U.S. patent application number 12/524334 was filed with the patent office on 2011-08-11 for bone anchoring systems.
This patent application is currently assigned to INTRINSIC THERAPEUTICS, INC.. Invention is credited to Thomas Boyajian, Jacob Einhorn, Sean Kavanaugh, Gregory Lambrecht, Robert Kevin Moore, Christopher Tarapata, Almir Velagic.
Application Number | 20110196492 12/524334 |
Document ID | / |
Family ID | 40429391 |
Filed Date | 2011-08-11 |
United States Patent
Application |
20110196492 |
Kind Code |
A1 |
Lambrecht; Gregory ; et
al. |
August 11, 2011 |
BONE ANCHORING SYSTEMS
Abstract
Embodiments relate generally to tissue anchors and methods of
delive.pi.ng same to the intervertebral disc or other sites within
the body. In some embodiments, the anchors provide increased
pull-out resistance, stability and/or contact with tissue involving
a reduced amount of penetration. In some embodiments, delivery
methods are minimally invasive and can include linear, lateral, and
off-angle implantation or driving of anchors along, against or
within tissue surfaces. Several embodiments disclose anchors and
ancho.pi.ng systems that effectively reconstruct or augment
vertebral endplate surfaces.
Inventors: |
Lambrecht; Gregory; (Natick,
MA) ; Boyajian; Thomas; (Wilmington, MA) ;
Velagic; Almir; (Melrose, MA) ; Moore; Robert
Kevin; (Natick, MA) ; Tarapata; Christopher;
(North Andover, MA) ; Einhorn; Jacob; (Brookline,
MA) ; Kavanaugh; Sean; (Eastham, MA) |
Assignee: |
INTRINSIC THERAPEUTICS,
INC.
Woburn
MA
|
Family ID: |
40429391 |
Appl. No.: |
12/524334 |
Filed: |
September 5, 2008 |
PCT Filed: |
September 5, 2008 |
PCT NO: |
PCT/US08/75496 |
371 Date: |
March 10, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60967782 |
Sep 7, 2007 |
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61066334 |
Feb 20, 2008 |
|
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61066700 |
Feb 22, 2008 |
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61126548 |
May 5, 2008 |
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Current U.S.
Class: |
623/17.16 |
Current CPC
Class: |
A61B 2017/0414 20130101;
A61F 2310/00029 20130101; A61B 17/0642 20130101; A61F 2/442
20130101; A61F 2002/30841 20130101; A61F 2/4455 20130101; A61F
2002/30451 20130101; A61B 2017/0464 20130101; A61F 2002/30899
20130101; A61F 2220/0091 20130101; A61B 2017/0437 20130101; A61B
2017/044 20130101; A61F 2/0811 20130101; A61F 2002/30481 20130101;
A61F 2002/30462 20130101; A61F 2220/0075 20130101; A61B 17/0682
20130101; A61B 2017/0412 20130101; A61F 2002/30904 20130101; A61B
2017/0409 20130101; A61F 2220/0058 20130101; A61F 2002/30062
20130101; A61F 2/30965 20130101; A61F 2002/30471 20130101; A61F
2002/305 20130101; A61F 2220/0025 20130101; A61F 2002/2835
20130101; A61B 17/0401 20130101; A61F 2210/0004 20130101; A61F
2002/3082 20130101; A61F 2002/30884 20130101; A61F 2310/00293
20130101; A61B 2090/036 20160201; A61F 2002/30492 20130101; A61F
2002/4435 20130101; A61F 2310/00017 20130101; A61F 2310/00023
20130101 |
Class at
Publication: |
623/17.16 |
International
Class: |
A61F 2/44 20060101
A61F002/44 |
Claims
1-24. (canceled)
25. A graft containment system, comprising: a support member for
containing a bone graft implanted in a disc space between two
vertebral bodies; and a bone anchor for insertion into an outer
surface and an endplate of a first vertebral body, wherein the bone
anchor comprises a neck having a length defined by a sharpened
leading edge and a trailing end, wherein said neck comprises an
attachment site along at least a portion of its length, wherein
said support member is coupled to the neck via the attachment site,
wherein said neck comprises a bottom portion terminating in two or
more keels, wherein said keels are configured for pull-out
resistance and stability by presenting a larger surface area below
the endplate and embedded in the outer surface, wherein said keels
form an angle of about 10 to about 180 degrees relative to each
other; wherein each of said keels comprises sharpened leading
edges, wherein the attachment site is offset relative to both the
anchor's angle of insertion and said neck to present said
attachment site along the first endplate, while said keels are
inserted into the outer surface, wherein the sharpened leading
edges of said keels are adapted to be driven into the outer surface
while the support member is simultaneously advanced along and
across the endplate, and wherein the support member is configured
to block the bone graft from extruding from the disc space.
26. The graft containment system of claim 25, wherein the support
member comprises a polymer and the anchor comprises titanium.
27. The graft containment system of claim 25, wherein the neck
comprises two keels that form an angle of about 180 degrees
relative to each other.
28. The graft containment system of claim 25, wherein the neck
comprises two keels that form an angle of about 180 degrees
relative to each other, and wherein the neck is perpendicular to
said keels to form a "T" shape.
29. The graft containment system of claim 25, wherein the support
member comprises an anulus augmentation device.
30. The graft containment system of claim 25, wherein the support
member comprises a nucleus augmentation device.
31. The graft containment system of claim 25, wherein the support
member comprises a biologically active or therapeutic agent.
32. The graft containment system of claim 25, wherein the support
member comprises a polymer.
33. The graft containment system of claim 25, wherein the bone
anchor further comprises an engagement portion.
34. The graft containment system of claim 33, wherein said
engagement portion comprises at least one barb, hook, or angled
projection.
35. The graft containment system of claim 33, wherein said
engagement portion comprises one or more teeth, spikes or
barbs.
36. The graft containment system of claim 33, wherein said
engagement portion comprises one or more protrusions.
37. The graft containment system of claim 33, wherein said
engagement portion comprises one or more friction plates.
38. The graft containment system of claim 25, wherein the bone
anchor comprises a biologically active or therapeutic agent.
39. The graft containment system of claim 25, wherein the anchor is
at least partially constructed from a material selected from the
group consisting of one or more of the following: nickel titanium
alloy, titanium, cobalt chrome alloy, and steel.
40. The graft containment system of claim 25, wherein said support
member and said anchor are integral.
41. A method of reconstructing or augmenting a vertebral endplate
to retain a graft, comprising: identifying a first vertebral body
and a second vertebral body, wherein said first vertebral body
comprises a first outer surface and a first endplate; identifying a
disc space bordered by the first vertebral body and the second
vertebral body, providing a bone graft containment system
comprising a bone graft, a support member for containing the bone
graft, and a bone anchor, wherein the bone anchor is configured for
insertion into the first outer surface and for presenting an
attachment site along the first endplate, wherein the first outer
surface is offset at an angle substantially perpendicular from the
first endplate, wherein the support member is coupled to the bone
anchor; wherein the bone anchor comprises a neck, wherein said neck
has a length defined by a sharpened leading edge and a trailing
end, wherein said neck comprises an attachment site along at least
a portion of its length, wherein said attachment site is attachable
to the support member, wherein the attachment site is configured to
extend above the first endplate, wherein said neck comprises a
bottom portion terminating in two or more keels, wherein said keels
are configured for pull-out resistance and stability by presenting
a larger surface area below the first endplate and embedded in the
first outer surface, wherein said keels form an angle of about 10
to about 180 degrees relative to each other; wherein each of said
keels comprises sharpened leading edges, wherein the attachment
site is offset relative to both the anchor's angle of insertion and
said neck to present said attachment site along the first endplate,
while said keels are inserted into the first outer surface;
inserting the bone graft into the disc space; driving the sharpened
leading edges of the keels into the first outer surface while
simultaneously advancing the support member along and across the
first endplate until said anchor is countersunk within said outer
surface; and positioning the support member to contain the bone
graft, thereby reconstructing or augmenting the endplate of the
first vertebral body to minimize extrusion of the bone graft from
the disc space.
42. The method of claim 41, wherein the neck comprises two keels
that form an angle of about 180 degrees relative to each other.
43. The method of claim 41, wherein the neck comprises two keels
that form an angle of about 180 degrees relative to each other, and
wherein the neck is perpendicular to said keels to form a "T"
shape.
44. A method of reconstructing or augmenting a vertebral endplate
to retain a graft, comprising: identifying a first vertebral body
and a second vertebral body, wherein said first vertebral body
comprises a first outer surface and a first endplate; identifying a
disc space bordered by the first vertebral body and the second
vertebral body, providing a bone graft containment system
comprising a support member for containing a bone graft and a bone
anchor, wherein the bone anchor is configured for insertion into
the first outer surface and for presenting an attachment site along
the first endplate, wherein the first outer surface is offset at an
angle substantially perpendicular from the first endplate, wherein
the support member is coupled to the bone anchor, wherein the bone
anchor comprises a neck, wherein said neck has a length defined by
a sharpened leading edge and a trailing end, wherein said neck
comprises an attachment site along at least a portion of its
length, wherein said attachment site is attachable to the support
member, wherein the attachment site is configured to extend above
the first endplate, wherein said neck comprises a bottom portion
terminating in at least one keel, wherein said keel is configured
for pull-out resistance and stability by presenting a larger
surface area below the first endplate and embedded in the first
outer surface, wherein said keel is substantially perpendicular to
said neck to form a T-shape, wherein said keel comprises a
sharpened leading edge, wherein the attachment site is offset
relative to both the anchor's angle of insertion and said neck to
present said attachment site along the first endplate, while said
keel is inserted into the first outer surface; inserting the bone
graft into the disc space; advancing the sharpened leading edge of
the keel against the first outer surface while simultaneously
advancing the support member along and across the first endplate;
and positioning the support member to contain the bone graft,
thereby reconstructing or augmenting the endplate of the first
vertebral body to minimize extrusion of the bone graft from the
disc space.
45. The method of claim 44, wherein the support member comprises a
polymer and the anchor comprises titanium.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional
application Nos. 60/967,782, filed Sep. 7, 2007, 61/066,334, filed
Feb. 20, 2008, 61/066,700, filed Feb. 22, 2008, and 61/126,548,
filed May 5, 2008.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The invention relates generally to tissue anchors, delivery
methods, and associated treatments. Anchors according to one or
more embodiments can provide superior pull-out resistance,
stability and may, in some embodiments, increase contact with
tissue involving a reduced amount of penetration. Delivery methods
include linear, lateral, and off-angle implantation or driving of
anchors along, against or within tissue surfaces.
[0004] 2. Description of the Related Art
[0005] Anchors described herein can be used throughout the human
body and have general applicability to fastener art. Such anchors
can be used to join or anchor like or disparate materials or
tissues together, maintain alignment of materials, reinforce a
fracture within a material, and provide an attachment site along or
within a materials surface. Generally the art includes both staples
and screws. For example, U.S. Pat. No. 7,131,973 to Hoffman
discloses an anchor and delivery system for treating urinary
incontinence. The distal portion of the delivery tool is curved and
hooked such that pulling on the instruments handle effects a
retrograde delivery of the anchor. U.S. Pat. No. 5,366,479 to
McGarry et al. discloses a staple and delivery system. The staple
is flat but contains a pair of inwardly curving prongs. U.S. Pat.
No. 5,391,170 to McGuire et al. discloses an angled screw driver
for inserting bone screws in ligament tunnels as part of a ligament
reconstruction procedure. U.S. Pat. No. 5,217,462 to Asnis et al.
discloses a screw and driver combination having threaded shank and
sleeve that cooperate to hold and release the screw. U.S. Pat. No.
5,002,550 to Li discloses a suture anchor with barbs and an
installation tool that includes a curved needle for attaching a
suture.
SUMMARY
[0006] As described above, tissue anchors exist in the prior art.
However, there remains a need for anchors and anchoring systems
that effectively reconstruct or augment vertebral endplate
surfaces. There also exists a need to effectively close defects
between opposing endplates.
[0007] In one embodiment, a method of reconstructing or augmenting
a vertebral endplate is provided. In one embodiment, the method
comprises: providing at least a first anchor and a second anchors,
wherein each anchor comprises an upper neck and a lower bone
engagement portion and wherein the neck has an attachment site for
coupling to an augmentation material. The method further comprises
identifying a vertebral endplate surface adjacent damaged or
removed tissue (or tissue that is otherwise weak or in need of
support) and driving the first and second anchors into and along
the vertebral endplate adjacent the damaged tissue, wherein the
lower bone engagement portion engages the vertebral endplate. The
method further comprises coupling the attachment site of the first
anchor to a first augmentation material and coupling the attachment
site of the second anchor to a second augmentation material. The
method also comprises positioning at least a portion of the first
and second augmentation material or the neck above the endplate
surface, and connecting the first anchor to the second anchor
and/or connecting the first augmentation material to the second
augmentation material, thereby reconstructing or augmenting the
vertebral endplate.
[0008] In one embodiment, the augmentation material comprises a
bone graft, an expandable frame and/or cement, or combinations
thereof. In one embodiment, the augmentation material comprises a
barrier, mesh, scaffold, band or suture, or combinations thereof.
In one embodiment, the first augmentation material and the second
augmentation material are a single unit or opposing portions of a
continuous construct. In other embodiments, they are separate
pieces. In one embodiment, the lower bone engagement portion
comprises a shaft, prong, plate or keel, or combinations thereof.
