U.S. patent application number 12/618578 was filed with the patent office on 2010-03-04 for implantable bone plate system and related method for spinal repair.
Invention is credited to David Lowry, Desmond O'Farrell, Scott Tuinstra, Roger Veldman.
Application Number | 20100057134 12/618578 |
Document ID | / |
Family ID | 39865351 |
Filed Date | 2010-03-04 |
United States Patent
Application |
20100057134 |
Kind Code |
A1 |
Lowry; David ; et
al. |
March 4, 2010 |
IMPLANTABLE BONE PLATE SYSTEM AND RELATED METHOD FOR SPINAL
REPAIR
Abstract
A system for performing surgical repair of the spine includes a
distractor and a permanently implanted bone plate system. A
surgical repair methodology is also disclosed that employs an
implanted bone plate system with a substantially void internal
volume which is attached to adjacent vertebrae subsequent to the
distraction and/or adjustment of curvature of the vertebrae and
prior to the excision of disc and/or end plate tissue through the
bone plate. The device further facilitates the subsequent delivery
of an interbody repair device for the purpose of either fusion or
dynamic stabilization, such as by disc arthroplasty. The plate may
be permanently implanted, such as when a fusion between the
attached vertebral bodies is desired, but it need not be
permanently implanted.
Inventors: |
Lowry; David; (Holland,
MI) ; O'Farrell; Desmond; (East Grand Rapids, MI)
; Tuinstra; Scott; (Holland, MI) ; Veldman;
Roger; (Hudsonville, MI) |
Correspondence
Address: |
SHAY GLENN LLP
2755 CAMPUS DRIVE, SUITE 210
SAN MATEO
CA
94403
US
|
Family ID: |
39865351 |
Appl. No.: |
12/618578 |
Filed: |
November 13, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11855124 |
Sep 13, 2007 |
|
|
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12618578 |
|
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60954511 |
Aug 7, 2007 |
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Current U.S.
Class: |
606/286 ;
600/201; 606/280 |
Current CPC
Class: |
A61B 17/7059 20130101;
A61B 17/8028 20130101; A61B 17/8042 20130101; A61F 2/4455 20130101;
A61B 2017/0256 20130101 |
Class at
Publication: |
606/286 ;
606/280; 600/201 |
International
Class: |
A61B 17/80 20060101
A61B017/80; A61B 1/32 20060101 A61B001/32 |
Claims
1. A system for establishing and securing adjacent vertebrae in a
defined spacial relationship prior to the excision and repair of
damaged tissue, said system comprising: at least one distraction
device configured for temporary placement between adjacent
vertebrae and engaging upon opposing inferior and superior end
plate surfaces of the adjacent vertebral bodies for achieving a
desired spatial relationship between the vertebrae; at least one
implantable vertebral frame configured to span between the adjacent
vertebrae, the frame being configured to attach to each of the
adjacent vertebra while the distraction device is in place to
postoperatively maintain the desired spatial relationship between
the vertebrae after the distraction device is removed, the frame
having at least one internal operating aperture there-through for
providing access to at least one intervertebral disk space, the
aperture sized to fit over the distraction device; at least one
interbody repair implant sized in relationship to the aperture of
the frame to fit there-through and into the intervertebral space to
compressively engage opposing inferior and superior surfaces of the
adjacent vertebral bodies as the implant is being inserted; and at
least one retention member attachable to the frame to cover at
least a portion of the aperture.
2. The system of claim 1, wherein said frame is configured to span
between and remain postoperatively attached to at least three
adjacent vertebrae.
3. The system of claim 1, wherein said frame comprises external
walls having integrally manufactured retractor blade engaging
features.
4. The system of claim 1, wherein said frame has a plurality of
through holes to facilitate attachment of said frame to adjacent
vertebrae by means of bone screws.
5. The system of claim 1, wherein said frame has a plurality of
protrusions thereon to facilitate attachment of said frame to the
adjacent vertebrae by means of impingement into the bone tissue of
the adjacent vertebrae.
6. The system of claim 1, wherein said frame has one or more
receiving elements to accept a locking member for securing the
retention member.
7. The system of claim 6, wherein said locking member is a threaded
screw device.
8. The system of claim 6, wherein the locking member is a snap lock
device.
