US20110196492A1 - Bone anchoring systems - Google Patents

Abstract

Embodiments relate generally to tissue anchors and methods of deliveπng 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 anchoπng systems that effectively reconstruct or augment vertebral endplate surfaces.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• 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
• 1. Field of the Invention
• 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.
• 2. Description of the Related Art
• 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
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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
• FIGS. 1A-B show an axial and sagittal view respectively of a spine segment and various anchor sites.
• FIG. 2 shows an exploded view of one embodiment of a curvilinear anchor and delivery instrument.
• FIG. 3 shows a perspective view of one embodiment of a curved two pronged staple type anchor.
• 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.
• FIG. 5 shows an exploded view of one embodiment of a delivery instrument and detachable sleeve.
• FIGS. 6A-G show a delivery sequence involving a vertebral endplate according to one embodiment.
• FIG. 7 shows a prior art bone screw and intervertebral anatomy.
• FIG. 8 shows an embodiment of an anchor according to one or more embodiments.
• FIG. 9 shows another embodiment of an anchor according to one or more embodiments.
• FIG. 10 shows another embodiment of an anchor according to one or more embodiments.
• FIG. 11 shows one embodiment a delivery tool.
• FIG. 12 shows the delivery tool in the previous figure with an anchor mounted
• FIG. 13 shows an axial cross sectional view of a vertebral body and implanted anchor.
• FIGS. 14A-B show an expanded view and a frontal view of the implanted anchor in the previous figure.
• FIG. 15 shows a sagittal view of the implanted anchor in the previous figures.
• 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.
• 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.
• FIGS. 18A-C show various views and features of anchors according to one or more embodiments.
• FIG. 19 shows various profiles of the keel portion of one or more anchors.
• 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.
• FIG. 21 shows a perspective view of another embodiment of an anchor according to one or more embodiments with an “eye” attachment means.
• 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.
• FIGS. 23A-B show a perspective view of another embodiment of an anchor according to one or more embodiments having a flexible linkage member.
• FIGS. 24A-C show a series of perspective views of one embodiment of an anchor and barrier system according to one or more embodiments.
• FIGS. 25A-C show a series of perspective views of another embodiment of an anchor and barrier system according to one or more embodiments.
• 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.
• FIG. 27A illustrates an embodiment of a stabilization assembly in combination with a separate anchor.
• FIG. 27B illustrates an embodiment of an anchor secured to bone tissue and connected to an implant.
• FIGS. 28A-28F illustrate various approaches of an implantation tool to target tissue.
• FIGS. 29A-29F illustrate a plurality of lateral views of various embodiments of anchors and attachment positions and locations with respect to patient tissue.
• FIG. 30A illustrates a top view of one embodiment of a support member.
• FIGS. 30B and 30C illustrate first and second configurations of an embodiment of a support member connected to an anchor.
• FIG. 31A illustrates an embodiment of an anchor partially engaged with a support member.
• FIG. 31B illustrates the embodiment of anchor and support member ofFIG. 31A in a fully engaged configuration.
• FIG. 31C illustrates a top view of an embodiment of a support member in an insertion configuration as maintained by a sleeve.
• FIG. 31D illustrates a support configuration of the support member ofFIG. 31C.
• FIG. 32 illustrates an embodiment including a plurality of anchors connected to respective gate numbers.
• FIG. 33 illustrates an embodiment of anchors and attached gate members in one embodiment of an implanted position.
• FIGS. 34A-34C illustrate a plurality of embodiments of anchors and attached gate members and corresponding implantation locations.
• FIGS. 35A and 35B illustrate two embodiments of anchors and attached gate members and corresponding implantation configurations.
• 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.
• FIG. 37 illustrates an embodiment of an anchor and attached gate member having a plurality of interweaved fingers.
• FIGS. 38A and 38B illustrate top and side schematic views respectively of various shapes and configurations of gate members.
• 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.
• 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.
• FIG. 39C illustrates schematic top views of various configurations of gate members including concave, multifaceted, and rounded.
• 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.
• 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.
• FIG. 41 illustrates an embodiment of anchors and attached gate members wherein opposed gate members are connected by an embodiment of a connector.
• FIGS. 42A and 42B illustrate side and end views respectively of embodiments of first and second anchor structures.
• FIGS. 43A-43D illustrate one embodiment of an implantation sequence of the embodiments of first and second anchor structures ofFIGS. 42A and 42B.
• FIG. 44A and 44B illustrates a side view of another embodiment of first and second anchor structures.
• FIGS. 45A-45C illustrate one embodiment of an implantation sequence of the embodiment of first and second anchor structures ofFIG. 44.
• FIGS. 46A and 46B illustrate perspective and side views respectively of an embodiment of a support implant.
• 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.
• 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.
• FIG. 49 illustrates an embodiment of a delivery tool configured to facilitate the implantation of embodiments of support implants.
• FIGS. 50A-50E illustrate one embodiment of an implantation sequence utilizing embodiments of the delivery tool ofFIG. 49.
• 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.
• FIGS. 52A-52E illustrate a plurality of configurations of a support implant deployed at various implantation locations.
• FIGS. 53A-53C illustrate an embodiment of an implantation process and cooperating anchor and delivery tool.
• FIGS. 54A-54C illustrate another embodiment of a delivery tool and embodiments of operation of the tool at various stages of an implantation procedure.
• FIGS. 55A and 55B illustrate embodiments of an implantable support anchor in an implanted side view and perspective view respectively.
• FIGS. 56A and 56B illustrate embodiments of an implantable support anchor in side view and end view respectively.
• FIG. 56C and 56D illustrate the embodiments of an implantable support anchor ofFIGS. 55A and 55B and an embodiment of driver adapted for use therewith.
• FIGS. 57A and 57B illustrate perspective views of embodiments of implantable support anchor with a support structure and multiple keel members.
• FIGS. 57C and 57D illustrate schematic side views of the embodiments illustrated byFIGS. 57A and 57B in an implanted position.
• FIGS. 58A and 58B illustrate perspective views of further embodiments of implantable support anchors.
• FIGS. 59A and 59B illustrate side views of embodiments of implantable support anchor having a movable arm.
• FIG. 59C illustrates a schematic side view of the embodiments illustrated byFIGS. 59A and 59B in an implanted position.
• FIG. 59D is a top view of the embodiments illustrated byFIGS. 59A and 59B.
DETAILED DESCRIPTION
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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
• 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 ¼ 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.
• 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.
• 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.
• 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