In one embodiment, the anchors are driven into and along the
vertebral endplate at an angle of about 0 to about 90 degrees,
preferably about 0-20 degrees. The step of interconnecting the
augmentation material comprises, in one embodiment, forming a band
around the entire periphery of the endplate.
[0009] In another embodiment of the invention, a method of
reconstructing or augmenting a vertebral endplate using a laterally
deliverable curvilinear anchor is provided. In one embodiment, the
method comprises providing an expandable frame comprising a distal
connection site for connecting to the anchor and delivering a bone
graft between two adjacent vertebral bodies. The method further
comprises advancing the frame proximal to the graft and expanding
the frame to retain the graft. The method further comprises
advancing the curvilinear anchor between the vertebral bodies
proximate to the frame along a first axis and coupling the frame to
the anchor. The method further comprises driving the curvilinear
anchor into an endplate of one of the vertebral bodies in an arc
such that the head of the anchor is roughly perpendicular to the
first axis and at least partially extends above the endplate,
thereby reconstructing or augmenting the endplate. In several
embodiments, an interbody spacer or other device is used instead of
or in addition to the bone graft. In one embodiment, the anchor is
delivered from a posterior approach across the vertebral endplate
and driven into an anterior portion of the vertebral endplate.
[0010] In yet another embodiment of the invention, a method of
attaching an anchor to a vertebral body endplate is provided. In
one embodiment, the method comprises (a) providing an anchor
comprising an upper attachment site connected to lower keel member;
(b) wherein the keel comprises a leading edge connected to a lower
screw coupling member; (c) driving a portion of the screw coupling
member into an outer surface of the vertebral body; (d) driving a
portion of the leading edge of the keel member into the vertebral
body; (e) driving a portion of the upper attachment site across the
vertebral endplate; wherein steps (c), (d) and (e) are performed
simultaneously. The method further comprises driving a screw into
an outer surface of the vertebral body; and coupling the screw with
the screw coupling member. The implant may comprise anulus and/or
nucleus augmentation material, or combinations thereof.
[0011] In one embodiment, a method of attaching an anchor to a
vertebral body endplate further comprises forming a pilot hole in
an outer surface of a vertebral body, aligning the screw coupling
member with the hole, and driving the anchor into the vertebral
body. In one embodiment, the method comprises attaching an implant
to the upper attachment site of the anchor.
[0012] In one embodiment, a method of closing a defect between
opposing vertebral endplates is provided. In several embodiments, a
duckbill-type device is used. In one embodiment, the method
comprises attaching a first gate member to a superior endplate and
attaching a second gate member to an inferior endplate. Both gates
have a proximal and distal end. The proximal end of the first gate
is coupled to the superior endplate. The distal end of the first
gate extends medially into an intervertebral disc space. The
proximal end of the second gate is coupled to the inferior
endplate. The distal end of the second gate extends medially into
the intervertebral disc space. The method further comprises
contacting the distal ends of the first and second gates to close a
defect between opposing endplates.
[0013] In one embodiment, the first and second gates have a length
greater than the distance spanning the opposing endplates at
maximum distraction. In one embodiment, the first and second gates
comprise flexible plates having a curved bias about a portion of
the distance between their proximal an distal ends. In another
embodiment, the first and second gates are at least partially
concave. In one embodiment, the gates are multi faceted. In another
embodiment, the distal ends of the gates form an angle between
about 0 to about 180 degrees.
[0014] In one embodiment of the invention, a bone anchor for
insertion into a first surface of a bone and along an adjacent
second surface of said bone is provided. In one embodiment, the
anchor comprises a neck having a length defined by a sharpened
leading edge and a trailing end. The neck comprises an attachment
site along at least a portion of its length. The neck also
comprises a bottom portion terminating in two or more keels. A
single keel may also be used in some embodiments. The keels are
configured for pull-out resistance and stability by presenting a
larger surface area below or embedded within said second surface of
the bone relative to said neck. The keels form an angle from about
10 to about 180 degrees relative to each other. The keels comprises
sharpened leading edges. The attachment site is offset relative to
both the anchor's angle of insertion and said neck to present said
attachment site along the second surface of said bone while said
keels are inserted into said first surface. The sharpened leading
edges of said keels are adapted to be driven into the first surface
of the bone while simultaneously advancing the attachment site
across said second surface. The attachment site is configured for
coupling to a tissue or a prosthetic implant for repairing said
bone or adjacent tissue. The anchor further comprises an arm
extension rotatably or flexibly coupled to the neck along its
length and terminates in at least one barb, hook, or angled
projection, or combinations thereof. The bone anchor may be
configured for use in the vertebral disc.
[0015] Although one anchor is provided in some embodiments, two,
three, four, five, ten or more anchors are used in alternative
embodiments. The anchor delivery tools and instruments described
below may be used to deliver any of the anchors described
herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIGS. 1A-B show an axial and sagittal view respectively of a
spine segment and various anchor sites.
[0017] FIG. 2 shows an exploded view of one embodiment of a
curvilinear anchor and delivery instrument.
[0018] FIG. 3 shows a perspective view of one embodiment of a
curved two pronged staple type anchor.
[0019] FIGS. 4A-E show a sequence involving loading an anchor into
a delivery instrument and forcing it out of the lateral opening at
the distal end of the delivery instrument according to one
embodiment.
[0020] FIG. 5 shows an exploded view of one embodiment of a
delivery instrument and detachable sleeve.
[0021] FIGS. 6A-G show a delivery sequence involving a vertebral
endplate according to one embodiment.
[0022] FIG. 7 shows a prior art bone screw and intervertebral
anatomy.
[0023] FIG. 8 shows an embodiment of an anchor according to one or
more embodiments.
[0024] FIG. 9 shows another embodiment of an anchor according to
one or more embodiments.
[0025] FIG. 10 shows another embodiment of an anchor according to
one or more embodiments.
[0026] FIG. 11 shows one embodiment a delivery tool.
[0027] FIG. 12 shows the delivery tool in the previous figure with
an anchor mounted
[0028] FIG. 13 shows an axial cross sectional view of a vertebral
body and implanted anchor.
[0029] FIGS. 14A-B show an expanded view and a frontal view of the
implanted anchor in the previous figure.
[0030] FIG. 15 shows a sagittal view of the implanted anchor in the
previous figures.
[0031] FIG. 16 shows an axial cross sectional view of a vertebral
body and a delivery tool inserted along an endplate in the vicinity
of an anulus defect or anulotomy.
[0032] FIG. 17 shows an axial cross sectional view of a vertebral
body wherein an anulus reinforcement device has been implanted
along and within the anulus and is attached to an anchor embedded
within the vertebral body.
[0033] FIGS. 18A-C show various views and features of anchors
according to one or more embodiments.
[0034] FIG. 19 shows various profiles of the keel portion of one or
more anchors.
[0035] FIG. 20 shows a perspective view of another embodiment of an
anchor according to one or more embodiments with a plate-like
attachment means suitable for three sutures.
[0036] FIG. 21 shows a perspective view of another embodiment of an
anchor according to one or more embodiments with an "eye"
attachment means.
[0037] FIGS. 22A-B show embodiments of the anchor and delivery
tool. FIG. 22A shows a perspective view of another embodiment of an
anchor according to one or more embodiments having a three legged
keel portion and designed such that only the attachment portion
remains proud on the tissue surface. FIG. 22B shows a delivery tool
for driving an anchor with a mated surface and alignment pins.
[0038] FIGS. 23A-B show a perspective view of another embodiment of
an anchor according to one or more embodiments having a flexible
linkage member.
[0039] FIGS. 24A-C show a series of perspective views of one
embodiment of an anchor and barrier system according to one or more
embodiments.
[0040] FIGS. 25A-C show a series of perspective views of another
embodiment of an anchor and barrier system according to one or more
embodiments.
[0041] FIGS. 26A-B show a side view and perspective view of an
anchor with a sharpened leading edge having a recessed region
corresponding to the cupped cortical rim of a vertebral
endplate.
[0042] FIG. 27A illustrates an embodiment of a stabilization
assembly in combination with a separate anchor.
[0043] FIG. 27B illustrates an embodiment of an anchor secured to
bone tissue and connected to an implant.
[0044] FIGS. 28A-28F illustrate various approaches of an
implantation tool to target tissue.
[0045] FIGS. 29A-29F illustrate a plurality of lateral views of
various embodiments of anchors and attachment positions and
locations with respect to patient tissue.
[0046] FIG. 30A illustrates a top view of one embodiment of a
support member.
[0047] FIGS. 30B and 30C illustrate first and second configurations
of an embodiment of a support member connected to an anchor.
[0048] FIG. 31A illustrates an embodiment of an anchor partially
engaged with a support member.
[0049] FIG. 31B illustrates the embodiment of anchor and support
member of FIG. 31A in a fully engaged configuration.
[0050] FIG. 31C illustrates a top view of an embodiment of a
support member in an insertion configuration as maintained by a
sleeve.
[0051] FIG. 31D illustrates a support configuration of the support
member of FIG. 31C.
[0052] FIG. 32 illustrates an embodiment including a plurality of
anchors connected to respective gate numbers.
[0053] FIG. 33 illustrates an embodiment of anchors and attached
gate members in one embodiment of an implanted position.
[0054] FIGS. 34A-34C illustrate a plurality of embodiments of
anchors and attached gate members and corresponding implantation
locations.
[0055] FIGS. 35A and 35B illustrate two embodiments of anchors and
attached gate members and corresponding implantation
configurations.
[0056] FIGS. 36A-36C illustrate embodiments of an anchor and
attached gate member and respective fixation locations with respect
to an inner and outer surface of an anulus fibrosus.
[0057] FIG. 37 illustrates an embodiment of an anchor and attached
gate member having a plurality of interweaved fingers.
[0058] FIGS. 38A and 38B illustrate top and side schematic views
respectively of various shapes and configurations of gate
members.
[0059] FIG. 39A illustrates an embodiment of multiple anchors and
attached respective gate members where the gate members are
interweaved but not aligned with each other.
[0060] FIG. 39B illustrates an embodiment of multiple anchors and
connected respective gate members wherein the gate members
associated with a respective anchor are substantially aligned with
each other.
[0061] FIG. 39C illustrates schematic top views of various
configurations of gate members including concave, multifaceted, and
rounded.
[0062] FIG. 40A illustrates an embodiment of anchors and attached
gate members, wherein opposing gate members are substantially
mirror images of each other and positioned in substantial
alignment.
[0063] FIG. 40B illustrates an embodiment of anchors and attached
gate members, wherein opposing gate members engage such that one
gate member at least partially nests within the opposite gate
member.
[0064] FIG. 41 illustrates an embodiment of anchors and attached
gate members wherein opposed gate members are connected by an
embodiment of a connector.
[0065] FIGS. 42A and 42B illustrate side and end views respectively
of embodiments of first and second anchor structures.
[0066] FIGS. 43A-43D illustrate one embodiment of an implantation
sequence of the embodiments of first and second anchor structures
of FIGS. 42A and 42B.
[0067] FIG. 44A and 44B illustrates a side view of another
embodiment of first and second anchor structures.
[0068] FIGS. 45A-45C illustrate one embodiment of an implantation
sequence of the embodiment of first and second anchor structures of
FIG. 44.
[0069] FIGS. 46A and 46B illustrate perspective and side views
respectively of an embodiment of a support implant.
[0070] FIGS. 47A and 47B illustrate an anterior posterior view and
lateral view respectively of an embodiment of a support implant
provided with a plurality of markers configured to indicate a
configuration of the support implant at an implantation
location.
[0071] FIG. 48 and Detail A are a schematic side view of an
embodiment of a support implant including an anchor and a moveable
support structure attached thereto.
[0072] FIG. 49 illustrates an embodiment of a delivery tool
configured to facilitate the implantation of embodiments of support
implants.
[0073] FIGS. 50A-50E illustrate one embodiment of an implantation
sequence utilizing embodiments of the delivery tool of FIG. 49.
[0074] FIG. 51 illustrates an embodiment of delivery tool and
attached support implant defining a plurality of adjacent locating
surfaces configured for support and alignment with patient
tissue.
[0075] FIGS. 52A-52E illustrate a plurality of configurations of a
support implant deployed at various implantation locations.
[0076] FIGS. 53A-53C illustrate an embodiment of an implantation
process and cooperating anchor and delivery tool.
[0077] FIGS. 54A-54C illustrate another embodiment of a delivery
tool and embodiments of operation of the tool at various stages of
an implantation procedure.
[0078] FIGS. 55A and 55B illustrate embodiments of an implantable
support anchor in an implanted side view and perspective view
respectively.
[0079] FIGS. 56A and 56B illustrate embodiments of an implantable
support anchor in side view and end view respectively.
[0080] FIG. 56C and 56D illustrate the embodiments of an
implantable support anchor of FIGS. 55A and 55B and an embodiment
of driver adapted for use therewith.
[0081] FIGS. 57A and 57B illustrate perspective views of
embodiments of implantable support anchor with a support structure
and multiple keel members.
[0082] FIGS. 57C and 57D illustrate schematic side views of the
embodiments illustrated by FIGS. 57A and 57B in an implanted
position.
[0083] FIGS. 58A and 58B illustrate perspective views of further
embodiments of implantable support anchors.
[0084] FIGS. 59A and 59B illustrate side views of embodiments of
implantable support anchor having a movable arm.
[0085] FIG. 59C illustrates a schematic side view of the
embodiments illustrated by FIGS. 59A and 59B in an implanted
position.
[0086] FIG. 59D is a top view of the embodiments illustrated by
FIGS. 59A and 59B.
