U.S. patent application number 13/371242 was filed with the patent office on 2012-08-16 for anterior intervertebral fusion with fixation system, device and method.
Invention is credited to Joshua Michael Aferzon.
Application Number | 20120209385 13/371242 |
Document ID | / |
Family ID | 46637503 |
Filed Date | 2012-08-16 |
United States Patent
Application |
20120209385 |
Kind Code |
A1 |
Aferzon; Joshua Michael |
August 16, 2012 |
Anterior intervertebral fusion with fixation system, device and
method
Abstract
A system, device, and method are disclosed for anterior
intervertebral fusion with fixation. An intervertebral fusion with
fixation device includes a spacer configured to fit into a disc
space between plural vertebrae, the spacer including through holes
between and through plural sidewalls. A first fixating element is
rigidly preloaded in a first portion of the spacer along a first
linear trajectory. A second fixating element is rigidly preloaded
in a second portion of the spacer along a second linear trajectory.
An integrated drill and screwdriver instrument is adapted to extend
through a cannula of the first fixating element and second fixating
element and penetrate the vertebra. The instrument is further
adapted to drive the head of the first fixating element and second
fixating element into the vertebra and lock the first fixating
element and second fixating element with respect to the spacer to
prevent extrusion from the spacer.
Inventors: |
Aferzon; Joshua Michael;
(Avon, CT) |
Family ID: |
46637503 |
Appl. No.: |
13/371242 |
Filed: |
February 10, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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61463239 |
Feb 15, 2011 |
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61517717 |
Apr 25, 2011 |
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Current U.S.
Class: |
623/17.16 |
Current CPC
Class: |
A61F 2/447 20130101;
A61F 2002/3023 20130101; A61F 2002/30879 20130101; A61F 2002/30266
20130101; A61F 2002/30326 20130101; A61F 2002/3082 20130101; A61F
2/442 20130101; A61B 17/8875 20130101; A61F 2002/30787 20130101;
A61F 2002/2835 20130101; A61B 17/864 20130101; A61F 2002/3008
20130101; A61B 17/1671 20130101 |
Class at
Publication: |
623/17.16 |
International
Class: |
A61F 2/44 20060101
A61F002/44 |
Claims
1. An intervertebral fusion with fixation device configured to be
implanted between plural vertebrae, the device comprising: a spacer
with an insertion wall, a trailing wall opposite to the insertion
wall, a first lateral wall, a second lateral wall opposite to the
first lateral wall, a top surface, and a bottom surface opposite to
the top surface; a first fixating element rigidly preloaded in a
first portion of the spacer along a first linear trajectory, the
first fixating element configured to penetrate and secure to a
first vertebra by advancing along the first linear trajectory; and
a second fixating element rigidly preloaded in a second portion of
the spacer along a second linear trajectory that is different from
the first linear trajectory, the second fixating element configured
to penetrate and secure to a second vertebra by advancing along the
second trajectory.
2. The intervertebral fusion with fixation device of claim 1,
wherein the spacer includes a through opening having an entrance
proximate the top surface and an exit proximate the bottom surface
to facilitate contact and in-growth of bone fusion material with
the first vertebra and second vertebra.
3. The intervertebral fusion with fixation device of claim 1,
wherein the spacer is made of polyetheretherketone (PEEK), other
polymers, metal, ceramics, or composites.
4. The intervertebral fusion with fixation device of claim 1,
wherein at least one of the first fixating element and the second
fixating element is a cannulated bone screw.
5. The intervertebral fusion with fixation device of claim 4,
wherein the cannulated bone screw includes a head that is
configured to integrate with a driving instrument.
6. The intervertebral fusion with fixation device of claim 4,
wherein the cannulated bone screw includes a head that has a
locking mechanism configured to penetrate and lock into spacer to
prevent screw toggling and extrusion.
7. An integrated drill and screwdriver instrument, the instrument
comprising: a handle; a driving element configured to engage a head
of a bone screw and to rotate the bone screw into a vertebra, a
drilling element extending from the driving element, the drilling
element configured to extend through a cannula of the bone screw
and to penetrate the vertebra, the driving element engaging the
head of the bone screw as the drilling element penetrates through a
vertebral endplate.
