U.S. patent application number 11/007648 was filed with the patent office on 2005-06-09 for nucleus replacement securing device and method.
This patent application is currently assigned to Innovative Spinal Technologies. Invention is credited to McAfee, Paul.
Application Number | 20050125066 11/007648 |
Document ID | / |
Family ID | 34635897 |
Filed Date | 2005-06-09 |
United States Patent
Application |
20050125066 |
Kind Code |
A1 |
McAfee, Paul |
June 9, 2005 |
Nucleus replacement securing device and method
Abstract
There is disclosed systems and methods for spinal nucleus
replacement by constructing channels through vertebral segments on
either side of an area into which the spinal nucleus is to be
positioned, the channels running from a channel end outside of the
area to a channel end abutting the area. One end of a suture is
inserted into the outside channel end of a first one of the
channels and passed through the first channel and into the area and
out of the area through the second channel until it emerges from
the second channel. The suture is then used to pull the nucleus
into the area.
Inventors: |
McAfee, Paul; (Sparks,
MD) |
Correspondence
Address: |
DALLAS OFFICE OF FULBRIGHT & JAWORSKI L.L.P.
2200 ROSS AVENUE
SUITE 2800
DALLAS
TX
75201-2784
US
|
Assignee: |
Innovative Spinal
Technologies
Plano
TX
|
Family ID: |
34635897 |
Appl. No.: |
11/007648 |
Filed: |
December 7, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60527855 |
Dec 8, 2003 |
|
|
|
Current U.S.
Class: |
623/17.16 ;
623/908 |
Current CPC
Class: |
A61F 2002/30235
20130101; A61F 2002/30133 20130101; A61F 2310/00029 20130101; A61F
2/4611 20130101; A61F 2002/30909 20130101; A61F 2002/444 20130101;
A61B 2017/0414 20130101; A61F 2220/0075 20130101; A61F 2230/0015
20130101; A61F 2002/448 20130101; A61B 2017/0458 20130101; A61F
2230/0069 20130101; A61F 2002/30462 20130101; A61B 17/842 20130101;
A61F 2/442 20130101; A61B 17/0401 20130101 |
Class at
Publication: |
623/017.16 ;
623/908 |
International
Class: |
A61F 002/44; A61F
002/46 |
Claims
What is claimed is:
1. A method for spinal nucleus replacement, said method comprising:
constructing channels through vertebral segments on either side of
an area into which a nucleus replacement is to be positioned; said
channels running from a channel end outside of said area to a
channel end abutting said area; inserting one end of a suture into
said outside channel end of a first one of said channels and
passing said suture end through said first channel and into said
area; inserting said suture end into the second of said channels
and passing said suture end through said second channel until it
emerges from said channel at said outside channel end of said
second channel; attaching at least one nucleus replacement to a
section of said suture between the ends of said suture; and pulling
on at least one end of said suture to thereby pull said nucleus
into said area.
2. The method of claim 1 wherein said attaching occurs prior to
said suture being pulled through said second channel.
3. The method of claim 1 wherein said attaching occurs outside of
said area.
4. The method of claim 1 further comprising: connecting ends of
said suture together outside of said area thereby holding said
replacement within said area.
5. The method of claim 4 wherein said connecting is elastic.
6. The method of claim 4 wherein said connecting is with a flexible
rod.
7. The method of claim 6 further comprising: adding a stiffener to
said flexible rod.
8. The method of claim 1 further comprising: securing each end of
said suture such that said end can not pass through each respective
channel.
9. The method of claim 1 further comprising: passing canulas
through said channels prior to inserting said suture end into said
channels.
10. The method of claim 1 wherein said nucleus replacement can have
at least one metal portion.
11. The method of claim 1 further comprising: inserting anchors
within said channels, said anchors protecting said vertebral
segments.
