Abstract: An intervertebral disc prosthesis comprises a left prosthesis component and a symmetric right prosthesis component positioned in an intervertebral space. Each prosthesis component includes a superior vertebra facing surface, an inferior vertebra facing surface, and a substantially spherical bearing surface. The bearing surface is positioned between the superior vertebra facing surface and the inferior vertebra facing surface. The superior vertebra facing surface is provided on a superior endplate and the inferior vertebra facing surface is provided on an inferior endplate. The superior endplate is operable to rotate relative to the inferior endplate upon the bearing surface. Each prosthesis component further comprises an elastic member positioned between an endplate and the bearing surface. The elastic member may be substantially cylindrical with a plurality of resilient ribs.

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: An artificial cervical vertebrae composite joint is composed of two upper and lower fixing members disposed vertically symmetrically, a cervical vertebrae body member, and two connection members, the cervical vertebrae body member being connected between the fixing members through the connection members. The fixing members each have an L shape and comprise a front wing part and a base part. A locking screw hole is formed in the front wing part, and a skidproof groove provided with an inverted tooth and a protrusion is disposed on a middle portion of the base part. A bone grafting hole is transversely disposed through a middle portion of the cervical vertebrae body member, and two cavities are disposed on both upper and lower sides of the cervical vertebrae body member at an axial center of the cervical vertebrae body member to mount the connection members.

Abstract: A space keeper for vertebrae or intervertebral disks is provided, which has a tubular section and teeth on the respective ends of the space keeper. On at least one end of the tubular section an element is provided, which has a top plate which is tiltable about an angle to the longitudinal axis of the tubular section.

Abstract: An improved composition of titanium sintered titanium carbide is provided. The composition provides an improved degree of strength and toughness and improved compatibility with medical imaging. The composition provides good compatibility with sintered polycrystalline diamond, achieving a good mechanical fit in terms of the combined compressibility and thermal expansion during the sintering process to minimize stress or cracking between the substrate and the diamond layer.

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: A stabilization system for a human spine is provided comprising at least one dynamic interbody device and at least one dynamic posterior stabilization system. In some embodiments the stabilization system comprises a pair of dynamic interbody devices and a pair of dynamic posterior stabilization systems. In some embodiments, a bridge may couple a dynamic interbody device to a dynamic posterior stabilization system.

Abstract: A prosthetic spinal implant having a deployable securing mechanism that is deployable into a portion of the vertebral space for affixing the implant between the vertebrae, the securing mechanism having tactile feedback means comprising a surface for transmitting tactile feedback during deployment of the securing mechanism. A spinal implant having deployable securing means that interface with the implant to prevent the deployable securing means from retracting after deployment. An implant that utilizes its resilient properties to provide the user with tactile feedback with which the user may ascertain the position of the securing mechanism. A system and tools for sizing and implanting implants with the aforementioned characteristics.

Abstract: A methodology for grafting together adjacent bony structures is provided using an implant device having an endplate with an inner disc portion and outer ring portion spaced from the inner disc portion by a connecting wall disposed therebetween. An endplate interior surface includes a retaining structure for securing the endplate to one of the bony structures, and endplate an exterior surface has an integrally formed socket. A ball-joint rod has a longitudinally extending body and an end, and at least a portion of the ball-joint rod end is curvilinear in shape. The curvilinear ball-joint rod end is rotatably disposed in the endplate socket to fixedly interconnect the bony structures.

Abstract: An intervertebral implant, alone and in combination with an insertion tool for inserting same and a method for inserting same. The implant has upper and lower parts which have universal movement relative to each other. Each of the upper and lower parts also has a surface engaging an adjacent vertebrae. Each part has a keel extending from said surface into a cutout in the adjacent vertebrae, and each keel has an anterior opening recess therein. An insert tool has a pair of arms which are received in the recess of the keels through the anterior opening to securely hold and insert the implant. Projections and matching indentations in each arm and the base of its recess securely attached each arm within its keel.