• Turning now toFIG. 2, shown is one embodiment of ananchor3 anddelivery instrument6 according to one or more aspects of the invention. A guide body4 has a cylindrical grip or hand hold and first proximal and second distal end. The body4 can be partially or fully hollow and contain a guide way chamber5 for holding and orienting an anchor orstaple3 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 chamber5 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 orstaple3 can be inserted within the chamber5 via a side loading window. Apusher rod1 is carried within or by the body4 and accesses or is in communication with the guide way chamber. Therod1 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, oranchor3 within the guide way chamber5. 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 thestaple3 is driven out through the curved slot of the chamber5. Therod1 may be rigid or at least partially flexible in construction.
• Also shown inFIG. 2 is adepth stop support2 which can be configured as a snap on sleeve that fits over the body4. 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.
• FIG. 3 is an example of an embodiment of a staple oranchor3 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.
• The series depicted inFIGS. 4A-E shows an embodiment of adelivery device6 being loaded with ananchor3 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 depthstop support sleeve2 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.
• InFIG. 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, analignment projection8 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.
• 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.
• 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.
• 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.
• 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.
• 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
• 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.
• An example of such prior art anchor and environment is depicted inFIG. 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• Turning to the drawings,FIG. 8 shows an embodiment of ananchor25 with aleading edge12,suture attachment sites11, ingrowth features or voids13, first and second plate-like legs orlateral extensions15,15′ defining the keel, arcuate central ridge or apex10, centering oralignment projection16, and feet orridges14,14′. 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.
• 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.
• InFIG. 9, an anchor similar to the one depicted in the previous figure is shown. The apex10, 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 areridges70 and scalloped teeth-like surface features71.
• FIG. 10 shows another embodiment of an anchor with deployedbarbs80 and80′ 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 recesses82 are adapted for holding the barbs during implantation to streamline the anchors profile.
• 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.Element81 can be arranged as an opposing barb or expansion means however one ormore barbs80,81 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.
• FIG. 11 shows a delivery tool with ashaft96 withdistal end95 having an anvil orstriking surface94 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 mountingmember90 may extend beyond the implant when the implant is mounted or loaded on the tool. The mountingmember90 includes a flattenedlower surface93 and a rounded blunt front surface91 for positioning along a bone surface, such as the top of a vertebral endplate, and a slot or engagement means92 for accepting and aligning an anchor.
• FIG. 12 shows theanchor25 mounted on the mountingmember90. The extendedlower surface93 and the leading edge of theimplant12 and12′ 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.
• FIG. 13 shows a cross-section of avertebral body24 having ananulus fibrosus23 bounding nucleus pulposus22 with ananchor25 embedded into a posterior aspect of an endplate and within or proximal to an anulotomy or defective region of theanulus fibrosus23. 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.
• FIG. 14A is an expanded view ofFIG. 13 and shows dotted lines to represent the keel portion of theanchor25 beneath the endplate surface.FIG. 14B is a dorsal view ofFIG.14A showing anchor25.
• InFIG. 15, a sagittal view of an implantedanchor25 is shown at least partially within thedefect33 and inferiorvertebral body32. Superiorvertebral body31 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.
• 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 avertebral body24 and adelivery instrument96 and ananchor25. 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 inFIG. 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 flatproximal end1602 for hammering, if needed and aknurled handle1600.
• FIG. 17 illustrates a top cross-sectional view of ananulus repair implant52 lying along the inner surface of the posterior anulus that can be coupled, attached, or sutured to ananchor25. The connection between the anchor and implant can be permanent or detachable. Theimplant52 can be delivered and positioned prior to, at the same time as, or subsequent to the implantation of theanchor25.FIGS. 18A-18C show various features of anchors.
• InFIG. 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, orimplant attachment site170,171,172,173,174 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.
• FIG. 19 shows various embodiments of the anchor cross-sections180-200 including several keel profiles from a front view resistant to pullout and offering various surface areas. Some are solid shapes as in anchor profiles182,184,187, and200 and others are hollow and have an open midsection as in anchor profiles183,185,188.
• Turning toFIG. 20, a perspective view of an anchor is shown with leadingedges12,12′, alignment means16, suture orfastener attachment11 site,neck10, and voids13. In this embodiment the apex does not run the entire length or depth of the anchor corresponding to the keel or opposingleg portions15,15′ 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. Theneck10 is shown perpendicular to thekeel15 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
• InFIG. 21, a “V” shaped anchor is shown. An “eye” orloop11 is integral to aneck extension portion10 that bifurcates into twolegs15,15′. Because the leadingedges12,12′ and at least a portion of theneck10 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 theneck10 and theleg portions15,15′ of the device function as a keel. This embodiment also showsridges12 and scalloped recesses170. Anchors according to other embodiments described herein may also comprise ridges and/or scalloped recesses.
• InFIG. 22A, another embodiment of an anchor is shown. Here, threelegs12,12′, and12″ defining the keel are provided. A relativelytaller neck10 is provided beneath a perpendicularsuture attachment member11. Theneck10 is set back distally from the leading edge of the keel portion.FIG. 22B shows the distal tip of a delivery tool. Shown areattachment pins180, anvil orstriking surface186,depth stop187, mountingmember185, andshaft96 withdistal end95.
• Turning toFIG. 23A, ananchor25 is shown with anattachment site189 for aflexible bridge818. Thebridge818 is shown inFIG. 23B and is coupled to theneck10 of theanchor25 with a first and secondflexible tab193,194 and has anattachment11 site at the opposing end.
• The series depicted inFIGS. 24A-24C shows an anulus reinforcement system.FIG. 24A shows an anchor similar to the ones depicted previously with abifurcated keel15,15′,neck10, andattachment plate112 with a first andsecond coupling member111,111′ or snap surface.FIG. 24B is an exploded view of a barrier, mesh, orreinforcement plate52 adjacent ananchor25 wherein theanchor25 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.
• Another embodiment of an anulus reinforcement system is shown inFIGS. 25A-25C. In this embodiment, a single attachment means111 is used that can function as a fulcrum or hinge site for aflexible barrier52 member shown inFIG. 25B. Behind or distal to the attachment means111 is asupport member112 or plate that is an extension of theneck10. This feature, in some embodiments, inhibits thebarrier52 from folding backwards and may also reinforce thebarrier52.FIG. 25C shows a hood orsleeve120 element that can be mounted on or carried by a delivery tool or instrument as described herein. Thehood120 retains the folded barrier until the anchor portion is fully established within the tissue whereupon it is retracted.