12. A nucleus replacement device comprising: a suture attached to
said replacement device, said suture having a length for running
from said nucleus replacement device into an area into which said
nucleus is to be positioned and then back through holes in
vertebral structures defining said area to a position outside of
said area.
13. The device of claim 12 further comprising: at least one metal
portion.
14. A spinal nucleus replacement system, said system comprising: a
nucleus replacement device for inserting into an area defined by
vertebral segments; and means for constructing channels through
said vertebral structures from a position outside said defined area
to a position within said defined area, said channels to be used to
assist in the insertion of said nucleus replacement from a position
outside said defined area to a position within said defined
area.
15. The system of claim 14 further comprising: means for attaching
a suture to said nucleus replacement device after said suture has
passed through at least one of said constructed channels.
16. The system of claim 14 further comprising: means outside said
defined area for controllably tensioning said nucleus when said
nucleus is within said defined area.
17. The system of claim 16 wherein said tensioning means comprises
at least one flexible element.
18. A method for spinal nucleus insertion, said method comprising:
constructing channels through vertebral structures, said vertebral
structures defining an area into which a nucleus is to be inserted,
said channels extending from a position outside said defined area
to a position within said defined area; positioning at least one
suture through said channels and through said defined area;
positioning a spinal nucleus outside said defined area; and pulling
said positioned spinal nucleus inside said defined area by use of
said positioned suture.
19. The method of claim 18 further comprising: connecting ends of
said suture together outside of said defined area thereby holding
said spinal nucleus within said area.
20. The method of claim 19 wherein said connecting is elastic.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application Ser. No. 60/527,855 entitled "Nucleus Replacement
Securing Device and Method", filed Dec. 8, 2003, the disclosure of
which is hereby incorporated herein by reference.
TECHNICAL FIELD
[0002] This invention relates to securing of a nucleus replacement
and more specifically, to assistance in placing, stabilizing, and
securing of a nucleus replacement in the disc space between two
adjacent vertebrae from a posterior, posterolateral, or lateral
approach.
BACKGROUND OF THE INVENTION
[0003] Spinal discs are the primary mechanical cushion for the
vertebral column and permit controlled motion between the vertebral
segments. Over time, these discs have a tendency to loose water
which in turn reduces their cushioning ability. Along with a
reduced hydraulic nature, the disc loses its ability to maintain
disc height and bear loads resulting in a cascade of degenerative
effects. As this degenerative process continues, a disc herniation
involving bulging or expelling of disc material can occur leading
to pain to the back and lower extremities. When this occurs, it is
necessary to remove the herniated disc and reestablish disc height,
ultimately in an effort to reduce or eliminate pain.
[0004] When the pain generating disc is removed, the disc space
will collapse resulting in instability and further trauma to
surrounding tissue and ensuing pain. Current treatments include
installing a bone brace, cage, or other load bearing means often
along with bone growth stimulators in an effort to cause fusion of
the segment and thus alleviate the pain. This process is, however,
believed to place undo stress on other vertebral levels as they
compensate for the lack of motion, in turn potentially leading to
premature failure of those other discs as well.
[0005] An improved solution includes replacing the removed internal
portion of the disc, or the nucleus, with a nucleus prosthesis to
act as the load bearing and motion stabilizing feature in an effort
to restore natural spine biomechanics.
[0006] Devices such as these are outlined in U.S. Pat. No.
6,602,291 wherein the nucleus replacement is inserted into the disc
space is a reduced size state, and then is hydrolyzed (or otherwise
expanded) to fill the gap. Current methods and concepts have
undergone human clinical trials to little success and suffers from
an inability to access, place, and then finally secure the nucleus
replacement in place. Several attempts at human trials have even
resulted in expulsion of these devices out of the disc space. This
problem must be addressed to make this technology a viable
possibility in spine treatment.