9. The system of claim 6, wherein the locking member is a cam lock
device.
10. The system of claim 6, wherein the one or more receiving
elements for the retention member accommodate the temporary
location of at least one tissue retractor pin.
11. The system of claim 1 wherein said retention member is
configured to retain the interbody implant in its surgically
established position.
12. The system of claim 1 wherein the frame is configured to
receive bone screws there-through to attach the frame to the
vertebrae, the retention member adapted to cover the bone screws
when the member is attached to the frame to prevent back-out of
said screws.
13. A method for applying the system in claim 1, wherein the
adjacent vertebrae are distracted and spacially oriented with the
distraction device, the vertebral frame is secured to the adjacent
vertebrae, the damaged tissue is excised through the operating
aperture in the vertebral frame, the vertebral interspace is
prepared to receive the repair implant, said implant being placed
through the operating aperture into said prepared interspace, and
the retention member is then installed onto the vertebral
frame.
14. A method for applying the system in claim 1, wherein the
vertebral frame is attached to one or more vertebrae, the vertebrae
are then distracted and spacially oriented by operating through the
operating aperture in the vertebral frame, the vertebral frame is
secured to each adjacent vertebrae, the damaged tissue is excised
through the operating aperture in the vertebral frame, the
vertebral interspace is prepared through the operating aperture to
receive the repair implant, said interbody implant is inserted
through the operating aperture into the prepared interspace and the
retention member is installed onto the vertebral frame.
15. The system of claim 4 wherein the holes are a combination of
elongated slots and circular holes to accommodate the insertion of
bone screws there-through into vertebral bone tissue.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser.
No. 11/855,124 (titled, "Implantable Bone Plate System and Related
Method for Spinal Repair") filed Sep. 13, 2007, which claims
priority to U.S. Provisional Patent Application Ser. No. 60/954,511
(titled "Implantable Bone Plate System and Related Method for
Spinal Repair") filed Aug. 7, 2007.
[0002] The present invention relates to a system for performing
surgical repair of the spine, such as for but not limited to the
delivery of an interbody repair device for the purpose of either
fusion or dynamic stabilization.
INCORPORATION BY REFERENCE
[0003] All publications and patent applications mentioned in this
specification are herein incorporated by reference to the same
extent as if each individual publication or patent application was
specifically and individually indicated to be incorporated by
reference.
BACKGROUND OF THE INVENTION
[0004] It is current practice in spinal surgery to use bone
fixation devices to improve the mechanical stability of the spinal
column and to promote the proper healing of injured, damaged or
diseased spinal structures. Typically, corrective surgery entails
the removal of damaged or diseased tissue, a decompression of one
or more neural elements, followed by the insertion of an
intervertebral implant for the purposes of a fusion or disc
arthroplasty. In cases where spinal fusion is the desired surgical
outcome, the final step is often to apply a bone plate in order to
immobilize adjacent vertebral bones to expedite osteogenesis across
said vertebral segments.
[0005] Most current surgical techniques require that damaged
vertebral tissue be placed under rigid axial distraction throughout
much of the procedure. This allows for greater ease in the removal
of tissue, provides a larger working space for instrument
maneuverability, enhances the surgeon's visibility and assists with
the fit of the interbody implant once the distractor apparatus is
removed. Conventional distraction of the spine typically employs
the use of temporary "distractor pins" placed directly into the
bone tissue adjacent to the disc space to be repaired, which are
subsequently induced to move axially by the attachment and
adjustment of a secondary tool. An alternative method employs the
use of a ratcheting spreader device which is inserted directly into
the vertebral interspace and is adjusted thereafter to achieve
desired distraction. These distraction methods offer an imprecise
means to restore preferred vertebral alignment, add several steps,
require more time to install and remove, increase the risk for
entwining of surrounding vascular structures or peripheral nerves
and can present significant physical impediments and technical
challenges to the surgeon. Additionally, because the distractor
device remains temporarily inserted during the decompression and
fusion portions of the procedure, the surgeon must essentially work
around the obtrusive projecting devices while completing the
majority of the surgery.