• Another embodiment is shown inFIGS. 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.
• 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.
• The anchor illustrated inFIG. 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 ansuture attachment site11 in the form of a loop on the other end. The leading edge of thelegs12 andneck10 are sharpened and the upper portion of the legs is recessed, profiled or formed with arelief113. Therelief profile113 can correspond to an anatomical structure. In this embodiment the forward recess orrelief112 corresponds to the concavity or cupping of an endplate. The angle between the keel plates is around 90 degrees. Theneck10 is about 0.1 millimeter high and about 0.2 wide millimeters wide and extends about 0.2 millimeters. Theneck10 andattachment site11, an “eye” or loop in this embodiment, are mounted at the trailing or aft potion of thekeel15.
• 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.
• 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.
• 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.
• 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
• FIG. 27A illustrates a lateral view of astabilizer assembly250 secured to patient tissue via a first andsecond fastener252aand252b.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 fastener252ais, in one embodiment, attached to or engaged with a superiorvertebral body31. Thesecond fastener252bis attached to or engaged with an inferiorvertebral body32. In this embodiment, thestabilizer assembly250 is arranged towards the posterior of the superior and inferiorvertebral bodies31,32. Also shown isanchor device25 that functions as an anterior buttress or graft containment device.
• InFIG. 27A, ananchor25 is implanted in an upper anterior region of the inferiorvertebral body32. A portion of theanchor25 extends above or is proud of an upper surface of the inferiorvertebral body32. In one embodiment, the portion of theanchor25 extending above the surface of the inferiorvertebral body32 is arranged to block or secure a graft, frame, plate, and/orbarrier35. 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, thegraft35 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 theanchor25.
• FIG. 27B illustrates another embodiment where ananchor25 is attached to a lower posterior portion of a superiorvertebral body31. 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 theanchor25 is proud of the surface of the superiorvertebral body31 and is further arranged to block or secure a nonfusionintervertebral device52. Thedevice52 can comprise an artificial disc or partial nucleus replacement device or other type of implant suitable for the needs of a particular implementation.
• FIGS. 28A-28F illustrate a plurality of approaches of animplantation tool6 having one ormore alignment structures7 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.
• FIG. 28B illustrates an embodiment of a posterior approach between adjacent end plates and advance of theimplantation tool6 such that a distal end of theimplantation tool6 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.
• 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 animplantation tool6 for proximal delivery of one or more anchors or other implants.
• FIG. 28F illustrates multiple approaches of animplantation tool6 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.
• FIGS. 29A-29F provide lateral or side views of various embodiments of one ormultiple anchors25 arranged to block and/or provide an attachment/securing site forgrafts35 and/orimplants52. InFIGS. 29A-29F, the left and right portions of each Figure corresponds generally to the outer rim or edges of superior and inferiorvertebral bodies31,32. 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 inFIGS. 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.
• FIG. 29A illustrates asingle anchor25 implanted through a lower end plate adjacent a defect in theanulus fibrosus23 proximal the cortical rim but extending inwardly into the inferiorvertebral body32. In this embodiment, theanchor25 is configured to block a nonfusionintervertebral device52 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.
• FIG. 29B illustrates ananchor25 blocking a fusion device orgraft35. In this embodiment, theanchor25 is arranged to rest proximal to thegraft35 but does not touch thegraft35.
• FIG. 29C illustrates an embodiment where ananchor25 is secured to an inferiorvertebral body32 such that theanchor25 is barely proud the surface of the inferiorvertebral body32. The portion of theanchor25 proud of the surface is connected to anintervertebral device35 that can be either a fusion or nonfusion device as illustrated and described infra.
• FIGS. 29D-29F illustrate a plurality of embodiments employingmultiple anchors25 where eachanchor25 can be substantially identical toother anchors25 or where different versions or configurations ofanchors25,25′ 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 inFIGS. 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.
• InFIG. 29F, two opposingvertebral bodies31,32 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.
• FIG. 30A illustrates a top view of an embodiment of areconfigurable support member60. Thesupport member60 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, thesupport member60 comprises a plurality of generally rigidelongate members62 connected via interposedflexible connections64. Theflexible connections64 are formed of a biocompatible resilient material to allow thesupport member60 to resiliently move between a first and a second configuration. In some embodiments, thesupport member60 can reconfigure itself automatically under resilient force provided by thesupport member60 itself. In some embodiments, thesupport member60 can be reconfigured under tension or compression force applied to thesupport member60. In some embodiments, theelongate members62 andflexible connections64 are formed of the same or similar materials. Theflexible connections64 can comprise weakened regions of thesupport member60 and/or regions where material comprising thesupport member60 is thinner and/or narrower than the material in the regions of theelongate members62.
• In some embodiments, thesupport member60 comprises aconnection portion66 configured to engage with ananchor25 as illustrated inFIGS. 30B and 30C. In some embodiments, theconnection portion66 engages with acorresponding anchor25 via a friction fit. In some embodiments, thesupport member60 can connect to arespective anchor25 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, thesupport member60 andanchor25 can be formed as an integral unit and need not comprise separate interconnected components.
• FIG. 31A illustrates a further embodiment of asupport member60 with a corresponding anchor partially engaged with aconnection region66 of thesupport member60.FIG. 31A also illustrates that thesupport member60 defines a transverse dimension indicated by the designator T and a longitudinal dimension indicated by the designator L.
• FIG. 31B illustrates a perspective view of thesupport member60 fully engaged with ananchor25. As previously noted, connections between theanchor25 andsupport member60 can comprise a wide variety of connection means including multiple means for connecting thesupport member60 andanchor25. In one non-limiting example, theanchor25 can connect to thesupport member60 via means for connecting comprising both a friction fit and a detent arrangement.
• FIG. 31C illustrates a top view of thesupport member60 in a configuration having a reduced transverse dimension and an elongated longitudinal dimension. In one embodiment, the configuration illustrated inFIG. 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 thesupport member60 can facilitate advancement of thesupport member60 towards a desire implantation location.
