Abstract:
An implantable orthopedic stability device is disclosed. The device can have a contracted and an expanded configuration. A method of using the device between adjacent vertebral surfaces for support and/or fixation of either or both of the adjacent vertebrae is also disclosed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 12/617,663, filed Nov. 12, 2009; and Ser. No. 12/617,526, filed Nov. 12, 2009, which claim the benefit of U.S. Patent Application No. 61/113,691, filed on Nov. 12, 2008. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Technical field 
         [0003]    Devices and methods for fixation of tissue are disclosed. More specifically, the devices and methods can be for inter facet fusion of vertebrae or fusion of other bones to one another. 
         [0004]    2. Background of the Art 
         [0005]    A vertebroplasty device and method that eliminates or reduces the risks and complexity of the existing art is desired. A vertebroplasty device and method that may reduce or eliminate the need to inject a liquid directly into the compression fracture zone is also desired. 
         [0006]    Other ailments of the spine result in degeneration of the spinal disc in the intervertebral space between the vertebral bodies. These include degenerative disc disease and traumatic injuries. In either case, disc degeneration can cause pain and other complications. Conservative treatment can include non-operative treatment requiring patients to adjust their lifestyles and submit to pain relievers and a level of underlying pain. Operative treatment options include disc removal. This can relieve pain in the short term, but also often increases the risk of long-term problems and can result in motor and sensory deficiencies resulting from the surgery. Disc removal and more generally disc degeneration disease are likely to lead to a need for surgical treatment in subsequent years. The fusion or fixation will minimize or substantially eliminate relative motion between the fixed or fused vertebrae. In surgical treatments, adjacent vertebra can be fixated or fused to each other using devices or bone grafts. These may include, for example, screw and rod systems, interbody spacers (e.g., PEEK spacers or allograft bone grafts) threaded fusion cages and the like. 
         [0007]    Some fixation or fusion devices are attached to the vertebra from the posterior side. The device will protrude and result in additional length (i.e., needed to overlap the vertebrae) and additional hardware to separately attach to each vertebrae. Fusion cages and allografts are contained within the intervertebral space, but must be inserted into the intervertebral space in the same dimensions as desired to occupy the intervertebral space. This requires that an opening sufficient to allow the cage or graft must be created through surrounding tissue to permit the cage or graft to be inserted into the intervertebral space. 
         [0008]    A spinal fixation or fusion device that can be implanted with or without the need for additional hardware is desired. Also desired is a fixation or fusion device that can be deployed in a configuration where overlapping the fixated or fused vertebrae is not required. 
         [0000]    Also desired is an intervertebral device the may be inserted in to the intervertebral space at a first smaller dimension and deployed to a second, larger dimension to occupy the intervertebral space. The ability to insert an intervertebral spacer at a dimension smaller than the deployed dimension would permit less disruption of soft and boney tissue in order to access the intervertebral space. 
       SUMMARY OF THE INVENTION 
       [0009]    A device that can replace or supplement the screw or rod elements of a typical fusion system is disclosed. The device can be placed in the inter-facet space to fuse adjacent vertebrae and/or create a bone mass within the facet joint in a patient&#39;s spine. The device can be placed between adjacent vertebral bodies in the vetebral body articulating space, for example after a partial or complete discectomy in place of the removed disc. 
         [0010]    The device can be less invasive than typical existing devices. For example, the device can be in a compacted (i.e., small) configuration when inserted into a patient and transformed into an expanded (i.e., large) configuration when positioned at the target site. For example, the device can be expanded when the device is between the inferior and superior facet surfaces. The device can create less soft tissue (e.g., bone) disruption than a typical fusion system. The device in an expanded configuration can improve anchoring within the joint, structural stability, and create an environment for bone healing and growth leading to fusion between adjacent vertebrae. 
         [0011]    The device can have a first plate and a second plate. The device can be inserted and positioned into the joint so the first plate is in contact with a first articulating surface of the joint, and the second plate is in contact with a second articulating surface of the joint opposite of the first surface of the joint. For example, the opposite articulating surfaces can be opposed surfaces of vertebral plates or sides of a facet joint. Once inserted into the joint, the first plate can be rotatingly tilted away from the second plate and locked into position. The tilting and locking of the device can fuse the first articulating joint to the second articulating joint. 
