U.S. patent application number 13/354781 was filed with the patent office on 2012-05-17 for cervical fusion plate.
This patent application is currently assigned to MI4SPINE, LLC. Invention is credited to Miguelangelo J. Perez-Cruet.
Application Number | 20120123476 13/354781 |
Document ID | / |
Family ID | 39668759 |
Filed Date | 2012-05-17 |
United States Patent
Application |
20120123476 |
Kind Code |
A1 |
Perez-Cruet; Miguelangelo
J. |
May 17, 2012 |
CERVICAL FUSION PLATE
Abstract
A fusion plate that comprises a plate body including extended
portions at one end of the plate body with a slot therebetween and
extended portions at an opposite end of the plate body with a slot
therebetween. The fusion plate further comprises a first pair of
holes in the plate body and a second pair of holes in the plate
body. The fusion plate also comprises a first locking member
slideably engageable to the plate body and being operable to slide
over the first pair of holes and a second locking member slideably
engageable to the plate body and being operable to slide over the
second pair of holes.
Inventors: |
Perez-Cruet; Miguelangelo J.;
(Bloomfield, MI) |
Assignee: |
MI4SPINE, LLC
Bloomfield Village
MI
|
Family ID: |
39668759 |
Appl. No.: |
13/354781 |
Filed: |
January 20, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12021640 |
Jan 29, 2008 |
8118737 |
|
|
13354781 |
|
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60887240 |
Jan 30, 2007 |
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Current U.S.
Class: |
606/246 |
Current CPC
Class: |
A61B 17/7059 20130101;
A61B 17/025 20130101; A61B 2017/0262 20130101 |
Class at
Publication: |
606/246 |
International
Class: |
A61B 17/70 20060101
A61B017/70 |
Claims
1. A fusion plate comprising a plate body including extended
portions at one end of the plate body with a slot therebetween and
extended portions at an opposite end of the plate body with a slot
therebetween, said fusion plate further comprising a first pair of
holes in the plate body and a second pair of holes in the plate
body, said fusion plate further comprising a first locking member
slideably engageable to the plate body and being operable to slide
over the first pair of holes and a second locking member slideably
engageable to the plate body and being operable to slide over the
second pair of holes.
2. The plate according to claim 1 wherein the first locking member
is a first bar having parallel rails and the second locking member
is a second bar having parallel rails, wherein the rails are
slideable in separate parallel slots in the plate to move the
bars.
3. The plate according to claim 2 further comprising a ridge
provided in each slot that engages the rail and holds the bar over
the holes.
4. The plate according to claim 1 wherein the plate body has a
narrowed center portion.
5. The plate according to claim 1 wherein the plate body has an
hour-glass configuration.
6. The plate according to claim 1 wherein the plate is a cervical
plate.
7. The plate according to claim 1 wherein the first pair of holes
includes a first hole positioned in a first extended portion at the
one end of the plate body and a second hole positioned in a second
extended portion at the one end of the body and the second pair of
holes includes a third hole positioned in a third extended portion
at the opposite end of the plate body and a fourth hole positioned
in a fourth extended portion at the opposite end of the plate
body.
8. The plate according to claim 1 wherein the extended portions
have rounded corners.
9. A fusion plate comprising a plate body having a first end and a
second end, said fusion plate further comprising a first pair of
holes in the plate body at the first end and second pair of holes
in the plate body at the second end, said fusion plate further
comprising a first locking member slideably engageable to the plate
body and being operable to slide over the first pair of holes and a
second locking member slideably engageable to the plate body and
being operable to slide over the second pair of holes.
10. The plate according to claim 9 wherein the first locking member
is a first bar having parallel rails and the second locking member
is a second bar having parallel rails, wherein the rails are
slideable in separate parallel slots in the plate to move the
bars.
11. The plate according to claim 10 further comprising a ridge
provided in each slot that engages the rail and holds the bar over
the holes.
12. The plate according to claim 9 wherein the plate body has a
narrowed center portion.
13. The plate according to claim 9 wherein the plate body has an
hour-glass configuration.
14. The plate according to claim 9 wherein the plate is a cervical
plate.
15. The plate according to claim 9 wherein the first pair of holes
includes a first hole positioned in a first extended portion at the
first end of the plate body and a second hole positioned in a
second extended portion at the first end of the body and the second
pair of holes includes a third hole positioned in a third extended
portion at the second end of the plate body and a fourth hole
positioned in a fourth extended portion at the second end of the
plate body.
16. The plate according to claim 9 wherein the extended portions
have rounded corners.