[0006] It is also known that current distraction methods, while
generally not designed or intended for this purpose, are often
employed to adjust or maintain the angular alignment of adjacent
vertebra in an attempt to restore normal lordotic curvature. The
outcomes are varied, the degree of distraction and the angular
correction produced by current distraction methods are often
imprecise, require substantial subjective assessment by the surgeon
and can vary significantly from patient to patient. Further,
excessive distraction can result in a negative surgical outcome
which can result in nerve damage or on-going post surgical pain for
the patient.
[0007] There is a high degree of dimensional variability in the
resulting intervertebral volume after distraction has been achieved
using these devices. As a result, the surgeon must often make
"trial and error" assessments as to the size and shape of the
interbody implant to be inserted and may be required to customize
the implant intraoperatively prior to final insertion.
[0008] In the conventional method, once the implant has been
inserted, the distractor device is removed and the vertebrae can be
secured by the attachment of a bone plate. Such bone plates,
including a plurality of bone screws, are applied near the
completion of the procedure to provide vertebral fixation and
prohibit undesirable migration of the intervertebral implant.
[0009] Several design constructs have already been proposed in
which a device is applied to adjacent vertebrae at the start of a
procedure, prior to tissue removal, for the purposes of achieving
and maintaining preferred vertebral alignment while serving also to
constrain tissue removal throughout the procedure. The disclosed or
published art in this method can generally be categorized into two
broad categories: removable devices and permanently implantable
devices.
[0010] The removable devices differ from the present proposed
invention in that the devices used to maintain preferred vertebral
alignment are temporary inserts and are subsequently removed after
tissue removal so that a repair device may be delivered thereafter.
The prior art which discloses permanently implantable devices
differs in that the devices function solely to maintain preferred
vertebral alignment and are not part of a comprehensive system and
related method to precisely control and permanently maintain the
preferred spatial relationship of adjacent vertebral members for
controlled tissue removal and delivery of a repair device.
Removable Devices
[0011] U.S. Pat. No. 7,153,304 entitled Instrument System for
Preparing a Disc Space Between Adjacent Vertebral Bodies to Receive
a Repair Device, issued Dec. 26, 2006 to Robie et al., discloses a
removable instrument system for preparing a disc space between
adjacent vertebral bodies using a series of distractors that
restore natural lordosis before a temporary template is attached
for vertebral immobilization and to function as a guide for an
insertable reamer meant for tissue removal.
[0012] U.S. Pat. No. 7,083,623 to Michelson, entitled Milling
Instrumentation and Method for Preparing a Space Between Adjacent
Vertebral Bodies, issued Aug. 1, 2006, discloses a removable
milling device and method for preparing a space between adjacent
vertebral bodies which essentially maintains preferred vertebral
alignment while functioning as a saw guide to control bone and soft
tissue removal.
[0013] US Pat. App. 2005/0043740 to Haid, entitled Technique and
Instrumentation for Preparation of Vertebral Members, published
Feb. 24, 2005, discloses a removable instrumentation set and
technique for preparation of vertebral members utilizing a docking
ring which is temporarily applied to the anterior spine to maintain
preferred vertebral alignment and to function as a docking plate
for an articulating bone removal device.
[0014] U.S. Pat. No. 7,033,362 to McGahan, entitled Instruments and
Techniques for Disc Space Preparation, issued Apr. 25, 2006,
discloses a removable instrumentation set and method for disc space
preparation whereby an intervertebral device is temporarily
inserted for the purpose of constraining tissue removal and guiding
the position of an intervertebral repair device.
[0015] US Pat. App. 2003/0236526 to Van Hoeck, entitled Adjustable
Surgical Guide and Method of Treating Vertebral Members, published
Dec. 25, 2003, discloses a removable surgical guide and method with
adjustable functionality for the preparation of adjacent
vertebra.
[0016] US Pat. App. No. 2006/0247654 to Berry, entitled Instruments
and Techniques for Spinal Disc Space Preparation, published Nov. 2,
2006, discloses a removable milling instrument assembly for
vertebral endplate preparation which constrains a cutting path
obliquely oriented to the axis of the vertebra.