         [0012]    During deployment into tissue (e.g., bone), one, two or more holes can be drilled into the target site to create a deployment hole in which to insert the device. The deployment hole can be round or non-round (e.g., by drilling more than one overlapping or adjacent hole, or crafting a square or rectangular hole), for example to substantially match the transverse cross-section of the device in a contracted configuration. 
         [0013]    The device can be cannulated, for example having a lateral (i.e., transverse or latitudinal) and/or lengthwise (i.e., longitudinal) channel through the device. The device can be deployed over a wire or leader, such as a guidewire. The device can be slid over the guidewire, with the guidewire passing through the longitudinal channel of the device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1   a  is a side perspective view of a variation of the device in a contracted configuration. 
           [0015]      FIG. 1   b  is a variation of cross-section A-A of  FIG. 1   a.    
           [0016]      FIG. 1   c  is a side perspective view of the device of  FIG. 1   a  in an expanded configuration. 
           [0017]      FIG. 1   d  is a variation of cross-section B-B of  FIG. 1   c.    
           [0018]      FIG. 2   a  is side view of a variation of cross-section A-A of  FIG. 1   a.    
           [0019]      FIG. 2   b  is side view of a variation of cross-section B-B of  FIG. 1   b.    
           [0020]      FIG. 3   a  is a variation of cross-section A′-A′ of  FIG. 1   a.    
           [0021]      FIG. 3   b  is a variation of cross-section B′-B′ of  FIG. 1   b.    
           [0022]      FIG. 3   c  is a variation of  FIG. 1   a  with the top plate absent. 
           [0023]      FIG. 4  illustrates a variation of the device in a longitudinally expanded configuration. 
           [0024]      FIG. 5  illustrates the device of  FIG. 4  is a longitudinally contracted and radially expanded configuration. 
           [0025]      FIG. 6  illustrates a visualization of a variation of a method for deploying the device into the spine between adjacent vertebrae. 
           [0026]      FIGS. 7   a  and  7   b  illustrate visualizations of variations of the device deployed into the spine between adjacent vertebrae. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    A device  1  is disclosed that can be inserted into a target site  73  with the device  1  in a compressed or contracted (i.e., small) configuration. Once positioned in the deployment site, the device  1  can be transformed into an expanded (i.e., larger, bigger) configuration. The device  1  can be inserted and expanded in orthopedic target sites  73  for fixation and/or support. For example, the device  1  can be inserted and expanded over a guidewire between adjacent vertebral facet surfaces (i.e., within a facet joint  55 ). 
         [0028]      FIGS. 1   a  through  3   c  illustrate that the device  1  can have a top plate  3  attached to a bottom plate  5 . The top plate  3  can be attached to the bottom plate  5  by one, two, three four or more pins  2 . The plates can have a substantially flat external surface facing outward from the device  1 . The pin longitudinal axes  13  can be substantially perpendicular to the plate surface planes of the external surfaces of the top  3  and bottom  5  plates when the device  1  is in a contracted configuration, and perpendicular to the device longitudinal axis  77 . 
         [0029]    The device  1  can have a middle plate  4  positioned between the top plate  3  and the bottom plate  5 . The middle plate  4  can be slidably attached to the top plate  3  and the bottom plate  5 . The pins  2  can be in pin slots  11  in the top  3  and/or bottom  5  and/or middle  4  plates. The pin slots  11  in the middle plate  4  can fix the pins  2  with respect to the position of the middle plate  4  in the direction of a device longitudinal axis  77 . The pin slots  11  in the top  3  and bottom  5  plates can allow the pins  2  to move along a device longitudinal axis  77  with respect to the top  3  and bottom  5  plates to the extent of the pin slots  11 , at which point the pin slots  11  will interference fit against the pins  2  to prevent further motion of the top  3  and bottom  5  plates. Accordingly, the top  3  and bottom  5  plates can slide with respect to each other and to the middle plate  4  in the direction of the device longitudinal axis  77  (and/or the middle plate  4  longitudinal axis). 
         [0030]    The top plate  3  can have one or more angled and/or curved ramps  7  on the middle plate  4 —side of the top plate  3 . The bottom plate  5  can have one or more angled and/or curved ramped  7  on the middle plate  4 —side of the bottom plate  5 . The middle plate  4  can have angled and/or curved wedges  6  on the top plate  3 —side and/or bottom plate  5 —side of the middle plate  4 . The wedges  6  can interface with the ramps  7 . For example, the top  3  and bottom  5  plates can be in a contracted, compressed, or otherwise non-expanded configuration when the middle plate  4  is in a first position relative to the top  3  and bottom plates  5 . The top and/or bottom  5  plates can be in an expanded, radially spread, or enlarged configuration when the middle plate  4  is in a second position (e.g., pulled away  9 ) relative to the top and/or bottom  5  plates. 