Abstract: A methodology for grafting together adjacent bony structures is provided using an implant device having an endplate with an inner disc portion and outer ring portion spaced from the inner disc portion by a connecting wall disposed there between. An endplate interior surface includes a retaining structure for securing the endplate to one of the bony structures, and endplate an exterior surface has an integrally formed socket. A ball-joint rod has a longitudinally extending body and an end, and at least a portion of the ball-joint rod end is curvilinear in shape. The curvilinear ball-joint rod end is rotatably disposed in the endplate socket to fixedly interconnect the bony structures.

Abstract: An intervertebral disc prosthesis comprises a left prosthesis component and a symmetric right prosthesis component positioned in an intervertebral space. Each prosthesis component includes a superior vertebra facing surface, an inferior vertebra facing surface, and a substantially spherical bearing surface. The bearing surface is positioned between the superior vertebra facing surface and the inferior vertebra facing surface. The superior vertebra facing surface is provided on a superior endplate and the inferior vertebra facing surface is provided on an inferior endplate. The superior endplate is operable to rotate relative to the inferior endplate upon the bearing surface. Each prosthesis component further comprises an elastic member positioned between an endplate and the bearing surface. The elastic member may be substantially cylindrical with a plurality of resilient ribs.

Abstract: Instrumentation for implanting an artificial intervertebral disc includes static trials and a dynamic trial for determining the appropriate size of disc to be implanted, static trial holders for manipulating the static trials, inserter/impactors for inserting and removing the static trials and for inserting the artificial intervertebral discs, repositioners/extractors for repositioning and extracting the static trials or the artificial intervertebral discs, and a leveler for setting the proper position of the artificial intervertebral disc. Methods for using the same are also disclosed. Features for artificial intervertebral discs and intervertebral spacer devices useful for manipulation by the instrumentation are also disclosed.

Abstract: The present invention is directed to the field of prosthetic devices. More particularly, one embodiment of the present invention is directed to an artificial disc that can be used as a replacement for an intervertebral disc (e.g., a human intervertebral lumbar disc, a human intervertebral cervical disc and/or a human intervertebral thoracic disc).

Abstract: An intervertebral implant has an implant structure providing a fixation surface for fixation to the endplate of a vertebral body. The fixation surface includes two bone contact regions at different heights in an axial direction. A transition between the two contact regions has a stepped form including at least two steps.

Abstract: In an intervertebral implant, having an upper part that has a support face for a vertebra and a lower part that has a support face for an adjacent vertebra, on each of which parts engagement elements, which are accessible from one side of the intervertebral implant, for a manipulation instrument are disposed, in order to minimize the structural height of the intervertebral implant upon insertion into an intervertebral space, it is proposed that the upper part and lower part each have protrusions and recesses aimed at the respectively other part, which are offset laterally from one another in such a way that when the upper part has been brought close to the lower part they mesh with one another; and that the engagement elements on the upper part and on the lower part are each disposed in protrusions of these parts in such a way that the engagement elements of the upper part and lower part are located side by side and at least partly overlap in the direction of the height of the intervertebral implant.

Abstract: An artificial disc prosthesis is provided. The prosthesis includes first and second end plates and a nucleus. Each end plate may have one or more rows of keels for fixation to vertebral bodies. The nucleus may engage a slot or trough in an inner surface of an end plate. The trough can be open on the posterior or anterior end to allow the nucleus to slide into the trough without undue distraction of adjacent vertebrae. The nucleus can be prevented from moving out of the trough by inserting a stop in the trough.

Abstract: A bone prosthesis device is comprised of an upper and lower abutment surfaces and an intervening malleable member. The device is sufficiently small so that implantation into an inter-vertebral disc space can be performed from a substantially posterior approach without significant impingement upon the neural elements.

Abstract: A cervical disc prosthesis or intervertebral disc prosthesis that includes a first disc comprising a protrusion connected to a disc body and a convex surface facing a first cervical vertebra when implanted, and a second disc comprising a socket recessed in a disc body, and a convex surface facing a second cervical vertebra when implanted. The second disc remains substantially parallel to the first disc and axially spaced from the first disc. The protrusion is adapted to fit into the socket to join the first disc with the second disc, and the protrusion is fit for pivoting movement into the socket. Also provided is a method for implanting the inventive cervical disc prosthesis or the inventive intervertebral disc prosthesis into an intervertebral disc area defined between two adjacent vertebrae.

