The disclosure includes methods and apparatus to impart a push distraction to increase the distance between two adjacent vertebrae. In some instances there may be a need to provide therapy to both the L5/sacrum intervertebral space but also to the adjacent superior L4/L5 space and to do so in a manner that requires independent control over the amount of distraction applied to each space.

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wherein a selected distraction is provided to the first motion segment through use of a threaded rod engaged with both the first vertebral body and an adjacent and more cephalad vertebral body through use of dissimilar thread pitch on threaded sections of the threaded rod. The leading edge 324 of the thread for the proximal threaded section grows from the minor diameter to the major diameter of the threaded section.

This application claims priority and incorporates by reference and commonly assigned U. The cavity 304 of the distal distraction rod 300 includes several apertures 332 that extend radially outward at the waist 316.

In this manner, devices are able to provide both stable anterior and posterior load support (e.g., loads that may approximate 10 times the body weight of a patient) and adequate medial-lateral and rotational support, without adjunctive posterior instrumentation and without accompanying osteogenesis.

More specifically, yet another advantage of the present disclosure is the concurrent implementation of a combination of therapies, i.e., deployment of spinal assemblies are disclosed that enable dynamic stabilization via implantation of one or more prosthetic nucleus devices or other mobility preservation/restoration devices, such as those disclosed and described previously in and commonly assigned U. MM devices (also referred to as mobility devices) decompress the disc and alleviate pain caused by nerve impingement, usually posterior, by means of either inducing slight segmental kyphosis (introduction of added convex curvature through increasing the height on the posterior side of the disc more than on the anterior side of the disc) or straight elevation, and by creating limits and resistance to segmental motion.

It is another object of the present disclosure to provide a spinal PND (prosthetic nucleus device) which preferably does not impede the mobility of, and is responsive to the physiological ICOR (instantaneous center of rotation).

Hence, in accordance with this aspect of the present disclosure, the mobility device assembly comprising one or more flexible member(s), in combination with at least one anchor portion(s), may be configured from among these design concepts and embodiments, including: helical flexure (flexible coupler) designs, comprising one-piece or two-piece devices that may be configured with or without an integral, elastomeric or elastic inflatable, i.e., expandable, membrane that serves to maximize surface area over which loads are distributed, and that may or may not assist in distraction; cable designs, comprising one piece of fixed length, with or without an inflatable membrane, or two or more parts of variable length; ball and track multi-part designs; “stacked washer” designs, and anchored nuclear replacements.

further comprising fusing a first motion segment comprising the first vertebral body, the first intervertebral space, and the second vertebral body after distraction of the first motion segment including insertion of material into the first intervertebral space through the first assembly wherein the material inserted into the first intervertebral space promotes fusion. 13, 2005 for Methods and Apparatus for Provision of Therapy to Adjacent Motion Segments. The use of dissimilar thread pitches allows for the controlled distraction of two vertebral bodies ( elements 404 and 408) when the distal threaded section 308 is engaged with a distal vertebral body 404 and the proximal threaded section 312 is engaged with the medial vertebral body 408. As rotation in one direction causes distraction, rotation in the opposite direction causes compression.

wherein the second assembly is used to in provisional of dynamic stabilization a first motion segment comprising the first vertebral body, the first intervertebral space, and the second vertebral body and material is inserted into the first intervertebral space to expand a flexible portion of the second assembly. Through the '655 application, this application claims priority and incorporates by reference U. The use of dissimilar thread pitches to distract vertebral bodies within a single motion segment is described in co-pending and commonly assigned U. The preferred embodiments of distal axial rod 300 include a chip breaker section 320 to facilitate screwing the distal end of the distal distraction rod into the distal vertebral body.

It is another object of the present disclosure to provide spinal axial stabilization system assemblies as disclosed herein that restore normal intervertebral disc height by distracting vertebral bodies within and among a plurality of adjacent motion segments, and to achieve mechanical stability of the joint by augmenting or replacing prosthetic nucleus material to distribute physiologic loads and/or managing motion in said spinal segments to eliminate chronic pain.