BRIEF SUMMARY OF THE INVENTION
[0007] There is disclosed systems and methods for spinal nucleus
replacement by constructing channels through vertebral segments on
either side of an area into which the spinal nucleus is to be
positioned, the channels running from a channel end outside of the
area to a channel end abutting the area. One end of a suture is
inserted into the outside channel end of a first one of the
channels and passed through the first channel and into the area and
out of the area through the second channel until it emerges from
the second channel. The suture is then used to pull the nucleus
into the area.
[0008] In a first embodiment, an alignment device mounts to the
posterior aspect of the spine and drills curved holes down through
the pedicle of the segment and into the disc space of the level. At
the adjoining level, holes are also drilled in the pedicle into the
adjoining disc space so that each exit of the curved hole meet at a
single disc space. A suture is then threaded through the first
curved hole, to the disc space, then is extracted from the disc
space to the posterior. The suture is threaded through a nucleus
replacement, or through the covering around a nucleus replacement,
and then back into the disc space where it is pulled through the
second hole and out to the pedicle. Having a suture that goes
through each pedicle and around the nucleus replacement allows the
suture to be pulled from both ends to urge the nucleus replacement
into position still secured to the suture. Plugs are then inserted
into the pedicle and attached to the suture so as to fix the suture
in place. The suture is then cut keeping the nucleus replacement in
a fixed position within the disc space. The suture holds the
nucleus replacement secured to a fixed position after it has been
guided into place. While the nucleus replacement may be permitted a
certain amount of movement in certain embodiments, it is secured
within the disc space so as not to be expelled therefrom.
[0009] In a second embodiment, the ends of the suture expelled from
both pedicles are joined with a tension band between the two
pedicles that can act as a further stabilizing effect to the
segment.
[0010] In a third embodiment, the pedicles of the same vertebra are
used as access into the adjacent disc space. The two sutures or
pathways are through the superior vertebral end place of the
vertebra. This allows preservation of the entire periphery of the
annulus fibrosis if the nucleus replacement is collapsible and can
be inserted through the pedicle.
[0011] The foregoing has outlined rather broadly the features and
technical advantages of the present invention in order that the
detailed description of the invention that follows may be better
understood. Additional features and advantages of the invention
will be described hereinafter. It should be appreciated that the
conception and specific embodiments disclosed may be readily
utilized as a basis for modifying or designing other structures for
carrying out the same purposes of the present invention. It should
also be realized that such equivalent constructions do not depart
from the invention. The novel features which are believed to be
characteristic of the invention, both as to its organization and
method of operation, together with further objects and advantages
will be better understood from the following description when
considered in connection with the accompanying figures. It is to be
expressly understood, however, that each of the figures is provided
for the purpose of illustration and description only and is not
intended as a definition of the limits of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a more complete understanding of the present invention,
reference is now made to the following descriptions taken in
conjunction with the accompanying drawing, in which:
[0013] FIG. 1 shows a side view of the first embodiment;
[0014] FIG. 2 shows a section view taken through line 2-2 of FIG.
1;
[0015] FIG. 3 shows a side view of the second embodiment;
[0016] FIGS. 4A and 4B show a top view and a side view of the third
embodiment;
[0017] FIGS. 5A and 5B show top and side views of a vertebra having
a collapsible reinforcement mesh; and
[0018] FIGS. 6A, 6B, and 6C show side views of a vertebral level
having the invention implanted, the invention including a flexible
rod which allows a supplemental rigid rod for salvage.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Turning now to FIG. 1, vertebral segment 10 includes
superior vertebral level 20 and inferior vertebral level 30. These
are shown as level L4 and level L5 in this example, however the
concepts taught herein could be used at any level in the spine. A
description of a first embodiment of a device and method for using
the device for inserting and securing a replacement nucleus within
a disc space is now described in connection with vertabral segment
10 of FIG. 1. FIG. 1 shows a nucleus replacement 50 which must be
inserted into the disc space 40. To assist this endeavor, two holes
53a and 53b are drilled into the vertebral levels 64, 65 using
fluoro to track a cutting bit in its path, starting from the
opening of the pedicles 55a, 55b and extending on a curved path to
the disc space 40 as shown.