DETAILED DESCRIPTION
[0087] Embodiments relate generally to tissue anchors and methods
of delivering tissue anchors to the intervertebral disc or other
sites within the body. In some embodiments, the tissue anchors
provide increased pull-out resistance, improved stability and/or
increased contact with tissue involving a reduced amount of
penetration. In some embodiments, delivery methods are minimally
invasive and include, but are not limited to, linear, lateral, and
off-angle implantation or driving of anchors along, against or
within tissue surfaces. In several preferred embodiments, bone
anchors are provided.
[0088] The term "anchor" as used herein shall be given its ordinary
meaning and shall also include, but not be limited to, nails,
staples, screws, fasteners, sutures, spikes, tacks, keys, pegs,
rivets, spikes, bolts, and pins. In several embodiments, the anchor
comprises one or more tines or prongs. In one embodiment, the
anchor is forked. In some embodiments, the anchor may be straight,
curved, or partially curved.
[0089] In several embodiments, the anchors disclosed herein are
particularly suited for hard tissues such as bone. In other
embodiments, soft tissue anchors are provided. One or more
embodiments of the anchor can be delivered into a tissue and be
secured within said tissue and resist extraction, migration, and/or
rotation. Such stability is especially important in environments
like the spine, where the anchor is adjacent delicate nerve tissue
such as the spinal cord. However, in several embodiments, the
anchoring system may be used in other delicate vasculature such as
the aorta.
[0090] Although several examples of sites appropriate for anchors
are described herein for use in the boney tissue of the spine and
particularly the vertebral endplates, anchors according to the
embodiments described herein have broad applications. For example,
the anchors described herein may be used in the radial head, ulnar
head, humeral head, tibial plateau, scapula, acromion, talus,
malleolus, tendons and ligaments such as the talo-fibular ligament,
anterior cruciate ligament, patella tibial tendon, Achilles tendon,
rotator cuff, and other tissues such as the meniscus. Further,
anchors according to one or more embodiments can be disposed within
artificial tissues and/or prosthetics.
[0091] FIG. 1A provides a sagittal view of a spine segment. Also
shown are numerous potential anchor sites and are marked as "X."
FIG. 1B is an axial view of the same spine segment and shows other
possible anchoring sites including along or within a vertebral
body, endplate, transverse process, spinous process, facet, and
pedicle. In other embodiments, an anchor can be placed along the
cortical rim of the endplate or medially within the cancellous bone
or relative to or within a pedicle, skull, or sacrum. Other
anchoring sites include, but are not limited to: relative to a
defect within the disc either in the area of the defect, at the
interface of the anulus and nucleus or in the area of the
nucleus.
[0092] In several embodiments, one or more anchors are used in
connection with an anulus or nucleus augmentative device, as
described in U.S. Pat. Nos. 6,425,919; 6,482,235; 6,508,839; and
6,821,276, all herein incorporated by reference. In one embodiment,
one or more anchors are used to anchor an anulus augmentation
device that is placed within or beyond a defect in the anulus to
the vertebral endplates.
[0093] One or more embodiments comprise anchors or gates disclosed
herein are made at least partially of one or more of the following
materials: any biocompatible material, material of synthetic or
natural origin, and material of a resorbable or non-resorbable
nature. The anchor may also be partially or wholly constructed from
material including, but not limited to, autograft, allograft or
xenograft; tissue materials including soft tissues, connective
tissues, demineralized bone matrix and combinations thereof;
resorbable materials including polylactide, polyglycolide, tyrosine
derived polycarbonate, polyanhydride, polyorthoester,
polyphosphazene, calcium phosphate, hydroxyapatite, bioactive
glass, collagen, albumin, fibrinogen and combinations thereof; and
non-resorbable materials including polyethylene, polyester,
polyvinyl alcohol, polyacrylonitrile, polyamide,
polytetrafluorethylene, polyparaphenylene terephthalamide,
cellulose, and combinations thereof. Further examples of
non-resorbable materials include carbon-reinforced polymer
composites, shape memory alloys, titanium, titanium alloys, cobalt
chrome alloys, stainless steel, and combinations thereof. In some
embodiments, the anchor comprises titanium alloys or cobalt
chrome.
[0094] In several embodiments, the anchor comprises an anchor body
and an anchor attachment site. In one embodiment, the anchor
attachment site is adapted to accept or connect to a suture,
linkage element, threaded screw, and/or provides a surface for
ingrowth into an adjacent structure. The anchor attachment site can
be integral to the anchor or a separate structure comprised of the
same or different material as the anchor body. The anchor
attachment site can be coupled to the anchor body. For example, the
anchor attachment site can be flexibly, rigidly, or rotationally
connected to the anchor body.
[0095] The anchor attachment site can comprise one or more of the
following structures: head, flange, plate, disc, protrusion,
channel, hole, cleat or eye. These structures can be placed at
various positions along the anchor. For example, one or more of
these structures may be placed at or near the ends of the anchor,
in the middle of the anchor, or at any other desired position. In
some embodiments, the anchor attachment site comprises mesh,
fabric, or membrane material, or a combination thereof. The site
may be parallel, perpendicular or angled with respect to the body
of the anchor. In one embodiment, the anchor attachment site is
located on an end or terminus of the anchor body.
[0096] In one embodiment, the anchor comprises one anchor body and
one anchor attachment site. In another body, the anchor comprises
one or more anchor bodies and one or more anchor attachment sites.
In one embodiment, the anchor comprises one body and two attachment
sites.
[0097] In one embodiment, at least a portion of the anchor or gate
comprises a biologically active or therapeutic agent. For example,
in some embodiments, at least a portion of the anchor can comprise
growth factors such as bone morphogenic proteins, insulin-like
growth factor 1, platelet derived growth factor, and fibroblast
growth factor. In one embodiment, both the anchor body and anchor
attachment portion of the anchor can be adapted to deliver a
biologically active or therapeutic agent. In other embodiments, at
least a portion of the anchor is coated with a biologically active
or therapeutic agent.
Curvilinear Anchor
[0098] Anchors (including staples, nails, and other fastening or
joining devices) according to one or more embodiments can be
partially or wholly arcuate or curvilinear. The radius of curvature
(the tightness or gentleness of the curve) can vary among
embodiments as can the section of a circle corresponding to the
anchor. For example, an anchor having a 90 degree curve would
appear as 1/4 of a circle. Other ranges of curves between 0-180
degrees are also possible. In some embodiments, for example, the
curvature is about 15, 30, 45, 60, 75, 90, 120, 150, or 180
degrees.
[0099] An anchor can also be at least partially curved with a
linear portion extending upward. In this embodiment the curved
portion is adapted for driving into a tissue and the straight
portion remains proud, or above the surface. Depending upon how the
anchor is driven into the surface, the proud portion of the anchor
can be anywhere from 0-180 degrees relative to the surface. The
curvature of an embodiment of the anchor can also be variable along
the anchor. Such a variable curvature could be employed to increase
or decrease pressure on tissues adjacent to the anchor. In one
embodiment, the proud portion is about 15, 30, 45, 60, 75, 90, 120,
150, or 180 degrees relative to the surface.
[0100] The surface or body of the anchor can be roughened, porous,
barbed, lubricated, coated or impregnated with a biologically
active or therapeutic agent. The anchor can be in the form of a
curved nail or staple with a crown or bridge and having two or more
prongs or legs extending therefrom. A slot or gap between the
prongs in one ore more embodiments of a staple can be aimed at a
suture or other structure already implanted in or along a surface
and then hammered in place thereby anchoring the suture in place.
The tips of the prongs of a staple can be beveled to effect a
wedging action. By beveling or angling the inner, outer, front,
and/or back of a prong tip, the prong will tend to travel in a
particular direction. Moreover, the beveled tips can complement
each other, work in opposition, or some combination thereof. In one
embodiment the prong tips are beveled on the outside edge, in
another embodiment the tips are beveled on the inside edge. In yet
another embodiment, the top of one prong is beveled and the bottom
of another is beveled. In addition, the cross section of prongs may
be variable along the length of the anchor. In one embodiment, the
anchor prong's smallest cross section is at or near the tip and at
its greatest furthest from the tip, creating a wedge along the
curve of the anchor. This may aid in increasing compression on all
or part of the bone or other tissue in contact with the anchor.
[0101] In another embodiment, an anchor can be resiliently flexible
such that after passing through a curved slot or deflecting surface
of the delivery device, the anchor (including staples, nails, etc)
straightens out to its original shape as it is advanced out of the
device and into the tissue. The original shape, predetermined
shape, first shape, or unrestrained shape can be, for example,
straight, angled, corkscrew, or offset. The prongs or legs of one
or more embodiments of the anchor, such as, for example, a staple,
can be straight, curved, angled, corkscrew, or offset with respect
to each other.
Anchor Delivery Tool
[0102] Turning now to FIG. 2, shown is one embodiment of an anchor
3 and delivery instrument 6 according to one or more aspects of the
invention. A guide body 4 has a cylindrical grip or hand hold and
first proximal and second distal end. The body 4 can be partially
or fully hollow and contain a guide way chamber 5 for holding and
orienting an anchor or staple 3 terminating in an opening at the
distal end of the guide body. The opening can be oriented axially
out of the front of the body or laterally and side mounted. The
guide way chamber 5 comprises a curved or angled slot or passage
and opens perpendicular or off angle (or between 0-180) with
respect to the long axis of the guiding body. The radius of
curvature along the passage can be constant or variable along the
sweep of the curve. A curved nail or staple 3 can be inserted
within the chamber 5 via a side loading window. A pusher rod 1 is
carried within or by the body 4 and accesses or is in communication
with the guide way chamber. The rod 1 has a first proximal end that
can be configured with a head or striking surface for hammering and
a second distal end for transmitting force to the end of a nail,
staple, or anchor 3 within the guide way chamber 5. The distal end
or anvil can be curved, beveled, or angled such that the linear
force of the rod can be transmitted downward or along an arc as the
staple 3 is driven out through the curved slot of the chamber 5.
The rod 1 may be rigid or at least partially flexible in
construction.
[0103] Also shown in FIG. 2 is a depth stop support 2 which can be
configured as a snap on sleeve that fits over the body 4. In other
embodiments a depth stop may simply be a projection off of the body
that limits further travel of the body and/or guide way chamber
opening within or adjacent a tissue. The depth stop may also be
adjustable to allow for different implantation depths or locations.
The depth stop may project in one or more directions from the long
axis of the tool. Depth stops and other instrumentation described
in U.S. Pat. No. 6,821,276, herein incorporated by reference, may
be incorporated in several embodiments.
[0104] FIG. 3 is an example of an embodiment of a staple or anchor
3 with two prongs or legs that are barbed and beveled on the
outside. When the staple is driven into a surface such as a bone
the prongs may or may not bend inward or be wedged together. This
action will pinch and compress the bone tissue between the prongs
while pressing outwardly against the sidewalls of the bone
facilitating a stable anchorage.
[0105] The series depicted in FIGS. 4A-E shows an embodiment of a
delivery device 6 being loaded with an anchor 3 and the push rod
applying force to the anchor and partially driving it out of the
curved guide way chamber opening or lateral opening. FIG. 4B also
shows the depth stop support sleeve 2 with a vertical slot
corresponding to the guiding body distal slot which is aligned with
the midline of the anchor and can be used to precisely implant or
drive the anchor or staple around a suture or linear structure.
[0106] In FIG. 5, an embodiment of the depth stop support is shown
as an attachable sleeve that fits on or over the distal end of the
guiding body. However, many of the features of the sleeve can be
machined, welded or attached directly to the body if so desired. In
addition to the vertical slot corresponding to the guiding body
distal slot and adjustable depth stop, an alignment projection 8 is
shown. The alignment projection can form a right angle with the
depth stop and have a beveled tip to ease insertion. The alignment
tip can be a relatively flat and rectangular projection that in use
can be rotated and rocked between to vertebrae or a hole in an
anulus to distract the vertebrae. Upon partial or full distraction
the tip and at least part of the guiding body can be inserted
between the adjacent vertebral bodies. The depth stop can limit the
amount of insertion by catching the edge of one or both of the
opposing vertebral endplates. Vertebral taxis or the resistance of
the anulus and endplates to further distraction can serve to
immobilize the guiding body as the anchor is hammered out.
Alternatively the body can be wedged along an inferior superior
plane to drive the opening of the guide way chamber against the
desired anchor site. In another embodiment one or more depth stop
surfaces may contain one or more barbs, spikes, nails, fasteners,
or means for engaging or immovably coupling the distal end of the
body to a boney structure such as a vertebral body. In one
embodiment an upper depth stop surface may be configured to engage
a superior vertebral body and a lower depth stop surface may be
configured to engage an inferior vertebral body.
[0107] Although the push rod and hammering method described infra
is a preferred method of delivery other methods and devices can be
used for this purpose. For example, compressed gas and hydraulics
can be utilized for driving. The push rod can be configured as a
piston or threaded rod (that can be rotated to expel the implant)
for imparting linear force. Also, the threaded rod or piston can be
flexible or have joints along its length to accommodate a curved or
flexible guiding body.
[0108] Delivery instruments and devices according to one or more
embodiments can also be used to implant other devices besides
anchors and the like. For example, a prosthetic device (including,
but not limited to, a barrier, mesh, patch, or collapsible implant)
can be attached or coupled to an anchor according to several
embodiments of the present invention, such as described in U.S.