17. A fusion plate comprising a plate body including a first
extended portion and second extended portion at a first end of the
plate body with a first slot therebetween and a third extended
portion and a fourth extended portion at a second end of the plate
body with a second slot therebetween, said fusion plate further
comprising a first hole in the first extended portion, a second
hole in the second extended portion, a third hole in the third
extended portion and a fourth hole in the fourth extended portion,
said fusion plate further comprising a first locking bar having
parallel rails slideably engageable within slots in the plate body
and being operable to slide over the first and second holes and a
second locking bar having parallel rails slideably engageable
within slots in the plate body and being operable to slide over the
third and fourth holes.
18. The plate according to claim 17 further comprising a ridge
provided in each slot that engages the rail and holds the bar over
the holes.
19. The plate according to claim 17 wherein the plate body has an
hour-glass configuration.
20. The plate according to claim 17 wherein the plate is a cervical
plate.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application Ser. No. 60/887,240, filed Jan. 30, 2007, titled
"Retractor Device for Cervical Spinal Fusion" and is a divisional
application of U.S. patent application Ser. No. 12/021,640, filed
Jan. 29, 2008, titled "Retractor Device for Cervical Spinal
Fusion."
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a retractor and anterior cervical
plate device for anterior cervical spinal fusion and
instrumentation where the device includes retractor support posts
mounted to the vertebrae that provide a multi-axial orientation
relative to the vertebrae to reduce retraction injury and an
integrated anterior cervical plate that facilitates instrumentation
placement.
[0004] 2. Discussion of the Related Art
[0005] The human spine includes a series of vertebrae
interconnected by connective tissue referred to as intervertebral
discs that act as a cushion between the vertebrae. The discs allow
for movement of the vertebrae so that the back and neck can bend
and rotate.
[0006] Neck and arm pain and other related symptoms may occur when
a cervical intervertebral disc herniates resulting in compression
of the spinal cord and/or nerve roots. A disc herniates when some
of the disc's nucleus pulposus bulges or ruptures through the
annulus fibrosis. To relieve the symptoms surgeons may perform an
anterior cervical discectomy to remove the offending disc material.
The intervertebral space is then filled with a piece of bone or a
cage filled with graft material to achieve a fusion between
adjacent vertebral bodies.
[0007] To facilitate the fusion process a plate is often applied
that acts to immobilize the segment and allow for bone growth
between adjacent vertebral bodies. In order to perform this
procedure, the surgeon makes a small incision in the front of the
patient's neck to reach the cervical spine. The procedure is
relatively pain free since the surgeon approaches the anterior
cervical spine between natural muscle plains. The trachea and
esophagus are retracted medially and the carotid artery retracted
laterally to reveal the disc space.
[0008] Retraction injuries can occur since the structure must be
retracted significantly for the surgeon to look straight down at
the front part of the vertebrae. Additionally, significant
retraction is maintained through the entire time of the procedure
resulting in the vast majority of these patients waking up with
significant swallowing difficulties. Up to 70% of patients
undergoing anterior cervical discectomy and fusion will experience
some element of swallowing difficulty after this procedure, most
likely from retraction of the esophagus since the surgeon is forced
to move the esophagus away from the midline. Hoarseness can also
result from retraction injury to the recurrent laryngeal nerve.
[0009] In addition, the current retractor systems used require the
post be inserted into adjacent vertebral bodies in order to
distract open the disc space in order to perform the discectomy and
place any graft material under compression. The posts are
distracted and then the graft material placed into the disc space,
releasing the distraction force and allowing for compression of the
graft material which promotes bone fusion. The distractor posts are
then removed and the anterior cervical plate is placed. Because the
initial midline location of the distractor post are lost as well as
their ability to expose the anterior cervical spine, the final
plate placement is often crooked or off to one side of the spine.
The current design takes into consideration that the distractor
posts, if properly placed, mark the midline of the vertebral body
and can be used to properly align and facilitate anterior cervical
plate placement. This could have a detrimental effect of loading
sharing forces on the plate and or intervertebral graft material
resulting in graft or plate failure. Additionally, the current
retractor systems often times slip out of place or rotated during
the procedure which can result in injury and even perforation of
the esophagus, trachea or carotid artery. It was with these
limitations and potential complications associated of the currently
used system that the present design was made. The currently
described modifications to the anterior cervical retractor system
works to reduce retractor related injury to the patient's neck
structures and facilitate the surgical exposure. Additionally, the
retractor system is designed to facilitate anterior plate
placement.