• In one embodiment, thesupport member60 comprises anattachment structure68 arranged at a first or leading end of thesupport member60. Theattachment structure68 can provide an attachment point for application of force to thesupport member60. For example, a tension force can be applied to the leading end of the support member adjacent theattachment structure68 to draw the leading end rearward so as to reduce the longitudinal dimension and expand the transverse dimension.
• In some embodiments,FIG. 31C illustrates the support member in a configuration having force applied. For example, in one embodiment, asleeve120 can be arranged about thesupport member60 to maintain a reduced transverse dimension T. Removal of thesleeve120 can then allow thesupport member60 to achieve a relaxed configuration having an expanded transverse dimension T and reduced longitudinal dimension L. In other embodiments, the configuration illustrated inFIG. 31C can be maintained by one or more sutures or clamps applied to opposed lateral sides of thesupport member60 to maintain the reduced transverse dimension T. Removal or severing of such sutures or clamps can release thesupport member60 to a relaxed state having an expanded transverse dimension T and a reduced longitudinal dimension L. This configuration is illustrated schematically inFIG. 31D with the reduced longitudinal dimension L′ and the expanded transverse dimension T′.
Opposing Gates
• FIG. 32 illustrates a side view of asupport assembly300 configured to support or retain patient tissue and/or a further implant member. In one embodiment, thesupport assembly300 comprises afirst anchor25 and an opposedsecond anchor25′. Afirst gate member302 is connected or attached to thefirst anchor25 and asecond gate member302′ is similarly connected or attached to the correspondingsecond anchor25′. In some embodiments, thegate members302,302′ are formed of flexible material. Polymers may be used. Nitinol may also be used. In some embodiments, thegate members302,302′ are formed of a resilient or elastic material. In some embodiments, thegate members302,302′ can be at least partially rigid and movably attached to therespective anchor25,25′ under resilient pre-loading for biased movement in a desired direction. Such embodiments provide the ability foropposed gate member302,302′ 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 thesupport assembly300.
• FIG. 33 illustrates a side view of asupport assembly300 in an implanted location. In this embodiment, afirst anchor25 is secured to a lower region of a superiorvertebral body31. Asecond anchor25′ is secured to an upper surface of an inferiorvertebral body32. Opposed first andsecond gate members302,302′ resiliently engage with each other and are connected or attached to therespective anchors25,25′. In this embodiment, thegate members302,302′ comprise a resilient and flexible biocompatible material. As illustrated inFIG. 33, the first andsecond gate members302,302′ 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 theopposed gate members302,302′. For example, in an embodiment where thesupport assembly300 is implanted to resist herniation ofnucleus pulposus22, thesupport assembly300 via the resilient engagement of theopposed gate members302,302′ can resist such herniation while accommodating relative movement of opposed end plates. A further advantage to certain embodiments of thesupport assembly300 is that the moveable ability of thegate members302,302′ 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.
• In some embodiments (including, but not limited to,FIG. 33), one ormore gate members302 can be substantially rigid and moveably attached to arespective anchor25. A connection or coupling between a substantiallyrigid gate member302 and acorresponding anchor25 can comprise a flexible connection, a pivoting connection, and/or a hinged connection. A connection between agate member302 and respective anchor can further comprise a resilient or spring aspect such that thegate member302 is urged in a particular direction of movement. In some embodiments, asupport assembly300 can comprise an integral assembly and need not comprise separate connectedgate member302 andanchor25 components.
• 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.
• FIGS. 34A-34C illustrate additional embodiments of asupport assembly300 and various embodiments of implantation location. For example,FIG. 34A illustrates asupport assembly300 with afirst anchor25 attached generally at a lower anterior region of a superiorvertebral body31 and asecond anchor25′ attached at an upper anterior corner of a inferiorvertebral body32.FIG. 34A illustrates an embodiment of thesupport assembly300 implanted in a defect located generally at an anterior position and oppositeintact anulus tissue23.FIG. 34B illustrates another embodiment ofsupport assembly300 where theanchors25 are configured generally as threaded or screw shaped structures. In this embodiment, theanchors25 are positioned generally at an anterior outer surface of superior and inferiorvertebral bodies31,32 In this embodiment, theopposed gate members302 further extend from an interstitial region between thevertebral bodies31,32 outwards towards the respective anterior surfaces of thevertebral bodies31,32 for connection with the respective anchors25.FIG. 34C illustrates a further embodiment where thesupport assembly300 is implanted at opposed inner surfaces of a superior and inferiorvertebral body31,32 along the endplates and within or beyond the anulus. Thesupport assembly300 may arranged at an posterior, anterior, or lateral position of thevertebral bodies31,32.
• FIGS. 35A and 35B illustrate further embodiments of asupport assembly300 and various embodiments ofanchor25 configurations.FIG. 35A illustrates that theanchors25 comprise a generally spiked or barbed plate profile configured to be driven into and attached to respectivevertebral bodies31,32.FIG. 35A further illustrates that the opposed anchors25 are presented to the patient tissue in a generally vertical anti-parallel approach.FIG. 3513 illustrates an embodiment where theanchors25 comprise a generally T-shaped or keel profile.FIG. 3513 further illustrates an embodiment wherein the opposed anchors25 are presented to the respectivevertebral bodies31,32 in a generally parallel transverse approach.
• FIGS. 36A-36C illustrate top views of embodiments ofsupport assembly300 and respective implantation locations with respect to patient tissue, such as ananulus23.FIG. 36A illustrates that ananchor25 can be implanted in adefect region33 such that theanchor25 is interposed between aninner surface26 and anouter surface27 of theanulus23.FIG. 36B illustrates an embodiment where theanchor25 is implanted substantially adjacent or flush with anouter surface27 of theanulus23.FIG. 36C illustrates an embodiment where theanchor25 is implanted substantially adjacent with aninner surface26 of theanulus23.
• FIG. 37 illustrates a further embodiment ofsupport assembly300 comprising a plurality of interleaved leaves orfingers304. In some embodiments, the individual leaves orfingers304 are generally aligned with other leaves orfingers304 and in other embodiments the multiple leaves orfingers304 are not generally aligned with each other.
• FIGS. 38A and 38B illustrate top and side views respectively of various configurations ofgate member302. As illustrated, agate member302 can define a generally non-square rectangular, a generally square, a triangular, a semi-circular, a circular, or an irregular profile. In some embodiments, agate member302 comprises a plurality of leaves orfingers304 arranged to extend in divergent directions so as to describe a brush-like configuration. In some embodiments, agate member302 can comprise a plurality of leaves orfingers304 extending generally parallel to each other so as to define a finger-like profile. Other shapes and profiles ofgate member302 are possible.FIG. 38B illustrates thatgate members302 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.
