factors may include, e.g., local inflammation,
pressure, tension, edema, motion, water content, and electrolytes
or other chemicals. The sensors allow a doctor to monitor patients
for response to healing, or may be used by the doctor to guide
serial adjustments to the patient's treatment. For example,
measurements from the sensing means could lead the doctor to change
the length or tension of a distraction rod or stabilization device.
Patients could adjust therapy based on measurements from the
sensing device, or could be alerted to notify their doctor should
certain measurements be of concern. The sensor is configured to be
adjustable to sensed stresses. The sensor may for example, be a
strain gauge, a pressure sensor accelerometer, position sensor,
imaging device, etc. The sensor may be used in the initial
adjustment of the prosthesis or may be monitored over time. The
sensor may sense shear/torsion tension/compression. Sensors may
sense stresses at various motion segments. The sensor may be used
to compare stresses at various motion segments or locations.
Various sensors may be selected from sensors that are known to one
of skill in the art or that are commercially available.
[0125] Anchoring of Therapeutic Devices
[0126] Some patients obtain back pain relief with injections of
steroids and anesthetic agents at the site of pain; however the
relief is temporary requiring that patients return for repeat
injections when their pain recurs.
[0127] One embodiment of the invention comprises an anchor device
with a therapeutic substance or drug delivery device, e.g. a drug
port and/or reservoir, or matrix attached to a vertebra. In one
embodiment, the device is anchored adjacent a site near where pain
is present. The port is configured to deliver steroids or
anesthetic agents via a catheter to a desired location, for
example, the facet joint, neural foramen, vertebral body, annulus,
nucleus, back muscles, back ligaments, bone metastases, intrathecal
space, epidural space, or other targets in, on, or around the
spine. The catheter can direct the drug to the correct location by
positioning the end of the catheter at a target location. The port
is configured to be refilled periodically percutaneously, e.g.
using an imaging device and a percutaneously placed needle that can
inject the refill into the port, e.g. through a biocompatible
polymer or rubber type port access mechanism. The device further
comprises a patient actuation mechanism for patient control of drug
delivery as needed for pain relief, manually or remotely using a
telemetrically triggered delivery from an external telemetry
control device. According one aspect of the invention such a device
is attached to a boney structure of the spine. Other device that
may be attached to the spine may include sensory or therapeutic
devices, including nerve stimulators, bone growth stimulators and
radioactive seeds.
[0128] In addition, a structural implant could be anchored to bone,
to which a sensory or therapeutic device could be attached. The
sensory or therapeutic device could be placed external to the bone,
on the surface of the bone, or internal to the bone.
[0129] FIGS. 25 and 26 illustrate drug delivery devices 370, 380,
respectively, in accordance with the invention. The drug delivery
device 370 includes a reservoir 375 attached by an anchor 371
configured to anchor the reservoir 375 to the bone of the spine. In
particular, in this embodiment, the anchor 371 comprises a pedicle
screw that anchors the device to the pedicle 373 of a vertebra 372.
The reservoir 375 includes a catheter 376 in communication with the
contents of the reservoir 375 and having an end positioned adjacent
or in a zygapophyseal joint 378 where the drug is directed to have
a therapeutic effect on the joint 378. The device may include a
telemetrically actuable pump mechanism for delivering the drug to
the joint upon telemetric actuation by an external control device.
The device 370 further comprises a port 377 for receiving (e.g. via
a percutaneously introduced needle) into the reservoir 375, refills
of the therapeutic substance or drug. Device 380 comprises a
similar catheter 386, and reservoir 385 attached by an anchor 381
to the spinous process 383 or alternatively an adjacent lamina 384.
The spinous process 383 or lamina 384 may be reinforced prior to
attachment of the anchor 381 or may be attached to a reinforcement
device positioned at the posterior arch of the spine, as described
herein with reference to FIGS. 1A-7B.
* * * * *