This invention improves upon prior art 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 partial hip prosthesis for reducing friction and wear in partial hip prosthesis by combining optimized geometry of the articulation and surface treatment of the prosthetic component. In the prosthesis, one of the articulating surfaceseither that of the reamed acetabulum, or that of the femoral head prosthesis is a-spherical so that a fluid-filled gap is formed at the area of major load transfer. The fluid-filled gap is sealed by an annular area of contact, over which the concave and the convex components are congruent. A prosthetic head is fixed to the femur by either a conventional stem, a perforated shell, or a femoral neck prosthesis screwed onto the femur so that it is partially covered by bone and partially exposed on the medial-inferior aspect, where it abuts the reamed cortex of the calcar region.

This invention improves upon prior art 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 prosthetic joint includes: (a) a first member comprising rigid material and having a perimeter flange defined by an undercut groove, the flange defining a wear-resistant first contact surface having a protruding rim; (b) a second member comprising rigid material and having a perimeter flange defined by an undercut groove, the flange defining a wear-resistant, second contact surface having a protruding rim; and (c) a third member comprising rigid material positioned between the first and second members, the third member defining opposed wear-resistant third and fourth contact surfaces; (d) wherein the first and second contact surfaces bear against the third and fourth contact surfaces, to transfer loads through the member, while allowing pivoting motion between the first and second members; (e) wherein the flanges can deform elastically such that the first and second contact surfaces conform to the third and fourth contact surfaces.

Composites having a substrate, a diamond film, and a metal boride film disposed between the substrate and the diamond film, together with methods for producing the composites.

An expandable interbody device used as a prosthesis during spinal surgery. The expandable interbody device is configured to be inserted into the space between spinal discs to provide stability. The expandable interbody device includes a drive block, a top endplate, a bottom endplate, a first drive arrangement, and a second drive arrangement; the first drive arrangement includes a first drive screw, a first left side slide, a second left side slide, a first upper left side linkage, a second upper left side linkage, a first lower left side linkage age and a second lower left side linkage; and the second drive arrangement includes a second drive screw, a first right side slide, a second right side slide, a first upper right side linkage, a second upper right side linkage, a first lower right side linkage and a second lower right side linkage.

An expandable interbody device used as a prosthesis during spinal surgery. The expandable interbody device is configured to be inserted into the space between spinal discs to provide stability. The expandable interbody device includes a drive block, a top endplate, a bottom endplate, a first drive arrangement, and a second drive arrangement; the first drive arrangement includes a first drive screw, a first left side slide, a second left side slide, a first upper left side linkage, a second upper left side linkage, a first lower left side linkage age and a second lower left side linkage; and the second drive arrangement includes a second drive screw, a first right side slide, a second right side slide, a first upper right side linkage, a second upper right side linkage, a first lower right side linkage and a second lower right side linkage.