Permanently Implanted Devices
[0017] US Pat. App. 2004/0097925 to Boehm, entitled Cervical Spine
Stabilizing System and Method, published May 20, 2004, discloses a
permanently implantable spine stabilizing system and method whereby
a plate configured to be positively centered along the midline is
placed to retain adjacent vertebra in a desired spatial
relationship during discectomy and fusion procedures. The disclosed
invention uses a series of temporary implants and removable drill
templates in an attempt to assure the alignment of the implanted
device along the midline of the spinal column. This alignment is
typically not considered to be significant in determined the
clinical outcome of the procedure and is further considered
impractical for the purposes of performing repair procedures on
multiple adjacent disk spaces due to the normal scoliotic curvature
of the spine.
[0018] US Pat. App. 2005/0149026 to Butler et al., entitled Static
and Dynamic Cervical Plate Constructs, published Jul. 7, 2005,
describes an implanted cervical bone plate having a graft window
located between the bone screw holes for the purposes of providing
visualization and access to an intervertebral implant. The device
described is applied after the intervertebral space has been
repaired and after the implant has been positioned. The
specification states specifically that an appropriately "sized
dynamic plate is placed over the inserted bone implant"; thereafter
the bone plate is located with respect to the implant by viewing
the implant through the graft window and secured in place using
bone screws.
[0019] Accordingly, it is apparent that there remains a need for
and advantage to a permanently implantable spinal repair system and
related method whereby the final preferred vertebral alignment and
fixation occurs prior to the surgical removal of damaged tissue,
without the use of temporary implants or fasteners and where the
surgical procedures can be performed there-through in the minimum
amount of time with the minimum number of entries into the surgical
field. It is further apparent that there is a need for a system
wherein subsequent recovery procedures can be performed with
minimal effort should implantation fail or should subsequent
surgery be required.
SUMMARY OF THE PRESENT INVENTION
[0020] The invention relates generally to systems and methods for
establishing and securing adjacent vertebrae in a defined spacial
relationship prior to the excision and repair of damaged tissue. In
one embodiment, the system includes at least one distraction
device, at least one implantable vertebral frame, at least one
interbody repair implant, and at least one retention member. In
this embodiment, the distraction device is configured for temporary
placement between adjacent vertebrae for achieving a desired
spatial relationship between the vertebrae. In this embodiment, the
implantable vertebral frame is configured to span between the
adjacent vertebrae, the frame being configured to attach to each of
the adjacent vertebra while the distraction device is in place to
postoperatively maintain the desired spatial relationship between
the vertebrae after the distraction device is removed, the frame
also having at least one internal operating aperture there-through
for providing access to at least one intervertebral disk space. In
this embodiment, the interbody repair implant is sized in
relationship to the aperture of the frame to fit there-through and
into the intervertebral space. And finally, in this embodiment, the
retention member is attachable to the frame to cover at least a
portion of the aperture.
[0021] In various embodiments of the above summarized system, the
frame may assume various forms and include various features that
will now be summarized. In some embodiments of the system, the
frame may be configured to span between and remain postoperatively
attached to at least three adjacent vertebrae. In some embodiments
of the system, the frame may include external walls having
integrally manufactured retractor blade engaging features. In some
embodiments of the system, the frame may have a plurality of
through holes to facilitate attachment of the frame to adjacent
vertebrae by means of bone screws. In some of these particular
embodiments, the holes may be a combination of elongated slots and
circular holes to accommodate the insertion of bone screws
there-through into vertebral bone tissue. In some embodiments of
the system, the frame may have a plurality of protrusions to
facilitate attachment of the frame to the adjacent vertebrae by
means of impingement into the bone tissue of the adjacent
vertebrae.
[0022] Further, in some embodiments of the system, the frame may
have one or more receiving elements to accept a locking member for
securing the retention member. In various of these particular
embodiments, the locking member may be any of a threaded screw
device, a snap lock device, or a cam lock device, and further in
some of these particular embodiments, the one or more receiving
elements for the retention member may accommodate the temporary
location of at least one tissue retractor pin.
[0023] Still further, in some embodiments of the system, the frame
may be configured to receive bone screws there-through to attach
the frame to the vertebrae, the retention member being adapted to
cover the bone screws when the member is attached to the frame to
prevent back-out of the screws.
[0024] In some embodiments of the system, the retention member may
be configured to retain the interbody implant in its surgically
established position.