         [0031]    The middle plate  4  can have no, one or two side walls  10 . The side walls  10  can extend to about the height of the top plate  3  and/or bottom plate  5  when the device  1  is in a contracted or expanded configuration. 
         [0032]    The top plate  3 , bottom plate  5 , side plates and combinations thereof can have ingrowth channels  12 , windows, or ports. The ingrowth channels  12  can be configured to encourage bone growth into the ingrowth channel. For example, the ingrowth channels  12  can have textured surface and/or be coated and/or partially or completely filled with one or more osteogenic or osteoinductive material, for example any of those disclosed below. 
         [0033]      FIGS. 3   a  and  3   b  illustrate that the pins  2  can be contained by the top  3  and bottom  5  plates during expansion  41  of the device  1 . The pins  2  can be radiopaque and/or anti-torque. The side walls  10  can brace or otherwise interference fit the top and/or bottom  5  plates, for example to minimize lateral movement of the top and/or bottom  5  plates relative to the middle plate  4 . 
         [0034]    When the device  1  is in an expanded configuration, the top plate surface plane  15  and the bottom plate surface plane  29  can rotate away from each other, as shown by arrow  8 , to form a device expansion angle  14 . The device expansion angle  14  can be from about 1° to about 45°, more narrowly from about 2° to about 20°. For example, the device expansion angle 1° can be about 5° or about 10°. The device  1  can have a ratchet, or steps or teeth on the ramp  7  and wedges  6  to allow the device expansion angle  14  to be expanded at discrete increments, such as increased at increments of about 0.25°, about 0.5°, about 1°, or about 2°. 
         [0035]      FIG. 4  illustrates that the top plate  3  can be rotatably attached to the bottom plate  5 . The top plate  3  can be resiliently (i.e., elastically) attached to the bottom plate  5 . The top plate  3  can be plastically defonnably (i.e., plastically) attached to the bottom plate  5 . The top plate  3  and the bottom plate  5  can be integral with or attached to a plate hinge  44 . The top plate  3  and bottom plate  5  can be attached at a first end at the plate hinge  44 . The top plate  3  and bottom plate  5  can be unattached at a second end away from the plate hinge  44 . 
         [0036]    The top plate  3  and/or bottom plate  5  can have a surface texture  17  on the outward-facing surface. For example, the surface texture  17  can be ribs  43  oriented along the longitudinal axis of the device  1 . 
         [0037]    The top plate  3  and bottom plate  5  can form a side port  46 . The middle plate  4  can be slidably received by the side port  46 . The middle plate  4  can have a side wall  10 . The side wall  10  can obstruct, cover, and/or seal the external side of the side port  46 . The side port  46  can expand near the hinge  44 . One or both side walls  10  can have inward-directed extensions that can snap-fit or otherwise engage into the expanded portions of the side ports  46 . When the side wall  10  slides into the expanded portion of the side port  46 , the side wall  10  can force the top plate  3  to rotate away from the bottom plate  5 . 
         [0038]    The middle plate  4  can have a middle plate port  47 . The plate hinge  44  can have a plate hinge port  45 . The middle plate port  47  and the plate hinge port  45  can be aligned along the longitudinal axis of the device  1 . A deployment tool  35  can be releasably attached to the middle plate port  47  and/or the plate hinge port  45 . The deployment tool  35  can compress the middle plate port  47  toward the plate hinge port  45 . 
         [0039]    The middle plate  4  can have one or more middle plate ramps  48 , for example positioned adjacent to the inner surfaces of the top plate  3  and the bottom plate  5 . When the middle plate  4  is longitudinally extended away from the top  3  and bottom  5  plates, as shown in  FIG. 4 , the plane of the top plate  3  can be can be substantially parallel to the plane of the bottom plate  5 . 
         [0040]      FIG. 5  illustrates that the middle plate  4  can be translated toward the plate hinge  44 . For example, a deployment tool  35  can exert a compression force on the plate hinge  44  and the middle plate  4 , translating the middle plate  4  toward the middle plate ramp  48 , as shown by arrow  50 . The top plate ramps can rotate, as shown by arrows  49 , the top plate  3  away from the bottom plate  5 . 