• FIG. 39A illustrates an embodiment ofsupport assembly300 comprising opposedgate members302,302′ each having a plurality of interleaved leaves orfingers304. In this embodiment, the individual leaves orfingers304 of eachgate member302 extend along different paths as seen in side view or are not generally aligned with each other.FIG. 39B illustrates an embodiment ofsupport assembly300 having opposedgate members302,302′ each having a plurality of individual leaves orfingers304. In this embodiment, the individual leaves orfingers304 of eachgate member302 are generally aligned with each other as seen in side view.
• FIG. 38C illustrates further embodiments ofgate members302 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.
• FIGS. 40A and 40B illustrate embodiments ofsupport assemblies300 comprising opposedgate members302 having a concave profile. In one embodiment as illustrated inFIG. 40A, opposedgate members302,302′ are substantially mirror images of each other having similar shapes, sizes and contours. Theopposed gate members302,302′ are further aligned so as to engage with each other to form a substantially continuous occlusion or seal aspect of thesupport assembly300.FIG. 40B illustrates another embodiment where theopposed gate members302,302′ are similar in shape and contour, however can have different sizes. In the embodiment illustrated inFIG. 40B, theopposed gate members302,302′ are configured and arranged to engage with each other in a nested configuration.
• FIG. 41 illustrates a further embodiment of support assembly that can be similar to any previously described embodiment ofsupport assembly300. In the embodiment illustrated inFIG. 41, aconnector306 is provided to clamp, connect or provide a pivotal axis between theopposed gate members302. Theconnector306 can be provided in alternative or in combination with a resilient or self-engaging aspect of thegate members302 to provide additional resistance to separation of theopposed gate members302. The embodiment illustrated inFIG. 41 can be preferred in implementations where the sealing or blocking function provided by thesupport assembly300 is preferably provided in a bi-directional manner.
Threaded Keel Anchor
• FIGS. 42A and 42B illustrate in side and end views respectively embodiments of afirst anchor structure310 and asecond anchor structure312. The first andsecond anchor structures310,312 can be secured or connected to each other, for example via afastener314. The first anchor structure comprises a first threadedprofile316 configured to allow thefirst anchor structure310 to threadably engage with patient tissue in a well known manner. Thefirst anchor structure310 further comprises a second threaded profile configured to threadably engage with thefastener314.
• Thesecond anchor structure312 comprises anattachment structure322 that can be configured as an attachment point for sutures and/or for connection to a separate implant (not illustrated). Thesecond anchor structure312 also comprises a foot orkeel structure324. The foot orkeel structure324 is configured to secure and align thesecond anchor structure312 for connection with thefirst anchor structure310. The foot orkeel portion324 can be further configured to engage with patient tissue to secure thesecond anchor structure312 thereto.
• FIGS. 43A-43D illustrate embodiments of an implantation and attachment process for the first andsecond anchor structures310,312. As illustrated inFIG. 43A, a pilot hole can be formed in patient tissue, for example comprising an anulus. As shown inFIG. 43B, thefirst anchor structure310 can be threadably inserted into the pilot hole via a combination of rotational and/or translational forces. As illustrated inFIG. 43C, thesecond anchor structure312 can then be laterally driven into the patient tissue and into engagement with thefirst anchor structure310, for example into the second threadedprofile320.FIG. 43D illustrates in end view that thefastener314 can be threadably engaged with the second threadedprofile320 of thefirst anchor structure310 to secure and connect thesecond anchor structure312 in position.
• FIGS. 44A and 44B illustrates another embodiment of afirst anchor structure330 and asecond anchor structure332. Thefirst anchor structure330 comprises afirst engagement surface334 configured and sized to engage with a cooperatingsecond engagement surface336 of thesecond anchor structure332. 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).
• FIGS. 45A-45C illustrate embodiments of introduction processes for securing the first andsecond anchor structures330,332 to each other and to patient tissue. As illustrated inFIG. 45A, an opening orpilot hole342 can be formed in patient tissue (e.g., vertebral body)340.FIG. 45B illustrates that thesecond anchor structure332 is introduced into the desired location in thepatient tissue340 via a generally linear translational introduction. However, it should be noted that theopening342 need not be formed prior to introduction of thesecond anchor structure332. For example, thesecond anchor structure332 can be introduced to thepatient tissue340 before formation of theopening342. Formation of theopening342 is optional and may be omitted. For example, depending on the relative size of thefirst anchor structure330 and the characteristics of thepatient tissue340, thefirst anchor structure330 can comprise a self-drilling aspect reducing or eliminating the need to form theopening342.FIG. 45C illustrates a further process wherein thefirst anchor structure330 is threaded into thepatient tissue340 and further so as to engage the first and second engagement surfaces334,336. Thus, thesecond anchor structure332 is secured and positioned both by its contact with thepatient tissue340 and via connection with thefirst anchor structure330 which is also engaged with thepatient tissue340.
• FIGS. 46A and 46B illustrate in perspective and side views respectively embodiments of asupport implant350 configured for closing, blocking, reinforcing, and/or repairing defects, openings, or weakened areas in a variety of patient tissues. In some embodiments, thesupport implant350 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 thesupport implant350 provide these benefits while limiting interference with spinal joint movement including flexion, extension, and lateral bending movement.
• Thesupport implant350 comprises ananchor25 that can be formed according to any of the previously described embodiments ofanchor25. In one embodiment, theanchor25 describes a generally T-shaped profile having two keel portions extending generally at right angles to each other. Theanchor25 can include solid features, roughness features, leading edges, or any other combination of features and profiles as described herein.
• Thesupport implant350 further comprises asupport structure352. Thesupport structure352 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. Thesupport structure352 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.
• FIGS. 47A and 47B illustrate an anterior-posterior view and a lateral view respectively of embodiments ofsupport implant350.FIGS. 47A and 47B are further presented as radiographic images, for example as may be obtained via radiographic imaging of thesupport implant350 in an implanted location. As seen inFIGS. 47A and 47B, thesupport implant350 comprises a first marker354aand asecond marker354b.Themarkers354a,354bcan 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 thesupport structure352 can comprise biocompatible materials which can be difficult to image in the implantation environment. The markers354 provide an enhanced ability to image thesupport implant350 and thereby determine the location and orientation of components of thesupport implant350 that may be otherwise difficult to determine.
• FIG. 48 and Detail A thereof provide a schematic side view illustration of embodiments of asupport implant350 comprising amoveable support structure352. In one embodiment, thesupport implant350 comprises a moveable joint356 between thesupport structure352 and ananchor25. In some embodiments, the moveable joint356 defines a pivotable or hinged connection between thesupport structure352 and theanchor25. In one embodiment, thesupport implant350 further defines first andsecond stop structures360aand360bconfigured to limit the range of motion of thesupport structure352. In some embodiments, thesupport structure352 is resiliently biased for movement in a desired direction.
