Abstract: A selectively expanding spine cage has a minimized cross section in its unexpanded state that is smaller than the diameter of the neuroforamen through which it passes in the distracted spine. The cage conformably engages between the endplates of the adjacent vertebrae to effectively distract the anterior disc space, stabilize the motion segments and eliminate pathologic spine motion. Expanding selectively (anteriorly, along the vertical axis of the spine) rather than uniformly, the cage height increases and holds the vertebrae with fixation forces greater than adjacent bone and soft tissue failure forces in natural lordosis. Stability is thus achieved immediately, enabling patient function by eliminating painful motion. The cage shape intends to rest proximate to the anterior column cortices securing the desired spread and fixation, allowing for bone graft in, around, and through the implant for arthrodesis whereas for arthroplasty it fixes to endpoints but cushions the spine naturally.

Abstract: The present invention relates to an apparatus and method for near-simultaneous and integrated delivery of bone graft material during the placement of surgical cages or other medical implants in a patient's spine. The integrated fusion cage and graft delivery device according to various embodiments delivers and disperses biologic material through a fusion cage to a disc space and, without withdrawal from the surgical site, may selectably detach the fusion cage for deposit to the same disc space. The integrated fusion cage and graft delivery device is formed such that a hollow tube and plunger selectively and controllably place bone graft material and a fusion cage in or adjacent to the bone graft receiving area.

Abstract: An artificial disc prosthesis having load-bearing characteristics that mimic those of the normal, healthy intervertebral disc so as to provide resist flexion and axial compression of the spine in a way that preserves normal spinal function. The disc prosthesis includes three main components, a frame, a cushion molded over the frame, and a sac containing a hydrogel for maintaining disc height that is confined within a cavity in the cushion. Disc height is changed by increasing and/or decreasing the amount of hydrogel in the sac in accordance with the particular needs of the patient into which the artificial disc is implanted. Also provided is a frame for an artifical intervertebral disc that allows the axis of rotation of the spine to shift in a manner that replicates, or mimics, the normal function of the intervertebral disc.

Abstract: A selectively expanding spine cage has a minimized diameter in its unexpanded state that is smaller than the diameter of the neuroforamen through which it passes in the distracted spine. The cage conformably engages between the endplates of the adjacent vertebrae to effectively distract the anterior disc space, stabilize the motion segments and eliminate pathologic spine motion. The cage enhances spinal arthrodesis by creating a rigid spine segment. Expanding selectively, the cage height increases and holds the vertebrae with fixation forces greater than adjacent bone and soft tissue failure forces in natural lordosis. Stability is thus achieved immediately, enabling patient function by eliminating painful motion. Greater distraction height is achieved without an increase in implant size through the use of interfitted stages.

Abstract: An instrument for inserting an elongated hydrogel prosthesis into an intervertebral disc includes an insertion cannula that is inserted through the annulus fibrosus of an intervertebral disc to provide access to the nucleus region of the disc, an elongated hydrogel prosthesis packaged within a tubular container adapted to be coupled to a proximal end of the insertion cannula, and a source of fluid pressure adapted to be coupled to a proximal end of the tubular container. Auxiliary instruments for use in convenient insertion of the insertion cannula through the nucleus pulposus and providing for a complete and controlled passage of the hydrogel prosthesis through the insertion cannula are provided in a kit with the insertion cannula.

Abstract: Inflatable multi-chambered devices are provided for repairing or replacing spinal discs and distracting neighboring vertebral elements. Also included are cushioning devices that may be used in a joint replacement device cushioning system. Further included are kits and systems that include such devices, methods for making such devices, and methods of treating patients in need of such devices. Examples further include cosmetic augmentation and restoration devices.

Abstract: A method and system for fusing a region in the spine involve the use of at least one guide tube to pass instruments and substances into the spinal region in a minimally invasive manner. In the preferred practice of the method, a guide tube is anchored to a vertebra and the guide tube is moved to thereby position the vertebra. A steerable drilling tool is passed through the guide tube and steered into position to abrade at least a portion of an intervertebral disc and thereby create a cavity in the disc. A flowable substance is passed into the cavity and permitted to solidify to establish fusion in the cavity. Optionally, an uninflated balloon is inserted into the cavity and the balloon is filled with the flowable substance to contain the flowable substance.