Abstract: A barrel holder apparatus for intervertebral disc prosthesis implantation, the apparatus comprising a first end having one or more apertures shaped to hold removable pins while the prosthesis is being implanted to prevent a first disc and a second disc of the prosthesis from separating, the removable pins being pre-threaded into the first disc and the second disc of the prosthesis prior to the implantation of the prosthesis, and a second end located opposite to the first end, the second end having an opening shaped to hold one of the removable pins while the barrel holder is being rotated to unthread the removable pin out of the prosthesis after the implantation is completed. Also provided is a method for implanting intervertebral disc prosthesis into an intervertebral disc area defined between adjacent cervical vertebrae, the method comprising threading removable pins into a first disc and a second disc of the prosthesis.

Abstract: A modular nucleus pulposus prosthesis comprising at least two generally mirror image complimentary disc segments combined to form a generally discoid endoprosthetic disc and to associated tools and methods for replacing the intervertebral disc. The complimentary segments are substantially identical including outer circumferential walls roughly equal to a semi-circle aligned along concave-convex inner wall inner walls forming a common border and a generally symmetrical discoid congruent structure which is positioned within the annulus of a spinal disc section. Disc segments may define structures to support, position and secure the segments to one another intradiscally. Surgical tools define structures for inserting and aligning disc members together. Also disclosed is a system and method for replacing the nucleus pulposus using the surgical tools adapted for placement and alignment of the disc.

Abstract: Spinal implants and methods of inserting the implants into an interspinous space and into engagement with spinous processes. The implants may include first and second arms that are separately inserted into the patient. The arms may be attached together within the patient in an overlapping arrangement and pivotally connected at a joint. The arms may be moved about the joint with first ends of each of the arms on a first side of the joint contacting against opposing lateral sides of a first spinous process and second ends of each of the arms on a second side of the joint contacting against opposing lateral sides of a second spinous process. A securing member may contact against the arms and secure the orientation of the arms.

Abstract: An intervertebral joint assembly includes an upper support and a lower support, each of which has two or more components. The upper and lower support components are arranged in situ to form the upper and lower supports, respectively. By arranging the supports in situ, the supports can be introduced from the back of the patient, for example with an arthroscope. Each of the upper and lower supports has a surface adapted to engage a vertebra and a surface adapted to engage the other support or an intermediate member to form an articulate joint which articulates the joint assembly. In some embodiments, the components of the upper and lower supports are assembled in situ, for example with pivoting, telescoping or bending, to form the upper and lower supports, respectively. The supports can be attached to vertebrae with pedicles screws, and/or other anchors attached to the supports.

Abstract: A disc prosthesis designed to effectively replace a damaged intervertebral disc, enabling the various normal movements between two adjacent vertebral bodies and controlling these movements and their extent within the same physiological limits that determine the relative motions of two adjacent vertebrae separated by a healthy intervertebral disc.

Abstract: A system for a dynamic facet replacement includes first and second inferior facets, first and second pars and first and second superior facets. The first and second inferior facets are configured to replace left and right natural inferior facets and each facet comprises an articulating surface. The first and second superior facets are configured to replace left and right natural superior facets and each facet comprises an articulating surface. Each of the first and second pars includes first and second articulating surfaces and is configured to articulately connect the first and second articulating surfaces with the first articulating surfaces of the inferior and superior facets, respectively.

Abstract: A methodology for grafting together adjacent bony structures is provided using an implant device having an endplate with an inner disc portion and outer ring portion spaced from the inner disc portion by a connecting wall disposed therebetween. An endplate interior surface includes a retaining structure for securing the endplate to one of the bony structures, and endplate an exterior surface has an integrally formed socket. A ball-joint rod has a longitudinally extending body and an end, and at least a portion of the ball-joint rod end is curvilinear in shape. The curvilinear ball-joint rod end is rotatably disposed in the endplate socket to fixedly interconnect the bony structures.