• FIG. 49 illustrates an embodiment of adelivery tool370 configured to hold and deliver embodiments ofsupport implants350. Structure and operation of thedelivery tool370 will be described in greater detail with respect toFIGS. 50A-50E and51 which illustrate a deployment sequence employing thesupport implant350 anddelivery tool370.
• As shown inFIG. 50A, a distal end of thedelivery tool370 comprisesfirst guide structure372. Thefirst guide structure372 is configured to engage withcorresponding guide structures362 of thesupport implant350. Thefirst guide structure372 can be configured as one or more of pins, posts, slots, grooves, dovetails, or other structures configured to maintain an alignment and orientation between thedelivery tool370 and thesupport implant350. In some embodiments, thefirst guide structure372 engages withguide structures362 formed in theanchor25.
• Thedelivery tool370 further comprisessecond guide structures374. Thesecond guide structures374 are configured to engage with thesupport structure352 and maintain thesupport structure352 at a desired orientation and position with respect to theanchor25. For example,FIG. 50B illustrates thesupport implant350 engaged with both the first andsecond guide structures372 and374.
• FIGS. 50C,50D, and50E illustrate a progression of thesupport implant350 engaging with thedelivery tool370. An end plate guide of thedelivery tool370 advances towards thesupport implant350 and urges thesecond guide structures374 to induce thesupport structure352 into adjacency with theanchor25. The adjacency of thesupport structure352 to theanchor25 provides a reduced cross-sectional profile, for example as illustrated inFIG. 50E, to facilitate introduction of thesupport implant350 to the desired implant location.
• FIG. 51 illustrates thesupport implant350 and engageddelivery tool370 at an implant location. In this embodiment, the implant location comprises a corner ofpatient tissue340, such as avertebral body31,32. Thesupport implant350 anddelivery tool370 define in one embodiment a pair of adjacent first and second locating surfaces380,382. The first and second locating surfaces380,382 can be positioned to contact thepatient tissue340 to inhibit further movement of thesupport implant350 ordelivery tool370 in multiple dimensions.
• As illustrated inFIGS. 52A and 52B, force can be applied, for example at a drivingsurface384 of thedelivery tool370 to urge theanchor25 into anchoring tissue. Thedelivery tool370 can then be withdrawn thereby releasing engagement between thefirst guide structure372 and the anchor and thesecond guide structure374 and thesupport structure352. Thesupport structure352 is then released to expand or move into a desired deployed location.
• FIGS. 52C-52E illustrate a variety of embodiments of deployment positions for thesupport implant350.FIG. 52C illustrates that theanchor25 is driven to extend substantially withincortical bone40 but also to extend along an interface between thecortical bone40 and adjacentcancellous bone41.FIG. 52C further illustrates that themoveable support structure352 extends to obstruct or occlude adefect33 in theanulus23. Movement of themoveable support structure352 can be inhibited by one or more stop structures360 as previously described and/or via interference with adjacent patient tissue, for example a superiorvertebral body31.Support structure352 can extend proximally from theanchor25 at roughly perpendicular to the endplate in which theanchor25 is implanted and then extend distally at an angle roughly parallel to the opposing endplate.
• FIG. 52D illustrates an embodiment where theanchor25 is driven into position to anchor in bothcortical bone40 andcancellous bone41.FIG. 52E illustrates an embodiment where theanchor25 is driven to secure substantially solely tocortical bone40 with little to no contact withcancellous bone41.FIG. 52E further illustrates theanchor25 deployed at a more medial location as compared to the more posterior locations ofanchor25 illustrated inFIGS. 52C and 52D.
• With reference to the curvilinear anchors and delivery devices depicted inter alia inFIGS. 2-4,FIGS. 53A-53C illustrate an embodiment of adelivery tool400 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 thedelivery tool400 andanchor25.
• As illustrated inFIG. 53A, thedelivery tool400 comprises an urgingmember402. The urgingmember402 is configured to apply a translational force to theanchor25. The urgingmember402 can provide force to theanchor25 arising from impact force, hydraulic pressure, pneumatic pressure, electromagnetic force, threaded motion, and the like.
• The urgingmember402 defines anengagement profile404 at a distal or driving end of the urgingmember402. Theengagement profile404 can comprise one or more beveled or curved profiles configured to engage with cooperatingengagement profile28 of theanchor25.
• FIG. 53 illustrates an initial or first contact position between the urgingmember402 and theanchor25 andrespective engagement profiles404,28. As illustrated inFIG. 53A, theanchor25 initially translates substantially along a longitudinal axis L upon initial contact with patient tissue. However, contact between the beveled orcurved engagement profiles404,28 and curvature of theanchor25 result in a camming action inducing theanchor25 to rotate or curve towards a transverse axis T during the progressive introduction of theanchor25 into patient tissue. In the views provided inFIGS. 53A-53C, theanchor25 rotates by approximately ninety degrees in a clockwise direction. As shown inFIG. 53C, during final stages of introduction of theanchor25 into patient tissue, theanchor25 expands substantially along the transverse axis T with significantly reduced relative motion along the longitudinal axis L of movement of the urgingmember402.
• FIGS. 53A-53C further illustrate a progressive camming or sliding movement between theopposed engagement profiles404 and28. The particular profiles or contours illustrated inFIGS. 53A-53C are simply illustrative of one example and a variety of curves and profiles can be provided in various embodiments of thedelivery tool400 andanchor25 depending on the needs of a particular application and the characteristics of the target patient tissue.
• FIGS. 54A-54C illustrate another embodiment of adelivery tool500 and sequence of operation of thedelivery tool500 in advancing ananchor25 into a desired location intarget tissue522. Thedelivery tool500 comprises aguide body502. Theguide body502 is configured to provide a user a grasping surface for manipulating and holding thedelivery tool500. Thedelivery tool500 further comprises an urgingmember504 to transmit force from thedelivery tool500 to one or more anchors25.
• Thedelivery tool500 further comprises adrive member506. Thedrive member506 is attached via a hingedconnection510 to theguide body502. The hingedconnection510 can comprise one or more of a pivot, pin, axle, hinge, bearings, bushings, and the like. The hingedconnection510 provides pivoting or hinged movement between thedrive member506 and theguide body502.
• Thedelivery tool500 further comprises afirst cam surface512 arranged generally at a forward surface of thedrive member506. Thefirst cam surface512 engages with a cooperatingsecond cam surface514 provided at a proximal end of the urgingmember504. The first and second cam surfaces512,514 cooperate such that hinged or pivoting movement of thedrive member506 induces a sliding relative motion between the first and second cam surfaces512,514 to urge or advance the urgingmember504 outwards. In various embodiments, one or both of the first and second cam surfaces512,514 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 surfaces512,514.
• Thedelivery tool500 also comprises adepth stop520 that in some embodiments is adjustable in position or location. As illustrated inFIG. 54B, thedepth stop520 provides a blocking or locating function with respect to thetarget tissue522 inhibiting undesired relative motion between thedelivery tool500 and thetarget tissue522.