Abstract: A selectively expanding spine cage has a minimized diameter in its unexpanded state that is smaller than the diameter of the neuroforamen through which it passes in the distracted spine. The cage conformably engages between the endplates of the adjacent vertebrae to effectively distract the anterior disc space, stabilize the motion segments and eliminate pathologic spine motion. The cage enhances spinal arthrodesis by creating a rigid spine segment. Expanding selectively, the cage height increases and holds the vertebrae with fixation forces greater than adjacent bone and soft tissue failure forces in natural lordosis. Stability is thus achieved immediately, enabling patient function by eliminating painful motion. The cage shape intends to rest proximate to the anterior column cortices securing the desired spread and fixation, allowing for bone graft in, around, and through the implant.

Abstract: A method includes moving a spinal implant such that a central portion of the spinal implant is disposed between adjacent spinous processes, radially extending a proximal portion of the spinal implant on a first side of the adjacent spinous processes such that movement of the proximal portion between the adjacent spinous processes is inhibited, and radially extending a distal portion of the spinal implant on a second side of the adjacent spinous processes opposite the first side such that movement of the distal portion between the adjacent spinous processes is inhibited.

Abstract: An artificial spinal disc prosthesis that can be implanted to replace a damaged natural spinal disc. A nucleus of compressible elastomeric material is surrounded by a winding of a slender strand of flexible tension-bearing material oriented at a pitch angle relative to a central axis. The orientation of the winding provides the prosthesis a limited amount of freedom of movement and flexibility. A pair of end caps of the prosthetic implant include angulated grooves that allow for insertion of the device between vertebral bodies from any of several directions. Special fasteners provide protruding points useful in anchoring the prosthesis.

Abstract: A method for treating a diseased or damaged spinal disc comprises the steps of: (a) providing access to the nucleus pulposus through the annulus; (b) removing at least a portion of the nucleus pulposus to create an intradiscal space; (c) determining the size of the intradiscal space; and (d) sealably introducing under pressure a curable biomaterial through the annulus directly into the intradiscal space. The step of determining the size of the intradiscal space may be accomplished by expanding a compliant balloon within the intradiscal space using a contrast medium capable of visualization under fluoroscopy. The curable material is sealably introduced through a vented needle inserted through the opening. The curable biomaterial is introduced until a quantity of the material flows into the vent.

Abstract: A device and method for a minimally invasive surgical implantation to reduce radicular symptoms by inserting an expandable cervical distraction implant in the facet joint and distracting the adjacent cervical vertebrae to increase the foraminal dimension. The implant, when positioned in the cervical facet joint, expands to via delivery of an inflation medium to increase the space between the vertebrae, thereby increasing the foraminal area or dimension, and reducing pressure on the nerves and blood vessels of the cervical spine.

Abstract: A spinal implant which is configured to be deployed between adjacent vertebral bodies. The implant has at least one extendable support element with a retracted configuration to facilitate deployment of the implant and an extended configuration so as to expand the implant and effectively distract the disc space, stabilize the motion segments and eliminate pathologic spine motion. Angular deformities can also be corrected, and natural curvatures restored. Preferably, the implant has a minimal dimension in its unexpanded state that is smaller than the dimensions of the neuroforamen through which it typically passes to be deployed within the intervertebral space. The implant is provided with a locking system preferably having a plurality of locking elements to lock the implant in an extended configuration. Bone engaging anchors also may be provided to ensure secure positioning.

Abstract: An interbody implant is provided. The interbody implant includes a body having a cavity configured to retain material deposited in the cavity. The cavity has an opening defining a passageway in communication with the cavity. The implant further includes a membrane disposed about the opening of the cavity having a first configuration covering the opening and a second configuration such that the membrane exposes the passageway in communication with the cavity.

Abstract: An orthopedic implant includes a first member that defines a longitudinal axis, a first wall and a second wall. The first wall defines at least a portion of a chamber. The second wall defines a first graft containment cavity. The chamber is separate from the first graft containment cavity. A second member defines a first wall disposed for sealed engagement with the first wall of the first member. The first wall of the second member defines at least a portion of the chamber. The second member is configured for movement along the longitudinal axis relative to the first member. Methods of use are disclosed.

Abstract: An interbody cage system includes an interbody cage having a proximal end, a distal end, and an interior. The interbody cage system also includes an insertion tool. A portion of the insertion tool extends into the proximal end and the interior.

