195 results about "Artificial disc" patented technology

This invention resides in an apparatus for inhibiting full extension between upper and lower vertebral bodies, thereby preventing pain and other complications associated with spinal movement. In the preferred embodiment, the invention provides a generally transverse member extending between the spinous processes and lamina of the upper and lower vertebral bodies, thereby inhibiting full extension. Various embodiments of the invention may limit spinal flexion, rotation and/or lateral bending while preventing spinal extension. In the preferred embodiment, the transverse member is fixed between two opposing points on the lower vertebral body using pedicle screws, and a cushioning sleeve is used as a protective cover. The transverse member may be a rod or cable, and the apparatus may be used with a partial or full artificial disc replacement. To control spinal flexion, rotation and/or lateral bending one or more links may be fastened to an adjacent vertebral body, also preferably using a pedicle screw. Preferably a pair of opposing links are used between the upper and lower vertebral bodies for such purposes.

An method and apparatus is provided for achieving stability of an implant in an intervertebral space of the human body, including an implant having a superior surface and an inferior surface, the surfaces having no significant protrusions extending therefrom and at least one modular projection mateable with one of each superior and inferior surface of the implant to achieve stability within the intervertebral space. The implants can be selected form a group of artificial discs and spinal fusion cages.

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.

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.

An artificial disc is provided having a rigid pre-formed phase. The disc is implanted in an elastic phase and activated to the pre-formed phase. The pre-formed shape provides corrective forces to stabilize or correct spinal abnormalities.

Devices and methods for manufacturing devices for treating degenerated and/or traumatized intervertebral discs are disclosed. Artificial discs and components of discs may include an artificial nucleus and/or an artificial annulus and may be comprised of shape memory materials synthesized to achieve desired mechanical and physical properties. An artificial nucleus and/or annulus according to the invention may comprise one or more hollow bodies that may be filled with a curable material for deployment. A hollow body according to the invention may comprise one or more partitions to define one or more chambers and may comprise means for directing the flow of material within said hollow body.

A distraction instrument includes a drive rod, a driver mechanism coupled to the drive rod, and a pair of arms linked to the driver mechanism. A method of implanting an artificial disc or a fusion implant in an intervertebral site includes preparing the intervertebral site, actuating a gear mechanism of a distraction instrument to distract the intervertebral site, and inserting at least a core of the artificial disc or fusion implant into the intervertebral site.

One or more rigid components associated with an articulating bone are used to encase, encapsulate, contain, or otherwise protect a compressible/resilient member. The embodiments are applicable not only to artificial disc replacement (ADR) devices, but also to joint situations including total knee and hip arthroplasty. The cushion elements in the preferred embodiments include synthetic rubbers, hydrogels, elastomers, and other polymeric materials such as viscoelastic polymers and foam polyurethanes. The invention effectively combines the advantages of such materials (cushioning, shape memory, and expansion after insertion in the case of hydrogels), while providing increased protection, particularly the elimination of shear stresses. When applied to an ADR, the invention also minimizes the risk of extrusion.

Methods and devices are provided for replacing a spinal disc. In an exemplary embodiment, artificial disc replacements and methods are provided wherein at least a portion of a disc replacement can be implanted using a posterolateral approach. With a posterolateral approach, the spine is accessed more from the side of the spinal canal through an incision formed in the patient's back. A pathway is created from the incision to the disc space between adjacent vertebrae. Portions of the posterolateral annulus, and posterior lip of the vertebral body may be removed to access the disc space, leaving the remaining annulus and the anterior and posterior longitudinal ligaments in tact. The disc implant can be at least partially introduced using a posterolateral approach, yet it has a size that is sufficient to restore height to the adjacent vertebrae, and that is sufficient to maximize contact with the endplates of the adjacent vertebrae.

Artificial disc replacement (ADR) components cooperate to limit axial rotation and/or lateral bending to a greater degree when the spine is extended than when the spine is a neutral to flexed position, thereby decreasing loads placed upon the facet joints. In the preferred embodiment, truncated articulating surfaces with non-articulating side surfaces allow increasing amounts of axial rotation and lateral bending as the total disc replacement (TDR) moves from full extension to full flexion. Limiting axial rotation and lateral bending of the TDR protects the facet joints and the Annulus Fibrosus, since the facet joints carry more load when the spine is extended than when the spine is flexed. Thus the invention serves to protect the facet joints while allowing normal or near-normal spinal motion.

