Abstract: The present invention relates to an artificial disc prosthesis system which includes a scaffold assembly and a fusion or disc prosthesis removably retained by the scaffold assembly. The artificial disc prosthesis system facilitates the removal, replacement or upgrade of disc prostheses without the need to remove the entire system from the intervertebral space in which it is disposed. Also provided are disc prostheses suitable for use in the artificial disc prosthesis system.

Abstract: In various embodiment of the invention an implant can be placed between two adjacent vertebral bodies using a lateral insertion method. The implant is characterized as having a first end plate and a second end plate which a crossbar spacer there between. The crossbar spacer preferably fits within a channel on the inner surfaces of the first end plate and the second end plate, where the spacer allows the first end plate to pivot, twist and/or rotate relative to the second end plate. The first end plate and the second end plate include a keel extending therefrom, where the keel traverses longitudinally between a first lateral side and a second opposed lateral side and is substantially perpendicular to the sagittal plane of the patient's spine.

Abstract: The present invention relates to an intervertebral disk prosthesis comprising at least three parts including a first plate, referred to as the upper plate (1), a second plate, referred to as the lower plate (2), and a core (3), the upper surface of the core (3) being in contact with at least part (10) of the lower surface of the upper plate (1) and the lower surface of the core (3) being in contact with at least part of the upper surface of the lower plate (2), and the lower plate (1) being movable at least with respect to the core (3), characterised in that there are cooperation means between the lower to plate (2) and the core (3), so as to limit or eliminate translation movements of the core (3) with respect to the lower plate (2) along an axis substantially parallel to the lower plate (2), and to limit or eliminate rotation movements of the core (3) with respect to the lower plate (2), around an axis substantially perpendicular to the lower plate (2), the planes passing through the upper (1) is and lower

Abstract: A modular prosthetic device is described. The modular prosthetic device is provided with an anchoring device having first and second end members, the first and second end members cooperating to receive a prosthetic insertion device. The first and second end members each include a first surface, at least one vertebral-engaging member extending from the first surface, a second surface in an opposed relation to the first surface, and at least one flange extending from the second surface. The anchoring device is adapted to receive a variety of prosthetic insertion devices such that the modular prosthetic device can be revised into a variety of modular prosthetic devices. A stacking member is also provided for use with the anchoring device to provide a variety of modular, stackable prosthetic devices.

Abstract: The subject invention provides a modular six-degrees-of-freedom spatial mechanism for spinal disc prosthesis, with up to three rotational and up to three translational degrees-of-freedom within the entire workspace of a Functional Spinal Unit (FSU). The prosthetic disc mechanism consists of up to three independent cylindrical joints, each joint providing one linear and one rotational degree of freedom. The superior and inferior vertebral plates of the device anchor to the superior and inferior vertebrae of an FSU and the device maintains an inseparable mechanical linkage between those vertebrae for all normal motions and positions of the FSU. The device utilizes resilient spring elements, components that self-adjust in position and orientation, in conjunction with a fiber reinforced boot and toroidal belt, as well as a unique hydraulic damping system to accommodate dynamic and static forces and sudden shocks on the FSU.

Abstract: An intervertebral joint prosthesis having a ball component (22) for engagement with a first vertebra (26) and a trough component (24) for engagement with a second vertebra (27) adjacent to the first vertebra is disclosed. The trough component (24) includes a generally concave surface (50) having a substantially flat portion (52). When the ball component (22) and the trough component (24) are engaged to their respective vertebrae, the ball component (72) and the trough component (24) engage each other, permitting rotation and translation of the vertebrae with respect to each other. Both components include a flange (34, 56) for engaging a vertebra. The invention also contemplates a method for and a tool for use in implanting a two-piece intervertebral joint prosthesis.