[0020] After the holes are drilled, a suture 60 starting with end
62 is passed through the L4 pedicle opening 55a, through the first
tunnel 53a, and into the disc space 40 passing the entry point 54a.
In the first embodiment, the suture would then be grasped and
pulled through a posterior opening in the disc space 40, and out to
the posterior of the patient. Suture 60 is then mated to nucleus
replacement 50, and suture 60 is passed back down the access port
to the disc space 40 where it is guided back down to the second
tunnel 53b through opening 54b. As an aide, a tool could be passed
through the opening of pedicle 55b, through tunnel 53b, into the
disc space 40. The tool would grab suture 60 and pull end 62
through opening 54b, through tunnel 53b, and out to pedicle opening
55b where it is pulled out of the body.
[0021] This method leaves end 62 of suture 60 extending out of the
patient and the opposite end 61 of suture 60 also extending out of
the patient. The suture would most likely have been cut off at the
appropriate length. Suture ends 61, 62 are then pulled out away
from the patent, pulling with it nucleus prosthesis 50 that is
attached to suture 60. In this way, nucleus replacement 50 is
pulled into disc space 40 so that holes 54a, 54b are directly in
line with the suture connection point at the nucleus
prosthesis.
[0022] At this point knots, anchors (not shown) or other stop
devices could be attached to suture ends 61, 62. If anchors are
used, they would be forcibly press fitted or threaded into the
pedicle. The anchors could have features on them that mate with the
suture to allow tension and reduction of length on suture ends 61,
62 in a zip tie approach so as to maintain position of suture 60
and thus of nucleus replacement 50 at all times. The remaining
suture ends would then be cut off flush or above flush to the
anchors.
[0023] In another embodiment, end 62 of suture 60, while being
installed, would pass from opening 54a of disc space 40 directly
into opening 54b and urged through tunnel 53b to opening 55b of the
L5 pedicle and pulled out of the patient. With end 62 of suture 60
extending out of the patient, a tool could be inserted through
opening 56 to disc space 40, grabbing the suture 60 and pulling
slack granted at either end through opening 56 and out of the
patient. At this point, nucleus 50 would be harnessed to suture 60
at points 51 and 52. In so doing, nucleus replacement 50 is now
secured to suture 60. Slack from suture 60 can now be pulled out by
suture ends 61, 62, thereby pulling nucleus replacement 50 into
disc space 40, with points 51, 52 positioned in line with openings
54a, 54b. Anchors would then be applied in the manner and fashion
described above.
[0024] While in some instances nucleus replacement 50 may be a
single device, in other implementations it may include multiple
devices that are inserted into disc space 40. Turning to FIG. 2, a
cross-section of the vertebral segment taken at line 2-2 of FIG. 1
is shown including vertebra 30 or L5 having spinus process 240,
transverse processes 220a, 220b, and pedicle openings 55b, 155b
which have been created by the method described above. The example
of FIG. 2 shows an implementation in which two nucleus replacement
devices (50a and 50b) have been inserted into disc space 40. For
example, nucleus replacement 50a is inserted in the manner
described above in connection with FIG. 1 for nucleus replacement
50, and nucleus replacement 50b is inserted in a similar manner.
Cannulas 210, 211 are placed over the openings 55b, 155b to pass
nucleus replacements 50a, 50b into the disc space 40. Suture 60 is
shown coming out of the page at points 60a, 60b through attachment
points 52a, 52b (not shown). The posterior longitudinal ligament
(PLL) 230 is also shown in this view as being saved, making this
method desirable for vertebral stability as the PLL 230 supplies
mach of the posterior stability.