Pat. Nos. 6,425,919; 6,482,235; and 6,508,839; 6,821,276, all
herein incorporated by reference. In several embodiments, the
prosthetic device can be loaded within or along the guiding body of
the device. The anchor and the prosthetic device may be constructed
from identical, similar, or different materials. The anchor and
prosthetic device may be coupled or removably or reversibly.
Connections between the anchor and the prosthetic device may be
temporary (such as restorable or dissolvable sutures) or permanent.
Instead of a prosthetic device that is coupled or attached to the
anchor, the prosthetic device may also be of unitary construct or
integral with the anchor.
[0109] In one embodiment, an implant such as collapsible patch is
coupled to the anchor and oriented along or within the guiding body
such that as the anchor is passed through the guide way chamber
slot in a downward direction the patch is extruded outwardly or
parallel to the long axis of the body. The patch can be held within
the body which can have linear slot adjacent the curved slot of the
guide way chamber or alternatively the patch can be mounted around
the guide way chamber while coupled to the anchor within the
chamber. Also, the depth stop sleeve can also be used to compress
and hold the patch in place.
[0110] In a further embodiment, one or more anchors can be
delivered separately from one or more implants. In one embodiment,
the implant is first delivered and positioned and then anchored in
place. In another embodiment, the anchor is first established in
the implantation site and then the implant is delivered and
connected to the anchor.
[0111] FIGS. 6A-L depicts an implantation sequence according to
various embodiments. FIG. 6A is an axial cross section of a
vertebral body, shown is a star shaped treatment zone along the
vertebral endplate. The sequence shows an anchor being implanted
into a posterior portion of a vertebral body along an endplate. The
surface of the endplate can be accessed through a hole in the
anulus. The hole in the anulus may be a naturally-occurring defect
or surgically created. Methods and devices of the various
embodiments are not limited to a single location along a vertebral
body or surgical approach.
Perpendicularly Driven Anchor
[0112] Various embodiments of anchor presented herein are designed
to improve upon the weaknesses in conventional bone screws and
staples that are limited by surgical access and suture or anchor
attachment site placement. For example, in the environment of the
spine, the posterior elements of vertebral bodies forming facet
joints, spinal canal, neural foramen, and the delicate nerve
tissues of the spinal cord create numerous obstacles for surgery
and diagnostic and interventional methods. Surgical approaches have
been adapted to minimize damage to these structures and involve
tight windows usually off angle to the target tissue.
[0113] An example of such prior art anchor and environment is
depicted in FIG. 7, which shows a bone screw driven into a
vertebral body from a posterior lateral approach. Here the anchor
on the outside of the vertebral body is ineffective for retaining
an implant within the disc and remains in dangerous proximity to
the spinal cord. Several embodiments are particularly advantageous
because the anchor does not present attachment sites originating at
a proximal end in the axial orientation from which they are driven.
Moreover, several embodiments are advantageous because the anchor
is adapted with an expansion mechanism that provides a
"mushrooming" effect, and thus the pull-out resistance is not
merely limited to the friction and forces generated by the
sidewalls of the material or tissue.
[0114] Several embodiments accommodate or exploit certain
geometries or anatomical structures of the body. For example, in
one embodiment, the attachment site of an anchor can be presented
distally from the insertion site in a direction perpendicular or
offset from the axial orientation of insertion. In one embodiment,
the anchor presents a larger surface area below or embedded within
a surface, thereby offering improved pull-out resistance without
requiring an expansion or "mushrooming" step or mechanism.
[0115] In several embodiments, one or more anchors are driven into
the surface of a first plane and present a portion on an adjacent
plane or surface perpendicular or angled relative the first plane.
Thus, the anchor is driven into a first surface and across an
adjacent surface in the same instance. In one or more embodiments,
at least a portion of the anchor such as the anchor attachment site
is adapted to remain above or proud of the upper or second tissue
surface or plane. With respect to the first surface (the front
facing or lower surface into which the anchor is driven), the
anchor can be driven in to a depth such that it is countersunk,
left flush, or left partially external to the frontal tissue
surface or plane. The anchor can also be delivered at a trajectory
or angle relative to the second or top surface such that it is
driven into the first surface and downwardly or upwardly across the
second surface.
[0116] In several embodiments, the anchor is a flat plate-like nail
or brad having a specialized keel portion and neck portion. In
other embodiments the anchor is flat, plate-like, curved,
corrugated, round, or a combination thereof. The neck can be
terminated in a head or present an attachment portion along its
length. The attachment portion or site can be comprised of a more
flexible piece of fabric, wire, linkage, fastener component, hook
eye, loop, or plate. The neck can be an extension, ridge, midline,
or the apex of the keel portion. The neck can be oriented at the
distal or proximal end of the keel or anywhere along its length.
The neck can be the same length as, longer than, or shorter than
the keel but preferably it is shorter. In one embodiment, the neck
is a thin rod or beam. The keel portion can have a cross-section
similar to a wedge, "V", "U", "T", and "W", "X", "O" and other
shapes.
[0117] Anchors according to one or more embodiments have dimensions
suitable to the implantation environment. For example, in one
embodiment, the anchor has a height of about 0.2 cm to about 5 cm
and a width of about 0.2 cm to about 5 cm. Anchors can have a
length or depth from 0.2 cm to about 5 cm. In some embodiments, the
length, width, height or depth can be less than 0.2 cm or greater
than 5 cm. In one embodiment, the anchor has a length of about 1 cm
and a width of about 0.5 cm. In yet another embodiment, the anchor
has a length of about 0.5 cm and a width of about 0.25 cm. In
another embodiment, the anchor is dimensioned as follows: about 0.3
cm wide, 1 cm long and 0.5 cm deep.
[0118] The length of the anchor can define a straight or curved
line defined by a radius of curvature of about 0-90 degrees (e.g.,
about 15, 30, 45, 60, or 90 degrees). The keel, legs, extensions,
blades, or fins can have a leading edge that is sharpened, left
dull, or serrated. Other features of the neck and keel or
extensions include, but are not limited to, barbs, tabs, roughened
surface geometry, polished surface, coatings seeded carrier or drug
eluting coatings or elements, concavities, scalloped ridges,
grooves, "feet", ridges, voids, slots, and ingrowth openings are
shown in the attached drawings. Secondary edges or ribs can
protrude along portions of the keel to provide enhanced engagement
with tissue. The neck or keel(s) can be hollow or tubular to accept
tissue incorporation, cement, adhesive, therapeutic agents or
another implant including a screw or pin. Portions of the keel or
neck can further be expanded after implantation and/or portions of
the neck or keel can be deflected or deployed as barbs after the
anchor is initially implanted.
[0119] In addition to the neck and anchor attachment site, the
anchor can also include an alignment means, engagement means or
guide. Variations of the anchor alignment means can function to
orient the anchor to a driver and couple it thereto. The anchor
alignment means can comprise alignment components such as a
protrusion, recess, or fastener component mated to a portion of a
delivery instrument. The anchor engagement means can comprise
engagement components or portions such as spikes, teeth, prongs,
barbs, friction zones, or a combination thereof. The guide can
comprise a protrusion, slot, arrow, tab, or a combination thereof.
Thus, in some embodiments, the anchor comprises means to align,
means to engage, means to guide, or a combination thereof.
[0120] Turning to the drawings, FIG. 8 shows an embodiment of an
anchor 25 with a leading edge 12, suture attachment sites 11,
ingrowth features or voids 13, first and second plate-like legs or
lateral extensions 15, 15' defining the keel, arcuate central ridge
or apex 10, centering or alignment projection 16, and feet or
ridges 14, 14'. Both the wedge-like shape of the keel portion of
the implant i.e., the legs and the ridges or flange like extensions
at the end of the legs function to hold the implant within a given
tissue and to resist rotation and pull out from a variety of
angles. The voids and ingrowth features serve to provide secondary
stabilization over time and/or to allow chemical transfer or
cellular respiration across the implantation site.
[0121] In a "V" shaped anchor or similar embodiment shown, the neck
portion is bifurcated into two legs, extensions, blades, fins, or
keels that meet at an apex and form an angle between about 10 and
about 170 degrees. In one embodiment, the angle is about 30-90
degrees. The apex at the point of bifurcation can define a flat
ridge or vertical extension or neck that can contain one or more
anchor attachment sites. In a "U" shaped embodiment the neck can be
in the form of an arc or eye projecting along the length of the
body of the anchor. "V" or "U" shaped anchors can be modified to
"L" shaped anchors in some embodiments.
[0122] In FIG. 9, an anchor similar to the one depicted in the
previous figure is shown. The apex 10, which would correspond to
the neck in other embodiments, does not extend and instead presents
a smooth curve which can present a less injurious profile to the
anatomy in certain applications. Also shown are ridges 70 and
scalloped teeth-like surface features 71.
[0123] FIG. 10 shows another embodiment of an anchor with deployed
barbs 80 and 80' These features can be held compressed within a
sleeve on a delivery instrument or simply forced to compress
inwardly as the implant is driven in to tissue. One or more slots
or recesses 82 are adapted for holding the barbs during
implantation to streamline the anchors profile.
[0124] One or more barbs can exert continuous outward pressure on
the sidewalls of a tissue or expand to form a shelf or flange if
the tissue geometry widens, expand or become more pliant. For
example, in a vertebral body the implant might be driven into
cortical bone and then further into cancellous bone. Upon reaching
the cancellous bone, the barbs flexible plate-like structure or
engagement means, can expand or extend outwards. In another example
the anchor is driven at least partially into the hollow of a boney
structure such that the barbs expand and engage the inner wall of
the bone. Element 81 can be arranged as an opposing barb or
expansion means however one or more barbs 80, 81 can be oriented
relative to each other from 0-360 degrees. For example, the barbs
or other barb-like components may be orientated relative to each
other at the following angles: 15, 30, 45, 60, 90, 120, 150, 180,
or 360 degrees.
[0125] FIG. 11 shows a delivery tool with a shaft 96 with distal
end 95 having an anvil or striking surface 94 defining a leading
edge mated to at least a portion of the cross section of the
trailing edge of the anchor. The shaft may be connected at its
proximal end to a handle or terminate in a striking surface.
Because a contour and size of the anvil surface is similar to those
of the anchor in some embodiments, both the anchor and at least
part of the distal end of the delivery tool can be driven into a
bone thereby counter sinking the anchor. Alternatively, anchors
according to one or more aspects of the invention can be left flush
or partially countersunk. A mounting member 90 may extend beyond
the implant when the implant is mounted or loaded on the tool. The
mounting member 90 includes a flattened lower surface 93 and a
rounded blunt front surface 91 for positioning along a bone
surface, such as the top of a vertebral endplate, and a slot or
engagement means 92 for accepting and aligning an anchor.
[0126] FIG. 12 shows the anchor 25 mounted on the mounting member
90. The extended lower surface 93 and the leading edge of the
implant 12 and 12' forms a means to engage bone or other tissue. In
one embodiment, the tissue (e.g., bone) engagement means comprises
a device having an angled surface that may be used to hook onto,
engage, or align the instrument with the edge of a vertebral body
or the intersection of two tissue planes. In one embodiment, the
engagement means can be used to align the implant with the top of a
vertebral endplate and its front outer surface, the anchor is then
driven into and across the endplate.
[0127] FIG. 13 shows a cross-section of a vertebral body 24 having
an anulus fibrosus 23 bounding nucleus pulposus 22 with an anchor
25 embedded into a posterior aspect of an endplate and within or
proximal to an anulotomy or defective region of the anulus fibrosus
23. This implantation site is also in the vicinity of the cortical
rim or ring of dense bone of the vertebral endplate. The anchor is
shown countersunk into the bone along the P-A axis but partially
proud along the inferior-superior axis (the dotted lines indicating
the portion of the implant below bone surface or level.
[0128] FIG. 14A is an expanded view of FIG. 13 and shows dotted
lines to represent the keel portion of the anchor 25 beneath the
endplate surface. FIG. 14B is a dorsal view of FIG. 14A showing
anchor 25.
[0129] In FIG. 15, a sagittal view of an implanted anchor 25 is
shown at least partially within the defect 33 and inferior
vertebral body 32. Superior vertebral body 31 is also shown. The
cross-section of the vertebral bodies depicts the denser and
thicker cortical bone at the edge or rim where the anchor is
implanted and the less dense cancellous bone within the vertebral
body.
[0130] FIG. 16 depicts a method of delivery for one embodiment of
the anchor and associated delivery tool. Shown is a top cross
sectional view of a vertebral body 24 and a delivery instrument 96
and an anchor 25. The delivery instrument or driver is used to
transmit the force of a hammer or other means to drive the anchor
in place. The driver can comprise a slot, holder, magnet, pins,
mateable surfaces, fastener or other means at its distal end to
engage or couple with the anchor. The anchor can also be attached
to the distal end of the driver and then released once the desired
delivery depth has been attained. Other features of a driver (not
shown in FIG. 16) can include a depth stop, bone engagement means
such as a spiked, hooked, or angled protrusion, and/or a
retractable sleeve to protect adjacent anatomy as the anchor is
positioned. FIG. 16 also shows a flat proximal end 1602 for
hammering, if needed and a knurled handle 1600.
[0131] FIG. 17 illustrates a top cross-sectional view of an anulus
repair implant 52 lying along the inner surface of the posterior
anulus that can be coupled, attached, or sutured to an anchor 25.
The connection between the anchor and implant can be permanent or
detachable. The implant 52 can be delivered and positioned prior
to, at the same time as, or subsequent to the implantation of the
anchor 25. FIGS. 18A-18C show various features of anchors.