[0025] According to an aspect of the invention, a vertebral implant
may be provided. Embodiments of the implant are configured to
rigidly interconnect at least two vertebrae, the implant being
manufactured from a generally rigid material having thereon contact
surfaces for engaging on vertebral bone material, the contact
surfaces including a biocompatible, compressible, polymeric
material. In some of these embodiments, the generally rigid
material may also include a biocompatible metallic material.
[0026] In another aspect of the invention, various embodiments of
methods are provided for applying the system and/or the vertebral
implant, as summarized above. In one method of applying the system,
the adjacent vertebrae are distracted and spacially oriented with
the distraction device, the vertebral frame is secured to the
adjacent vertebrae, the damaged tissue is excised through the
operating aperture in the vertebral frame, the vertebral interspace
is prepared to receive the repair implant, said implant being
placed through the operating aperture into said prepared
interspace, and the retention member is then installed onto the
vertebral frame.
[0027] Another embodiment of a method for applying the system is
also provided. In this embodiment, the vertebral frame is attached
to one or more vertebrae, the vertebrae are then distracted and
spacially oriented by operating through the operating aperture in
the vertebral frame, the vertebral frame is secured to each
adjacent vertebrae, the damaged tissue is excised through the
operating aperture in the vertebral frame, the vertebral interspace
is prepared through the operating aperture to receive the repair
implant, the interbody implant is inserted through the operating
aperture into the prepared interspace and the retention member is
installed onto the vertebral frame.
[0028] In another aspect of the invention, a method for treating a
portion of a spinal column is provided. The method includes
distracting and spacially orienting adjacent vertebral bodies of
the spinal column, securing a vertebral frame to the adjacent
vertebral bodies, the vertebral frame having at least one operating
aperture there-through, preparing a vertebral interspace to receive
an interbody implant, inserting the interbody implant through the
operating aperture and into the prepared interspace, and
maintaining the vertebral frame in place on the vertebral bodies
postoperatively.
[0029] In some embodiments of this method for treating a portion of
a spinal column, the distracting step is performed using a
distraction device placed between the vertebral bodies, and the
distraction device is removed from between the vertebral bodies
through the operating aperture in the vertebral frame after the
vertebral frame is secured to the vertebral bodies. In some of
these methods for treating a portion of the spinal column, the
method may further include the step of excising damaged tissue
through the operating aperture in the vertebral frame.
[0030] In another embodiment, the method may further include the
step of installing a retention member onto the vertebral frame
after inserting the interbody implant. In still other embodiments,
the step of preparing a vertebral interspace to receive an
interbody implant may be performed through the operating aperture
of the vertebral frame.
[0031] In some embodiments of the method for treating a portion of
the spinal column, the vertebral frame may have particular features
or aspects. Thus, in some embodiments, the vertebral frame may be
attached to at least one of the vertebral bodies before the
distraction step, the distraction step being performed through the
operating aperture in the vertebral frame. In other embodiments,
the vertebral frame may be secured to more than two adjacent
vertebral bodies. In still other embodiments, the vertebral frame
may be maintained in place permanently, generally from the time it
is first secured to the vertebral bodies.
[0032] According to some aspects of the present invention, a means
and method to precisely control and permanently maintain the
preferred spatial relationship of adjacent vertebral members prior
to the surgical removal of damaged tissue may be provided.
[0033] According to some aspects of the invention, a means may be
provided whereby preferred spatial relationship of adjacent
vertebra can be achieved and permanently maintained using
conventional vertebral distraction methods or in conjunction with a
novel intervertebral distractor apparatus disclosed separately in
the co-pending patent application Ser. No. 60/954,507 titled
"Device and Method for Variably Adjusting Intervertebral
Distraction and Lordosis" filed on Aug. 7, 2007.
[0034] According to some aspects of the invention, the surgical
removal of damaged tissue may be constrained in order to minimize
the risk of damage to the adjacent tissue.
[0035] According to some aspects of the invention, the preferred
spatial relationship of adjacent vertebral members may be precisely
controlled and permanently maintained with a device having a low
profile, allowing the surgeon to work in an unrestricted manner,
within, around, above and below the device.
[0036] According to some aspects of the invention, the preferred
spatial relationship of adjacent vertebral members may be precisely
controlled and permanently maintained for the insertion of a spinal
repair device.