SUMMARY OF THE INVENTION
[0010] In accordance with the teachings of the present invention, a
fusion plate is disclosed that comprises a plate body including
extended portions at one end of the plate body with a slot
therebetween and extended portions at an opposite end of the plate
body with a slot therebetween. The fusion plate further comprises a
first pair of holes in the plate body and a second pair of holes in
the plate body. The fusion plate also comprises a first locking
member slideably engageable to the plate body and being operable to
slide over the first pair of holes and a second locking member
slideably engageable to the plate body and being operable to slide
over the second pair of holes.
[0011] Additional features of the present invention will become
apparent from the following description and appended claims, taken
in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a blown-apart perspective view of a retractor
device positioned relative to cervical vertebrae, according to an
embodiment of the present invention;
[0013] FIG. 2 is a perspective view of a post and rod assembly in
the retractor device shown in FIG. 1;
[0014] FIG. 3 is a perspective view of a tool for threading the
post into a cervical vertebra;
[0015] FIG. 4 is a perspective view of the retractor device shown
in FIG. 1 and a distractor device positioned relative to the
cervical vertebrae;
[0016] FIG. 5 is a top view of the retractor device shown in FIG. 3
and a cervical plate mounted to the vertebrae;
[0017] FIG. 6 is a top view of the cervical plate shown in FIG. 4
separated from the vertebrae;
[0018] FIG. 7 is a cross-sectional view of the cervical plate
mounted to the vertebrae; and
[0019] FIG. 8 is an end view of a combined retractor and distractor
device, according to another embodiment of the present
invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0020] The following discussion of the embodiments of the invention
directed to a retractor device for retracting anatomical structures
during cervical spinal fusion surgery is merely exemplary in
nature, and is in no way intended to limit the invention or its
applications or uses. For example, the retractor device of the
invention has particular application for cervical spinal fusion.
However, as will be appreciated by those skilled in the art, the
retractor device of the invention may have other surgical
applications, including thoracic and lumbar spinal fusion.
[0021] FIG. 1 is a blown-apart perspective view of a retractor
device 10 employed in cervical spinal fusion procedures, such as to
fuse two vertebrae 12 and 14 together after a disc 16 therebetween
has been removed, according to an embodiment of the present
invention. FIG. 1 shows anatomical structures 18 and 20, such as
muscle, tissue, esophagus, carotid artery, trachea, etc., that may
be covering or be close to the surgical area in the patient's neck.
The retractor device 10 retracts or separates the anatomical
structures 18 and 20 so that the surgeon is able to more easily
perform the procedure. Initially, holes are drilled in the
vertebral bodies of the vertebrae 12 and 14 along the midline of
the spine, and retractor posts 26 and 28 are threaded into the
drilled holes. Retractor rods 32 and 34 are mounted to the
retractor posts 28 and 30, respectively, to allow for multi-axial
orientation to help reduce retraction. The multi-axial nature of
these post (as opposed to currently designed solid straight posts)
allow for less retraction of the trachea and esophagus which is
anticipated to reduce swallowing difficulties. The rods 32 and 34
can be mounted to the posts 26 and 28 after the posts 26 and 28 are
threaded into the vertebrae 12 and 14, or the posts and rods can be
part of an assembly that is mounted to the vertebrae 12 and 14.
[0022] FIG. 2 is a perspective view of the retractor post 28 and
the rod 32 separated from the device 10, where the post 28 and the
rod 32 are combined as an assembly, according to one non-limiting
embodiment of the invention. The coupling between the post 28 and
the rod 32 is multi-axial in that the rod 32 can pivot freely
relative to the post 28 when the post 28 is threaded into the
vertebra 12. Any suitable technique can be used to provide the
multi-axial coupling between the post 28 and the rod 32. In this
non-limiting embodiment, the post 28 includes a spherical head 36
mounted thereto that is inserted into a more than hemispherical
opening 38 in the rod 32. Thus, the rod 32 can be pivoted relative
to the post 28. In this embodiment, a bore 40 extends through the
rod 32.
[0023] FIG. 3 is a perspective view of a tool 22 for threading the
posts 28 and 30 into the vertebrae 12 and 14, respectively. The
tool 22 includes an elongated hex-shaped body portion 24 that is
inserted down the bore 40 and into an associated hex-shaped opening
42 centered at a top of the head 36. The tool 22 also includes a
T-handle 36 that allows the surgeon to rotate the tool 22. Thus,
the tool 22 operates as a wrench to rotate the post 28 and thread
it into the drilled hole in the vertebra 12, where the post 28 can
rotate independently of the rod 30.