Abstract: The present invention discloses a technique for forming a hardened orthopaedic paste in a bone cavity, which involves a forced-feeding balloon rupture mechanism. This mechanism includes continuously or intermittently injecting a liquid or gas into a perforated balloon containing a hardened orthopaedic paste therein in a bone cavity until the perforated balloon is dilated to exceed a critical size, and thus ruptures.

Abstract: Devices, systems and methods for dynamically stabilizing the spine are provided. The devices include an expandable spacer having an undeployed configuration and a deployed configuration, wherein the spacer has axial and radial dimensions for positioning between the spinous processes of adjacent vertebrae. The systems include one or more spacers and a mechanical actuation means for delivering and deploying the spacer. The methods involve the implantation of one or more spacers within the interspinous space.

Abstract: An intervertebral implant including a central axis, a bottom cover plate and a top cover plate, which are respectively provided with an exterior surface that extends transversal to the central axis, and a central part.

Abstract: A medical implant includes a flexible container having two layers of flexible surrounding walls, each surrounding wall being provided with a plurality of through holes; a tubular fitting being connected to an open end of the flexible container for inserting or infusing a medical filling material into the flexible container through the tubular fitting; and a thrust part connected to the flexible surrounding walls of the flexible container and at a distal end of the flexible container. The thrust part has a receiving seat and a ring, the receiving seat having a central bore and an annular groove surrounding the central bore and opposite to the central bore, wherein a tubular surrounding wall is inserted into the ring and is folded so that the two layers of flexible surrounding walls are formed with the ring imbedded between the two layers of flexible surrounding walls, and the ring with the two layers of flexible surrounding walls are received in the annular groove and detained therein due to friction.

Abstract: The invention relates to a biocompatible settable polymer useful in retaining an implant, more evenly distributing any force loading on the implant, and/or promoting tissue growth around and onto the implant.

Abstract: An intervertebral spacer for positioning between vertebral members. The spacer may include contact surfaces that are configured to contact against the vertebral members. A fluid cylinder may be positioned between the first and second contact surfaces and configured to contain a fluid. The fluid cylinder may include an outer cylinder with an open first end that telescopingly receives an inner cylinder. The spacer is configured to maintain the distance between the contact surfaces at a desired amount.

Abstract: A method of performing a procedure on an intervertebral disc includes inserting a cannulated delivery tube through an opening in an annulus fibrosus of the intervertebral disc, positioning an expandable portion of the tube within the opening in the annulus fibrosus, expanding the expandable portion into contact with the annulus fibrosus about the opening to create a seal between the expandable portion and the annulus fibrosus, performing a procedure through the cannulated delivery tube within the annulus fibrosis, removing the tube, and closing the opening in the annulus fibrosus.

Abstract: A spinal fusion apparatus includes a cage body configured to be inserted between two vertebral bodies and which has internal sidewalls that define a cavity which extends vertically through the cage body, and an internal compression member which includes a movable sidewall which defines at least one side of the cavity, and which is movable in a lateral direction from a first position located in the cavity to a second position located in the cavity such that a space within the cavity is reduced when the movable sidewall is at the second position. The internal compression member includes a compression mechanism coupled to the moveable sidewall, and moves the movable sidewall from the first position to the second position. Fusion material is disposed in the cavity is compressed and compacted by the movable sidewall as the moveable sidewall moves from the first position to the second position.

Abstract: A method for stabilizing at least one spinal motion segment includes an expandable spacer in a collapsed state into the interspinous space between superior and inferior vertebrae such that the spacer extends through the sagittal plane defined by the spinous processes of the superior and inferior vertebrae. The spacer has a flexible membrane defining an interior cavity. The method includes expanding the spacer to an expanded state by forcing a fill material in a fluid state into the cavity with the spacer disposed in the interspinous space, and thereafter solidifying the fill material to a solid state in the cavity. The method may be performed through a percutaneous penetration in the patient's skin and may cause the first and second vertebrae to be distracted.

Abstract: A kit of parts is provided that comprises: a cannula, the distal end of the cannula adapted to be inserted through the disc annulus; an injection needle, the distal end adapted to be inserted into the proximal end of the cannula and configured for relatively close sliding fit therewithin; and a syringe for containing a quantity of curable biomaterial, the syringe adapted to be coupled to the proximal end of the needle and to inject the biomaterial into the needle under pressure. The kit may further comprise a quantity of curable biomaterial that is selected to have upon curing strong adhesive properties such as a protein polymer.