Abstract: An intervertebral disc prosthesis comprises a first endplate, a second endplate, and a bearing surface positioned between the first endplate and the second endplate. The bearing surface may be provided by a mobile bearing disc including a convex bearing surface configured to engage the first endplate and a concave bearing surface configured to engage the second endplate. The multiple bearing surfaces of the mobile bearing disc engage articulating surfaces on the endplates to form a plurality of articulating joints. Each articulating joint is configured to facilitate a particular type of movement for the segmental unit. Furthermore, each articulating joint is defined by a distinct center of rotation. The contact pair formed by the convex bearing surface of the bearing component and the concave bearing surface of the first endplate may provide a flexion/extension center of rotation for the prosthesis.

Abstract: Disclosed is an intervertebral disc prosthesis for the total replacement of a natural intervertebral disc within the lumbar and cervical spine, comprising of articulating sliding partners. The upper sliding partner has means for a firm assembly to an upper vertebral body and the lower sliding partner has means for a firm assembly to a lower vertebral body. At least one sliding surface is between two sliding partners. Two- and three-part functional designs are planned and both having in common, that, as a result of the shape of the articulating surface(s), the laterolateral and dorsoventral motion amplitudes differ. The resulting angles including the rotation around a fictitious vertical axis can be defined to a desired extent.

Abstract: The present invention is directed to the field of prosthetic devices. More particularly, one embodiment of the present invention is directed to an artificial disc that can be used as a replacement for an intervertebral disc (e.g., a human intervertebral lumbar disc, a human intervertebral cervical disc and/or a human intervertebral thoracic disc).

Abstract: An artificial disc device for replacing a damaged nucleus is disclosed. In one form, the device may be inserted in components such that the device may be assembled within and retained by the natural annulus therein. In another form, the device may be inserted into the natural annulus in a collapsed or compressed state or arrangement and then be expanded within and retained by the annulus therein.

Abstract: A prosthetic spinal implant having a securing member for fixing the implant relative to an adjacent bone. In one form, the securing member is deployable into a portion of the vertebral space for affixing the implant between the vertebrae. The securing member may be disposed substantially within the body of a bearing member of the implant when the securing member is in an undeployed orientation. In other forms, the securing member is provided separately from the implant such that it may be inserted into the intervertebral space after the implant has been placed in an implanted orientation between the vertebrae. In such forms, the securing member is configured for ease of insertion between an outer bearing surface of the implant and an adjacent bone via linear or rotary motion.

Abstract: A total disc implant (TDI) is provided for total replacement of a spinal disc or discs in a human patient or other mammal, wherein the TDI is designed to maintain a substantially full range of natural motion (ROM) following implantation. The TDI generally comprises, in one preferred form, upper and lower end plates for affixation to adjacent vertebral bodies, with an intervening insert disposed therebetween. The end plates each include elongated part-cylindrical surfaces oriented, generally perpendicular to each other, with one of the surfaces extending in an anterior-posterior direction and the other extending in a medial-lateral direction. The intervening insert defines concave upper and lower part-cylindrical seats oriented, for respectively engaging these part-cylindrical surfaces, wherein these part-cylindrical seats are defined by offset radii to include a somewhat flattened central base region merging smoothly with upwardly curving radiused sides.

Abstract: An artificial spinal disk prosthesis comprised of an artificial disk (101), mounting bracket (105) assembly that secures the disk to at least one vertebrae and a sliding rod (104) that connects the two whereby the shape of the components determines the range of motion of the disk, thus allowing desirable motions of the disk consistent with normal body motions and preventing undesirable motions of the artificial disk. In the preferred embodiment, the angular motion of the disk is controlled by a hinge that is on the side of the artificial disk. In the preferred embodiment, the artificial disc is connected to the spine via one vertebra.

Abstract: Described is an articulating intervertebral disc prosthesis including a first member having a vertebra engaging portion and a bearing surface; a second member having a vertebra engaging portion and a bearing surface, which in use abuts the first member bearing surface to form a first bearing joint, —and motion restraint means adapted to provide ax-ticulation restraint of the bearing joints at predetermined limits of articulation similar to the natural motion restraint of a facet joint; wherein the prosthesis is longitudinally—split into two bodies so that the two bodies can be laterally separated, each body having an articulating bearing joint. Preferably, the second member bearing surface is shaped to include at least a portion of a first substantially circular curve when viewed in a first section, and at least a portion of a second substantially circular curve when viewed in a second section, said first and second curves being of respectively different sizes of circle.