8. An intervertebral fusion with fixation system, the system
compromising: an intervertebral fusion with fixation device
configured to be implanted between plural vertebrae, the device
comprising: a spacer with an insertion wall, a trailing wall
opposite to the insertion wall, a first lateral wall, a second
lateral wall opposite to the first lateral wall, a top surface, and
a bottom surface opposite to the top surface; a first fixating
element rigidly preloaded in a first portion of the spacer along a
first linear trajectory, the first fixating element configured to
penetrate and secure to a first vertebra by advancing along the
first linear trajectory; and a second fixating element rigidly
preloaded in a second portion of the spacer along a second linear
trajectory that is different from the first linear trajectory, the
second fixating element configured to penetrate and secure to a
second vertebra by advancing along the second trajectory; and an
integrated drill and screwdriver instrument, the instrument
comprising: a handle; a driving element configured to engage a head
of a bone screw and to rotate the bone screw into a vertebra; and a
drilling element extending from the driving element, the drilling
element configured to extend through a cannula of the bone screw
and to penetrate the vertebra, the driving element engaging the
head of the bone screw as the drilling element penetrates through a
vertebral endplate.
9. A method to secure plural vertebrae, the method comprising:
implanting an intervertebral fusion with fixation device between
plural vertebrae, the device comprising: a spacer with an insertion
wall, a trailing wall opposite to the insertion wall, a first
lateral wall, a second lateral wall opposite to the first lateral
wall, a top surface, and a bottom surface opposite to the top
surface; a first fixating element rigidly preloaded in a first
portion of the spacer along a first linear trajectory; and a second
fixating element rigidly preloaded in a second portion of the
spacer along a second linear trajectory that is different from the
first linear trajectory, the second fixating element configured to
penetrate and secure to a second vertebra by advancing along the
second trajectory; driving the first fixating element along the
first linear trajectory to penetrate the first vertebra and to
secure the spacer to the first vertebra; and driving the second
fixating element along the second linear trajectory to penetrate
the second vertebra and to secure the spacer to the second
vertebra.
10. The method of claim 9, the method comprising: introducing an
integrated drill and screwdriver instrument to the first fixating
element of the intervertebral fusion with fixation device, the
instrument comprising: a handle; a driving element configured to
engage a head of the first fixating element; and a drilling element
extending from the driving element, the drilling element configured
to extend through a cannula of the first fixating element; and
drilling the first vertebra with the drilling element; engaging the
first fixating element with the driving element as the drilling
element penetrates through a vertebral endplate of the first
vertebra; and rotating the first fixating element via the driving
element to penetrate the first vertebra and to secure the spacer to
the first vertebra.
11. The method of claim 10, the method comprising: locking the
first fixating element with respect to the spacer to prevent the
first fixating element from extruding from the spacer.
12. The method of claim 9, the method comprising: introducing the
instrument to the second fixating element of the intervertebral
fusion with fixation device; drilling the second vertebra with the
drilling element; engaging the second fixating element with the
driving element as the drilling element penetrates through a
vertebral endplate of the second vertebra; and rotating the second
fixating element via the driving element to penetrate the second
vertebra and to secure the spacer to the second vertebra.
13. The method of claim 12, the method comprising: locking the
second fixating element with respect to the spacer to prevent the
second fixating element from extruding from the spacer.
14. A method to assemble an intervertebral fusion with fixation
device, the method comprising: providing a spacer that includes an
insertion wall, a trailing wall opposite to the insertion wall, a
first lateral wall, a second lateral wall opposite to the first
lateral wall, a top surface, and a bottom surface opposite to the
top surface; preloading a first fixating element rigidly in a first
portion of the spacer along a first linear trajectory, the first
fixating element configured to penetrate and secure to a first
vertebra by advancing along the first linear trajectory; and
preloading a second fixating element rigidly in a second portion of
the spacer along a second linear trajectory that is different from
the first linear trajectory, the second fixating element configured
to penetrate and secure to a second vertebra by advancing along the
second trajectory.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/463,239, filed on Feb. 15, 2011, and U.S.