Abstract: A subcutaneously formed in place orthopedic fixation device is provided, such as for fixation of the spine or other bone or bones. The device comprises an inflatable member, such as a tubular balloon. The balloon is positioned at a treatment site in the body while in a flexible, low crossing profile configuration. The balloon is thereafter inflated with a hardenable epoxy media comprising one or more epoxy compounds and one or more amine curing compounds that cures rapidly in place with low to moderate exotherm. Methods and delivery structures are also disclosed.

Abstract: A system for replacement of the natural facet joints of the spine is provided. The system is designed to be placed using a minimally-invasive technique, with passage of a unitized prosthesis through a working channel. Alternative embodiments of the prosthesis and method are also provided. The inventor also contemplates a similar system for the cervical and thoracic spine.

Abstract: A device is disclosed for reducing a vertebral compression fracture, comprising a superior end plate and an inferior end plate disposed along a vertical axis. The superior end plate and the inferior end plate are slidably separable in a vertical direction along the vertical axis. An interior chamber is provided in fluid communication with a port extending from an exterior to the interior chamber. The device is deployable within a vertebral body and expandable within the vertebral body by injecting a flowable material into the interior chamber thereby displacing the superior and inferior end plates along the vertical axis.

Abstract: A spinal intervertebral support implant, for fusion or for dynamic stabilization purposes. A rod, preferably in the form of a screw, is inserted obliquely from the pedicle of an inferior vertebra into the body of a neighboring superior vertebra, through the disc space. The rod can be anchored into the body of the superior vertebra by means of a force fit or a screw thread. A pile of elements is disposed on the rod in the disc space like a pile of washers, so that the compression load between vertebrae is carried partly by these elements. These elements can be inserted through the bore through which the rod was inserted in a tightly folded configuration, and deployed into their washer-like form only when in position in the intervertebral space, such that there is no need for any additional incisions.

Abstract: A system and method is provided for distracting opposite surfaces from the interior of a bone, such as a vertebral body. A working channel cannula provides a working channel through which an inserter and an injection cannula can simultaneously pass. The inserter transports a plurality of wafers into the interior of the bone to form a load-bearing stack bearing against the opposite surfaces. The injection cannula is used to inject a fluent material into and/or around the stack. In certain embodiments, the fluent material is a load-bearing or hardenable material, such as bone cement. In other embodiments, the fluent material can be a BMP, HAP, or other osteo-inductive, osteo-conductive, or pharmaceutical compositions. A syringe containing the fluent material is engaged to the injection cannula and is operable to inject the fluent material into the vertebral body under controlled pressure.

Abstract: Devices, systems and methods for dynamically stabilizing the spine are provided. The devices include an expandable spacer or member having an unexpanded configuration and an expanded configuration, wherein the expandable member in an expanded configuration has a size, volume and/or shape configured for positioning between the spinous processes of adjacent vertebrae in order to distract the vertebrae relative to each other. The systems include one or more expandable members and a mechanical actuation means for expanding the expandable member. The methods involve the implantation of one or more devices or expandable spacers.

Abstract: An expandable spinal implant for insertion into and positioning in an intervertebral disc space for intervertebral stabilization, the implant comprising a first implant section, an opposing second implant section and at least one expander attached between the first and second implant sections. The at least one implant expander can be selectively expanded to thereby actuate the spinal implant from a collapsed to an expanded position. The at least one implant expander is expanded via injection of an expanding material, such as bone cement. Also, the at least one implant expander is selectively expanded to impart substantially vertical expansion, angular expansion or vertical and angular expansion to the spinal implant. The expandable implant comprises polyetheretherketone (PEEK) or Titanium implant sections coupled to the implant expander whereby the implant is positioned between adjacent vertebral endplates where the implant can be expanded in the disc space between adjacent vertebral bodies.

Abstract: A spinal implant includes a first component including a first surface configured for engagement with a first vertebral surface and a second surface configured to define at least a portion of an implant support cavity. A second component is connected to the first component and includes a first surface configured for engagement with a second vertebral surface and a second surface configured to define at least a portion of the implant support cavity. A removable intermediate component is configured for disposal in the implant support cavity. The intermediate component is inflatable to move the first component relative to the second component to expand the interbody implant from a first configuration to a second, expanded configuration. At least one agent is configured to replace the intermediate component in the implant support cavity in the second configuration. Methods of use are disclosed.