Abstract: An intervertebral implant system for positioning between an upper vertebra and a lower vertebra is provided. The implant system comprises an intervertebral implant and a staple. The implant comprises an inferior plate and a superior plate, while the superior plate has a vertebral surface facing the upper vertebra and the inferior plate has a vertebral surface facing the lower vertebra. There are two grooves on at least one vertebral surface extending at an angle outward from a centerline on the vertebral surface as they extend from the anterior portion of the plate toward the posterior portion of the plate. When in use, the staple is associated with the two grooves for maintaining stability of the intervertebral implant and preventing backing out of the intervertebral implant. The staple also has two arms and has a generally rectangular shape prior to use.

Abstract: An artificial intervertebral disc includes housing members including spaced inner surfaces facing each other and oppositely facing outer surfaces for engaging spaced apart vertebral surfaces. Bearing surfaces extend from each of the inner surfaces for engaging each other while allowing for low friction and compression resistant movement of the housing members relative to each other while under compression. Load sharing pads are disposed between the inner surfaces and about at least a portion of the bearing surfaces for sharing absorption compressive loads with the bearing surfaces while limiting the relative movement of the housing members.

Abstract: An intervertebral implant comprises a first member for engaging a first vertebral body and a second member for engaging a second vertebral body. The first member has a first surface with a first curve, and the second member has a second surface with a second curve. The first member is translatable with respect to the second member and the second curve is positioned within the first curve to bias the first and second curved surfaces towards central alignment along a longitudinal axis passing through the first and second vertebral bodies.

Abstract: A prosthetic device for placement in an intervertebral space defined between an upper vertebra and a lower vertebra to provide articulating motion to the upper and lower vertebrae may includes an upper articular portion configured to be at least partially disposed in the intervertebral space and a lower articular portion configured to be at least partially disposed in the intervertebral space. The lower articular portion may be configured to cooperate with the upper articular portion to provide articulating motion to the upper and lower vertebrae. An attachment element may extend in the general direction of the spinal column. The attachment element may be configured to be fastened to at least one of the upper and the lower vertebrae to at least partially secure in place said one of the upper and lower articular portions. A method of implanting also is disclosed.

Abstract: In one aspect, an intervertebral prosthetic device for implantation within a disc space between adjacent first and second vertebral endplates includes a body including a main body with an outer surface bearing portion configured to interface with and articulate relative to one of the first and second vertebral endplates. It also comprises an orientation protrusion shaped in a manner to at least partially inhibit rotation of the body in the disc space. The body is sized in at least one direction to fit inside a boundary defined by a travel path of the first vertebra relative to the second vertebra, the travel path forming an arc about a center of rotation of the first vertebra, the travel path being spaced from the center of rotation a distance substantially equivalent to the distance from the center of rotation to the second vertebral endplate.

Abstract: The invention concerns an intervertebral disc prosthesis (10) with a first prosthesis plate (20) and a second prosthesis plate (30), wherein the first prosthesis plate (20) has on its side (20b) facing the second prosthesis plate (30) a concave recess (22) in which engages a convex projection (32) arranged on the side (30b) of the second prosthesis plate (30) facing the first prosthesis plate (10), wherein the convex projection (32) and/or the concave recess has at least one elastic element (35).

Abstract: A problem with total disc implant surgery appears to be the positioning of the implant which if not correct may lead to pain and eventually new surgery. The present invention relates to an improved disc implant (1) for total disc replacement, comprising two inter-vertebral elements (2) which are flexibly connected via coupling means (4,5). Following surgery, the relative movability of said two inter-vertebral elements is decreased overtime, as bone ingrowth occurring around the implant and specifically through osseointegrative sections gradually degrease the movability of the elements relative to each other Following, the relative movability of the implant elements is replaced by fixation of the elements. The fixation has flowingly occurred in a position affected by the movement of the patient, and is thereby more acceptable to the patient.

Abstract: An artificial intervertebral disc having a pair of opposing plate members for seating against opposing vertebral bone surfaces, separated by a spring mechanism. The preferred spring mechanism is at least one spirally slotted belleville washer having radially extending grooves. One plate member has a centrally located ball-shaped protrusion that is rotatably coupled in a central socket in the narrow end of the belleville washer, and the wide end of the belleville washer is held against the other plate member by a shield with rivets. Therefore, the disc assembly will not come apart under tension loads applied to the plate members, and the location of the ball joint coupling provides the disc assembly with a centroid of motion that is centrally located between the vertebral bone surfaces, both causing the disc assembly to behave similarly in these respects to a healthy natural intervertebral disc.