[0132] In FIG. 18A, the surface level of a bone such as a vertebral
endplate is shown as a dotted line. A side view is depicted. Here
the leading edge of the keel or leg portion of the implant is
thinner than the trailing edge. Accordingly, in other embodiments
of anchors at least a portion of the leading edge, profile,
proximal edge or side of an implant can have a thinner or tapered
profile than an opposing end, distal end, or trailing edge or
profile. FIG. 18B shows a series of anchor variations from a side
view in which the top portion, apex, neck, or implant attachment
site 170, 171, 172, 173, 174 is symmetrical, rounded, wedge shaped,
oriented at the distal or proximal end of the anchor. FIG. 18C
shows another side view along the bone surface level depicting and
anchors with features discussed infra such as a serrated leading
edge, voids or ingrowth holes, and a recess for engaging a delivery
tool.
[0133] FIG. 19 shows various embodiments of the anchor
cross-sections 180-200 including several keel profiles from a front
view resistant to pullout and offering various surface areas. Some
are solid shapes as in anchor profiles 182, 184, 187, and 200 and
others are hollow and have an open midsection as in anchor profiles
183, 185, 188.
[0134] Turning to FIG. 20, a perspective view of an anchor is shown
with leading edges 12, 12', alignment means 16, suture or fastener
attachment 11 site, neck 10, and voids 13. In this embodiment the
apex does not run the entire length or depth of the anchor
corresponding to the keel or opposing leg portions 15, 15' of the
anchor. Also, the neck is oriented towards the proximal end of the
anchor forming a cut-out along the top portion of the anchor. The
neck 10 is shown perpendicular to the keel 15 but can be
alternatively oriented in a range from 0-180 degrees relative to
it. In one embodiment, the neck is oriented at an angle of about
15, 30, 45, 60, 75, 90, 120, 150, or 180 degrees relative to the
keel
[0135] In FIG. 21, a "V" shaped anchor is shown. An "eye" or loop
11 is integral to a neck extension portion 10 that bifurcates into
two legs 15, 15'. Because the leading edges 12, 12' and at least a
portion of the neck 10 is sharpened, this anchor can be driven more
flush to the upper or first surface of a bone such as a vertebral
endplate. Here both the neck 10 and the leg portions 15, 15' of the
device function as a keel. This embodiment also shows ridges 12 and
scalloped recesses 170. Anchors according to other embodiments
described herein may also comprise ridges and/or scalloped
recesses.
[0136] In FIG. 22A, another embodiment of an anchor is shown. Here,
three legs 12, 12', and 12'' defining the keel are provided. A
relatively taller neck 10 is provided beneath a perpendicular
suture attachment member 11. The neck 10 is set back distally from
the leading edge of the keel portion. FIG. 22B shows the distal tip
of a delivery tool. Shown are attachment pins 180, anvil or
striking surface 186, depth stop 187, mounting member 185, and
shaft 96 with distal end 95.
[0137] Turning to FIG. 23A, an anchor 25 is shown with an
attachment site 189 for a flexible bridge 818. The bridge 818 is
shown in FIG. 23B and is coupled to the neck 10 of the anchor 25
with a first and second flexible tab 193, 194 and has an attachment
11 site at the opposing end.
[0138] The series depicted in FIGS. 24A-24C shows an anulus
reinforcement system. FIG. 24A shows an anchor similar to the ones
depicted previously with a bifurcated keel 15, 15', neck 10, and
attachment plate 112 with a first and second coupling member 111,
111' or snap surface. FIG. 24B is an exploded view of a barrier,
mesh, or reinforcement plate 52 adjacent an anchor 25 wherein the
anchor 25 is partially inserted or mounted within the distal end of
a delivery tool. FIG. 24C shows all three elements connected and
mounted and ready to be driven into a tissue site.
[0139] Another embodiment of an anulus reinforcement system is
shown in FIGS. 25A-25C. In this embodiment, a single attachment
means 111 is used that can function as a fulcrum or hinge site for
a flexible barrier 52 member shown in FIG. 25B. Behind or distal to
the attachment means 111 is a support member 112 or plate that is
an extension of the neck 10. This feature, in some embodiments,
inhibits the barrier 52 from folding backwards and may also
reinforce the barrier 52. FIG. 25C shows a hood or sleeve 120
element that can be mounted on or carried by a delivery tool or
instrument as described herein. The hood 120 retains the folded
barrier until the anchor portion is fully established within the
tissue whereupon it is retracted.
[0140] Another embodiment is shown in FIGS. 26A-26B. This
embodiment shows an anchor especially adapted for use in a
vertebral body and includes an upside down "V" shaped keel portion
with a sharpened leading edge. The leading edges enable the anchor
to be directly driven into the bone and do not require a pilot hole
or pre-cut. and One feature of this embodiment is the leading step
in the sharpened edge which presents more cutting surface blow the
surface of the bone and more forward of the distal attachment site.
Alternatively, the leading edge can have multiple steps or be
curved and rounded. This profile reduces the risk that the leading
edge might pierce or damage the endplate (which is not flat but has
a "dip" or cupped portion in the middle). This feature facilitates
insertion of a longer, stronger anchor into a disc that would
otherwise (because of a pronounced dip) be difficult to position at
the proper height and depth into the bone without damaging the
endplate.
[0141] The following Example illustrates one embodiment and is not
intended in any way to limit the invention. Moreover, although the
following Example describes an anchor used in a spinal application,
the anchors described herein can be used throughout the animal body
and have general applicability to fastener art. Such anchors can be
used to join or anchor like or disparate materials or tissues
together, maintain alignment of materials, reinforce a fracture
within a material, and provide an attachment site along or within a
materials surface.
[0142] The anchor illustrated in FIG. 26 is used by way of example.
The anchor is in the form of an upside down "Y" defined by a neck
portion terminating at one end into two plate-like rectangular legs
forming a keel and terminating into an suture attachment site 11 in
the form of a loop on the other end. The leading edge of the legs
12 and neck 10 are sharpened and the upper portion of the legs is
recessed, profiled or formed with a relief 113. The relief profile
113 can correspond to an anatomical structure. In this embodiment
the forward recess or relief 112 corresponds to the concavity or
cupping of an endplate. The angle between the keel plates is around
90 degrees. The neck 10 is about 0.1 millimeter high and about 0.2
wide millimeters wide and extends about 0.2 millimeters. The neck
10 and attachment site 11, an "eye" or loop in this embodiment, are
mounted at the trailing or aft potion of the keel 15.
[0143] The entire structure is made of nickel titanium and is
machined from bar stock. To be delivered, the anchor is mounted on
the distal end of a driver. The driver has a striking surface on
one end and an anvil on the opposing end. The anvil has the
identical cross-section as the trailing edge of the anchor and
extends about 0.2 cm to allow for countersinking. The anchor is
coupled to the anvil by a forked protrusion that holds the neck and
a pin that fits into the eye.
[0144] In one application, the anchor is used to secure an anulus
repair device relative to a defect in the disc. A posterior-lateral
approach is used to obtain access to the damaged disc. Part of the
posterior elements on the opposing vertebral bodies may have to be
removed in order to reach the disc. The anulus repair device is
then implanted through the defect and along the inner surface of
the anulus.
[0145] Next the anchor, which is mounted on the distal end of the
driver, is aimed at the top edge or endplate of the inferior
intervertebral body. An alignment projection forming a right angle
at the tip of the drive is used to align the bottom potion of the
attachment loop of the anchor with the upper surface of the
endplate and to center the anchor within the defect. The anchor is
then driven forward into the bone with light hammering applied to
the driver. The anchor is driven roughly perpendicular to the outer
surface of the vertebral body and roughly parallel to the
endplate.
[0146] The depth of insertion is controlled by the 0.2 cm
countersinking anvil and the depth dimension of the anchor, in this
case 0.5 cm for a total depth of 0.7 cm which is still shy of the
border of the cortical rim and the cupping of the endplate. Only
the upper potion of the loop remains proud of the endplate surface
and the annular repair device can then be connected to it with a
suture.
Graft Containment
[0147] FIG. 27A illustrates a lateral view of a stabilizer assembly
250 secured to patient tissue via a first and second fastener 252a
and 252b. The stabilizer or spinal fixation assembly can comprise
the embodiments disclosed in for example U.S. Pat. Nos. 6,562,040,
6,364,880 5,437,669 and 5,262,911, all herein incorporated by
reference. The first fastener 252a is, in one embodiment, attached
to or engaged with a superior vertebral body 31. The second
fastener 252b is attached to or engaged with an inferior vertebral
body 32. In this embodiment, the stabilizer assembly 250 is
arranged towards the posterior of the superior and inferior
vertebral bodies 31, 32. Also shown is anchor device 25 that
functions as an anterior buttress or graft containment device.
[0148] In FIG. 27A, an anchor 25 is implanted in an upper anterior
region of the inferior vertebral body 32. A portion of the anchor
25 extends above or is proud of an upper surface of the inferior
vertebral body 32. In one embodiment, the portion of the anchor 25
extending above the surface of the inferior vertebral body 32 is
arranged to block or secure a graft, frame, plate, and/or barrier
35. In this embodiment, the anchor is implanted in the anterior
portion of the endplate. In other embodiments, the anchor may be
implanted in the posterior portion. Additionally more than one
anchor or anchor type as disclosed herein may be used in more than
one location to block the implant. In one embodiment, the graft 35
comprises a femoral allograft. A wide variety of other grafts and
devices, such as loose bone grafts and/or cages can also be secured
or blocked by the anchor 25.
[0149] FIG. 27B illustrates another embodiment where an anchor 25
is attached to a lower posterior portion of a superior vertebral
body 31. In addition to the curvilinear anchor depicted in the
illustration, other anchors disclosed herein and included in
various figures may be used for the same purpose. For example,
plate-shaped or screw anchor may be used. In one embodiment, a
portion of the anchor 25 is proud of the surface of the superior
vertebral body 31 and is further arranged to block or secure a
nonfusion intervertebral device 52. The device 52 can comprise an
artificial disc or partial nucleus replacement device or other type
of implant suitable for the needs of a particular
implementation.
[0150] FIGS. 28A-28F illustrate a plurality of approaches of an
implantation tool 6 having one or more alignment structures 7
configured to align and locate an anchor or other implant. FIG. 28A
illustrates one embodiment of a posterior lateral approach where an
anchor or other implant can be driven into the posterior rim of
either adjacent spinal end plate or proximal tissue.
[0151] FIG. 28B illustrates an embodiment of a posterior approach
between adjacent end plates and advance of the implantation tool 6
such that a distal end of the implantation tool 6 is advanced to an
anterior aspect of the respective vertebral body. FIG. 28B
illustrates that an anchor or other implant can be delivered to the
vertebral end plate along its anterior cortical rim or tissue
proximal thereto. In some embodiments, multiple anchors or other
implants can be delivered along similar approaches to anchor or
block native tissues and/or intervertebral devices such as one or
more grafts, fusion devices, cages, anulus augmentations, nucleus
augmentation devices, and the like.
[0152] FIG. 28C illustrates an embodiment of an anterior approach
for delivery of an anchor or other implant at an anterior delivery
location. FIG. 28D illustrates a transpsoas approach for delivery
of one or more anchors or other implants at a proximal delivery
location. FIG. 28E illustrates an embodiment of a transforaminal
approach of an implantation tool 6 for proximal delivery of one or
more anchors or other implants.
[0153] FIG. 28F illustrates multiple approaches of an implantation
tool 6 for delivery of a plurality of anchors or other implants at
respective delivery sites. FIGS. 28A-28F illustrate some of a wide
variety of embodiments and appropriate approach vectors and
delivery sites can be readily determined by the clinician based on
the particular needs of the patient. In one embodiment a multitude
of anchor devices are implanted about at least a portion of the
periphery of a vertebral endplate forming an elevated rim or
artificial uncus. In another embodiment the anchors a placed apart
and connected together with one more band, mesh, tube, plate, or
suture.
[0154] FIGS. 29A-29F provide lateral or side views of various
embodiments of one or multiple anchors 25 arranged to block and/or
provide an attachment/securing site for grafts 35 and/or implants
52. In FIGS. 29A-29F, the left and right portions of each Figure
corresponds generally to the outer rim or edges of superior and
inferior vertebral bodies 31, 32. M addition to the curvilinear
anchors depicted in the illustrations, other anchors disclosed
herein and included in the figures such as plate and keel type
anchors may be employed and implanted in a like manner as disclosed
in FIGS. 29A-29F. Multiple anchors may be delivered about the
periphery of the endplate or uncus to partially reconstruct damaged
bone and/or tissue. Anchors may be connected with one or more
membranes and/or frames as described herein.
[0155] FIG. 29A illustrates a single anchor 25 implanted through a
lower end plate adjacent a defect in the anulus fibrosus 23
proximal the cortical rim but extending inwardly into the inferior
vertebral body 32. In this embodiment, the anchor 25 is configured
to block a nonfusion intervertebral device 52 from exiting the disc
space to the left of the Figure while the remaining intact anulus
is blocking the device from extruding from the right side of the
Figure.
[0156] FIG. 29B illustrates an anchor 25 blocking a fusion device
or graft 35. In this embodiment, the anchor 25 is arranged to rest
proximal to the graft 35 but does not touch the graft 35.
[0157] FIG. 29C illustrates an embodiment where an anchor 25 is
secured to an inferior vertebral body 32 such that the anchor 25 is
barely proud the surface of the inferior vertebral body 32. The
portion of the anchor 25 proud of the surface is connected to an
intervertebral device 35 that can be either a fusion or nonfusion
device as illustrated and described infra.