Abstract: A device and method for biologic vertebral reconstruction utilizes a biologically active jacket inserted into a cavity formed in a vertebra to be reconstructed. An artificial bone material is inserted into the biologically active jacket and allowed to set. The structure and method described herein provide for effective biologic vertebral reconstruction. The use of a biological material and artificial bone enables the host bone to replace the artificial bone over a period of time. Additionally, the structure of the biologically active jacket minimizes any impact into the spinal canal and the paravertebral spaces. Moreover, because of its biomechanical characteristics, which approximate the host bone, there is relative protection of the neighboring vertebral against fracture. Still further, the materials of the biologically active jacket may be impregnated with various substances to achieve various advantageous tasks.

Abstract: The present disclosure relates to a spinal fusion impactor tool that includes an attachment means for securing an implant device to the distal end of the tool, a means for adjusting the angle of the distal head relative to the handle to better position the implant for introduction into the implant site, means for remotely releasing the implant device at the distal end and a clamp device on the shaft of the tool to secure tabs, attachments and other devices. The impactor tool is preferably used in conjunction with implantation of an intervertebral fusion cage that is equipped with shims having tabs or other removing means, but may also be used to introduce, for example, an implant, graft, fusion device, wedge or distractor device into any joint space or bony region in preparation for implantation.

Abstract: Prosthesis for inserting into a damaged intervertebral disc. The prosthesis has an elongated tubular main prosthesis body with a length to fit laterally from one side of a disc to the other at its mid-plane. The main prosthesis body is composed of two parts transversely oriented and has a vertical height deliberately greater than the height of normal disc space. Heads having a vertical height greater than the vertical height of the main prosthesis body are mounted on the ends of the main prosthesis body.

Abstract: A surgical barrier to be introduced during spinal fusion surgery in order to protect a specified area of the patient from adverse effects associated with surgical techniques. A method of using the surgical barrier including: establishing an operative corridor to a target surgical site; introducing a spinal fusion implant into the through said operative corridor, the fusion implant including fusion-enhancing material; introducing at least a portion of an intraoperative surgical barrier through the operative corridor to the surgical target site, the intraoperative surgical barrier including an expandable seal member; and expanding the expandable seal member to establish a barrier between the fusion implant and at least a portion of the surgical target site and the operative corridor.

Abstract: A prosthesis for replacing or supplementing a nucleus pulposus of an intervertebral disk is an expandable container having flexible walls, the container being adapted to be inserted into a central cavity of an intervertebral disk through a narrow cannula, and the flexible walls are made from a biocompatible hydrogel. A preferred hydrogel is a cryogel formed from an aqueous solution of poly(vinyl alcohol) and poly(vinyl pyrrolidone). The prosthesis may be prepared by dip-coating a mandrel with an aqueous solution of a hydrogel-forming polymer or mixture of such polymers, gelling the coated solution by chilling, and subjecting the gelled coating to a series of repeated freeze-thaw treatments. In use, the prosthesis is inserted into a central cavity of an intervertebral disk and filled with biocompatible material, e.g., a biocompatible liquid, a biocompatible polymer, and a biocompatible hydrogel, particularly a thermogelling hydrogel.

Abstract: An apparatus for stabilizing a vertebral body using a structural support to stabilize the vertebral body. The apparatus includes a first curable material deposit proximal to a first endplate of a vertebral body for providing support to the first endplate of the vertebral body and a second curable material deposit proximal to a second endplate of a vertebral body for providing support to a second endplate of the vertebral body. The apparatus also utilizes a stabilizing structure between the first curable material deposit and the second curable material deposit and connecting the first curable material deposit and the second curable material deposit for providing support to the vertebral body.

Abstract: A method for repairing a defect in the annulus of an intervertebral disc uses a port through a vertebra adjacent the disc for passage of a rivet insertion tool to place a first part of a two-part annulus repair rivet against an internal surface of the annulus adjacent the defect. A separate rivet insertion tool places a second part of the annulus repair rivet on an external surface of the annulus adjacent the defect. The first and second parts are secured together, repairing the defect.