Provisional Application No. 61/517,717, filed on Apr. 25, 2011,
which are incorporated herein by reference in their entirety.
FIELD
[0002] The present disclosure relates to spinal implants and
associated instrumentation. Various embodiments are directed to an
anterior intervertebral fusion with fixation system, device and
method.
DESCRIPTION OF RELATED ART
[0003] A healthy spinal disc (intervertebral disc) is a
fibroelastic structure with a non-compressible viscous center that
articulates adjacent vertebrae. Due to its deformable geometry, the
disc not only supports normal functional loads of the human body,
but also evenly distributes the stresses applied during body
movement and positioning. The disc interfaces with associated
superior and inferior vertebrae via large surface areas known as
vertebral endplates. Normally, vertebral endplates are thin regions
of dense bone (e.g. 1 mm-3 mm) that support high stresses at
articulating junctions.
[0004] Intervertebral discs and adjacent articulations
progressively deteriorate with age. This natural degenerative
process results in various degrees of pathological changes, mostly
affecting the geometry and elasticity of a vertebral disc. In
severe cases, reduced disc volume results in foraminal compression
that mechanically irritates nerve roots and causes neurocompressive
syndrome. This often causes severe chronic pain that can only be
resolved surgically.
[0005] Historically, surgical treatment of degenerative spinal disc
disease required fusion, which immobilizes two adjacent vertebral
bodies (vertebrae) to prevent motion-sensitive pain and
inflammation. This is accomplished by distracting the vertebrae to
a healthy disc height, inserting a disc implant and allowing bone
to grow between and through the disc implant until the vertebrae
fuse into a solid bony structure. To facilitate proper healing
under normal conditions of motion, the disc implant is used to
maintain temporary positioning until the bone achieves fusion. The
implant is secured to the vertebrae using fixation elements.
[0006] The effectiveness of the disc implant can be evaluated with
the following criteria: (i) its ability to restore and maintain
normal disc height and curvature; (ii) its ease of delivery and
fixation to the disc space; (iii) its ability to facilitate fusion
of associated vertebrae; and (iv) its ability to restrict movement
of associated vertebrae.
[0007] Disc implants share the same fundamental characteristics to
meet the effectiveness criteria. Implants aim to restore disc
height through the use of variable geometries. Lordotic curvature
is preserved through the use ergonomic designs that conform to
spinal curvature and height between the vertebrae. Also, the disc
implants are sufficiently porous or hollow to promote the growth of
vertebral bone into and through the implant. However,
independently, these implants can only restrict spinal flexion and
intervertebral compression. Any excessive lateral, sliding, or
extension motion may cause device failure and/or extrusion. To
avoid this risk, it is customary to provide additional fixation of
the disc implant to the vertebrae.
[0008] Devices and systems may integrate fixating members directly
into the disc implant. These implants have garnered the nickname
"standalone" due to their ability to self-fixate without the use of
secondary fixation elements. In the foregoing standalone implants,
obtrusive fixation elements are delivered directly through implant
pilot openings into the vertebra, which fixate the implant to the
vertebrae and prevent implant failure under remaining ranges of
motion (e.g., lateral, sliding, extension). Nevertheless, during
these motions, connectivity between fixation elements and vertebrae
may become weakened causing the fixation elements to slip or
extrude out of the implant. To prevent unwanted fixation element
slipping or extrusion, it is customary to include a locking
mechanism for the implant.
SUMMARY
[0009] In a particular embodiment, an intervertebral fusion with
fixation device is disclosed. The device includes a spacer with an
insertion wall, a trailing wall opposite to the insertion wall, a
first lateral wall, a second lateral wall opposite to the first
lateral wall, a top surface, and a bottom surface opposite to the
top surface. The intervertebral fusion with fixation device further
includes a first fixating element rigidly preloaded in a first
portion of the spacer along a first linear trajectory, the first
fixating element configured to penetrate and secure to a first
vertebra by advancing along the first linear trajectory. The device
also includes a second fixating element rigidly preloaded in a
second portion of the spacer along a second linear trajectory that
is different from the first linear trajectory, the second fixating
element configured to penetrate and secure to a second vertebra by
advancing along the second trajectory. Further, the intervertebral
fusion with fixation device includes a through opening having an
entrance proximate the top surface and an exit proximate the bottom
surface to facilitate contact and in-growth of bone fusion material
with the first vertebra and second vertebra.