Abstract: A methodology for grafting together adjacent bony structures is provided using an implant device having an endplate with an inner disc portion and outer ring portion spaced from the inner disc portion by a connecting wall disposed therebetween. An endplate interior surface includes a retaining structure for securing the endplate to one of the bony structures, and endplate an exterior surface has an integrally formed socket. A ball-joint rod has a longitudinally extending body and an end, and at least a portion of the ball-joint rod end is curvilinear in shape. The curvilinear ball-joint rod end is rotatably disposed in the endplate socket to fixedly interconnect the bony structures.

Abstract: The present invention relates to an expandable prosthetic implant device for engagement between vertebrae generally comprising an inner member, outer member, and gear member positioned coaxial with respect to each other such that the inner and outer members are moveable relative to each other along an axis. The gear member is axially fixed to the outer member and freely rotatable with respect to the outer member and the gear member threadedly engages a threaded portion of the inner member to translate inner member along the axis. The implant is configured to engage the vertebrae in a predetermined alignment and the gear member includes gear teeth exposed to the exterior and configured to be accessible by a tool member at a plurality of angular positions around the perimeter of the implant device.

Abstract: An intervertebral implant for separating an upper vertebra and a lower vertebra. The implant includes an upper mount having a first surface sized and shaped for mounting on the upper vertebra and a second surface opposite the first surface. The implant includes a lower mount having a first surface sized and shaped for mounting on the lower vertebra and a second surface opposite the first surface. The implant includes an element positioned between the upper mount and the lower mount spacing the first surface of the upper mount from the first surface of the lower mount by a predetermined distance. The element is configured to permit the upper mount to pivot relative to the lower mount. The element allows the upper vertebra to pivot relative to the lower vertebra while maintaining spacing between the upper vertebra and the lower vertebra.

Abstract: Instrumentation for implanting an artificial intervertebral disc includes static trials and a dynamic trial for determining the appropriate size of disc to be implanted, static trial holders for manipulating the static trials, inserter/impactors for inserting and removing the static trials and for inserting the artificial intervertebral discs, repositioners/extractors for repositioning and extracting the static trials or the artificial intervertebral discs, and a leveler for setting the proper position of the artificial intervertebral disc. Methods for using the same are also disclosed. Features for artificial intervertebral discs and intervertebral spacer devices useful for manipulation by the instrumentation are also disclosed.

Abstract: A prosthesis is adapted for implantation into the spine. The prosthesis has a first member and a second member. The first member and the second member have a permitted range of rotational motion with respect to one another. The amount of permitted rotation of the first member relative to the second member is dependant on the extent of flexion and extension of the spine.

Abstract: The Maphbe 1: Artificial Tissue and Joint Replacement System is a method of replicating the physiological function of tissue as described in the claims. The Maphbe 1 is unique because it employs methods of manufacturing needed to successfully combine the different materials needed to replicate tissue.

Abstract: The subject invention provides a modular six-degrees-of-freedom spatial mechanism for spinal disc prosthesis, with up to three independent rotational and up to three independent translational degrees-of-freedom. The prosthesis can maintain non-separable, and non-restrictive, mechanical linkage by establishing a linked series, or chain, of kinematic pairs (joints) between components. In embodiment, a superior plate links to a planar pair (two independent degrees of translational freedom), which links to spherical pair (three independent degrees of rotational freedom), which links to a prismatic pair (one independent degree of translational freedom), which links to an inferior plate, completing the jointed kinematic chain. The kinematic pairs can be lower (surface contact) or higher (point, line, and/or curve contact) order pairs, or combinations.