• FIG. 54B further illustrates a generally transversely oriented force applied to thedrive member506 indicated by the designator F₁and arrow directed generally inwardly towards thedelivery tool500 along a substantially transverse axis T where thedelivery tool500 extends substantially along a longitudinal axis L. In use, a user would hold thedelivery tool500 in a desired position, for example by grasping theguide body502. As the user holds thedelivery tool500 in the desired location, the generally transversely directed force F₁applied to thedrive member506 is coupled to the distal end of thedelivery tool500 to a second generally transverse force F₂directed towards thetarget tissue522. In this embodiment, thedelivery tool500 acts as a third class lever to transmit force applied to the drive member F₁as a similarly directed force F₂at the distal end of thedelivery tool500.
• As previously noted, in some embodiments, for example as illustrated and described with respect toFIGS. 53A-53C, ananchor25 can curve or rotate during an introduction procedure to transition from a generally longitudinal approach through a transition into a substantially transverse approach. As theanchor25 begins and continues transverse motion into thetarget tissue522, a reaction or recoil force F₃is generated tending to drive the distal end of thedelivery tool500 and the attachedanchor25 away from thetarget tissue522. As the force F₂at the distal end of thedelivery tool500 is opposite to the reaction or recoil force F₃, these forces will tend to counteract each other helping to maintain the distal end of thedelivery tool500 at the desired location and facilitating more accurate and easier introduction of theanchor25 into thetarget tissue522.
• As previously noted, engagement profiles404 and28 can be provided on the distal end of the urgingmember504 and theanchor25 respectively to facilitate the transition of advancement of theanchor25 from generally longitudinal motion transitioning to generally transverse motion. The contour and relative position of the engagement profiles404 and28 can be adapted for more efficient transmission of force particularly through the transition from generally longitudinal to generally transverse movement while maintaining thedelivery tool500 in substantially the same position and orientation.
• FIG. 54C illustrates an embodiment of thedelivery tool500 and engagedanchor25 at a generally terminal step in an advancement procedure of theanchor25. It can be seen that theanchor25 in this embodiment extends substantially in a transverse direction.FIG. 54C illustrates further advantages of thedelivery tool500 in providing a self-limiting function. The engagement between thedrive member506 and theguide body502 via the hinged connection can be configured such that motion of thedrive member506 is limited with respect to theguide body502. The dimensions and contours of the urgingmember504 and drivemember506 and the first and second cam surfaces512 and514 can preferably be selected such that the inward movement limit of thedrive member506 corresponds to a desired limit of advancement of theanchor25 with respect to the distal end of thedelivery tool500. This provides the advantage of automatically limiting the extent of protrusion of the urgingmember504 and can provide more repeatable advancement of theanchor25 to a desired implantation depth and along a desired introduction path.
• FIG. 55A illustrates an embodiment ofanchor600 comprising a neck/keel portion610 and ascrew portion620 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 portion610 can be independently rotatable so as to extend from thescrew portion620 toward the disc space, providing an anchoring platform andsite611 from which to attach sutures, graft containment devices, and/or other medical devices. Thescrew portion620 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. InFIG. 55B theanchor600 is illustrated including thedistal tip613 of thescrew portion620 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.
• 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 thekeel610 to thescrew portion620 may provide for substantially free and independent rotation of thescrew portion620 without imparting a significant rotational force upon thekeel610. Alternatively thekeel610 can be connected or attached to thescrew portion620 such that it is inhibited from rotation before and/or after thescrew portion620 has been implanted.
• In one or more of the embodiments thekeel610 can be aligned in a desired direction such as vertically, e.g. extending away from the vertebral endplate and into the disc space. Thekeel610 can be attached to thescrew portion620 in a number of ways.FIGS. 56A-C illustrate various views of a screw andkeel anchor assembly600. InFIG. 56A, thekeel610 forms aring630 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. Thescrew portion620 “captures” the keel's610ring630 or rings and allows the screw to spin freely about thekeel610.
• The most proximal end of theproximal ring630′ of thekeel610 as illustrated inFIG. 56B may also include one ormore features640 that allow a driver to restrain rotation and align thekeel620 in the desired direction. In the illustration this is a series of small holes in thekeel ring630 and small pins in a corresponding driver641 (FIG. 56C).FIG. 56C illustrates theanchor600 and one embodiment of driver641 (FIG. 56D). Thedriver641 also may have a shoulder (not illustrated) that rests on the bone when the bone anchor is fully advanced that inhibits advancing thescrew620 beyond a desired depth.
• 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 theanchor device600 in which there is neck portion defining anattachment site611 and abifurcated keel610 and610′. In this embodiment the keels and neck portion are mounted at thedistal tip613 of the screw. Thescrew portion620 can be concentric or offset off axis about which the one or more keels extend.FIG. 57B is substantially similar to the embodiment illustrated inFIG. 57A except that theattachment site611 and keels610,610′ are mounted at the proximal end of thescrew portion620 of theanchor600.
• FIG. 57C illustrates embodiments of implants similar to the implant illustrated inFIG. 57A in an implanted orientation within an intervertebral disc. In this case the implant was delivered from an anterior surgical approach and thekeel610 andattachment site611 of the implant are situated at the posterior lateral portion of the endplate. Turning toFIG. 57D, an implant similar to the implant illustrated inFIG. 57B is provided and has been delivered via a posterior lateral surgical approach.
• 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.
• 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.
• 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.
• 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.
• 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 andkeel type anchor600 is implanted in an inferior endplate at about 45 degrees relative to the endplate. InFIG. 58B twoanchors700,700′ with a neck and keel are implanted in the inferior and superior endplates of a vertebral body. In this embodiment, theanchors700,700′ are implanted at angles of approximately 10-25 degrees.
• The anchors depicted inFIGS. 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.
• 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-likelower keel710 and aneck720 extending generally perpendicularly therefrom. Theneck720 andkeel710 can further comprise various features described infra. Along theneck720 is arranged an arm orextension725 that is rotatably or flexibly engaged to the neck and terminates in one or more barb, hook, orangled projection726. In other embodiments, theextension725 is a separate floating member that slides along theneck720. In use, as illustrated schematically inFIG. 58B, thearm725 is raised as theneck720 andkeel710 are driven across and into a bone surface. When the desired implantation side is reached, thearm726 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. Thearm725 can pivot freely or be under tension to compress the bone between the plate and thearm725. Further embodiments of this locking feature includearm725 that extends beyond the plate as illustrated inFIG. 59C and aplate710 with voids or a “U” shapedtip728 or engagement zone as depicted inFIG. 59D that function to engage or couple theangled projection726 with theplate710.
• 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.
• 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.

