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: 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: An intervertebral disc placement system includes a multi part intervertebral disc, such as a mobile core disc, and an associated placement instrument. The placement instrument holds the disc securely with the disc endplates angled for ease of placement of the disc into an intervertebral disc space and quickly releases the implant within the disc space. The disc includes upper and lower plates having notches in inner surfaces for engagement of the placement instrument. The placement instrument has a rotatable key configured to fit into the first and second notches to grasp the disc from the interior and eliminate the need for an external grasping mechanism which could interfere with disc placement.

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 disc placement system includes a multi part intervertebral disc, such as a mobile core disc, and an associated placement instrument. The placement instrument holds the disc securely with the disc endplates angled for ease of placement of the disc into an intervertebral disc space and quickly releases the implant within the disc space. The disc includes upper and lower plates having notches in inner surfaces for engagement of the placement instrument. The placement instrument has a rotatable key configured to fit into the first and second notches to grasp the disc from the interior and eliminate the need for an external grasping mechanism which could interfere with disc placement.

Abstract: A method for inserting an intervertebral disc prosthesis into a space between two vertebrae involves inserting the prosthesis partway into the space under constraint to prevent endplates of the prosthesis from articulating, releasing the prosthesis from constraint, and inserting the unconstrained prosthesis farther into the space. In some embodiments, the method involves grasping the prosthesis with a grasping device to insert the prosthesis partway under constraint, loosing the grasping device to release the prosthesis from constraint, and pushing the prosthesis farther into the disc space using the grasping device and/or one or more separate pusher devices. A system includes a grasping device, at least one separate pushing device, and optionally a vertebral spreading device and/or a vertebral midline indicator device.

Abstract: An intervertebral disc for a prosthetic intervertebral disc system for insertion from a posterior of the spine includes first and second end plates sized and shaped to fit within an intervertebral space, each end plate having a vertebral contacting surface and an inner surface, a first bearing surface on an inner surface of the first end plate, and a second bearing surface on an inner surface of the second end plate. A mobile core is configured to be received between the first and second bearing surfaces, the first and second end plates being articulable and rotatable relative to each other via sliding motion of at least one of the first and second bearing surfaces over the core. The core is movable with respect to at least one of the first and second end plates.

Abstract: A spinal midline indicator (10) has a body (14) of radiolucent material for insertion between adjacent vertebrae (18, 20) and a radiographic marker (12) located centrally with the body to indicate the position of the spinal midline (22) in anterior-posterior images when the body is centrally located between the vertebrae. The radiographic marker is typically an elongate metal handle. The body may carry secondary radiographic markers (16) on opposite sides of and equidistant from the handle so that the handle indicates the position of the spinal midline when the body is placed centrally between the vertebrae.

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 upper and lower plates and a core having upper and lower curved surfaces disposed between the plates. At least one of the plates and/or the core includes a resilient material for absorbing shock or other forces applied by vertebrae. Optionally, resilient support members may be disposed within the resilient material to connect two portions of a plate or the core. Such support members may be springs, cylinders, wires or other resilient structures. The resilient material is held within the core or plate(s) via a surrounding retaining structure, such as a membrane. The resilient material disposed in one or more components of the prosthetic disc provides for shock absorption.

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: 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: A spinal midline indicator (10) has a body (14) of radiolucent material for insertion between adjacent vertebrae (18, 20) and a radiographic marker (12) located centrally with the body to indicate the position of the spinal midline (22) in anterior-posterior images when the body is centrally located between the vertebrae. The radiographic marker is typically an elongate metal handle. The body may carry secondary radiographic markers (16) on opposite sides of and equidistant from the handle so that the handle indicates the position of the spinal midline when the body is placed centrally between the vertebrae.

Abstract: A prosthetic disc for insertion between adjacent vertebrae includes upper and lower plates and a core having upper and lower curved surfaces disposed between the plates. At least one of the plates and/or the core includes a resilient material for absorbing shock or other forces applied by vertebrae. Optionally, resilient support members may be disposed within the resilient material to connect two portions of a plate or the core. Such support members may be springs, cylinders, wires or other resilient structures. The resilient material is held within the core or plate(s) via a surrounding retaining structure, such as a membrane. The resilient material disposed in one or more components of the prosthetic disc provides for shock absorption.

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: 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: A prosthesis system comprises plates that can be positioned against vertebrae and a selected resilient core that can be positioned between the plates to allow the plates to articulate. The selected resilient core can be chosen from a plurality of cores in response to patient characteristics, such as age and/or intervertebral mobility, such that the prosthesis implanted in the patient is tailored to the needs of the patient. The plurality of cores may comprise cores with different resiliencies, and one of the cores can be selected such that the upper and lower plates articulate with the desired shock absorbing resiliency and/or maximum angle of inclination when the one selected core is positioned between the plates.

Abstract: An intervertebral prosthesis for insertion between adjacent vertebrae, in one embodiment, includes upper and lower prosthesis plates and a movable core. The prosthesis plates and optionally the core are formed of polyaryletherketone (PAEK) for improved imaging properties. A metallic insert is provided on each of the PAEK prosthesis plates providing a bone ongrowth surface.

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.