[0158] FIGS. 29D-29F illustrate a plurality of embodiments
employing multiple anchors 25 where each anchor 25 can be
substantially identical to other anchors 25 or where different
versions or configurations of anchors 25, 25' can be employed.
FIGS. 29A-29F are simply illustrative of certain embodiments and a
variety of configurations and placements can be adapted to the
needs of a particular patient. Though the anchors depicted in FIGS.
27-30 are depicted as curvilinear anchors it should be understood
that this is for illustrative purposes only and any anchor
described herein may alternatively or additionally be used
according to the methods described.
[0159] In FIG. 29F, two opposing vertebral bodies 31, 32 are shown.
Along the periphery of the opposing endplates are implanted a
series of anchored implants. Implants are used to augment (e.g.,
build up) or replace weakened, damaged or missing hard or soft
tissue, such as bone or anulus. In some embodiments, the anchored
implants extend the uncus or cortical rim of the endplates. In
certain embodiments, the anchored implants further comprise a
membrane and optionally a frame. The anchored implants comprise a
head, neck or engagement surface to attach or engage an adjacent
anchored implant or another device (e.g., a barrier, band, or
graft). Multiple anchored implants can be interconnected or stacked
to form a fence, augmented or raised surface (e.g., above the
endplate) to reduce or prevent the escape of extrusion of a graft
or other material (artificial or natural) from the enclosed area.
In one embodiment, graft containment can be achieved effectively by
using a series of interconnected anchored implants, thus augmenting
the uncus and reconstructing the endplate. Opposing endplates can
be reconstructed in this manner. In one embodiment, both the
inferior and superior endplates are reconstructed.
[0160] FIG. 30A illustrates a top view of an embodiment of a
reconfigurable support member 60. The support member 60 is
configured to block, provide support or serve as a barrier to
inhibit herniation of tissue or migration of a graft or implant. In
one embodiment, the support member 60 comprises a plurality of
generally rigid elongate members 62 connected via interposed
flexible connections 64. The flexible connections 64 are formed of
a biocompatible resilient material to allow the support member 60
to resiliently move between a first and a second configuration. In
some embodiments, the support member 60 can reconfigure itself
automatically under resilient force provided by the support member
60 itself. In some embodiments, the support member 60 can be
reconfigured under tension or compression force applied to the
support member 60. In some embodiments, the elongate members 62 and
flexible connections 64 are formed of the same or similar
materials. The flexible connections 64 can comprise weakened
regions of the support member 60 and/or regions where material
comprising the support member 60 is thinner and/or narrower than
the material in the regions of the elongate members 62.
[0161] In some embodiments, the support member 60 comprises a
connection portion 66 configured to engage with an anchor 25 as
illustrated in FIGS. 30B and 30C. In some embodiments, the
connection portion 66 engages with a corresponding anchor 25 via a
friction fit. In some embodiments, the support member 60 can
connect to a respective anchor 25 via suturing, one or more
fasteners, biocompatible adhesives, ultrasonic welding, snap fit,
or a variety of other methods, materials, and/or processes for
joining separate elements. In some embodiments, the support member
60 and anchor 25 can be formed as an integral unit and need not
comprise separate interconnected components.
[0162] FIG. 31A illustrates a further embodiment of a support
member 60 with a corresponding anchor partially engaged with a
connection region 66 of the support member 60. FIG. 31A also
illustrates that the support member 60 defines a transverse
dimension indicated by the designator T and a longitudinal
dimension indicated by the designator L.
[0163] FIG. 31B illustrates a perspective view of the support
member 60 fully engaged with an anchor 25. As previously noted,
connections between the anchor 25 and support member 60 can
comprise a wide variety of connection means including multiple
means for connecting the support member 60 and anchor 25. In one
non-limiting example, the anchor 25 can connect to the support
member 60 via means for connecting comprising both a friction fit
and a detent arrangement.
[0164] FIG. 31C illustrates a top view of the support member 60 in
a configuration having a reduced transverse dimension and an
elongated longitudinal dimension. In one embodiment, the
configuration illustrated in FIG. 31C of the support member
corresponds to a relaxed configuration for a natural configuration
of the support member absent applied force. The reduced transverse
dimension T of the support member 60 can facilitate advancement of
the support member 60 towards a desire implantation location.
[0165] In one embodiment, the support member 60 comprises an
attachment structure 68 arranged at a first or leading end of the
support member 60. The attachment structure 68 can provide an
attachment point for application of force to the support member 60.
For example, a tension force can be applied to the leading end of
the support member adjacent the attachment structure 68 to draw the
leading end rearward so as to reduce the longitudinal dimension and
expand the transverse dimension.
[0166] In some embodiments, FIG. 31C illustrates the support member
in a configuration having force applied. For example, in one
embodiment, a sleeve 120 can be arranged about the support member
60 to maintain a reduced transverse dimension T. Removal of the
sleeve 120 can then allow the support member 60 to achieve a
relaxed configuration having an expanded transverse dimension T and
reduced longitudinal dimension L. In other embodiments, the
configuration illustrated in FIG. 31C can be maintained by one or
more sutures or clamps applied to opposed lateral sides of the
support member 60 to maintain the reduced transverse dimension T.
Removal or severing of such sutures or clamps can release the
support member 60 to a relaxed state having an expanded transverse
dimension T and a reduced longitudinal dimension L. This
configuration is illustrated schematically in FIG. 31D with the
reduced longitudinal dimension L' and the expanded transverse
dimension T'.
Opposing Gates
[0167] FIG. 32 illustrates a side view of a support assembly 300
configured to support or retain patient tissue and/or a further
implant member. In one embodiment, the support assembly 300
comprises a first anchor 25 and an opposed second anchor 25'. A
first gate member 302 is connected or attached to the first anchor
25 and a second gate member 302' is similarly connected or attached
to the corresponding second anchor 25'. In some embodiments, the
gate members 302, 302' are formed of flexible material. Polymers
may be used. Nitinol may also be used. In some embodiments, the
gate members 302, 302' are formed of a resilient or elastic
material. In some embodiments, the gate members 302, 302' can be at
least partially rigid and movably attached to the respective anchor
25, 25' under resilient pre-loading for biased movement in a
desired direction. Such embodiments provide the ability for opposed
gate member 302, 302' to resiliently engage with each other to
thereby provide an obstruction or resilient support inhibiting
passage of patient tissue, fluids, and/or implanted materials from
passing the support assembly 300.
[0168] FIG. 33 illustrates a side view of a support assembly 300 in
an implanted location. In this embodiment, a first anchor 25 is
secured to a lower region of a superior vertebral body 31. A second
anchor 25' is secured to an upper surface of an inferior vertebral
body 32. Opposed first and second gate members 302, 302'
resiliently engage with each other and are connected or attached to
the respective anchors 25, 25'. In this embodiment, the gate
members 302, 302' comprise a resilient and flexible biocompatible
material. As illustrated in FIG. 33, the first and second gate
members 302, 302' can flex to accommodate patient movement and
variable loading resulting therefrom while maintaining a seal or
blocking function facilitated by the resilient flexible engagement
of the opposed gate members 302, 302'. For example, in an
embodiment where the support assembly 300 is implanted to resist
herniation of nucleus pulposus 22, the support assembly 300 via the
resilient engagement of the opposed gate members 302, 302' can
resist such herniation while accommodating relative movement of
opposed end plates. A further advantage to certain embodiments of
the support assembly 300 is that the moveable ability of the gate
members 302, 302' inhibit passage of patient tissue, fluids and/or
implanted materials yet allow the inflow of nutrients, tissue
fluids and the like by providing a duckbill or reed valve
configuration.
[0169] In some embodiments (including, but not limited to, FIG.
33), one or more gate members 302 can be substantially rigid and
moveably attached to a respective anchor 25. A connection or
coupling between a substantially rigid gate member 302 and a
corresponding anchor 25 can comprise a flexible connection, a
pivoting connection, and/or a hinged connection. A connection
between a gate member 302 and respective anchor can further
comprise a resilient or spring aspect such that the gate member 302
is urged in a particular direction of movement. In some
embodiments, a support assembly 300 can comprise an integral
assembly and need not comprise separate connected gate member 302
and anchor 25 components.
[0170] In one embodiment, (including, but not limited to, FIG. 33),
a method of closing a defect between opposing vertebral endplates
is provided. In several embodiments, a duckbill-type device is
used. In one embodiment, the method comprises attaching a first
gate member to a superior endplate and attaching a second gate
member to an inferior endplate. Both gates have a proximal and
distal end. The proximal end of the first gate is coupled to the
superior endplate. The distal end of the first gate extends
medially into an intervertebral disc space. The proximal end of the
second gate is coupled to the inferior endplate. The distal end of
the second gate extends medially into the intervertebral disc
space. The method further comprises contacting the distal ends of
the first and second gates to close a defect between opposing
endplates. The distal end may touch or may be adjacent to one
another. In one embodiment, the gates are partially or wholly
positioned along an endplate beyond a defective region of the
anulus. In another embodiment, the gates are partially or wholly
positioned in the defect. In one embodiment, the anchor portion is
in the defect and the gates are in front of the defect. A method
that uses the gate system to close or barricade a defect in which
the system is placed beyond the defect is advantageous in one
embodiment because it reduces or prevents the extrusion or
expulsion of nuclear material through the defect (which may be a
weakened area vulnerable to additional damage). In one embodiment,
the gates are about 2-4 mm wide, about 3-6 mm long, and about 0.5-2
mm thick.
[0171] FIGS. 34A-34C illustrate additional embodiments of a support
assembly 300 and various embodiments of implantation location. For
example, FIG. 34A illustrates a support assembly 300 with a first
anchor 25 attached generally at a lower anterior region of a
superior vertebral body 31 and a second anchor 25' attached at an
upper anterior corner of a inferior vertebral body 32. FIG. 34A
illustrates an embodiment of the support assembly 300 implanted in
a defect located generally at an anterior position and opposite
intact anulus tissue 23. FIG. 34B illustrates another embodiment of
support assembly 300 where the anchors 25 are configured generally
as threaded or screw shaped structures. In this embodiment, the
anchors 25 are positioned generally at an anterior outer surface of
superior and inferior vertebral bodies 31, 32 In this embodiment,
the opposed gate members 302 further extend from an interstitial
region between the vertebral bodies 31, 32 outwards towards the
respective anterior surfaces of the vertebral bodies 31, 32 for
connection with the respective anchors 25. FIG. 34C illustrates a
further embodiment where the support assembly 300 is implanted at
opposed inner surfaces of a superior and inferior vertebral body
31, 32 along the endplates and within or beyond the anulus. The
support assembly 300 may arranged at an posterior, anterior, or
lateral position of the vertebral bodies 31, 32.
[0172] FIGS. 35A and 35B illustrate further embodiments of a
support assembly 300 and various embodiments of anchor 25
configurations. FIG. 35A illustrates that the anchors 25 comprise a
generally spiked or barbed plate profile configured to be driven
into and attached to respective vertebral bodies 31, 32. FIG. 35A
further illustrates that the opposed anchors 25 are presented to
the patient tissue in a generally vertical anti-parallel approach.
FIG. 3513 illustrates an embodiment where the anchors 25 comprise a
generally T-shaped or keel profile. FIG. 3513 further illustrates
an embodiment wherein the opposed anchors 25 are presented to the
respective vertebral bodies 31, 32 in a generally parallel
transverse approach.
[0173] FIGS. 36A-36C illustrate top views of embodiments of support
assembly 300 and respective implantation locations with respect to
patient tissue, such as an anulus 23. FIG. 36A illustrates that an
anchor 25 can be implanted in a defect region 33 such that the
anchor 25 is interposed between an inner surface 26 and an outer
surface 27 of the anulus 23. FIG. 36B illustrates an embodiment
where the anchor 25 is implanted substantially adjacent or flush
with an outer surface 27 of the anulus 23. FIG. 36C illustrates an
embodiment where the anchor 25 is implanted substantially adjacent
with an inner surface 26 of the anulus 23.
[0174] FIG. 37 illustrates a further embodiment of support assembly
300 comprising a plurality of interleaved leaves or fingers 304. In
some embodiments, the individual leaves or fingers 304 are
generally aligned with other leaves or fingers 304 and in other
embodiments the multiple leaves or fingers 304 are not generally
aligned with each other.
[0175] FIGS. 38A and 38B illustrate top and side views respectively
of various configurations of gate member 302. As illustrated, a
gate member 302 can define a generally non-square rectangular, a
generally square, a triangular, a semi-circular, a circular, or an
irregular profile. In some embodiments, a gate member 302 comprises
a plurality of leaves or fingers 304 arranged to extend in
divergent directions so as to describe a brush-like configuration.
In some embodiments, a gate member 302 can comprise a plurality of
leaves or fingers 304 extending generally parallel to each other so
as to define a finger-like profile. Other shapes and profiles of
gate member 302 are possible. FIG. 38B illustrates that gate
members 302 can define a generally straight profile, an upwardly
curved, a downwardly curved, a serpentine or undulating curve, an
upward angled bend, a downward angled bend, angled bends of
approximately zero to ninety degrees, angled bends of approximately
90 degrees, angled bends of approximately ninety to one hundred
eighty degrees, concave, convex, and/or multifaceted profiles.
