Abstract: A prosthesis for the replacement of at least a portion of the bone of a facet located on a mammalian vertebra, comprising: an articulating surface that articulates with another facet; a bone contacting surface that contacts a surface of the vertebra, the articulating surface being connected to the bone contacting surface; and a fixation element that attaches the bone contacting surface to the vertebra, the fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra; wherein the prosthesis is configured so that no portion of the prosthesis contacts the posterior arch of the vertebra.

Abstract: A cement-directing structure for use in cement-injection bone therapy includes a collapsible, self-restoring braided structure with regions of differential permeability to the bone cement. The regions of differential permeability may be provided by areas where the braided mesh density is greater or lesser than surrounding areas and/or by means of a baffle. After the structure is placed in a void within a bony structure, cement is injected into the interior of the structure then oozes out in preferred directions according to the locations of the regions of differential permeability.

Abstract: A system for replacing at least a portion of a natural facet joint includes a fixation member implantable in a vertebra, an inferior facet articular surface and an inferior strut which may be formed separately from the inferior articular surface. The inferior strut has a first end securable to the fixation member and a second end which may comprise a sphere with a hemispherical surface. An attachment mechanism may include a capture feature shaped to receive the second end of the inferior strut, and the mechanism may provide an adjustable configuration, allowing polyaxial adjustment between the inferior articular surface and the second end. A locking member may be actuated to exert force on the second end to provide a locked configuration. The system may further include a superior facet joint implant with a superior articular surface shaped to articulate with the inferior articular surface.

Abstract: Cephalad and caudal vertebral facet joint prostheses and methods of use are provided. The cephalad prostheses are adapted and configured to be attached to a lamina portion of a vertebra without blocking a pedicle portion of the cephalad vertebra.

Abstract: The invention relates to a method of creating a curvilinear cavity within a vertebral body or other bony structure. The invention also relates to devices that may be used to perform the steps to create the curvilinear cavity. In one embodiment, a method of forming a curvilinear void in bony structure may include the steps of accessing a bony structure with a cannula, inserting a distal end of a drill device through the cannula and into the bony structure, manipulating the distal end of the drill device to create a curvilinear void in the bony structure, enlarging the void by expansion of a balloon element mounted to the drill device, and deflating the balloon element and removing the drill device from the cannula.

Abstract: A bone filler mixing and delivery device includes a mixing section adapted to mix components to form bone filler. A syringe barrel is coupled to the mixing section and has an opening through which the bone filler can be dispensed. A controllable portal can be manipulated to open a flow path between the mixing section and the syringe barrel. A plunger assembly is adapted to extend telescopically in an axial direction through the syringe barrel to dispense the bone filler through the opening.

Abstract: The invention relates to a cement director for insertion within a vertebral body or other body structure, and related methods of use. An example method includes creating a cavity in a vertebral body, inserting a collapsible mesh structure into the cavity in a collapsed state, wherein the collapsible mesh structure comprises regions of different permeability to a bone cement, inflating a balloon within the collapsible mesh structure to expand the mesh structure, and injecting a bone cement into the mesh structure, wherein the bone cement flows preferentially out of the mesh structure through at least one region of greater permeability.

Abstract: Superior and/or inferior facets of one or more facet joints may be replaced by superior and/or inferior facet joint prostheses. In one embodiment, a kit of superior or inferior prostheses is provided, in which the prostheses have at least two dimensions that vary among members of the kit independently of each other. Each prosthesis may have a bone engaging surface having a surface that is polyaxially rotatable against a corresponding resection of a vertebra. Each prosthesis may also have an articulating surface shaped such that, after attachment to the spine, the replaced or partially replaced facet joints provide a larger medial-lateral range of motion when the spine is flexed than when the spine is extended. Crosslinks may be used to connect left and right prosthesis together in such a manner that they are stabilized in a position in which they are seated directly against the vertebra.

Abstract: 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.

Abstract: A facet joint replacement system includes an inferior implant with an inferior articular surface, and a superior implant with a superior articular surface. The implants may be coupled together by a detachable coupler which can align and rigidly hold the inferior and superior articular surfaces in a preferred alignment relative to one another. A portion of the coupler may be deformable to allow detachment of the coupler from at least one of the implants. In one method of implantation, the superior and inferior implants may be aligned and coupled together with the coupler, and then secured to fixation members anchored in adjacent vertebrae. Alternatively, a first implant may be secured to a fixation member anchored in a first vertebra, and a second implant coupled to the coupler, aligned with the first implant and then secured to a fixation member anchored in a second vertebra.

Abstract: The present invention provides tools and methods designed to aid in the placement of artificial facet joints at virtually all spinal levels. One aspect of the present invention is a measurement tool for installing an artificial cephalad facet joint including a fixation measurement element and a support arm element. This measurement tool assists in the selection and/or configuration of an artificial cephalad facet joint for implantation in a patient. Another aspect is a measurement tool for installing a caudad facet joint including a stem element and a trial caudad bearing surface element. This measurement tool assists in the selection and/or configuration of a caudad facet joint for implantation in a patient. Yet another aspect is a measurement tool holder including a measurement surface connected to a holder element. This tool holder assists in determining the measurements obtained with the caudad facet joint measurement tool.