[0025] As a method, the nucleus replacements 50a, 50b are passed
through cannulas 210, 211, through opening 56a, 56b of the disc
space, and passed into the disc space 40. The nucleus replacement
travel ends when holes 51a, 51b, and 52a, 52b (not shown), line up
with holes 54a, 54b and 64a, 64b (not shown) with suture 60a
passing though the left prosthesis 50a, and suture 60b passing
through the right prosthesis 50b.
[0026] Turning to FIG. 3, anchors 70, 71 are shown entering into
pedicle holes 55a and 55b. At the proximal end of anchors 70, 71
are suture 60 securing means 72, 73 from which suture 60 is
expelled. In this unique embodiment, suture ends 61 and 62 are
joined at the ends to an elastic tension member 80 serving as a
ligament to the anchors to achieve distraction of the disc space
and to promote healthy biomechanics throughout the segment. The
nucleus replacement 50 is shown in position within the disc
space.
[0027] Turning to FIGS. 4A and 4B, a lower vertebra is shown in
FIG. 4A with anchors 401 placed in the pedicles. The anchors allow
for passage of suture through the pedicle to secure nucleus
replacement 50 as described above. To assist with bone absorption
and subsidence, as shown in FIG. 4B, nucleus replacement 50 could
have a metal base 402 placed on one side to provide stability
against the end plate. This metal base plate could be cobalt chrome
or another biocompatible metal or it could be plastic, or rigid
material. The nucleoplasty would be delivered in a translateral
lumbar approach to the disc space. The anchors would be used to
maintain position of the device and aid in insertion as described
above.
[0028] Turning to FIGS. 5A and 5B, a vertebral segment is shown
including a cross section through the disc space of the lower
vertebra. More specifically, FIG. 5A corresponds generally with the
view of FIG. 1 and FIG. 5B corresponds generally with the view of
FIG. 2. Also shown are a plurality of reinforcement mesh elements
500 (shown as elements 500A and 500B in FIG. 5B) which are
collapsible under load. These mesh elements function to reinforce
the end plate and the bone central to the end plate. That is, mesh
elements 500 include a hole through which suture 60 is pulled,
wherein mesh elements 500 reinforce the end plate and the bone
central to the end plate to, for example, aid in preventing the
hole in the underlying bone from growing larger over time due to
stress presented thereto by the suture 60. This in turn allows for
greater load bearing capability while avoiding bone absorption by
the body as well as subsidence of an intervertebral implant. Suture
ends 62A and 62B are shown in illustration (a), which are pulled
through holes 501A and 501B of mesh elements 500A and 500B,
respectively.
[0029] Turning to FIGS. 6A, 6B, and 6B, a side view of a vertebral
segment is shown in FIG. 6A having pedicle anchors 601 which have a
tension member 602 positioned at the distal end of the anchors. In
this embodiment, a flexible rod 603 is secured to the anchors 601
between the segments to provide a dynamic stabilization system
including the tension member in front and the counter tension
member posterior. As shown in FIG. 6B, a salvage means including a
supplemental rigid rod 604 which further secures to flexible rod
603 or anchors 601 can be used to allow for rigid fixation for
fusion. One such fixation means of the supplemental rigid rod is
shown in FIG. 6C which entails a piggy-back and interlock design.
Rigid rod 604 includes a cylindrical cut that mates to flexible rod
603. It then locks to flexible rod 603 to make a conventional
fusion.
[0030] Although the present invention and its advantages have been
described in detail, it should be understood that various changes,
substitutions and alterations can be made herein without departing
from the invention. Moreover, the scope of the present application
is not intended to be limited to the particular embodiments of the
process, machine, manufacture, composition of matter, means,
methods and steps described in the specification. As one will
readily appreciate from the disclosure, processes, machines,
manufacture, compositions of matter, means, methods, or steps,
presently existing or later to be developed that perform
substantially the same function or achieve substantially the same
result as the corresponding embodiments described herein may be
utilized. Accordingly, the invention is intended to encompass
within its scope such processes, machines, manufacture,
compositions of matter, means, methods, or steps.
* * * * *