[0010] In another particular embodiment, an integrated drill and
screwdriver instrument is disclosed. The integrated drill and
screwdriver includes a handle, a driving element configured to
engage a head of a bone screw and rotate the bone screw into a
vertebra, and a drilling element extending from the from the
driving element. The drilling element is configured to extend
through a cannula of the bone screw and to penetrate the vertebra.
The driving element is configured to engage the head of the bone
screw as the drilling element penetrates through a vertebral
endplate.
[0011] In a further particular embodiment, an intervertebral fusion
with fixation system is disclosed. The system includes an
intervertebral fusion with fixation device configured to be
implanted between plural vertebrae. The device includes a spacer
with an insertion wall, a trailing wall opposite to the insertion
wall, a first lateral wall, a second lateral wall opposite to the
first lateral wall, a top surface, and a bottom surface opposite to
the top surface. The device further includes a first fixating
element rigidly preloaded in a first portion of the spacer along a
first linear trajectory, the first fixating element configured to
penetrate and secure to a first vertebra by advancing along the
first linear trajectory. Additionally, the device also includes a
second fixating element rigidly preloaded in a second portion of
the spacer along a second linear trajectory that is different from
the first linear trajectory, the second fixating element configured
to penetrate and secure to a second vertebra by advancing along the
second trajectory. The system also includes an integrated
integrated drill and screwdriver instrument. The integrated
instrument includes a handle, a driving element configured to
engage a head of a bone screw and rotate the bone screw into a
vertebra, and a drilling element extending from the from the
driving element. The drilling element is configured to extend
through a cannula of the bone screw and to penetrate the vertebra.
The driving element is configured to engage the head of the bone
screw as the drilling element penetrates through a vertebral
endplate.
[0012] In yet another particular embodiment, a method to secure
plural vertebrae is disclosed. The method includes implanting an
intervertebral fusion with fixation device between plural
vertebrae. The fusion with fixation device includes a spacer, a
first fixating element rigidly preloaded in a first portion of the
spacer along a first linear trajectory, and a second fixating
element rigidly preloaded in a second portion of the spacer along a
second linear trajectory that is different from the first linear
trajectory. The method further includes driving the first fixating
element along the first linear trajectory to penetrate the first
vertebra and to secure the spacer to a first vertebra, and driving
the second fixating element along the second linear trajectory to
penetrate the second vertebra and to secure the spacer to a second
vertebra. The method also includes extending an integrated drill
and screwdriver instrument through a cannula of the first fixating
element and a cannula of the second fixating element, drilling the
plural vertebrae with a drilling element, engaging the first
fixating element and second fixating element with a driving element
as the drilling element penetrates through a vertebral endplate of
the plural vertebrae, and rotating the first fixating element and
second fixating element via the driving element to penetrate the
plural vertebrae and to secure the spacer to the plural vertebrae.
The method further includes locking the first fixation element and
second fixation element with respect to the spacer to prevent the
first fixation element and second fixation element from extruding
from the plural vertebrae and from the spacer.
[0013] In a further embodiment, a method to assemble an
intervertebral fusion with fixation device is disclosed. The method
includes rigidly preloading a first fixating element in a first
portion of a spacer along a first linear trajectory and a second
fixating element in a second portion of the spacer along a second
linear trajectory, the first linear trajectory being different from
the second linear trajectory.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 is a perspective view of an example spacer of an
intervertebral fusion with fixation device;
[0015] FIG. 2 is a front view of the example spacer shown in FIG.
1;
[0016] FIG. 3 is a side view of the example spacer shown in FIG.