[0037] According to some aspects of the invention, the insertion of
a spinal repair device may be spatially controlled.
[0038] According to some aspects of the invention, a locking member
may be accommodated to prevent undesirable migration of the spinal
repair device and bone screws.
[0039] According to some aspects of the invention, the method and
device may be utilized across one or multiple vertebral
segments.
[0040] According to some aspects of the invention, a permanent
rigid internal fixation may be provided across one or multiple
vertebral segments.
[0041] In one particular embodiment, a permanent semi-rigid
fixation is provided across one or multiple vertebral segments.
[0042] In one particular embodiment, a retractor apparatus is
accommodated by providing integrally manufactured receiving and
engaging means for the tissue control blades of said retractor.
[0043] In one particular embodiment, removable templates which
locate and constrain the surgical removal of tissue to the desired
vertebral area are accommodated.
[0044] In one particular embodiment the vertebral fixation element
in the system is manufactured using two biocompatible materials,
the structural component being manufactured from a high modulus
rigid material such as Titanium, Stainless steel or other metal and
having therein contact elements for engaging on the vertebral
tissue, said contact pads being manufactured from a bio-compatible
compliant material such as polyethylene or a silicone. These
contact pads are intended to be plastically deformed under
compressive loads and to be compressed and deformed by the
insertion of the bone screws in order to act as damping elements to
absorb vibration during bone tissue removal and consequently to
minimize the risk of associated screw dislocation. These pads
further increase the initial friction between the vertebral fixing
element and the vertebrae thereby reducing premature dynamic
compression of the distracted vertebrae. Finally, the compliant
elements act as shock absorbers during patient healing and promote
osteogenesis within the implanted repair device.
[0045] In one particular embodiment, the inventive device may be
coupled with a stereotactic navigational system for preferred
device positioning and to constrain the surgical removal of
tissue.
DESCRIPTION OF INVENTION
[0046] The invention described herein includes a system and
surgical method for use in surgical spinal repair or reconstruction
procedures whereby preferred and final vertebral axial and angular
positioning and fixation occurs prior to the cutting and removal of
the tissue.
[0047] In one embodiment, the system can generally be described as
a combination of: [0048] 1) An intervertebral distraction device
placed temporarily between adjacent vertebrae for purposes of
achieving a desired spatial relationship between adjacent
vertebrae. [0049] 2) A vertebral plate. [0050] 3) A locking and
retention member engaging with said vertebral plate. [0051] 4) An
implantable interbody repair device. [0052] 5) Bone screws. [0053]
6) The vertebral plate having through holes for the purposes of
accommodating attachment to the vertebrae using the bone screws.
[0054] 7) Said vertebral plate having a generally open interior
volume through which the removal of damaged tissue is performed.
[0055] 8) Said vertebral plate having a generally open interior
volume which constrains the insertion and prevents migration of an
intervertebral repair device. [0056] 9) Said vertebral plate having
accommodation means for attaching the locking and retention member
for retention of the implanted repair device and the bone screws.
[0057] 10) One embodiment of the surgical method may be generally
described as the sequence of spacially orienting adjacent
vertebrae, locking said vertebrae in their prescribed relative
positions using the vertebral plate and bone screws, preparing and
repairing the intervertebral space through the operating window in
the installed vertebral plate and securing the implant in place by
securing a locking member to the vertebral plate. [0058] 11) An
alternate surgical method may be generally described as the
sequence of attaching the vertebral plate to one of the adjacent
vertebrae, spacially orienting the adjacent vertebrae through the
operating window in the vertebral plate, locking said vertebrae in
their prescribed relative positions using the vertebral plate and
bone screws, preparing and repairing the intervertebral space
through the operating window in the installed vertebral plate and
securing the implant in place by securing a locking member to the
vertebral plate. [0059] 12) In an alternate surgical method, the
vertebrae are partially distracted and held in this position by the
insertion of bone screws through slots in the vertebral plate. In
this instance the final distraction is achieved by the forcible
insertion of an interbody repair device which has a cranio-caudal
dimension that is larger than the dimension of the receiving
intervertebral space. The differences in the two dimensions results
in a further, final distraction of the adjacent vertebrae. This
final movement of the vertebrae is accommodated by the movement of
the screws within the slots in the vertebral plate.