         [0041]    The device  1  can have one or more radiopaque and/or echogenic markers  51 . For example, the device  1  can have aligned markers  51  on the top plate  3 , middle plate  4  and bottom plate  5 . When the device  1  is in a contracted pre-deployment configuration, the markers  51  can be located immediately adjacent to one another, for example appearing as a single marker  51 . When the device  1  is in an expanded configuration, the markers  51  can move apart from each other, indicating to a doctor performing the implantation and deployment procedure using visualization (e.g., x-ray or ultrasound-based) that the device  1  has expanded. Under visualization the markers  51  can also indicate the location and orientation of the device  1 . 
       Method of Using 
       [0042]      FIG. 6  illustrates the deployment tool  35  inserted to a target site  73  in vivo between a first vertebra  84  and a second vertebra  85 . For example, the device  1  can be placed at the target site  73  after a partial or complete discectomy. When the device  1  is in a contracted configuration, the tool can position the device  1  between a first vertebral body  92  of the first vertebra  84  and a second vertebral body  93  of the second vertebra  85 . The device  1  can be inserted into the target site  73  a direction substantially parallel to the surfaces of the vertebral body end plates. The device  1  can be placed between a first vertebral end plate  90  of the first vertebral body  92  and the adjacent second vertebral end plate  91  of the second vertebral body  93 . In this inter-vertebral location, the top plate  3  of the device  1  can be in contact with or directly adjacent to the first vertebral end plate  90 . The bottom plate  5  of the device  1  can be in contact with or directly adjacent to the second vertebral end plate  91 . 
         [0043]      FIGS. 7   a  and  7   b  illustrate that the deployment tool  35  can radially expand the device  1  between the first vertebral end plate  90  and the second vertebral end plate  91 . The top plate  3  can press against and/or embed into the first vertebral end plate  90 . The bottom plate  5  can press against and/or embed into the second vertebral end plate  91 . The device  1  can fuse the first vertebra  84  to the second vertebra  85 . 
         [0044]    The device  1  can be filled with a filled before or after radial expansion. Tissue ingrowth can occur into the top plate  3  through the top ports  42 , bottom plate  5  through the bottom ports, and elsewhere through the device  1 . 
         [0045]    Any or all elements of the device  1  and/or other devices or apparatuses described herein can be made from, for example, a single or multiple stainless steel alloys, nickel titanium alloys (e.g., Nitinol), cobalt-chrome alloys (e.g., ELGILOY® from Elgin Specialty Metals, Elgin, Ill.; CONICHROME® from Carpenter Metals Corp., Wyomissing, Pa.), nickel-cobalt alloys (e.g., MP35N® from Magellan Industrial Trading Company, Inc., Westport, Conn.), molybdenum alloys (e.g., molybdenum TZM alloy, for example as disclosed in International Pub. No. WO 03/082363 A2, published 9 Oct. 2003, which is herein incorporated by reference in its entirety), tungsten-rhenium alloys, for example, as disclosed in International Pub. No. WO 03/082363, polymers such as polyethylene teraphathalate (PET), polyester (e.g., DACRON® from E. I. Du Pont de Nemours and Company, Wilmington, Del.), poly ester amide (PEA), polypropylene, aromatic polyesters, such as liquid crystal polymers (e.g., Vectran, from Kuraray Co., Ltd., Tokyo, Japan), ultra high molecular weight polyethylene (i.e., extended chain, high-modulus or high-performance polyethylene) fiber and/or yarn (e.g., SPECTRA® Fiber and SPECTRA® Guard, from Honeywell International, Inc., Morris Township, N.J., or DYNEEMA® from Royal DSM N.V., Heerlen, the Netherlands), polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), polyether ketone (PEK), polyether ether ketone (PEEK), poly ether ketone ketone (PEKK) (also poly aryl ether ketone ketone), nylon, polyether-block co-polyamide polymers (e.g., PEBAX® from ATOFINA, Paris, France), aliphatic polyether polyurethanes (e.g., TECOFLEX® from Thermedics Polymer Products, Wilmington, Mass.), polyvinyl chloride (PVC), polyurethane, thermoplastic, fluorinated ethylene propylene (FEP), absorbable or resorbable polymers such as polyglycolic acid (PGA), poly-L-glycolic acid (PLGA), polylactic acid (PLA), poly-L-lactic acid (PLLA), polycaprolactone (PCL), polyethyl acrylate (PEA), polydioxanone (PDS), and pseudo-polyamino tyrosine-based acids, extruded collagen, silicone, zinc, echogenic, radioactive, radiopaque materials, a biomaterial (e.g., cadaver tissue, collagen, allograft, autograft, xenograft, bone cement, morselized bone, osteogenic powder, beads of bone) any of the other materials listed herein or combinations thereof. Examples of radiopaque materials are barium sulfate, zinc oxide, titanium, stainless steel, nickel-titanium alloys, tantalum and gold. 