1;
[0017] FIG. 4 is a perspective view of an example fixation element
of the intervertebral fusion with fixation device;
[0018] FIG. 5 is a cross-sectional side view of the example
fixation element show in FIG. 4;
[0019] FIG. 6 is a side view of an example integrated drill and
screwdriver driving instrument;
[0020] FIG. 7 is a perspective exploded view of a tip of the
example integrated drill and screwdriver drilling tip shown in FIG.
6;
[0021] FIG. 8 is a perspective view of an example intervertebral
fusion with fixation device with the example fixation elements
shown in FIG. 4 preloaded in the example spacer shown in FIG.
1;
[0022] FIG. 9 is a perspective view of the example intervertebral
fusion with fixation device of FIG. 8 with the example integrated
drill and screwdriver of FIG. 6 actuating a fixation element shown
in FIG. 4.
[0023] FIG. 10 is a translucent perspective view of an example
intervertebral fusion with fixation device with the example
fixation element of FIG. 4 in a locked position within a
vertebra.
DETAILED DESCRIPTION
[0024] FIG. 1 is a perspective view of an example spacer 100 of an
intervertebral fusion with fixation device. The intervertebral
fusion with fixation device is illustrated in FIG. 8. The spacer
100 is made of a weight-bearing material, such as a polymer, metal,
ceramic, biological material, or composite thereof, that is capable
of withstanding the normal stresses of bodily movement and
positioning, while also allowing sufficient elasticity. The
material can have a flexural modulus and tensile strength
comparable to bone. For example, the spacer 100 can be made of
polyetheretherketone (PEEK), a thermoplastic with a flexural
modulus of 4.2 GPa and a tensile strength of 95 MPa. Another
benefit of PEEK is its high level of biocompatibility in a dynamic
and immunoreactive environment. Other materials and combinations of
materials are possible.
[0025] The spacer 100 includes an insertion wall 110, trailing wall
112, lateral walls 106, 108, top surface 102, bottom surface 104,
and through opening 114 extending between and through the top
surface 102 and bottom surface 104 for bone graft insert.
[0026] In various embodiments, the dimensions of the spacer 100 are
approximately the following: the length of the spacer 100 between
an insertion wall 110 and trailing wall 112 is between about 10 mm
and 80 mm; the width of the spacer 100 between a first lateral wall
106 and second lateral wall 108 is between about 10 mm and 80 mm;
and the height of the spacer 100 between a top surface 102 and
bottom surface 104 is between about 4 mm and 30 mm. The foregoing
dimensions are non-limiting and are intended to be adjusted
depending on the specific spinal anatomy of the patient.
[0027] The opening 114 can have a volume approximately between 0
cm.sup.3 and 8 cm.sup.3. Other volumes can be provided. While the
insertion wall 110, trailing wall 112, and lateral walls 106, 108
are generally flat surfaces, the top surface 102 and bottom surface
104 may be tapered or curved with respect to one another to conform
to intervertebral lordosis or curvature. The lateral walls 106, 108
can also have a tapered geometry to conform to intervertebral
space. In some embodiments, the angle between the lateral surfaces
106, 108 can be from about 0 degrees to about 16 degrees.
[0028] The trailing wall 112 includes a plurality of through holes
202 (shown in FIG. 2) extending from the central opening 114 to the
exterior of the spacer 100 to receive, secure, and guide plural
fixation elements 400 (shown in FIG. 4). Each of the foregoing
holes 202 is oriented to provide a trajectory for a fixation
element (shown in FIG. 4). The trajectories of the holes 202 can be
oriented in directions lateral, medial, superior, inferior, or any
combination thereof to the spacer to provide multi-axial fixation
to the vertebrae. In some embodiments, the holes 202 can direct the
fixation elements 400 in divergent trajectories to counterbalance
one another from any opposing torques or shear stresses initiated
by vertebral motion. The dimensions of the holes 202 are
approximately the following: the medial and/or lateral angle in
respect to lateral walls 106, 108 is between about 0 degrees and 25
degrees, and the superior and/or inferior angle in respect to
surfaces 102, 104 is between about 30 degrees and 50 degrees. The
diameters of the foregoing holes 202 are approximately between 0.5
mm and 10 mm.