Abstract: Various spinal implants and methods for stabilizing the spine are provided. In one exemplary embodiment, a spinal implant is provided having an expandable container with an interior volume that is selectively expandable between a compressed condition and an expanded condition. The expandable container is coupled to a superior endplate member having a bone-contacting surface and an engagement surface effective to mate with a superior surface of the expandable container, and an inferior endplate member having a bone-contacting surface and an engagement surface effective to mate with an inferior surface of the expandable container. In addition, at least one inlet port is formed in the expandable container and is effective to communicate a fluid to at least one cavity disposed within the interior volume of the expandable container.

Abstract: Spinal disk including a shell, first endplate, second endplate and core. The shell includes sidewalls, back wall, front wall, top wall and bottom wall defining a compartment. The first endplate includes a first base, first top and first attachment. The first base is retained in the compartment. The first top is disposed in a first opening in the top wall forming a contact surface continuous with a surface of the top wall. The first attachment extends from the first top portion. The second endplate includes a second base, second top and second attachment. The second base is retained in the compartment. The second top is disposed in a second opening in the bottom wall forming a contact surface continuous with a surface of the bottom wall. The second attachment extends from the second top portion. The core is disposed in the compartment between the first endplate and the second endplate.

Abstract: A surgical access device comprises a conduit comprising a proximal portion and a distal portion. An inflatable member at least partially surrounds a portion of the conduit and is positioned proximate to the distal portion of the conduit. In various embodiments, a protective sleeve can at least partially surround a portion of the conduit and is movable between at least a first position and a second position. In at least one embodiment, the protective sleeve is configured to at least partially cover the inflatable member when in the first position and is configured to expose the inflatable member when in the second position.

Abstract: A system and method is provided for distracting opposite surfaces from the interior of a bone, such as a vertebral body. A working channel cannula provides a working channel through which an inserter and an injection cannula can simultaneously pass. The inserter transports a plurality of wafers into the interior of the bone to form a load-bearing stack bearing against the opposite surfaces. The injection cannula is used to inject a fluent material into and/or around the stack. In certain embodiments, the fluent material is a load-bearing or hardenable material, such as bone cement. In other embodiments, the fluent material can be a BMP, HAP, or other osteo-inductive, osteo-conductive, or pharmaceutical compositions. A syringe containing the fluent material is engaged to the injection cannula and is operable to inject the fluent material into the vertebral body under controlled pressure.

Abstract: An intervertebral cage, an implanting apparatus and an operating method thereof are provided. The intervertebral cage for being implanted between two adjacent vertebral bodies includes a body and a connecting portion. The body has a lateral convex surface, an inclined surface, a lateral concave surface and a connecting surface connected sequentially. The connecting portion includes a main portion and a protrusion. The main portion connected to the connecting surface has a through hole. The protrusion is protruded from the main portion into the through hole to form first and second inner arc surfaces. The maximum width of the intervertebral cage is a distance between first and second lines. The first and second lines are substantially parallel to a tangent line of the lateral convex surface and the first line, respectively. The distance between the inclined surface and the first line decreases gradually along a direction away from the connecting portion.

Abstract: Inflatable multi-chambered devices are provided for repairing or replacing spinal discs and distracting neighboring vertebral elements. Also included are cushioning devices that may be used in a joint replacement device cushioning system. Further included are kits and systems for making such devices, and methods of treating patients in need of such devices. Examples further include cosmetic augmentation and restoration devices.

Abstract: A percutaneous path is established into a selected bone having an interior volume occupied, at least in part, by a cancellous bone, e.g., a vertebral body. An expandable stent structure is introduced into the cancellous bone by deployment of a tool through the percutaneous path into the cancellous bone. The expandable stent structure is expanded within cancellous bone.

Abstract: In at least one embodiment of the present invention, a method for stabilizing a collapsed vertebra of a patient is provided. The method comprises introducing a supercooled liquid into the collapsed vertebra. A solid structure that supports the collapsed vertebra is then form by solidifying the supercooled liquid.

Abstract: An expansion band includes a first layer, a second layer, a shrinking layer for shrinking said first layer and said second layer, a bond line for sealing said first layer and said second layer to form an inner space therein and dividing said inner space into a plurality of air passages which can communicate with each other, a plurality of air passages formed between said first layer and said second layer, and an air nozzle communicate with said air passage.