[0024] The retractor device 10 includes a first retractor blade 44
and a second retractor blade 46. The retractor blade 44 includes an
L-shaped blade arm 48 having an eyelet 50 mounted to one end.
Likewise, the retractor blade 46 includes an L-shaped blade arm 52
having an eyelet 54 mounted to one end. Once the post and rod
assemblies are mounted to the vertebrae 12 and 14, the blades 44
and 46 are mounted to the rods 32 and 34, respectively, by sliding
the eyelets 50 and 52 down the rods 32 and 34.
[0025] FIG. 4 is a perspective view of the retractor device 10
provided in the retractor position, where the blades 44 and 46 are
positioned relative to the vertebrae 12 and 14 to retract the
structural anatomies 18 and 20 and expose the disc 16, as shown.
The length, dimensions, size, angles, etc. of the blade arms 48 and
52 is selected so that the structural anatomies 18 and 20 are
pushed a desirable distance away from the center line of the
vertebrae 12 and 14. The retractor blades 44 and 46 can come in a
variety of sizes and shapes. Once the retractor blades 44 and 46
are in the desired position, nuts 58 and 60 are threaded down the
rods 32 and 34, respectively, and are positioned against the
eyelets 50 and 54, respectively, to secure the blades 44 and 46 to
the rods 32 and 34. Because the blades 44 and 46 will have a
tendency to rise up, the nuts 58 and 60 will securely hold the
blades 44 and 46 in place. Thus, the blades 44 and 46 are rigidly
held in place, and the structural anatomies 18 and 20 are prevented
from falling back into the surgical area. In an alternate
embodiment, the rods 32 and 34 have a hexagonal shape and the
eyelets 50 and 54 have corresponding hexagonal shape so as to lock
the retractor blades 44 and 46 to the rods 32 and 34,
respectively.
[0026] Because the rods 32 and 34 are pivotally mounted to the
posts 28 and 30, respectively, the rods 32 and 34, and thus the
retractor blades 44 and 46, can be positioned at a slightly angled
orientation relative to the mid-line of the vertebrae 12 and 14.
This allows the surgeon to operate from an angle "off-center" so
that more sensitive structures, such as the esophagus, do not need
to be pulled away from their normal position as far, thus resulting
in less swallowing difficulties and discomfort to the patient after
the surgical procedure. To provide this feature of the invention,
the rod 32 needs to be locked at the desired angle relative to the
post 28 and the rod 34 needs to be locked at the desired angle
relative to the post 30. Returning to FIG. 2, the head 36 includes
a plurality of hex-shaped openings 62 provided around the
centerline of the head 36, as shown. A suitable tool, such as the
tool 22 used to thread the post 12 into the vertebra 12, can be
extended down the bore 40 and be positioned in a particular opening
62 to lock the rod 32 at the desirable angle relative to the post
28.
[0027] Once the retractor device 10 is positioned in the desired
orientation, a distractor device 70 is used to separate the rods 32
and 34, and hold the vertebrae 12 and 14 apart while the disc 16 is
removed from the disc space between the vertebrae 12 and 14.
Typically, the injured disc 16 may be partially collapsed, where
the disc height needs to be restored. The distractor device 70
holds the vertebrae 12 and 14 apart the desired distance so that
bone graft material can be placed in the cleared disc space and a
cervical plate can be attached to the vertebrae 12 and 14 to
provide the fusion for the proper disc height.
[0028] The distractor device 70 can be any suitable distractor
device for the purposes described herein. In this non-limiting
embodiment, the distractor device 70 includes a first arm 72 and a
second arm 74. The first arm 72 includes an eyelet 76 at an end
thereof and the second arm 74 includes an eyelet 78 at an end
thereof. A first nut 80 is threaded down the post 34 to the desired
position and a second nut 82 is threaded down the post 32 to the
desired position. The eyelet 76 is then slid down the post 34 so
that it rests on the nut 80, and the eyelet 78 is slid down the
post 32 so that it rests on the nut 82. A distractor knob 84 is
rotated to cause the arms 72 and 74 to move apart, which causes the
posts 32 and 34 to separate providing the distraction.