Abstract: An instrument for inserting an implant is provided. The implant includes a protrusion having a protrusion width for extending into a portion of a bone structure. The instrument includes an elongated member and a first member connected to the elongated member. The first member is adapted for selectively engaging the implant. The first member has a width substantially equal to or less than the protrusion width. A second member may be in movable communication with the first member for selectively engaging the implant.

Abstract: In an intervertebral implant with a top contacting element, a bottom contacting element and arranged between these a core which with an upper, spherical bearing surface engages a spherical bearing socket, having the same radius, of the top contacting element and with a lower, spherical bearing surface engages a spherical bearing socket, having the same radius, of the bottom contacting element, in order to improve the kinematics and the endurance, it is proposed that the radius of the bearing surface and of the bearing socket receiving it differ on opposing sides of the core at least by the factor 5.

Abstract: The invention concerns an intervertebral prosthesis comprised of a first prosthetic end plate (20) and a second prosthetic end plate (30) as wall as a prosthetic core (10) located between the first prosthetic end plate (20) and the second prosthetic end plate (30), wherein the first prosthetic end plate (20) has a hemispherical shaped recess (21) with a radius (R3), in which a hemispherical segment (11) of the prosthetic core (10) engages, and wherein the second prosthetic end plate (30) has an essentially planar recess (31), in which an essentially flat segment (15) of the prosthetic core (10), connected to the hemispherical segment (11), engages, wherein the essentially flat segment (15) of the prosthetic core (10) is slideably moveable in the essentially planar recess (31).

Abstract: A prosthesis for a vertebral column has an upper part (10) for attachment to an upper vertebrae, a lower part (12) for attachment to a lower vertebrae and a middle part (11) located between the upper and the lower parts, wherein the upper part has a lower surface portion with a first radius of curvature, the middle part has an upper surface portion with a second radius of curvature and a lower surface with a third radius of curvature and the lower part has an upper surface with a fourth radius of curvature. The centre of the radius of curvature for at least two surfaces is offset rearwardly with respect to a central vertical axis (13) through the upper and lower vertebrae and/or the upper and lower parts. Also defined is device for linking bones, in the form of a band with attachment portions having a number of filaments that provide zones conducive to cellular growth as well as a method of modelling a prosthesis and a process for analysing performance of a prosthesis.

Abstract: A prosthetic disc for insertion between adjacent vertebrae includes a core having upper and lower curved surfaces and upper and lower plates. At least one of the curved surfaces of the core is metallic, and in some embodiments the entire core is metallic. Each plate has an outer surface which engages a vertebra and a metallic inner curved surface which is shaped to slide over one of the curved surfaces of the core. In some embodiments, the center of rotation of the core is free to move relative to the upper and lower metallic plates. In some embodiments, one or more channels extend across one or both of the curved surfaces of the core for allowing passage of bodily fluid to promote lubrication between the core and at least one of the plates.

Abstract: A prosthetic disc for insertion between adjacent vertebrae includes a core having upper and lower curved surfaces and upper and lower plates. At least one of the curved surfaces of the core is metallic, and in some embodiments the entire core is metallic. Each plate has an outer surface which engages a vertebra and a metallic inner curved surface which is shaped to slide over one of the curved surfaces of the core. In some embodiments, the center of rotation of the core is free to move relative to the upper and lower metallic plates. In some embodiments, one or more channels extend across one or both of the curved surfaces of the core for allowing passage of bodily fluid to promote lubrication between the core and at least one of the plates.

Abstract: An implant, in particular an intervertebral implant, comprising (A) two articulating parts (4; 5) having each a central axis (1; 26), each a curved slide surface (6; 7) intersecting the central axes (1; 26), and each an axially outermost end (14; 15) that can be connected to a bone, where (B) the slide surfaces (6; 7) are curved and displaceable one on the other, where (D) the second articulating part (5) is rotatable about two mutually skewed axes of rotation (10; 11) relative to the first articulating part (4).