[0176] FIG. 39A illustrates an embodiment of support assembly 300
comprising opposed gate members 302, 302' each having a plurality
of interleaved leaves or fingers 304. In this embodiment, the
individual leaves or fingers 304 of each gate member 302 extend
along different paths as seen in side view or are not generally
aligned with each other. FIG. 39B illustrates an embodiment of
support assembly 300 having opposed gate members 302, 302' each
having a plurality of individual leaves or fingers 304. In this
embodiment, the individual leaves or fingers 304 of each gate
member 302 are generally aligned with each other as seen in side
view.
[0177] FIG. 38C illustrates further embodiments of gate members 302
including a concave multifaceted three dimensional profile, a
concave generally smooth monotonic profile, and a profile combining
both generally smooth curved portions and generally flat or flange
contours.
[0178] FIGS. 40A and 40B illustrate embodiments of support
assemblies 300 comprising opposed gate members 302 having a concave
profile. In one embodiment as illustrated in FIG. 40A, opposed gate
members 302, 302' are substantially mirror images of each other
having similar shapes, sizes and contours. The opposed gate members
302, 302' are further aligned so as to engage with each other to
form a substantially continuous occlusion or seal aspect of the
support assembly 300. FIG. 40B illustrates another embodiment where
the opposed gate members 302, 302' are similar in shape and
contour, however can have different sizes. In the embodiment
illustrated in FIG. 40B, the opposed gate members 302, 302' are
configured and arranged to engage with each other in a nested
configuration.
[0179] FIG. 41 illustrates a further embodiment of support assembly
that can be similar to any previously described embodiment of
support assembly 300. In the embodiment illustrated in FIG. 41, a
connector 306 is provided to clamp, connect or provide a pivotal
axis between the opposed gate members 302. The connector 306 can be
provided in alternative or in combination with a resilient or
self-engaging aspect of the gate members 302 to provide additional
resistance to separation of the opposed gate members 302. The
embodiment illustrated in FIG. 41 can be preferred in
implementations where the sealing or blocking function provided by
the support assembly 300 is preferably provided in a bi-directional
manner.
Threaded Keel Anchor
[0180] FIGS. 42A and 42B illustrate in side and end views
respectively embodiments of a first anchor structure 310 and a
second anchor structure 312. The first and second anchor structures
310, 312 can be secured or connected to each other, for example via
a fastener 314. The first anchor structure comprises a first
threaded profile 316 configured to allow the first anchor structure
310 to threadably engage with patient tissue in a well known
manner. The first anchor structure 310 further comprises a second
threaded profile configured to threadably engage with the fastener
314.
[0181] The second anchor structure 312 comprises an attachment
structure 322 that can be configured as an attachment point for
sutures and/or for connection to a separate implant (not
illustrated). The second anchor structure 312 also comprises a foot
or keel structure 324. The foot or keel structure 324 is configured
to secure and align the second anchor structure 312 for connection
with the first anchor structure 310. The foot or keel portion 324
can be further configured to engage with patient tissue to secure
the second anchor structure 312 thereto.
[0182] FIGS. 43A-43D illustrate embodiments of an implantation and
attachment process for the first and second anchor structures 310,
312. As illustrated in FIG. 43A, a pilot hole can be formed in
patient tissue, for example comprising an anulus. As shown in FIG.
43B, the first anchor structure 310 can be threadably inserted into
the pilot hole via a combination of rotational and/or translational
forces. As illustrated in FIG. 43C, the second anchor structure 312
can then be laterally driven into the patient tissue and into
engagement with the first anchor structure 310, for example into
the second threaded profile 320. FIG. 43D illustrates in end view
that the fastener 314 can be threadably engaged with the second
threaded profile 320 of the first anchor structure 310 to secure
and connect the second anchor structure 312 in position.
[0183] FIGS. 44A and 44B illustrates another embodiment of a first
anchor structure 330 and a second anchor structure 332. The first
anchor structure 330 comprises a first engagement surface 334
configured and sized to engage with a cooperating second engagement
surface 336 of the second anchor structure 332. The first anchor
structure may be a screw. The second anchor structure may be a keel
terminating in a collar or other such engagement surface. The
second anchor structure may have a void or hole that facilitates
coupling to an implant (e.g., a barrier).
[0184] FIGS. 45A-45C illustrate embodiments of introduction
processes for securing the first and second anchor structures 330,
332 to each other and to patient tissue. As illustrated in FIG.
45A, an opening or pilot hole 342 can be formed in patient tissue
(e.g., vertebral body) 340. FIG. 45B illustrates that the second
anchor structure 332 is introduced into the desired location in the
patient tissue 340 via a generally linear translational
introduction. However, it should be noted that the opening 342 need
not be formed prior to introduction of the second anchor structure
332. For example, the second anchor structure 332 can be introduced
to the patient tissue 340 before formation of the opening 342.
Formation of the opening 342 is optional and may be omitted. For
example, depending on the relative size of the first anchor
structure 330 and the characteristics of the patient tissue 340,
the first anchor structure 330 can comprise a self-drilling aspect
reducing or eliminating the need to form the opening 342. FIG. 45C
illustrates a further process wherein the first anchor structure
330 is threaded into the patient tissue 340 and further so as to
engage the first and second engagement surfaces 334, 336. Thus, the
second anchor structure 332 is secured and positioned both by its
contact with the patient tissue 340 and via connection with the
first anchor structure 330 which is also engaged with the patient
tissue 340.
[0185] FIGS. 46A and 46B illustrate in perspective and side views
respectively embodiments of a support implant 350 configured for
closing, blocking, reinforcing, and/or repairing defects, openings,
or weakened areas in a variety of patient tissues. In some
embodiments, the support implant 350 is particularly adapted for
use in the intervertebral disc region, such as for reinforcing a
weakened anulus and/or for closing defects. The support implant can
inhibit herniation of disc material or augmentation implants
outside the anulus or into defects in the anulus. Embodiments of
the support implant 350 provide these benefits while limiting
interference with spinal joint movement including flexion,
extension, and lateral bending movement.
[0186] The support implant 350 comprises an anchor 25 that can be
formed according to any of the previously described embodiments of
anchor 25. In one embodiment, the anchor 25 describes a generally
T-shaped profile having two keel portions extending generally at
right angles to each other. The anchor 25 can include solid
features, roughness features, leading edges, or any other
combination of features and profiles as described herein.
[0187] The support implant 350 further comprises a support
structure 352. The support structure 352 can comprise one or more
of meshes, grafts, patches, gates, membranes, stents, plugs,
frames, and the like, suitable for augmenting, fortifying, bulking,
closing, blocking, occluding, and/or delivering one or more
therapeutic and diagnostic agents to weakened or damaged tissues.
The support structure 352 can be expandable, can be concave or
convex along one or multiple axes, oversized with respect to a
defect region, correspond generally to the size of the defect
region, or be sized to cover all or a portion of a region of intact
tissue.
[0188] FIGS. 47A and 47B illustrate an anterior-posterior view and
a lateral view respectively of embodiments of support implant 350.
FIGS. 47A and 47B are further presented as radiographic images, for
example as may be obtained via radiographic imaging of the support
implant 350 in an implanted location. As seen in FIGS. 47A and 47B,
the support implant 350 comprises a first marker 354a and a second
marker 354b. The markers 354a, 354b can comprise iridium, platinum,
platinum-iridium alloys, or other materials configured to provide
an enhanced in vivo image, for example as may be obtained with
radiographic imaging. It will be appreciated that some embodiments
of the support structure 352 can comprise biocompatible materials
which can be difficult to image in the implantation environment.
The markers 354 provide an enhanced ability to image the support
implant 350 and thereby determine the location and orientation of
components of the support implant 350 that may be otherwise
difficult to determine.
[0189] FIG. 48 and Detail A thereof provide a schematic side view
illustration of embodiments of a support implant 350 comprising a
moveable support structure 352. In one embodiment, the support
implant 350 comprises a moveable joint 356 between the support
structure 352 and an anchor 25. In some embodiments, the moveable
joint 356 defines a pivotable or hinged connection between the
support structure 352 and the anchor 25. In one embodiment, the
support implant 350 further defines first and second stop
structures 360a and 360b configured to limit the range of motion of
the support structure 352. In some embodiments, the support
structure 352 is resiliently biased for movement in a desired
direction.
[0190] FIG. 49 illustrates an embodiment of a delivery tool 370
configured to hold and deliver embodiments of support implants 350.
Structure and operation of the delivery tool 370 will be described
in greater detail with respect to FIGS. 50A-50E and 51 which
illustrate a deployment sequence employing the support implant 350
and delivery tool 370.
[0191] As shown in FIG. 50A, a distal end of the delivery tool 370
comprises first guide structure 372. The first guide structure 372
is configured to engage with corresponding guide structures 362 of
the support implant 350. The first guide structure 372 can be
configured as one or more of pins, posts, slots, grooves,
dovetails, or other structures configured to maintain an alignment
and orientation between the delivery tool 370 and the support
implant 350. In some embodiments, the first guide structure 372
engages with guide structures 362 formed in the anchor 25.
[0192] The delivery tool 370 further comprises second guide
structures 374. The second guide structures 374 are configured to
engage with the support structure 352 and maintain the support
structure 352 at a desired orientation and position with respect to
the anchor 25. For example, FIG. 50B illustrates the support
implant 350 engaged with both the first and second guide structures
372 and 374.
[0193] FIGS. 50C, 50D, and 50E illustrate a progression of the
support implant 350 engaging with the delivery tool 370. An end
plate guide of the delivery tool 370 advances towards the support
implant 350 and urges the second guide structures 374 to induce the
support structure 352 into adjacency with the anchor 25. The
adjacency of the support structure 352 to the anchor 25 provides a
reduced cross-sectional profile, for example as illustrated in FIG.
50E, to facilitate introduction of the support implant 350 to the
desired implant location.
[0194] FIG. 51 illustrates the support implant 350 and engaged
delivery tool 370 at an implant location. In this embodiment, the
implant location comprises a corner of patient tissue 340, such as
a vertebral body 31, 32. The support implant 350 and delivery tool
370 define in one embodiment a pair of adjacent first and second
locating surfaces 380, 382. The first and second locating surfaces
380, 382 can be positioned to contact the patient tissue 340 to
inhibit further movement of the support implant 350 or delivery
tool 370 in multiple dimensions.
[0195] As illustrated in FIGS. 52A and 52B, force can be applied,
for example at a driving surface 384 of the delivery tool 370 to
urge the anchor 25 into anchoring tissue. The delivery tool 370 can
then be withdrawn thereby releasing engagement between the first
guide structure 372 and the anchor and the second guide structure
374 and the support structure 352. The support structure 352 is
then released to expand or move into a desired deployed
location.
[0196] FIGS. 52C-52E illustrate a variety of embodiments of
deployment positions for the support implant 350. FIG. 52C
illustrates that the anchor 25 is driven to extend substantially
within cortical bone 40 but also to extend along an interface
between the cortical bone 40 and adjacent cancellous bone 41. FIG.
52C further illustrates that the moveable support structure 352
extends to obstruct or occlude a defect 33 in the anulus 23.
Movement of the moveable support structure 352 can be inhibited by
one or more stop structures 360 as previously described and/or via
interference with adjacent patient tissue, for example a superior
vertebral body 31. Support structure 352 can extend proximally from
the anchor 25 at roughly perpendicular to the endplate in which the
anchor 25 is implanted and then extend distally at an angle roughly
parallel to the opposing endplate.
[0197] FIG. 52D illustrates an embodiment where the anchor 25 is
driven into position to anchor in both cortical bone 40 and
cancellous bone 41. FIG. 52E illustrates an embodiment where the
anchor 25 is driven to secure substantially solely to cortical bone
40 with little to no contact with cancellous bone 41. FIG. 52E
further illustrates the anchor 25 deployed at a more medial
location as compared to the more posterior locations of anchor 25
illustrated in FIGS. 52C and 52D.
[0198] With reference to the curvilinear anchors and delivery
devices depicted inter alia in FIGS. 2-4, FIGS. 53A-53C illustrate
an embodiment of a delivery tool 400 adapted to drive one or more
anchors into a desired implantation or anchor location in patient
tissue (patient tissue not illustrated). FIGS. 53A-53C also
illustrate embodiments of a deployment sequence employing the
delivery tool 400 and anchor 25.
[0199] As illustrated in FIG. 53A, the delivery tool 400 comprises
an urging member 402. The urging member 402 is configured to apply
a translational force to the anchor 25. The urging member 402 can
provide force to the anchor 25 arising from impact force, hydraulic
pressure, pneumatic pressure, electromagnetic force, threaded
motion, and the like.
[0200] The urging member 402 defines an engagement profile 404 at a
distal or driving end of the urging member 402. The engagement
profile 404 can comprise one or more beveled or curved profiles
configured to engage with cooperating engagement profile 28 of the
anchor 25.
[0201] FIG. 53 illustrates an initial or first contact position
between the urging member 402 and the anchor 25 and respective
engagement profiles 404, 28. As illustrated in FIG. 53A, the anchor
25 initially translates substantially along a longitudinal axis L
upon initial contact with patient tissue. However, contact between
the beveled or curved engagement profiles 404, 28 and curvature of
the anchor 25 result in a camming action inducing the anchor 25 to
rotate or curve towards a transverse axis T during the progressive
introduction of the anchor 25 into patient tissue. In the views
provided in FIGS. 53A-53C, the anchor 25 rotates by approximately
ninety degrees in a clockwise direction. As shown in FIG. 53C,
during final stages of introduction of the anchor 25 into patient
tissue, the anchor 25 expands substantially along the transverse
axis T with significantly reduced relative motion along the
longitudinal axis L of movement of the urging member 402.
