41 results about "Total disc replacement" patented technology

A total disc replacement (TDR) system for use in the spine and related methods, involving a first anchor plate having a first surface for engaging a first vertebra and a second surface including a semi-cylindrical articular surface, a second anchor plate having a first surface for engaging a second vertebra and a second surface including a semi-cylindrical articular surface, and an intradiscal element including a first articular surface having a generally arcuate cross-section for articulating with said semi-cylindrical articular surface of said first anchor plate, and a second articular surface having a generally arcuate cross-section for articulating with said semi-cylindrical articular surface of said second anchor plate.

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.

The Annulus Fibrosus Stent (AFS) is a platform of barriers used in the intervertebral disc. The barrier can be inserted into an intervertebral disc to act to reinforce and / or supplement the disc. The AFS can be inserted at any of the many different stages of disc pathology. The AFS can be inserted to prevent pressure and dissection of disc material which in and of itself can decrease and / or eliminate pain from damaged AF fibers. The AFS can be inserted before disc pathology progresses to a substantial event such as a disc herniation. It can be inserted at any time in the progression of the natural history of disc disease. It can even be inserted when substantially the entire intervertebral disc has been removed. It can be inserted in conjunction with another procedure such as a Nucleus Pulposus Replacement (NPR) or Total Disc Replacement (TDR), etc. The various shapes and material of the AFS in this patent are designed to address particular clinical situations, particular anatomy and particular stages of disc degeneration. The AFS can be inserted directly through the AF, or by a technique of detaching part of the AF with bone without actually cutting a substantial part of AF fibers or layers of fibers or by the Transosseous approach.

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 involves a system and methods for nerve testing during anterior surgery, including but not limited to anterior total disc replacement surgery, nucleus replacement, and interbody fusion.

The invention provides an artificial spinal disc prosthesis that can be implanted to replace a damaged natural spinal disc. The implant includes a synthetic polymer ring. The polymers of the ring are oriented along a common pitch angle relative to a common central axis. Orientation of the polymers provides the ring with added strength and durability. Each synthetic polymer ring further comprises an exterior surface and an interior surface thereby forming a hollow area wherein an additional ring or a nucleus may be enclosed. A pair of angulated prosthetic endplates for use with the implant allow for insertion of the device from a multitude of approaches.

Total disc replacement systems and related methods involving a lateral, trans-psoas surgical approach to the spine while performing at least one of continuous and intermittent intra-operative neural monitoring of the psoas muscle to avoid injury during introduction.

An improved total disc replacement system and related methods, wherein a pair of anchor plates, each adapted to engage a vertebral body, and a translating internal member are provided. The translating internal member boasts the ability to move or translate between the anchor plates without compromising the conformity of the interface between the translating internal member and the anchor plates. In a significant aspect, the anchor plates may be locked in place relative to one another after implantation to effect fusion between the vertebral bodies.

A total disc replacement (TDR) system for use in the spine and related methods, involving a first anchor plate having a first surface for engaging a first vertebra and a second surface including a semi-cylindrical surface, a second anchor plate having a first surface for engaging a second vertebra and a second surface including a semi-cylindrical surface, a pair of intradiscal liners, each having a first semi-cylindrical surface for engaging with said anchor plates and a second semi-cylindrical surface for engaging with an intradiscal element, and an intradiscal element including a first articular surface having a generally arcuate cross-section for articulating with said first intradiscal liner, and a second articular surface having a generally arcuate cross-section for articulating with said second intradiscal liner.

This invention improves upon prior aft total disc replacements (TDRs) by more closely replicating the kinematics of a natural disc. The preferred embodiments feature two or more fixed centers of rotation (CORs) and an optional variable COR (VCOR) as the artificial disk replacement (ADR) translates from a fixed posterior COR that lies posterior to the COR of the TDR to facilitate normal disc motion. The use of two or more CORs allows more flexion and more extension than permitted by the facet joints and the artificial facet (AF). AF joint-like components may also be incorporated into the design to restrict excessive translation, rotation, and / or lateral bending.

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.

A vertebral disc replacement includes superior and inferior end plates separated by a leaf spring. The leaf spring includes two opposed legs that extend from a floating intermediate portion of the leaf spring to the superior end plate and two opposed legs that extend from the floating intermediate portion to the inferior end plate. The disc replacement device is compact and provides freedom of movement along three axes, translational along the caudal / cranial axis, lateral bending and flexion / extension.

Total disc replacement systems and related methods involving a lateral, trans-psoas surgical approach to the spine while performing at least one of continuous and intermittent intra-operative neural monitoring of the psoas muscle to avoid injury during introduction.

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 tissue-engineered intervertebral disc (IVD) suitable for total disc replacement in a mammal and methods of fabrication. The IVD comprises a nucleus pulposus structure comprising a first population of living cells that secrete a hydrophilic protein and an annulus fibrosis structure surrounding and in contact with the nucleus pulposus structure, the annulus fibrosis structure comprising a second population of living cells and type I collagen. The collagen fibrils in the annulus fibrosis structure are circumferentially aligned around the nucleus pulposus region due to cell-mediated contraction in the annulus fibrosis structure. Also disclosed are methods of fabricating tissue-engineered intervertebral discs.