Abstract: An artificial spinal implant for placement between adjacent vertebrae to replace disk material and to stabilize the involved vertebrae is described. The artificial disk may be disassembled for installation and/or removal for repair, replacement or adjustment, and may be assembled from the front of the spine as individual component parts, thereby permitting alignment of the spine during the assembly process, and the stabilization of the involved vertebrae once assembly has been completed. Further, the components may be chosen from a set of similar components having different sizes, thereby enabling the implant to be tailor fit to the requirements of the patient.

Abstract: An implant having a first member having a first elongated channel and a second member having a second elongated concave channel that becomes generally opposed when the first and second members are mounted to a first and second vertebra. A ball bearing is received in each of the channels to both separate and maintain a predetermined distance between the first and second member and also to facilitate movement in a plane that intersects an axis of the spinal column. The ball bearing is seated in and cooperates with the channels to permit pivotal movement about a plurality of axes. A method for replacing a disc is also shown using the implant.

Abstract: An artificial intervertebral disc having a pair of opposing plate members for seating against opposing vertebral bone surfaces, separated by a ball joint coupling. One plate member has a centrally located ball-shaped protrusion that is rotatably coupled in a central socket in a cone-shaped protrusion on the other plate member. Thereby, the plate members are angulatable with respect to one another. Further, the disc assembly will not come apart under tension loads applied to the plate members, and the location of the ball joint coupling provides the disc assembly with a stationary centroid of motion that is centrally located between the vertebral bone surfaces, both causing the disc assembly to behave similarly in these respects to a healthy natural intervertebral disc.

Abstract: An apparatus and method for supporting upper and lower vertebral bodies, including first and second end members adapted for engagement with the vertebral bodies, and at least one elongate support member coupled between the end members to maintain an axial space between the vertebral bodies. In one aspect of the invention, each of the end members has a parametrical or horseshoe-shaped configuration extending about an open inner region and defining a lateral passage communicating with the open inner region to facilitate insertion of the apparatus or the individual end members into the intervertebral space via a posterior surgical approach. In a further aspect of the invention, a fusion member is positioned within the axial space to promote bony fusion between the upper and lower vertebral bodies.

Abstract: The invention relates to an artificial intervertebral disc for placement between adjacent vertebrae. The artificial intervertebral disc is preferably designed to restore disc height and natural disc curvature, allow for a natural range of motion, absorb shock and provide resistance to motion and axial compression. Furthermore, the intervertebral disc may be used in the cervical, the thoracic, or the lumbar regions of the spine. The artificial intervertebral disc may include either singularly or in combination: an interior including at least one spring member preferably incorporating a arcuate surface member, a flexible core, the flexible core preferably being a slotted core, a ring spring, a winged leaf spring, or a leaf spring, or The articulating member preferably being attached to one of the endplate by an intermediate shock absorbing element.

Abstract: An artificial vertebral joint for interposition between a superior vertebra and an inferior vertebra comprises a pair of bilateral joint subcomponents. Each joint subcomponent includes a superior component including a superior vertebra engaging surface and an inferior component including an inferior vertebra engaging surface. Each joint subcomponent further includes a spacer extending between the superior component and the inferior component. The spacer includes a first modulus of elasticity and a second modulus of elasticity. The first modulus transitions to the second modulus with a gradient change.

Abstract: The intervertebral disk prosthesis comprises first and second parts (2, 3) intended to be attached respectively to two adjacent vertebrae, an intermediate part (4) inserted between the first and second parts (2, 3) and comprising articular surfaces (9, 10) that cooperate with respective articular surfaces (6, 8) of the first and second parts (2, 3), and means (11, 12) for coupling the first part (2) and the intermediate part (4). The coupling means (11, 12) are arranged to leave the intermediate part (4) free relative to the first part (2) during a first phase of a tilting movement of the first part (2) relative to the second part (3), but to displace the intermediate part (4) toward an end (E2) of the prosthesis that is opposite to an end (E1) toward which the first part (2) is displaced by tilting relative to the second part (3), during a second phase of the tilting movement of the first part (2).