Abstract: Prostheses, systems, and methods are provided for replacement of natural facet joints between adjacent vertebrae using polyaxial attachment mechanisms for securing the prostheses to the vertebrae. A cephalad prosthesis attached to a superior adjacent vertebra replaces the inferior half of a natural facet joint. A caudal prosthesis attached to an inferior adjacent vertebra replaces the superior half of a natural facet joint. Both the cephalad and caudal prostheses are configured with artificial facet joint structures that include articulating surfaces that cooperate and form an artificial articular configuration. The polyaxial attachment mechanism permits adjustment of the position of the artificial facet joint structure along more than one axis at or after the time the cephalad or caudal prosthesis is attached to a vertebra.

Abstract: A system includes an implant with an articulation surface, a fixation member which may be anchored in a bone, and a base portion which may receive the fixation member. The base member may comprise a bone-engaging portion and an attachment portion. The base member may receive the fixation member such that a threaded portion of the fixation member and the bone-engaging portion of the base member may be seated in the bone. The implant may be attached to the attachment portion of the base member. The base member may be configured in a variety of shapes and may include fins, teeth, pegs or other anti-rotation features, and may include a bone ingrowth surface. The attachment portion may be tapered and attachable to the implant through a taper-lock.

Abstract: 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.

Abstract: Modular spinal prosthesis having one of both of adaptable and configurable components are provided. The modular spinal prosthesis described herein provide an artificial articular configuration to replace damaged, worn or otherwise removed spinal facet elements.

Abstract: An apparatus is designed to attach an implant to bone in a manner that permits rotational adjustment of the implant about multiple axes prior to securement via the apparatus. The apparatus includes separate rotational and translational fasteners that can be individually locked to independently restrict rotation and translation of the implant relative to the bone. The rotational fastener includes an interpositional member, an expandable engagement member, and a rotational locking member that urges the expandable engagement member to advance along the interpositional member. The resulting expansion of the engagement member causes it to engage the implant. The rotational fastener is slidable along a fixation member implanted in the bone until the translational fastener is applied to restrict relative translation between the rotational fastener and the bone.

Abstract: Superior and/or inferior facets of one or more facet joints may be replaced by superior and/or inferior facet joint prostheses. In one embodiment, a kit of superior or inferior prostheses is provided, in which the prostheses have at least two dimensions that vary among members of the kit independently of each other. Each prosthesis may have a bone engaging surface having a surface that is polyaxially rotatable against a corresponding resection of a vertebra. Each prosthesis may also have an articulating surface shaped such that, after attachment to the spine, the replaced or partially replaced facet joints provide a larger medial-lateral range of motion when the spine is flexed than when the spine is extended. Crosslinks may be used to connect left and right prosthesis together in such a manner that they are stabilized in a position in which they are seated directly against the vertebra.

Abstract: Superior and/or inferior facets of one or more facet joints may be replaced by superior and/or inferior facet joint prostheses. In one embodiment, a kit of superior or inferior prostheses is provided, in which the prostheses have at least two dimensions that vary among members of the kit independently of each other. Each prosthesis may have a bone engaging surface having a surface that is polyaxially rotatable against a corresponding resection of a vertebra. Each prosthesis may also have an articulating surface shaped such that, after attachment to the spine, the replaced or partially replaced facet joints provide a larger medial-lateral range of motion when the spine is flexed than when the spine is extended. Crosslinks may be used to connect left and right prosthesis together in such a manner that they are stabilized in a position in which they are seated directly against the vertebra.

Abstract: A facet joint replacement system includes an inferior implant with an inferior articular surface, a superior implant with a superior articular surface, and an optional crossbar. The inferior implant and the superior implant are each polyaxially adjustably connected to fixation elements which anchor the implants to adjacent vertebrae. The optional crossbar may be polyaxially adjustably connected to bilateral implants. The system components may be provided in kits which provide components of various sizes and shapes. A set of surgical instruments may facilitate implantation of the facet joint replacement system by providing tools for bone preparation, trialing, implant insertion, implant alignment, and lock-out of modular interconnections.

Abstract: A fixation system is designed to lock an elongated member within a housing member, permitting positional and/or orientational adjustment of the elongated member prior to locking. The system includes a housing member, a slotted spherical collet, an elongated member, and may include a tapered wedge, which may be a discrete component or formed as part of the elongated member. The housing member and/or elongated member may be implantable. The elongated member may be positioned in the wedge, the wedge in the collet, and the collet in the housing such that when compression force is applied to the wedge and the collet, the wedge contracts about the elongated member and the collet expands to engage the housing, thus locking the elongated member relative to the housing. The collet may have a tapered channel with a degree of taper equal to the tapered wedge. The collet may have multiple slots to allow uniform radial expansion and compression.