[0060] In an anticipated procedure a conventional intervertebral
distractor apparatus is manually inserted into or between the
vertebrae resulting in axial distraction of the vertebrae. In the
case of a standard wedge style distractor the degree of distraction
results from a combination of the included angle and the depth to
which it is inserted between the vertebrae. In the case of a
distractor pin system the distraction results from the manipulation
of a secondarily applied axial adjustment device.
[0061] In a further embodiment the included angle of the distractor
device is variably adjustable by the surgeon after insertion
between the vertebrae, this adjustment being achieved mechanically
by means of a screw adjustment or the use of another adjusting
tool. Such a distractor device is disclosed in the co-pending
application Ser. No. 60/954,507 titled "Device and Method for
Variably Adjusting Intervertebral Distraction and Lordosis" filed
on Aug. 7, 2007.
[0062] In a further embodiment the distractor apparatus can be
mated with a stereotactic navigational device to establish, monitor
and control the positioning of the device relative to the adjacent
vertebra.
[0063] After distraction and lordotic adjustment has been achieved
the spinal bridge is located on the vertebrae relative to the
distractor device and attached to the adjacent vertebra by at least
two bone screws, securing the vertebrae in their prescribed
positions.
[0064] If intervertebral distractor devices have been employed they
are removed, exposing a predefined accessible and constrained
operating field allowing the controlled cutting and removal of
tissue to occur.
[0065] In a further embodiment the vertebral plate can accommodate
insertable control templates which can be placed within it by the
surgeon to further assist precise tissue removal.
[0066] In a further embodiment the vertebral plate can serve as a
mounting base for the attachment of soft tissue retractors, further
aiding the surgeon by assuring an un-impeded surgical field.
[0067] In a further embodiment the vertebral plate can be removed
after the placement of a disc arthroplasty device.
[0068] The intervertebral repair device may be generally wedge
shaped, it may have an initial radius or taper for engagement with
the adjacent vertebrae or it may be conically or cylindrically
shaped.
[0069] Further, this device may have surface contours thereon which
are intended to increase the surface area of contact between said
surfaces and the exposed cancellous bone tissue and to increase the
intimate compressive engagement with said cancellous tissue so as
to induce and encourage osteogenesis therein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0070] FIG. 1a shows the typical sequence of steps in a current
surgical procedure.
[0071] FIG. 1b shows the sequence of one embodiment of the
inventive method herein.
[0072] FIG. 2a is an anterolateral isometric view of a single level
implantable bone plate.
[0073] FIG. 2b is a posterolateral isometric view of a single level
implantable bone plate.
[0074] FIG. 3a is an anterior isometric view of a multi-level
implantable bone plate.
[0075] FIG. 3b is a lateral isometric view of a multi-level
implantable bone plate.
[0076] FIG. 4 is an oblique perspective view of a multi-level bone
plate.
[0077] FIG. 5 illustrates a retention member relative to the
vertebral frame.
[0078] FIG. 6 depicts a retention member in an installed position
on the vertebral frame.
[0079] FIG. 7 is an anterior (surgical) view of a vertebral frame
in its installed position on adjacent vertebrae.
[0080] FIG. 8 is an anterolateral perspective view of the vertebral
frame in its installed position on adjacent vertebrae.
[0081] FIGS. 9 and 10 depict a retention member in-situ after
installation onto the vertebral plate.
DETAILED DESCRIPTION OF THE INVENTION
[0082] FIG. 1a describes the typical operational sequence currently
employed, wherein vertebrae are distracted, tissue is excised, an
implant in placed between adjacent vertebrae and a bone plate is
attached. FIG. 1b describes the preferred operational sequence
associated with this invention, wherein vertebrae are distracted
and placed in their preferred relative angular positions and a
vertebral frame is attached to adjacent vertebrae using bone screws
to maintain the prescribed spatial relationship during the
subsequent steps. In an alternative sequence, the vertebral frame
may be attached to adjacent vertebrae prior to distraction and
preferred positioning. Thereafter tissue is excised though the
aperture in the frame, the implant is inserted through said
aperture. A retaining member may be attached to said vertebral
frame to maintain the position of the implanted insert and to
prevent back-out of the bone screws.