Abstract: Exemplary implants and methods are provided for stabilizing adjacent vertebrae. In one embodiment, an implant is provided having a shape that allows the implant to be positioned between adjacent vertebrae using a posterior approach while avoiding contact with the spinal cord. For example, the implant can include an anterior portion that is adapted to be positioned between adjacent vertebrae, and a posterior portion that is adapted to extend around a spinal cord. In certain exemplary embodiments, the implant can also be configured to allow motion between the adjacent vertebrae.

Abstract: An intervertebral prosthesis for insertion between adjacent vertebrae includes upper and lower prosthesis plates locatable against respective vertebrae and having opposing, concavely curved recesses therein, and a core located between the plates. The core has opposed, convexly curved surfaces received in the recesses of the plates to allow the plates to slide in articulated manner over the core. The opposed surfaces of the core and the recesses of the plates have cooperating spherical curvatures. The recess of each plate surrounds a locating peg projecting centrally from the base of the recess and is bounded by an annular rim, such that the annular rims of the plates are arranged to contact one another at a predetermined limit of sliding movement of the plates over the core. The peg locates loosely in an opening located centrally in a curved surface of the core, whereby the plates can slide over the core in all directions while the peg holds the core captive.

Abstract: The present invention is directed to an implant that can be placed between two adjacent vertebral bodies using a lateral insertion method. The implant is characterized as having a first end plate and a second end plate which a crossbar spacer therebetween. The crossbar spacer preferably fits within a channel on the inner surfaces of the first end plate and the second end plate, whereby the crossbar spacer allows pivots, twisting and/or rotational movement of the spine. The first end plate and the second end plate include a keel extending therefrom, whereby the keel traverses longitudinally between a first lateral side and a second opposed lateral side and is substantially perpendicular to the sagittal plane of the patient's spine.

Abstract: The present invention provides artificial disc prostheses, methods and instrumentation for implantation and revision thereof. Each prosthesis may comprise superior and inferior end plates and a nucleus positioned between articular surfaces of the end plates. The end plates may have planar bone engagement surfaces with a plurality of self-cutting teeth. The articular surfaces of the end plates may be planar or include a flattened portion. The nucleus includes superior and inferior articular surfaces which may comprise flattened portions such that when the articular surfaces of the nucleus and the end plates are placed in cooperation in a preferred orientation, the flattened and/or planar portions are aligned. Each prosthesis may provide flexion/extension, anterior/posterior translation, lateral bending, and/or axial rotation degrees of freedom.

Abstract: A prosthetic device for anterior-oblique insertion into an intervertebral space is provided. The prosthetic device includes a first component having a first flange for engaging a first vertebra from an anterior-oblique approach, the first flange being angled relative to the longitudinal and transverse axes of the first component, and a second component having a second flange for engaging a second vertebra from an anterior-oblique approach, the second flange being angled relative to the longitudinal and transverse axes of the second component, and wherein the first and second components cooperate to permit articulating motion between the first and second components.

Abstract: Articulating diamond-surfaced spinal implants are disclosed. Materials which may be used to make the spinal implants and manufacturing and finishing techniques for making the implants are also disclosed.

Abstract: Apparatus including a first spinal prosthetic member attachable to a first spinal structure, and a second spinal prosthetic member attachable to a second spinal structure, the first and second spinal prosthetic members being movably attached to one another with a fastening device, the fastening device having a non-tightened position which permits spatial movement of the first and second spinal prosthetic members with respect to one another at a desired orientation, and a tightened position which fixes the first and second spinal prosthetic members at the desired orientation.