[0029] FIG. 2 is a front view of the example spacer 100 shown in
FIG. 1. Now with reference to FIGS. 1 and 2, the spacer 100
includes ridges 116 on surfaces 102, 104 proximate the holes 202 to
reinforce the spacer 100 during advancement of the fixation
elements 400. For example, ridges 116 can be provided about the
exits to the outside of the spacer 100 and can be of various
dimensions and tapers along the surfaces 102, 104. In some
embodiments, the ridges 116 can be omitted. The spacer 100 further
includes ridges 118 along the surfaces 102, 104 that penetrate
surrounding vertebrae during implantation and provide stability to
the spacer 100 through micro-scale contact with the vertebral
plates.
[0030] The spacer 100 can include plural radiopaque markers 120 to
enhance radiographic visualization of the spacer 100. The markers
120 can be made of a biocompatible radiopacic material, such as
tantalum, platinum alloys, gold alloys, or palladium alloys. Other
applicable materials may also be employed. Plural markers 120 can
be provided near the walls 106, 108, 110, 112 and surfaces 102, 104
to provide additional visual references of the spacer 100 for
clinicians during radiographic imaging. Furthermore, the markers
120 can assume various geometries and volumes within the spacer 100
depending on visualization requirements. In various embodiments,
the markers 120 can be omitted.
[0031] FIG. 3 is a side view of an example spacer 100 of an
intervertebral fusion with fixation device of FIG. 8. In a
particular embodiment, the trailing height 302 gradually decreases
to the insertion height 304 at a taper to approximate natural
lordosis. Additionally, the ridges 116 can be also tapered to
minimize friction during insertion and facilitate smooth entry of
the spacer 100 into the intervertebral space.
[0032] FIG. 4 is a perspective view of an example fixation element
400. In a particular embodiment, the fixation element 400 can be
made of a biocompatible metal, such as a titanium alloy. Other
applicable materials may also be employed. The fixation element 400
includes a tip 405 that locks into and interfaces with the holes
202 during assembly to maintain a preloaded position, and
penetrates bone during engagement with vertebral endplates. The
fixation element 400 has a minor diameter 402 that is between about
1 mm and 10 mm. The fixation element 400 also includes a major
diameter 404 of threading that is between 2 mm and 15 mm to provide
cutting during engagement.
[0033] Additionally, the tip 405 includes flutes 406 to facilitate
penetration into the vertebra during initial engagement. The
fixation element 400 further includes a head 407 with a conically
shaped body 408 to pressure-fit into the holes 202 after
advancement via an instrument receiver 410. The instrument receiver
410 can interface with a driving instrument (shown in FIG. 6). In a
particular embodiment, the head 407 includes a hook protrusion 412
with a sharp edge that can cut into the hole 202 after the fixation
element 400 is advanced (e.g., fully) into the vertebra and the
head 407 is in contact with the spacer 100. The contact between the
sharp edge of the hook protrusion 412 and the hole 202 functions as
a locking mechanism to prevent extrusion of the fixation element
400.
[0034] FIG. 5 is a cross-sectional side view of an example fixation
element 400 of FIG. 4. As illustrated, the fixation element 400
includes a cannula 502 that allows a drilling tip of the driving
instrument (shown in FIG. 6) to pass into and through the fixation
element 400 to facilitate vertebral endplate pre-drilling and
preparation for advancement of the fixation element 400. The
fixation element 400 further includes a platform 504 that connects
or interfaces the driving instrument receiver 410 and cannula 502
to contact and limit the depth of motion of the driving instrument
(shown in FIG. 6) in relation to the fixation element 400.
[0035] FIG. 6 is a side view of an example integrated drill and
screwdriver driving instrument (driving instrument) 600. In a
particular embodiment, the driving instrument 600 can be made of a
metal, such as titanium. Other applicable materials may also be
employed. The driving instrument 600 includes an integrated tip 614
that can penetrate and pre-drill vertebral endplates with a drill
tip 606 as well as engage the driving instrument receiver 410 of a
fixation element 400 with a fixation element interface 604.