[0202] FIGS. 53A-53C further illustrate a progressive camming or
sliding movement between the opposed engagement profiles 404 and
28. The particular profiles or contours illustrated in FIGS.
53A-53C are simply illustrative of one example and a variety of
curves and profiles can be provided in various embodiments of the
delivery tool 400 and anchor 25 depending on the needs of a
particular application and the characteristics of the target
patient tissue.
[0203] FIGS. 54A-54C illustrate another embodiment of a delivery
tool 500 and sequence of operation of the delivery tool 500 in
advancing an anchor 25 into a desired location in target tissue
522. The delivery tool 500 comprises a guide body 502. The guide
body 502 is configured to provide a user a grasping surface for
manipulating and holding the delivery tool 500. The delivery tool
500 further comprises an urging member 504 to transmit force from
the delivery tool 500 to one or more anchors 25.
[0204] The delivery tool 500 further comprises a drive member 506.
The drive member 506 is attached via a hinged connection 510 to the
guide body 502. The hinged connection 510 can comprise one or more
of a pivot, pin, axle, hinge, bearings, bushings, and the like. The
hinged connection 510 provides pivoting or hinged movement between
the drive member 506 and the guide body 502.
[0205] The delivery tool 500 further comprises a first cam surface
512 arranged generally at a forward surface of the drive member
506. The first cam surface 512 engages with a cooperating second
cam surface 514 provided at a proximal end of the urging member
504. The first and second cam surfaces 512, 514 cooperate such that
hinged or pivoting movement of the drive member 506 induces a
sliding relative motion between the first and second cam surfaces
512, 514 to urge or advance the urging member 504 outwards. In
various embodiments, one or both of the first and second cam
surfaces 512, 514 can include substantially flat surfaces and
curved surfaces. The curved surfaces can describe varying radii of
curvature along different portions of the first and/or second cam
surfaces 512, 514.
[0206] The delivery tool 500 also comprises a depth stop 520 that
in some embodiments is adjustable in position or location. As
illustrated in FIG. 54B, the depth stop 520 provides a blocking or
locating function with respect to the target tissue 522 inhibiting
undesired relative motion between the delivery tool 500 and the
target tissue 522.
[0207] FIG. 54B further illustrates a generally transversely
oriented force applied to the drive member 506 indicated by the
designator F.sub.1 and arrow directed generally inwardly towards
the delivery tool 500 along a substantially transverse axis T where
the delivery tool 500 extends substantially along a longitudinal
axis L. In use, a user would hold the delivery tool 500 in a
desired position, for example by grasping the guide body 502. As
the user holds the delivery tool 500 in the desired location, the
generally transversely directed force F.sub.1 applied to the drive
member 506 is coupled to the distal end of the delivery tool 500 to
a second generally transverse force F.sub.2 directed towards the
target tissue 522. In this embodiment, the delivery tool 500 acts
as a third class lever to transmit force applied to the drive
member F.sub.1 as a similarly directed force F.sub.2 at the distal
end of the delivery tool 500.
[0208] As previously noted, in some embodiments, for example as
illustrated and described with respect to FIGS. 53A-53C, an anchor
25 can curve or rotate during an introduction procedure to
transition from a generally longitudinal approach through a
transition into a substantially transverse approach. As the anchor
25 begins and continues transverse motion into the target tissue
522, a reaction or recoil force F.sub.3 is generated tending to
drive the distal end of the delivery tool 500 and the attached
anchor 25 away from the target tissue 522. As the force F.sub.2 at
the distal end of the delivery tool 500 is opposite to the reaction
or recoil force F.sub.3, these forces will tend to counteract each
other helping to maintain the distal end of the delivery tool 500
at the desired location and facilitating more accurate and easier
introduction of the anchor 25 into the target tissue 522.
[0209] As previously noted, engagement profiles 404 and 28 can be
provided on the distal end of the urging member 504 and the anchor
25 respectively to facilitate the transition of advancement of the
anchor 25 from generally longitudinal motion transitioning to
generally transverse motion. The contour and relative position of
the engagement profiles 404 and 28 can be adapted for more
efficient transmission of force particularly through the transition
from generally longitudinal to generally transverse movement while
maintaining the delivery tool 500 in substantially the same
position and orientation.
[0210] FIG. 54C illustrates an embodiment of the delivery tool 500
and engaged anchor 25 at a generally terminal step in an
advancement procedure of the anchor 25. It can be seen that the
anchor 25 in this embodiment extends substantially in a transverse
direction. FIG. 54C illustrates further advantages of the delivery
tool 500 in providing a self-limiting function. The engagement
between the drive member 506 and the guide body 502 via the hinged
connection can be configured such that motion of the drive member
506 is limited with respect to the guide body 502. The dimensions
and contours of the urging member 504 and drive member 506 and the
first and second cam surfaces 512 and 514 can preferably be
selected such that the inward movement limit of the drive member
506 corresponds to a desired limit of advancement of the anchor 25
with respect to the distal end of the delivery tool 500. This
provides the advantage of automatically limiting the extent of
protrusion of the urging member 504 and can provide more repeatable
advancement of the anchor 25 to a desired implantation depth and
along a desired introduction path.
[0211] FIG. 55A illustrates an embodiment of anchor 600 comprising
a neck/keel portion 610 and a screw portion 620 that is implanted
along the axis of an anulotomy and disc access, just below or above
the disc space into an adjacent vertebral body. The neck/keel
portion 610 can be independently rotatable so as to extend from the
screw portion 620 toward the disc space, providing an anchoring
platform and site 611 from which to attach sutures, graft
containment devices, and/or other medical devices. The screw
portion 620 has an outer or major diameter that includes the
threads. The base of the threads defines an inner diameter or minor
diameter that forms an axle or rod to support the threads. In FIG.
55B the anchor 600 is illustrated including the distal tip 613 of
the screw portion 620 which can be drill-tipped (for self drilling
anchors), or blunt or cone shaped for anchors that are pre-drilled
in a previous step in the procedure.
[0212] In various embodiments one or more lateral projections in
the form of neck, keel, fin, or plate can be mounted along the
length of a screw or proximal to either end thereof. The attachment
of the keel 610 to the screw portion 620 may provide for
substantially free and independent rotation of the screw portion
620 without imparting a significant rotational force upon the keel
610. Alternatively the keel 610 can be connected or attached to the
screw portion 620 such that it is inhibited from rotation before
and/or after the screw portion 620 has been implanted.
[0213] In one or more of the embodiments the keel 610 can be
aligned in a desired direction such as vertically, e.g. extending
away from the vertebral endplate and into the disc space. The keel
610 can be attached to the screw portion 620 in a number of ways.
FIGS. 56A-C illustrate various views of a screw and keel anchor
assembly 600. In FIG. 56A, the keel 610 forms a ring 630 at two
locations, both with outer diameters equal to or less than the
screw's minor diameter, and generally encircling the screw's axle
at a region where there are no threads and a reduced axle diameter.
The screw portion 620 "captures" the keel's 610 ring 630 or rings
and allows the screw to spin freely about the keel 610.
[0214] The most proximal end of the proximal ring 630' of the keel
610 as illustrated in FIG. 56B may also include one or more
features 640 that allow a driver to restrain rotation and align the
keel 620 in the desired direction. In the illustration this is a
series of small holes in the keel ring 630 and small pins in a
corresponding driver 641 (FIG. 56C). FIG. 56C illustrates the
anchor 600 and one embodiment of driver 641 (FIG. 56D). The driver
641 also may have a shoulder (not illustrated) that rests on the
bone when the bone anchor is fully advanced that inhibits advancing
the screw 620 beyond a desired depth.
[0215] In certain other embodiments, there may be more than one
neck, keel, fin, plate, or projection, joined together or
independently to the screw, in one or more directions. The keel may
be bifurcated, form a ring or loop and/or comprise a neck and a
bridge attachment site. FIG. 57A illustrates an embodiment of the
anchor device 600 in which there is neck portion defining an
attachment site 611 and a bifurcated keel 610 and 610'. In this
embodiment the keels and neck portion are mounted at the distal tip
613 of the screw. The screw portion 620 can be concentric or offset
off axis about which the one or more keels extend. FIG. 57B is
substantially similar to the embodiment illustrated in FIG. 57A
except that the attachment site 611 and keels 610, 610' are mounted
at the proximal end of the screw portion 620 of the anchor 600.
[0216] FIG. 57C illustrates embodiments of implants similar to the
implant illustrated in FIG. 57A in an implanted orientation within
an intervertebral disc. In this case the implant was delivered from
an anterior surgical approach and the keel 610 and attachment site
611 of the implant are situated at the posterior lateral portion of
the endplate. Turning to FIG. 57D, an implant similar to the
implant illustrated in FIG. 57B is provided and has been delivered
via a posterior lateral surgical approach.
[0217] Further embodiments can include the addition of features to
control the alignment and depth of an anchor, in relation to the
surgical access and desired final implantation location of either
the keel, the screw, or both. Besides the use of stops for depth
control, an indicator and/or the use of X-ray imaging to visualize
screw depth, an alignment pin oriented along the end of the keel
parallel to the axis of the screw can facilitate visual or physical
alignment of the screw and keel toward the desired location.
Various lengths of screws and length and depth of keels, relative
to the countersunk bony surface, can provide a range of options in
terms of patient anatomy to properly place the strongest and most
convenient anchor and neck keel platform.
[0218] In other embodiments, the keel itself need not extend
perpendicular from the screw's longitudinal axis, but can be jogged
to one or more sides of the screw, and/or angled toward or away
from the distal end of the screw as needed to accommodate target
anatomy. In some embodiments, the keel or lateral projection can be
mounted or coupled at or along a medial portion of the screw, at a
distal end, at a proximal end, or anywhere else along its
length.
[0219] Various embodiments of keel/screw anchor device described
herein can also be adapted to resist back-out or unscrewing or
other undesired movement after implantation by the addition of a
locking or engaging feature. For example, once implanted to a
desired depth with the bone, the keel, fin, plate, and/or
projection locks or engages the screw. In this position the screw
is inhibited from rotating because the torque and/or translation
force acting on the keel is resisted by the shear force of the
bone.
[0220] Delivery methods described herein may alternatively or in
addition include the delivery of bone cement or any suitable
adhesive within, though, or adjacent the implant. The step of
delivering bone cement such as polymethylmetacrylate (PMM) can also
be used to fill in the area left by a countersunk anchor to aid to
prevent further fracture, back-out of the screw or keel and to aid
in healing if the cement is admixed with prophylactic antibiotics
other agents.
[0221] In some embodiments, anchors can be driven at trajectories
other than parallel to an endplate ranging from 1-360 and
preferably 10-80 degrees. FIG. 58A illustrates an embodiment
wherein a screw and keel type anchor 600 is implanted in an
inferior endplate at about 45 degrees relative to the endplate. In
FIG. 58B two anchors 700, 700' with a neck and keel are implanted
in the inferior and superior endplates of a vertebral body. In this
embodiment, the anchors 700, 700' are implanted at angles of
approximately 10-25 degrees.
[0222] The anchors depicted in FIGS. 58A-B (and the other anchors
throughout the disclosure) can be implanted flush to the vertebral
body or endplate or countersunk. In other embodiments, anchors are
driven at or proximal to the intersection or edge of a vertebral
body endplate and vertebral body outer surface.
[0223] FIGS. 59A-D illustrate an embodiment involving a locking or
back-out feature for an anchor. FIG. 59A is a side view of an
anchor having a plate-like lower keel 710 and a neck 720 extending
generally perpendicularly therefrom. The neck 720 and keel 710 can
further comprise various features described infra. Along the neck
720 is arranged an arm or extension 725 that is rotatably or
flexibly engaged to the neck and terminates in one or more barb,
hook, or angled projection 726. In other embodiments, the extension
725 is a separate floating member that slides along the neck 720.
In use, as illustrated schematically in FIG. 58B, the arm 725 is
raised as the neck 720 and keel 710 are driven across and into a
bone surface. When the desired implantation side is reached, the
arm 726 can be driven downward by striking it along its
longitudinal axis and/or released from a flexed raised position
such that it rotates downward to engage and at least partially
penetrates the bone surface, such as an endplate. The arm 725 can
pivot freely or be under tension to compress the bone between the
plate and the arm 725. Further embodiments of this locking feature
include arm 725 that extends beyond the plate as illustrated in
FIG. 59C and a plate 710 with voids or a "U" shaped tip 728 or
engagement zone as depicted in FIG. 59D that function to engage or
couple the angled projection 726 with the plate 710.
[0224] Any of the devices or methods herein may be used to anchor
or attach implants, grafts, tendons, patches, orthodontia, sutures,
etc. in a variety of orthopedic applications including the knee,
shoulder, wrist, cranium, ankle, heel and jaw.
[0225] Modifications can be made to the embodiments disclosed
herein without departing from the spirit of the present invention.
For example, method steps need not be performed in the order set
forth herein. Further, one or more elements of any given figure
described herein can be used with other figures. The titles and
headings used herein should not be used to limit the scope of any
embodiments. Features included under one heading may be
incorporated into embodiments disclosed under different headings.
Therefore, it should be clearly understood that the forms of the
present invention are illustrative only and are not intended to
limit the scope of the present invention. Further, no disclaimer of
subject matter is intended and the scope of the embodiments
disclosed herein should be ascertained from a full and fair reading
of the claims.
* * * * *