An artificial intervertebral disc for at least partially replacing a diseased or damaged intervertebral disc. The artificial disc includes a concave-convex articulating surface. The artificial disc can be used in the cervical region of the spine, where a concave-convex articulating surface is advantageous for improved anatomical fit and region appropriate kinematics. The artificial disc of the present invention also includes an anchor for attachment to bone.

A distraction instrument distracts two adjacent vertebra segments to receive an artificial disc, the instrument including a measurement indication related to a distracted disc space. The measurement indication can be the force required to distract the disc space, the distance between the adjacent vertebra, the lordotic angle of a pair of vertebra defining the disc space, and the width of the disc space.

A lumbar disc prosthesis is provided including a pair of disc members. The first member of the disc pair has a vertebral disc contact surface and a recessed portion on an opposing surface thereof. The second member of the disc pair has a vertebral disc contact surface and a protruding portion on an opposing surface thereof. The protruding portion of the second member engages with the recessed portion of the first member in use. Each of the first and second disc members are provided with at least three sections; a middle section and two end sections. The recessed and protruding portions are provided in the middle section of the respective disc members and each of the two end sections have a narrowing taper towards the ends of the disc members. The facet joint prosthesis includes a first member for attachment to a first posterior lumbar disc in use and a second member for attachment to a second posterior lumbar disc in use. At least a part of the first member is telescopically mounted in at least a part of the second member in use.

This invention is directed to improved methods and devices to attach arthroplasty devices, particularly the spine, distract the disc space, machine the disc space to improve the fit between ADRs and the vertebrae, to hold and remove ADRs, and to facilitate spinal fusion for a failed ADR surgery. One aspect of the invention places anchor devices in the spine during a first operation. Spinal devices are connected to the anchoring devices during a second procedure. The second procedure is generally performed months after the insertion of the anchoring devices. The time between the two procedures allows bone to grow into the anchoring devices. Minimal forces are exerted on the anchoring devices between the procedures. Other embodiments are described where a previously implanted ADR having a pair of opposing endplates is immobilized using a device the attached to the endplates, fits between the endplates, or both.

Barriers are used to hold prosthetic components, including intradiscal devices, in position while allowing natural movement within a “safe zone.” In the preferred embodiments, the barrier is in the form of a “buttress” plate coupled to a controlled linkage that prevents the device from moving into a dangerous position. The movable member(s) allow an intradiscal device to move through a safe zone while permitting mobile artificial disc replacements (ADRs) or other intradiscal devices to self-center with movement of the vertebrae. The link member(s) broadly serve as a “tether” to prevent extrusion of the intradiscal device into the spinal canal, or outside of the disc space. The intradiscal device may be mobile, or attached to one or both of the vertebral endplates. Other mechanisms to accommodate the movable link members are also disclosed. The plates are preferably constructed of metal, but the invention is not limited in terms of the biocompatible material(s) used for the plate or link members.

An artificial disc having a pair of opposing baseplates, for seating against opposing vertebral bone surfaces, separated by a ball and socket joint that includes a ball compression locked to a post extending from one of the baseplates. The ball is captured within a curvate socket formed in a peak of a convex structure attached to the other of the baseplates. The socket is formed by opposing curvate surfaces, one on the convex structure and one on the other of the baseplates. While the ball angulates freely in the socket, the rotation of the ball in the socket has a limited range due to interference between a protrusion on the convex structure that extends into the socket and a curvate recess on the ball. The ball and socket joint therefore permits the baseplates to rotate relative to one another through a limited range and also angulate relative to one another.

An artificial intervertebral disc comprising at least two individual disc units that create a single center of rotation within an intervertebral space. An artificial intervertebral disc including housing members including spaced inner surfaces facing each other and oppositely facing outer surfaces for engaging spaced apart intervertebral surfaces; self-adjusting bearing mechanisms operatively disposed between the inner surfaces for moving relative to the housing members to adjust and compensate for vertebral disc motion; and a flange formed on an outer surface of said housing members for aligning the disc in an intervertebral space. A method for posteriorly inserting an artificial disc assembly by inserting at least two artificial disc assemblies around a spine and into an intervertebral space.