Abstract: An artificial spinal disc implant system for intervertebral disc replacement (0810) is disclosed which is formed from an upper (0801) and lower (0802) bracket which mate to upper and lower spinal vertebrae via upper (0831) and lower (0832) vertebral contact surfaces on the upper (0801) and lower (0802) brackets. The upper (0801) and lower (0802) brackets are joined together via springs (0811) connected to the upper bracket (0801) which rest in spring guide tracks (0812) on the lower bracket. The springs (0811) are connected to the upper bracket (0801) via the use of spring fasteners (0821, 0822). The upper (0801) and lower (0802) brackets may be installed in sections (0851, 0861, 0871, 0852, 0862, 0872) using laparoscopic surgical techniques and are attached to upper/lower spinal vertebrae respectively via adhesive means applied using injection holes/ports (0841, 0842) in the upper (0801) and lower (0802) brackets respectively.

Abstract: A spinal implant is inserted between adjacent vertebrae to function as an disk prosthesis. The prosthesis has two plates fastened to adjacent vertebrae facing each other. The facing sides of the plates each have a depending skirt formed as concentric arcs of about 90 degrees. The skirts are either bowed or tapered in the axial direction. Depressions are centrally located between the arcs of the plates and a ball is universally movable in the depressions. A spring mechanism is centrally located in the plates to provide axial compression. One plate has a through bore and one plate has a receptacle, each, receiving a sleeve with a depression for holding the ball.

Abstract: An intervertebral implant (1), including an upper section (10) provided with a ventral side area (11), a dorsal side area (12), two lateral side areas (13,14), a top apposition surface (15) and a bottom surface (16), a lower section (20) provided with a ventral side area (21), a dorsal side area (22), two lateral side areas (23,24), a bottom apposition surface (25) and a top surface (26), wherein the two sections (10,20) are moveable in relation to each other by means of two joints (38;39) arranged between the two sections (10;20), and wherein each of the joints (38;39) has a swivel axle (3;4) and the two swivel axles (3;4) are arranged perpendicular to each other, each of the joints (38;39) comprises at least one axle (34;36) coaxial to the relevant swivel axle (3;4) and a bearing shell (35;37) receiving the axle (34;36), and roll bodies (70) are inserted between the axles (34;36) and the bearing shells (35;37).

Abstract: An artificial intervertebral implant including a first baseplate having a top surface, a bottom surface, an aperture extending therethrough and a strap attached to the bottom surface of the first baseplate and underlying the aperture. The implant further includes a second baseplate juxtaposed with the first baseplate. The second baseplate includes a top surface with a cavity exposed therein. An articulating element is attached to a pair of opposing sidewalls of the cavity for retaining the strap within the cavity.

Abstract: A method of implanting an intervertebral implant or component thereof, in which each component is selected to have an inner surface and an outer surface which engages an adjacent vertebra and presents only three distinct points of contact with a cortical rim of the vertebra. The outer surface is selected to have a footprint which is sized to be within that of the cortical rim. In disclosed embodiments, the footprint can be convexo-concave shaped or kidney shaped. The intervertebral implant can be provided with upper and lower (or first and second) components which engage adjacent first and second vertebrae and which move relative to one another. The implant has both the first and second outer surfaces sized to present a respective footprint sufficient for two lateral-anterior and one posterior points of contact with an adjacent cortical rim of the respective first and second vertebra.

Abstract: An intervertebral device includes a first plate having an outer face and an inner face, and a second plate juxtaposed with the first plate, the second plate having an outer face, an inner face that opposes the first plate and a concavity that opposes the first plate. The device includes an elongated member extending from the first plate toward the second plate, the elongated member having a distal end with a spherical surface that is engageable with the concavity of the second plate for providing an articulating joint between the first and second plates. The device also includes a resilient member extending at least partially around and being in contact with the elongated member for counteracting compressive loads on the plates, the resilient member being surrounded by the concavity of the second plate.

Abstract: The present invention is directed to a device that can be placed between two vertebrae. The implant is characterized by having a first plate and a second plate with a crossbar therebetween. The crossbar fits within cavities on each of the first and second plates and allows for pivotal or rotational motion and also for twisting motion.