[0036] The drill tip 606 of the integrated tip 614 can pass into
and through the cannula 502 of the fixation element 400 in order to
penetrate and pre-drill a vertebral endplate. The fixation element
interface 604 can contact the driving instrument receiver 410 once
the drill tip 606 has penetrated through the vertebral endplate
into the softer bony layer. In a particular embodiment, both the
fixation element interface 604 and corresponding driving instrument
receiver 410 are of a quadrilateral shape to facilitate rigid
contact between the surfaces and allow engagement of the fixation
element 400.
[0037] The driving instrument 600 includes a body 602 to increase
operational distance from the spacer 100 and provide access under
various angulations. The body 602 is smoothly mated to the
integrated tip 614 with a conical transition element 610.
Furthermore, the driving instrument 600 includes a handle 612 that
can be operated manually or by an electrical or mechanical tool. In
a particular embodiment, the handle 612 can be constructed as a
hexagonal bit to fit a standard screwdriver. The handle 612 is
smoothly mated to the body 602 with a conical transition element
603.
[0038] FIG. 7 is an exploded perspective view of the example
integrated tip 614. The integrated tip 614 includes cutting blades
702 to facilitate vertebral penetration during advancement. The
integrated tip 614 further includes a rounded transition element
704 between the fixation element interface 604 and the drill tip
606 to allow smooth contact between the fixation element interface
604 and driving instrument receiver 410 during the initial
engagement of the fixation element 400.
[0039] FIG. 8 is a perspective view of an example intervertebral
fusion with fixation device 800 with the plural example fixation
elements 400 of FIG. 4 preloaded in the example spacer 100 of FIG.
1. As illustrated, the fixation elements 400 can be preloaded into
the spacer 100 via holes 202. The flutes 406 and threading 404 cut
into and secure the fixation elements 400 to the spacer 100 via
holes 202 to maintain a preloaded assembly. This preloaded assembly
ensures fixed trajectories for the fixation elements 400 during
delivery of the device 800 and eliminates the need for alignment
post-implantation.
[0040] FIG. 9 is a perspective view of an example intervertebral
fusion with fixation device of FIG. 8 with an example driving
instrument 600 of FIG. 6 actuating a fixation element 400 of FIG.
4. As illustrated, the integrated tip 614 is delivered into and
through the cannula 502 of the fixation element 400 to pre-drill
the vertebral endplate with the cutting blades 702 of the fixation
element 400. The penetration of the integrated tip 614 through the
vertebral endplate combined with the linear force applied to the
handle 612 drives the fixation element interface 604 into contact
with the driving instrument receiver 410 of the fixation element
400. Simultaneously, the torque from the handle 612 engages the
fixation element interface 604, which in turn actuates the driving
instrument receiver 410 and advances the fixation element 400 into
vertebral endplate. Additionally, the fixation element flutes 406
and major threading 404 penetrate and secure the fixation element
400 to the endplate of the vertebra.
[0041] FIG. 10 is a translucent perspective view of an example
intervertebral fusion with fixation device 800 with the plural
example fixation elements 400 of FIG. 4 in a locked position and
secured to a vertebra 1001. In a particular embodiment, the hook
protrusion 412 of the fixation element 400 pressure fits the holes
202 of the spacer 100 to prevent the fixation element 400 from
toggling and backing-out. Furthermore, the hook protrusion 412
rigidly cut into the spacer 100 via its sharp edge to limit the
ability of the fixation element 400 to torque towards the trailing
wall 112 of the device 800 and away from the vertebra 1001.
Additionally, the ridges 118 penetrate adjacent vertebral endplates
and provide ancillary stability.
[0042] Other apparent modifications and configurations of the
invention will be appreciated by those skilled in the art to allow
varying applications of the disclosed embodiments without departing
from the scope of the embodiments described herein. The disclosed
specifications and principles are intended to be used for
illustrative purposes only, with the true scope and spirit of the
patent document being defined by the following claims.
* * * * *