[0083] FIGS. 2a and 2b depict a single level vertebral frame,
intended to secure two adjacent vertebrae. The device has surfaces
101 and 102 which are generally contoured to engage positively with
the anterior surfaces of the adjacent vertebrae. The device has
through holes 103 and 104 intended to accommodate the insertion of
bones screws into the vertebral tissue. Holes 104 may be elongated
to accommodate post surgery dynamic settling of the vertebrae. The
device further has one or more holes 105 intended for receiving
screws (or other fixation devices) securing the retaining member
thereto or there-through. The receiving holes 105 also provide a
mounting means for the insertion of temporary soft tissue retractor
pins. The device has an operating window defined by the side walls
106, 107, 108 and 109. This window is intended to allow unimpaired
access to the intervertebral space in order to excise tissue and
subsequently to allow the insertion of the interbody repair device
there-through.
[0084] FIG. 3a depicts a multi-level vertebral frame 200, intended
to facilitate the orientation, fixation and repair of three or more
vertebrae.
[0085] FIG. 3b depicts a side view of a multilevel device and
illustrates the presence of a receiving means 201 on the vertebral
frame, thereby permitting the plate to accommodate the location and
retention of soft tissue retractor blades.
[0086] Referencing FIGS. 4 and 5; the retention member 300 has a
posterior surface 301 contoured to match the anterior surface of
the vertebral frame 200 and through holes 302 which align with the
receiving holes 105 in the vertebral frame, these holes being
intended to secure the retention member 300 to the vertebral frame
200 in order to retain the interbody implant in position and to
prevent the back-out of the bone screws used to secure frame 200 to
the vertebral bone tissue.
[0087] FIG. 6 shows retention member 300 installed to the vertebral
frame 200, the anterior surface of the retention member having a
contour 401 which generally matches that of the vertebral frame 200
to create a smooth, continuous surface after installation.
[0088] FIG. 6 further shows the retention member having extensions
420 that cover the bone screws and thereby preventing screw
back-out.
[0089] FIG. 7 depicts the vertebral frame in position on adjacent
vertebrae and illustrates the operating window in the region of the
disk space. The operating window is defined by the cross members
503, 504, 505 and 506 respectively which produce a contained area
through which all procedures may be executed. Further, these
members act to restrain the surgeon during tissue excision and
thereby minimize the risk of accidental damage to surrounding
tissue.
[0090] FIG. 7 further illustrates how the device provides access to
facilitate the removal of disk material 502 and the preparation of
the intervertebral space 501 prior to the insertion of the
interbody implant.
[0091] FIG. 8 is a perspective side view of the vertebral frame in
the installed position on adjacent vertebrae. The device has
clearance spaces 601 in the region of the disk material to
accommodate a better fit to the vertebral surfaces and to provide
additional clearance to allow for the removal of unwanted bone
material after device installation.
[0092] FIGS. 9 and 10 depict the retention member 300 placed
in-situ on the vertebral frame 200 after the insertion of the
interbody implant. The member 300 is located so as to prevent
substantial movement of the interbody implant and thereby promote
bone tissue growth therein.
[0093] Instead of screws, or in combination therewith, one or more
snap lock devices may be used to attach retention member 300 to
vertebral frame 200. Such devices may employ a compressible
feature, such as a split barb, that locks into place when inserted
sufficiently into hole 105 or other mating feature. By using snap
lock device(s), member 300 can be simply aligned with frame 200 and
pressed into place without requiring the surgeon to align screws
and install them with a driver. One or more cam lock devices may
also be used, alone or with screws and/or snap lock devices. In
some cam lock embodiments a torsional force is applied to a
component, inducing rotation and causing it to become engaged in a
corresponding feature within a receiving element. This twisting
action causes the component to turn and lock under another
component, again with less effort than required when installing a
screw.
[0094] The system offers substantial benefits over those previously
disclosed and those currently employed. These benefits include, but
are not limited to:
[0095] 1) A novel method which allows for precise control and
fixation of optimal vertebral position.
[0096] 2) Constrained and controlled tissue removal
[0097] 3) Elimination of patient to patient variation
[0098] 4) Integration of soft tissue retraction devices
[0099] 5) Reduction in surgical time and maneuvers throughout the
case.
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