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

Devices for implantation within a Functional Spinal Unit (FSU) that can provide up to six independent degrees of freedom from a neutral position are provided. Such devices can comprise two endplates, a nucleus, a sled, and an optional, elastic boot attached to the endplates and enclosing the contents of the device, namely, the nucleus. The sled on one end of the nucleus can be moveably attached to one of the endplates and a spherical cap affixed to the opposite end of the nucleus can be operably engaged with the other endplate. The endplates can provide outer surface features that allow fusion of the plates to the superior and inferior vertebrae of a FSU and can prevent expulsion of the device immediately after implanting. The nucleus can have compliant elements or can be rigid. It can comprise a tripartite construction of three elements of possibly different materials that can be fitted together, or it can be a single unified element or can be a material with graded mechanical moduli axially and radially. The endplates and nucleus can maintain connection through the sled and the extension of the central core. Additionally, one or more specialized rotational joint stops can be utilized to provide profile-closure of the spherical joint between the top endplate and the spherical cap.

The present invention involves a system and methods for nerve testing during anterior surgery, including but not limited to anterior total disc replacement surgery, nucleus replacement, and interbody fusion.

A method of tailoring a spinal implant to correspond to a specific patient's needs includes: pre-operatively evaluating a patient to determine a desired spinal segment response; and modifying one or more features of flexures of an implant to provide the desired spinal segment response. Modifying one or more features of flexures of the implant can include modifying one or more of a thickness, width, length and / or shape of the features of the flexures. Various systems for executing the methodologies taught herein are also provided.

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

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.

Artificial disc replacements (ADRs) and total disc replacements (TDRs) are based upon two, directly articulating components, resulting in a restricted-motion system that better approximates more normal spinal flexion, extension, and lateral bending. One component has a concave articulating surface, and the other with a convex articulating surface. The radius of curvature of the articulating surface is smaller in the anterior to posterior direction of the ADR than radius of curvature of the articulating surface in the left to right direction of the ADR. The use of an articulating surface with two or more radius of curvature also limits axial rotation, thereby protecting the facet joints and the Annulus Fibrosus (AF). The two different radii used to create the articulating surfaces also naturally leads to an oval shape as seen from the top, which better fits the oval shape of the vertebral endplate better than circularly shaped ADRs. Both components are preferably made of a hard material and are highly polished to reduce friction.

An intervertebral implant for implantation between an upper vertebra and a lower vertebra having a central axis. The implant may have a first member with a top surface for contacting at least a portion of the upper vertebra and a bottom surface as well as a second member with a top surface and a bottom surface for contacting at least a portion of the lower vertebra. An elastic spacer may be disposed between the first member and the second member. The bottom surface of the first member and the top surface of the second member may have a first constraint means and the other of the bottom surface of the first member and the top surface of the second member may be provided with a second constraint means, to limit the amount of lateral movement between the first and second members. Additionally, the constraint means may be sized and configured such that a gap with a width greater than zero is provided at least transversely to the central axis between the first and second constraint means in an unloaded state.

Devices for implantation within a Functional Spinal Unit (FSU) that can provide up to six independent degrees of freedom from a neutral position are provided. Such devices can comprise two endplates, a nucleus, a sled, and an optional, elastic boot attached to the endplates and enclosing the contents of the device, namely, the nucleus. The sled on one end of the nucleus can be moveably attached to one of the endplates and a spherical cap affixed to the opposite end of the nucleus can be operably engaged with the other endplate. The endplates can provide outer surface features that allow fusion of the plates to the superior and inferior vertebrae of a FSU and can prevent expulsion of the device immediately after implanting. The nucleus can have compliant elements or can be rigid. It can comprise a tripartite construction of three elements of possibly different materials that can be fitted together, or it can be a single unified element or can be a material with graded mechanical moduli axially and radially. The endplates and nucleus can maintain connection through the sled and the extension of the central core. Additionally, one or more specialized rotational joint stops can be utilized to provide profile-closure of the spherical joint between the top endplate and the spherical cap.

The present invention provides a next generation, closed profile, total disc replacement device with mechanical features designed to sustain, restrain and guide the larger motions required to preserve normal mechanical motion, while at the same time, providing a flexion component to guide and restrain the finer motions reached at the extremes of the mechanical motion preservation components.

An intervertebral implant for mounting between superior and inferior vertebrae includes first and second endplates and an inlay. The first endplate has a first vertebra engagement surface and a first inner surface. The first vertebra engagement surface is mounted to the superior vertebra in an implant positions. The second endplate has a second vertebra engagement surface and a second inner surface. The second vertebra engagement surface is mounted to the inferior vertebra in the implanted position. The inlay is mounted to and between the first and second inner surfaces in an assembled configuration. The inlay includes a first mounting plate, a second mounting plate, a first W-shaped spring and a second W-shaped spring. The first and second W-shaped springs are mounted between the first and second mounting plates. The first and second W-shaped springs have longitudinal axes that are generally parallel to the insertion axis.

An intervertebral implant for mounting between superior and inferior vertebrae includes first and second endplates and an inlay. The first endplate has a first vertebra engagement surface and a first inner surface. The first vertebra engagement surface is mounted to the superior vertebra in an implant positions. The second endplate has a second vertebra engagement surface and a second inner surface. The second vertebra engagement surface is mounted to the inferior vertebra in the implanted position. The inlay is mounted to and between the first and second inner surfaces in an assembled configuration. The inlay includes a first mounting plate, a second mounting plate, a first W-shaped spring and a second W-shaped spring. The first and second W-shaped springs are mounted between the first and second mounting plates. The first and second W-shaped springs have longitudinal axes that are generally parallel to the insertion axis.

Artificial disc replacements (ADRs) and total disc replacements (TDRs) are based upon two, directly articulating components, resulting in a restricted-motion system that better approximates more normal spinal flexion, extension, and lateral bending. One component may have a concave articulating surface, and the other a convex articulating surface. The radius of curvature of the articulating surface may be smaller in the anterior-to-posterior direction of the ADR than the radius of curvature of the articulating surface in the left-to-right direction of the ADR. Both components are preferably made of a hard material and are highly polished to reduce friction.