Abstract: A posterior dynamic stabilization system that allows a) elongation through a ligament connected to the bone anchors that ultimately reaches its full length to provide a secure flexion limit, and b) compression through a spacer positioned between bone anchors to provide an extension limit.

Abstract: A spine stabilization system having a dynamic screw comprises at least one bone anchor assembly comprising a receiver member and a bone engaging member pivotably connected to the receiver member. A bearing is provided in the receiver member that engages a portion of the bone engaging member. An elongated connecting member is connected to the receiver member. A retention member insert is provided within the receiver member between the elongated connecting member and the bearing. The retention member is configured to secure the bearing within the retention member.

Abstract: Methods and devices are provided for spinal fixation. In one exemplary embodiment, the methods and devices provide one or more points of fixation located adjacent to a first fixation point at which a bone anchor is implanted in bone. For example, an extension member can be coupled, either directly or indirectly, to a bone anchor, and a fastener can be used to anchor the extension member to bone at a second point of fixation adjacent to the first point of fixation. The second point of fixation can be effective to prevent rotation or other movement of the bone anchor, thereby stabilizing the bone anchor. The methods and devices are particularly useful for unilateral fixation, in which one or more levels of the spine are stabilized along a single lateral side of the spine.

Abstract: A spine stabilization system having a dynamic screw comprises at least one bone anchor assembly comprising a receiver member and a bone engaging member. In one embodiment, the bone engaging member is a screw shank extending from the receiver member. A rod is connected to the receiver member. In one embodiment, the rod comprises a ball-shaped member that engages a bearing surface provided within a cavity of the receiver member. In this embodiment, the rod is pivotably connected to the receiver member. In one such embodiment, a central axis defined by the rod pivots about a pivot point located on the central axis when the rod pivots relative to the receiver member. Accordingly, the pivot point for the rod may be provided within the cavity of the receiver member. The rod may be a fixed length or adjustable to accommodate different segmental units and patients of different sizes.

Abstract: Devices and methods are provided for replacing a spinal disc, and in particular devices and methods are provided that rely on buckling to control movement of adjacent vertebrae. In one embodiment, an artificial disc replacement implant is provided and includes an implantable body having a superior surface adapted to be positioned adjacent to an endplate of a superior vertebra, and an opposite inferior surface adapted to be positioned adjacent to an endplate of an adjacent inferior vertebrae. The implantable body includes at least one wall formed therein and extending between the superior and inferior surfaces. The wall(s) can be adapted such that, when the implantable body is disposed between the endplates of adjacent superior and inferior vertebrae, the wall(s) will buckle by moving laterally and shorting in height under a load applied thereto by movement of the adjacent vertebrae.

Abstract: Various methods and devices are provided for a facet replacement device. In one embodiment of the invention, a facet replacement device is provided and includes an elongate member matable to a first vertebra and a housing. The housing can have a connector formed thereon and matable to an adjacent second vertebra and an inner lumen formed therein. The housing can also include a deformable member disposed within the inner lumen and having an opening formed therein for slidably receiving at least a portion of the elongate member such that the elongate member can be angularly oriented relative to a longitudinal axis of the lumen.

Abstract: Various methods and devices are provided for bone screw fixation. In one exemplary embodiment, the methods and devices provide a bone fixation device that includes a receiving head having a recess adapted to seat a spinal rod therein and a shank extending distally from the receiving head. An anti-rotation mechanism can be located distal of a distal end of the receiving head and around a proximal portion of the shank, and it can be configured to interact with bone to prevent rotation of at least a portion of the bone fixation device relative to the bone.

Abstract: A multi-level spine stabilization system comprises a plurality of securing members configured for attachment to a plurality of vertebrae. A plurality of adjustable rods segments extend between the plurality of securing members. The adjustable rod comprises a first rod segment that engages a second rod segment in an adjustable relationship. The length of the rod may be adjusted by moving the first rod segment relative to the second rod segment. For example, the first rod segment may be in a slideable relationship with the second rod segment such that sliding the first rod segment relative to the second rod segment results in a change in the length of the rod. In one embodiment, portions of both the first rod segment and the second rod segment are positioned within and secured to the securing member. Advantageously, the multi-level spine stabilization system described herein may be used to center dynamic portions of the rod between securing members.

Abstract: Various methods and devices are provided for stabilizing adjacent vertebrae in a patient's spinal column. In one exemplary embodiment, a spinal stabilization device is provided having a first cross-connector that is adapted to mate to opposed lateral sides of a first vertebra, a second cross-connector that is adapted to mate to opposed lateral sides of a second vertebra, and a flexible member that is coupled to the first and second cross-connectors and that is adapted to allow movement between first and second adjacent vertebrae coupled to the first and second cross-connectors.