Abstract: A prosthetic disc for insertion between adjacent vertebrae includes upper and lower plates, a core disposed between the plates, and at least one projection extending from at least one of the upper and lower curved surfaces of the core into at least one recess of one of the inner surfaces of the plates. The recess is oversize with respect to the projection to allow sliding movement of the plate over the core while retaining the core between the plates during such sliding movement. The projection(s) may include a rod extending through an axial hole in the core, multiple surface features of the core, or the like.

Abstract: Disclosed is an intervertebral implant (1) comprising a central axis (2), a bottom cover plate (3) and a top cover plate (4), which are respectively provided with an exterior surface (7; 8) that extends transversal to the central axis (2), and a central part (10). Said central part (10) is located between the cover plates (3; 4) and is provided with a sleeve (12) encompassing a fiber system (5) that is connected to the cover plates (3; 4) and is embedded in an enveloping body (25) made of a homogeneous material. In analogy with the anatomic structure of the natural disk, the inventive intervertebral implant (1) can transfer occurring compressive forces onto the cover plates (3, 4) thereof as tensile forces that are applied to the individual fibers of the fiber system (5) thereof.

Abstract: An intervertebral prosthesis for insertion between adjacent vertebrae includes upper and lower prosthesis plates locatable against respective vertebrae and having opposing, concavely curved recesses therein, and a core located between the plates. The core has opposed, convexly curved surfaces received in the recesses of the plates to allow the plates to slide in articulated manner over the core. The opposed surfaces of the core and the recesses of the plates have cooperating spherical curvatures. The recess of each plate surrounds a locating peg projecting centrally from the base of the recess and is bounded by an annular rim, such that the annular rims of the plates are arranged to contact one another at a predetermined limit of sliding movement of the plates over the core. The peg locates loosely in an opening located centrally in a curved surface of the core, whereby the plates can slide over the core in all directions while the peg holds the core captive.

Abstract: An artificial disc includes a top vertebra-attachment portion and a lower spacer support connected to the top vertebra-attachment portion; a bottom vertebra-attachment portion and an upper spacer support connected to the bottom vertebra-attachment portion. The spacer supports are disposed between the vertebra-attachment portions, and the lower spacer support is disposed between the bottom vertebra-attachment portion and the upper spacer support. The disc further includes a first elastic spacer positioned between the spacer supports for compressively resisting tensile loading of the disc; and a second spacer disposed between the bottom vertebra-attachment portion and the lower spacer support or between the top vertebra-attachment portion and the upper spacer support for compressively resisting compressive loading of the disc.

Abstract: An intervertebral implant, or disc prosthesis, comprises a pair of cooperating elements being provided in a generally “X” shaped structure. The elements are comprised of cooperating shells that are maintained separated by a resilient material provided therebetween. The elements allow for rotational and translational movement when implanted.

Abstract: An artificial disc is provided which more closely matches the movement of the natural spine. The artificial disc uses one or more projections and corresponding recesses to provide a sliding articulation. The artificial joint is inherently stable in that compressive forces placed on the disc such as the weight placed upon the joint or the tension of surrounding tissues urges the joint towards a neutral position and not farther away from a neutral position.

Abstract: Artificial disc replacements (ADRs) use mobile spacers between vertebral endplates. In the preferred embodiment, spherical spacers are used between metal or ceramic plates placed over or in the endplates of the vertebrae. The spherical spacers may be made of metal, ceramics or polymers such as polyethylene. One or more of the bearings may be used in each disc replacement, and one or more disc replacements may be inserted into the disc space. The small bearings allow the preservation of the vertebral endplates. Although the preferred embodiment use mobile units preferably in the form of small spheres and two ADRs per level, alternatives are disclosed, wherein the mobile unit is non-spherical, including oblong shapes. Further alternative configurations include an elongated mobile bearing contained by interdigitating projections from superior and/or inferior endplates.

Abstract: Intervertebral disc prostheses are provided. More particularly, the invention provides disc prostheses that have adjustable disc heights, that are readily converted into fusion prostheses and that provide a range of motions that effectively mimic the natural range of motions of a spinal disc.