An artificial disc replacement (ADR) includes a pair of opposing endplate components, each attached to one of the upper and lower vertebrae, a cushioning component disposed between the endplate components; and a filler material contained within the cushioning component. The filler material may be a gas, liquid, foam, or gel, including a hydrogel. In a preferred embodiment, the ADR may further include one or more opposing, spaced-apart projections configured to impinge if the endplate components are subjected to an excessive force. Such projections may allow for unrestricted motion between the endplates until impingement, or may restrict translation between the endplates until a greater excessive force is reached. One or both of the endplate components may include a modified surface to increase adherence to the respective vertebral endplates.

Artificial disc replacement (ADR) systems with intradiscal components feature non anterior-posterior (A-P) or oblique-oriented keels such that the great vessels do not require as much retraction during insertion. The system may further include guides for aligning the ADR prior to insertion, and for cutting an oblique slot into a vertebral endplate to receive the keel. A screw adapted to penetrate a vertebral body may be used in conjunction with the keel. The screw and keel may converge, diverge or intersect. The screw may further include a mechanism providing a locking relationship with the keel. The system may further including a guide to direct drill bits and screws through holes in the keel. ADRs according to the invention may additionally, independently include a non-symmetrical endplate shaped so as to decrease the risk of injuring the great vessels. By virtue of the invention, a second ADR may be installed at a second level having a keel oriented differently from that of the ADR having an orientation other than anterior-to-posterior.

The present invention relates to a device and method which may be used to reinforce the native annulus during spinal surgery. The device is a catheter based device which is placed into the inter-vertebral space following discectomy performed by either traditional surgical or endoscopic approaches. The distal end of the catheter is comprised of an expansile loop which may be increased in diameter by advancement of a portion of the catheter via its proximal end, such proximal end remaining external to the body. The expansile loop may be formed of a woven or braided material and may be made of a polymer such as nylon, polyurethane, polyester, polyethylene, polypropylene or any of the well known and biocompatible polymers. Alternatively the expansile portion of the catheter may be formed from a metallic braid of stainless steel, elgiloy, Nitinol, or other biocompatible metals. The expansile loop may be formed such that when the loop is diametrically contracted the loop feeds into its other end, similar to a snake eating its own tail. Stabilization of the outer portion of the loop and pulling out the inner portion will thereby increase the overall diameter of the loop while maintaining it as a closed loop or torus. The present invention comprises four embodiments and can be used to 1) facilitate disk fusing, 2) perform an artificial replacement of the nucleus, 3) perform an artificial replacement of the annulus, or 4, perform an artificial replacement of both the nucleus and annulus.

A prosthetic intervertebral disc includes an upper plate and a lower plate and employs congruent stepped features to provide limited articulating motion between the plates. The stepped features can be used to provide articulating motion of a rocking type rather than a rubbing or translating type of motion provided in many artificial discs. Each of two parts of the intervertebral disc includes two or more stepped bearing surfaces, having curved or flat shapes, which mate with one another to provide the articulation to the disc. The stepped features can be designed to restrict motion in flexion-extension or lateral bending to less than a predetermined angle. The stepped design can be modified to either allow or prevent rotational motion between the plates. The limited motion disc substantially prevents translation, however some limited translation can be provided by modification of the relative sizes of the stepped features.

Artificial disc replacements (ADRs) use articulating components to permit normal spinal movement(s). According to the invention, an ADR situated between upper and lower vertebral bodies comprises a first endplate affixed to one of the vertebral bodies providing a first articulating surface having a first radius of curvature, a second endplate affixed to the other one of the vertebral bodies providing a second articulating surface having a second radius of curvature which is different from the first radius of curvature, and a spacer component having opposing surfaces that cooperate with the first and second articulating surfaces. In the preferred embodiment, the first endplate is affixed to the upper vertebral body, the first articulating surface is concave, the second endplate is affixed to the lower vertebral body, the second articulating surface is convex, and the first radius of curvature is larger than the second radius of curvature. The spacer may include a surface that congruently cooperates with the first and/or articulating surface(s).