[0029] Once the disc 16 has been removed and a suitable bone graft
material has been positioned within the disc space, a cervical
plate 90, according to the invention, is then secured to the
vertebrae 12 and 14. FIG. 5 is a top view of the surgical area
being discussed herein with the retractor device 10 and the
cervical plate 90 in place, but with the distractor device 70
removed. FIG. 6 is a top view of the cervical plate 90 removed from
the vertebrae 12 and 14. The cervical plate 90 includes a body 92
having extended portions 94 and 96 with a slot 98 therebetween at
one end and extended portions 100 and 102 with a slot 104
therebetween at an opposite end. The body 92 has a general
hour-glass configuration so that the bone graft material can be
viewed in the disc space. When the plate 90 is attached to the
vertebrae 12 and 14, the extended portions 94 and 96 are positioned
on opposite sides of the rod 32 so that the rod 32 extends through
the slot 98, and the extended portions 100 and 102 are positioned
on opposite sides of the rod 34 so that the rod 34 extends through
the slot 104.
[0030] A pair of holes 106 and 108 are provided through the body 92
proximate the extended portions 94 and 96, and a pair of holes 110
and 112 are provided through the body 92 proximate the extended
portions 100 and 102, as shown. Holes (not shown) are drilled into
the vertebral bodies of the vertebrae 12 and 14 that align with the
holes 106, 108, 110 and 112. Suitable screws 114, 116, 118 and 120
are threaded into the drilled holes in the vertebrae 12 and 14
through the holes 106, 108, 110 and 112, respectively, in the
cervical plate 90 to secure the plate 90 to the vertebrae 12 and 14
to provide the fusion. The retractor device 10 and the distractor
device 70 can then be removed.
[0031] Once the screws 106, 108, 110 and 112 have been threaded
into the vertebrae 12 and 14, it is generally desirable to lock the
screws 106, 108, 110 and 112 in place because they have a tendency
to later thread out of the vertebrae 12 and 14 as the patient moves
about during normal activity. According to the invention, the plate
90 includes a locking bar 130 for locking the screws 106 and 108 in
place, and a locking bar 132 for locking the screws 110 and 112 in
place. The locking bar 130 slides along slots 134 and 136 and the
locking bar 132 slides along slots 138 and 140.
[0032] FIG. 7 is a cross-sectional view through line 7-7 of the
plate 90 attached to the vertebra 12 showing the locking bar 130
positioned within the slots 134 and 136, where the screws 114 and
116 are screwed into the vertebra 12 through the holes 106 and 108
in the plate 90. The locking bar 130 includes rails 142 and 144
that are positioned within the slots 134 and 136 in a secure
engagement, such as shown, that allows the locking bar 130 to slide
in the slots 134 and 136, but be prevented from being removed from
the slots 134 and 136.
[0033] Once the screws 114 and 116 are threaded into the vertebra
12, the locking bar 130 is slid along the slots 134 and 136, so
that ends of the locking bar 130 cover the screws 114 and 116, as
shown, to hold them in place. A ridge 150 is provided in the slot
134 and a ridge 152 is provided in the slot 126 so that the rails
142 and 144 are forced over the ridges 150 and 152, respectively,
and the locking bar 130 is snapped in place to prevent it from
moving backwards in the slots 134 and 136 once it is covering the
screws 114 and 116. Likewise, the slots 138 and 140 include ridges
154 and 156 to lock the locking bar 132 over the screws 110 and
112.
[0034] FIG. 8 is a side view of a combined retractor and distractor
assembly 170, according to another embodiment of the present
invention, where like elements described above are identified by
the same reference numeral. In this embodiment, the distractor arm
72 is replaced with a distractor arm 172 that is angled up-wards,
as shown. The distractor arm 74 would be replaced with a similar
distractor arm coupled to the rod 34. The nuts 80 and 82 have been
eliminated. The nut 58 holds both the retractor arm 48 and the
distractor arm 172 in place. Likewise, the nut 60 holds both the
retractor arm 52 and the other distractor arm in place.
[0035] The combination of the retractor device 10, the distractor
device 70 and the cervical plate 90 offer a number of advantages
over those devices known in the art. For example, the retractor
device 10 is intimately associated with the vertebral distraction
posts 26 and 28, unlike current systems in which they are separate.
Further, the retractor blades 44 and 46 slip easily over the rods
32 and 34. The cervical plate 90 is properly positioned over the
distractor posts 26 and 28. Currently, the distractor posts need to
be removed and then the plate is placed.
[0036] The foregoing discussion discloses and describes merely
exemplary embodiments of the present invention. One skilled in the
art will readily recognize from such discussion and from the
accompanying drawings and claims that various changes,
modifications and variations can be made therein without departing
from the spirit and scope of the invention as defined in the
following claims.
* * * * *