Claims (22)

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 ofclaim 25, wherein the support member comprises a polymer and the anchor comprises titanium.

27. The graft containment system ofclaim 25, wherein the neck comprises two keels that form an angle of about 180 degrees relative to each other.

28. The graft containment system ofclaim 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 ofclaim 25, wherein the support member comprises an anulus augmentation device.

30. The graft containment system ofclaim 25, wherein the support member comprises a nucleus augmentation device.

31. The graft containment system ofclaim 25, wherein the support member comprises a biologically active or therapeutic agent.

32. The graft containment system ofclaim 25, wherein the support member comprises a polymer.

33. The graft containment system ofclaim 25, wherein the bone anchor further comprises an engagement portion.

34. The graft containment system ofclaim 33, wherein said engagement portion comprises at least one barb, hook, or angled projection.

35. The graft containment system ofclaim 33, wherein said engagement portion comprises one or more teeth, spikes or barbs.

36. The graft containment system ofclaim 33, wherein said engagement portion comprises one or more protrusions.

37. The graft containment system ofclaim 33, wherein said engagement portion comprises one or more friction plates.

38. The graft containment system ofclaim 25, wherein the bone anchor comprises a biologically active or therapeutic agent.

39. The graft containment system ofclaim 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 ofclaim 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 ofclaim 41, wherein the neck comprises two keels that form an angle of about 180 degrees relative to each other.

43. The method ofclaim 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 ofclaim 44, wherein the support member comprises a polymer and the anchor comprises titanium.

Images