Abstract: Various methods and devices are provided for implanting a motion segment repair system. In particular, exemplary methods and devices are provided for implanting a spinal disc implant and/or a PDS device using a posterior surgical approach, including methods and devices for distracting adjacent vertebrae using a posterior surgical approach, methods and devices for posteriorly introducing a spinal implant into a disc space between adjacent vertebrae, and methods and devices for coupling a PDS device to the adjacent vertebrae to provide a complete motion segment repair system that is implanted using a posterior surgical approach.

Abstract: Various methods and devices are provided for stabilizing the posterior elements of the spine, and more preferably methods and devices are provided for sharing the load with the intervertebral disc, the facet joints, the ligaments, and the muscles of the spinal column. In certain exemplary embodiments, methods and devices are provided for substantially controlling or providing resistance to movement, e.g., flexion, extension, lateral bending, and/or axial rotation, of the adjacent vertebrae.

Abstract: Various methods and devices are provided for stabilizing the posterior elements of the spine, and more preferably methods and devices are provided for sharing the load with the intervertebral disc, the facet joints, the ligaments, and the muscles of the spinal column. In certain exemplary embodiments, methods and devices are provided for substantially controlling or providing resistance to movement, e.g., flexion, extension, lateral bending, and/or axial rotation, of the adjacent vertebrae.

Abstract: Various methods and devices are provided for stabilizing the posterior elements of the spine, and more preferably methods and devices are provided for sharing the load with the intervertebral disc, the facet joints, the ligaments, and the muscles of the spinal column. In certain exemplary embodiments, methods and devices are provided for substantially controlling or providing resistance to movement, e.g., flexion, extension, lateral bending, and/or axial rotation, of the adjacent vertebrae.

Abstract: Various methods and devices are provided for stabilizing the posterior elements of the spine, and more preferably methods and devices are provided for sharing the load with the intervertebral disc, the facet joints, the ligaments, and the muscles of the spinal column. In certain exemplary embodiments, methods and devices are provided for substantially controlling or providing resistance to movement, e.g., flexion, extension, lateral bending, and/or axial rotation, of the adjacent vertebrae.

Abstract: Various methods and devices are provided for stabilizing the posterior elements of the spine, and more preferably methods and devices are provided for sharing the load with the intervertebral disc, the facet joints, the ligaments, and the muscles of the spinal column. In certain exemplary embodiments, methods and devices are provided for substantially controlling or providing resistance to movement, e.g., flexion, extension, lateral bending, and/or axial rotation, of the adjacent vertebrae.

Abstract: Various methods and devices for replacing damaged, injured, diseased, or otherwise unhealthy posterior elements, such as the facet joints, the lamina, the posterior ligaments, and/or other features of a patient's spinal column, are provided. In one exemplary embodiment, the methods and devices are effective to mimic the natural function of the spine by allowing flexion, extension, and lateral bending of the spine, while substantially restricting posterior-anterior shear and rotation of the spine.

Abstract: Various methods and devices for replacing damaged, injured, diseased, or otherwise unhealthy posterior elements, such as the facet joints, the lamina, the posterior ligaments, and/or other features of a patient's spinal column, are provided. In one exemplary embodiment, a posterior implant is provided and it can be adapted to control movement of two or more adjacent vertebrae. In particular, the implant can be adapted to control extension, flexion, and lateral bending of the adjacent vertebrae. The implant can also be adapted to substantially prevent rotation of the adjacent vertebrae. In another exemplary embodiment, the implant can have an envelope of motion that is within an envelope of motion of a disc, either natural or artificial, that is disposed between the adjacent vertebrae. In other words, the implant can be configured to allow flexion, extension, lateral bending of the vertebrae to within the amount of flexion, extension, and lateral bending allowed by the particular disc.

Abstract: Various methods and devices for replacing damaged, injured, diseased, or otherwise unhealthy posterior elements, such as the facet joints, the lamina, the posterior ligaments, and/or other features of a patient's spinal column, are provided. In one exemplary embodiment, the methods and devices are effective to mimic the natural function of the spine by allowing flexion, extension, and lateral bending of the spine, while substantially restricting posterior-anterior shear and rotation of the spine.

Abstract: A posterior stabilization device is provided for controlling movement between adjacent vertebrae. In one exemplary embodiment, the stabilization device can include one or more joints that rely on rotational or sliding movement to allow flexion of adjacent vertebrae, and that control extension, lateral bending, axial rotation, and anterior-posterior shear, preferably by providing one or more flexible connectors and/or a flexible central spacer for connecting to the adjacent superior and inferior vertebrae.

Abstract: Various methods and devices for replacing damaged, injured, diseased, or otherwise unhealthy posterior elements, such as the facet joints, the lamina, the posterior ligaments, and/or other features of a patient's spinal column, are provided. In certain exemplary embodiments, a four bar linkage mechanism can be used to construct spinal stabilization devices and methods for restoring function to adjacent vertebrae. In particular, spinal stabilization devices can be provided that kinematically form a four-bar linkage mechanism with adjacent vertebrae and a disc or other element disposed between the adjacent vertebrae.