         [0046]    The device  1  can be made from substantially 100% PEEK, substantially 100% titanium or titanium alloy, or combinations thereof. 
         [0047]    Any or all elements of the device  1  and/or other devices or apparatuses described herein, can be, have, and/or be completely or partially coated with agents for cell ingrowth. 
         [0048]    The device  1  and/or elements of the device  1  and/or other devices or apparatuses described herein can be filled, coated, layered and/or otherwise made with and/or from cements, fillers  70 , and/or glues known to one having ordinary skill in the art and/or a therapeutic and/or diagnostic agent. Any of these cements and/or fillers  70  and/or glues can be osteogenic and osteoinductive growth factors. 
         [0049]    Examples of such cements and/or fillers  70  includes bone chips, demineralized bone matrix (DBM), calcium sulfate, coralline hydroxyapatite, biocoral, tricalcium phosphate, calcium phosphate, polymethyl methacrylate (PMMA), biodegradable ceramics, bioactive glasses, hyaluronic acid, lactoferrin, bone morphogenic proteins (BMPs) such as recombinant human bone morphogenetic proteins (rhBMPs), other materials described herein, or combinations thereof. 
         [0050]    The agents within these matrices can include any agent disclosed herein or combinations thereof, including radioactive materials; radiopaque materials; cytogenic agents; cytotoxic agents; cytostatic agents; thrombogenic agents, for example polyurethane, cellulose acetate polymer mixed with bismuth trioxide, and ethylene vinyl alcohol; lubricious, hydrophilic materials; phosphor cholene; anti-inflammatory agents, for example non-steroidal anti-inflammatories (NSAIDs) such as cyclooxygenase-1 (COX- 1 ) inhibitors (e.g., acetylsalicylic acid, for example ASPIRIN® from Bayer AG, Leverkusen, Germany; ibuprofen, for example ADVIL® from Wyeth, Collegeville, Pa.; indomethacin; mefenamic acid), COX-2 inhibitors (e.g., VIOXX® from Merck &amp; Co., Inc., Whitehouse Station, N.J.; CELEBREX® from Pharmacia Corp., Peapack, N.J.; COX-1 inhibitors); immunosuppressive agents, for example Sirolimus (RAPAMUNE®, from Wyeth, Collegeville, Pa.), or matrix metalloproteinase (MMP) inhibitors (e.g., tetracycline and tetracycline derivatives) that act early within the pathways of an inflammatory response. Examples of other agents are provided in Walton et al, Inhibition of Prostoglandin E 2  Synthesis in Abdominal Aortic Aneurysms, Circulation, Jul. 6, 1999, 48-54; Tambiah et al, Provocation of Experimental Aortic Inflammation Mediators and Chlamydia Pneumoniae, Brit. J. Surgery 88 (7), 935-940; Franklin et al, Uptake of Tetracycline by Aortic Aneurysm Wall and Its Effect on Inflammation and Proteolysis, Brit. J. Surgery 86 (6), 771-775; Xu et al, Spl Increases Expression of Cyclooxygenase-2 in Hypoxic Vascular Endothelium, J. Biological Chemistry 275 (32) 24583-24589; and Pyo et al, Targeted Gene Disruption of Matrix Metalloproteinase-9 (Gelatinase B) Suppresses Development of Experimental Abdominal Aortic Aneurysms, J. Clinical Investigation 105 (11), 1641-1649 which are all incorporated by reference in their entireties. 
         [0051]    Any elements described herein as singular can be pluralized (i.e., anything described as “one” can be more than one). Any species element of a genus element can have the characteristics or elements of any other species element of that genus. The above-described configurations, elements or complete assemblies and methods and their elements for carrying out the invention, and variations of aspects of the invention can be combined and modified with each other in any combination.