An expandable spacer, comprising: an axial tube having a surface, a proximal end and a distal end and a length, wherein, said surface defines a plurality of slits, said plurality of slits defining at least two axially displaced extensions, such that when said tube is axially compressed, said extensions extend out of said surface and define a geometry of an expanded spacer. Preferably the spacer is adapted to be inserted between two spinal vertebrae of a human.

A prosthesis for the replacement of multiple diseased or traumatized spinal facets comprises a portion that replaces at least a bony portion of the facets to be replaced and where the prosthesis attaches to the vertebra in a manner that does not require attachment to, or abutment against, the lamina. Multiple configurations of the prosthesis provide for replacement of the two inferior facets, the two superior facets, a superior and inferior facet, or all four facets. A method of installing the prosthesis is provided that is comprised of the steps of resecting at least a portion of the facets that carry the diseased or traumatized spinal facets and attaching the prosthesis in a manner that does not require attachment or abutment against the lamina.

A polymeric material comprised of (i) at least one random copolymer comprised of ethylene oxide and one or more other alkylene oxide(s) and (ii) at least one non-random polymer comprised of one or more poly(alkylene oxide)s has been discovered. Preferably, it is a polymer alloy. Alkylene oxide homo-polymers or block copolymers may be the non-random polymer. In a related discovery, an adhesive material can be made by suspending (a) particles in (b) a matrix of at least one poly(ethylene oxide) copolymer of ethylene oxide and propylene oxide, or a combination thereof. The handling characteristics may be adjusted for different utilities (e.g., from runny oil to hard wax). Applications include use as adhesive, cohesive, filler, lubricant, surfactant, or any combination thereof. In particular, the hard materials may be used for cleaning or waxing.

A prosthesis for the replacement of multiple diseased or traumatized spinal facets comprises a portion that replaces at least a bony portion of the facets to be replaced and where the prosthesis attaches to the vertebra in a manner that does not require attachment to, or abutment against, the lamina. Multiple configurations of the prosthesis provide for replacement of the two inferior facets, the two superior facets, a superior and inferior facet, or all four facets. A method of installing the prosthesis is provided that is comprised of the steps of resecting at least a portion of the facets that carry the diseased or traumatized spinal facets and attaching the prosthesis in a manner that does not require attachment or abutment against the lamina.

A prosthesis replaces all or a portion of a natural facet joint on a vertebral body. The prosthesis has a prosthesis body accommodating fixation to the vertebral body at or near a pedicle and without support by a lamina. The prosthesis body has a fastening element installed within the vertebral body at or near a pedicle. The prosthesis further has an artificial facet joint structure carried by the prosthesis body at a location spaced from the fastening element. The artificial facet joint structure is adapted and configured to replace all or a portion of a natural facet joint.

A prosthesis for the replacement of multiple diseased or traumatized spinal facets comprises a portion that replaces at least a bony portion of the facets to be replaced and where the prosthesis attaches to the vertebra in a manner that does not require attachment to, or abutment against, the lamina. Multiple configurations of the prosthesis provide for replacement of the two inferior facets, the two superior facets, a superior and inferior facet, or all four facets. A method of installing the prosthesis is provided that is comprised of the steps of resecting at least a portion of the facets that carry the diseased or traumatized spinal facets and attaching the prosthesis in a manner that does not require attachment or abutment against the lamina.

A prosthesis replaces all or a portion of a natural facet joint on a vertebral body. The prosthesis has a prosthesis body accommodating fixation to the vertebral body at or near a pedicle and without support by a lamina. The prosthesis body has a fastening element installed within the vertebral body at or near a pedicle. The prosthesis further has an artificial facet joint structure carried by the prosthesis body at a location spaced from the fastening element. The artificial facet joint structure is adapted and configured to replace all or a portion of a natural facet joint.