Abstract: Spacerless artificial disc replacements (ADR) are disclosed. One preferred embodiment includes two saddle-shaped components to facilitate more normal spinal flexion, extension, and lateral bending while limit axial rotation, thereby protecting the facet joints and the annulus fibrosus (AF). Either or both of the superior and inferior components are made of a hard material such as chrome cobalt, titanium, or a ceramic including alumina, zirconia, or calcium phosphate. The articulating surfaces of the ADR are also preferably highly polished to reduce friction between the components. Metals, alloys or other materials with shape-memory characteristics may also prove beneficial.

Abstract: An intervertebral disk prosthesis is provided. The prosthesis comprises: a first plate for engaging a first vertebral body, said first plate comprising a first slot formed through the first plate; a second plate for engaging a second vertebral body, said second plate comprising a second slot formed through the second plate; a first anchor member, said first anchor member positioned and slidable through the first slot and having a sharp edge for penetrating into the first vertebral body; and a second anchor member, said second anchor member positioned and slidable through the second slot and having a sharp edge for penetrating into the second vertebral body. The first plate and the second plate engage with one another by way of complimentary concave and convex spherical cap portions to provide relative movement between the first plate and the second plate.

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), characterized 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: Artificial disc devices are disclosed that restore correct anatomical intervertebral spacing for damaged discs while maintaining a substantially normal range of biomechanical movement for the vertebrae between which they are implanted. The disc devices include center bearing and outer or annular bearing portions with the center bearing portion including generally axially extending locating surfaces which cooperate with the facing vertebral surfaces to resist migration. The outer bearing portion is for load bearing or load sharing with the center bearing portion and includes surfaces that extend radially toward the periphery of the vertebrae so that subsidence about the center bearing portion is minimized. Alternate forms of the disc devices include one with an axially enlarged center ball bearing having an annular ring bearing extending thereabout and another having upper and lower plate members with a central bumper member and a surrounding resilient annular member therebetween.

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 intervertebral disk prosthesis system, which is used for forming an artificial intervertebral disk and comprises a first and a second prosthesis component wherein each of the two prosthesis components comprises a first and a second vertebral body contacting element for placement on neighboring vertebral bodies bounding an intervertebral disk space of a spinal column and a joint element that is mounted between and is moveable relative to at least one of the first and second vertebral body contacting elements, attains a substantially natural range of motion independent of the positioning of the two prosthesis components relative to each other and to the neighboring vertebral bodies. Each prosthesis component has a ball joint formed between the first and second vertebral body contacting elements.

Abstract: The present invention relates to an intervertebral disc prosthesis comprising at least three pieces including an upper plate, a lower plate, and a movable core at least in relation to a plate, wherein it also comprises two anatomic adaptation elements of which each has, on one hand, a surface in contact with a surface of a vertebra and, on the other hand, a face of which at least a part has a surface in contact with at least a part of the plate opposite to which the anatomic adaptation element is mounted, the anatomic adaptation elements being fixed onto the plates via fixation means.

Abstract: The present invention overcomes the problem of undesirable bone growth and/or unwanted scar tissue formation on the articulating surfaces and in the articulating spaces of prosthetic intervertebral discs. The invention comprises a method for preserving motion in a prosthetic disc having at least one articulating surface comprising applying an anti-infiltration agent on and around an articulating surface of the prosthetic disc. Suitable anti-infiltration agents include but are not limited to, hemostatic compounds, anti-adhesion compounds, bone-formation inhibiting compounds, or any combination thereof.

Abstract: A spinal implant prosthesis includes a pair of end plates for affixation to adjacent vertebral bone structures and respectively defining inter-engaged convex and concave articulatory surfaces of elliptical profile. These elliptical articulatory surfaces are elongated in an anterior-posterior direction, and are comparatively shorter in a medial-lateral direction. With this configuration, in response to angular displacement and/or axial rotation, the elliptical surfaces displace in a manner increasing the distance between the adjacent vertebral bone structures, thereby tensioning the prosthesis and producing counteracting forces which urge the components back toward a substantially centered or neutral position. In addition, in the preferred form, the anterior-posterior length of the concave articulatory surface in incrementally greater than the anterior-posterior length of the convex articulatory surface to accommodate a limited range of anterior-posterior translation.