Disclosed are methods and apparatus for the provision of spinal therapy to two or more adjacent motion segments accessed through a trans-sacral approach. This is the case whether the method of implant deployment is by an anterior (preferred), or a posterior approach, and it will be understood that references to anterior approaches, while preferred, are for convenience only, and that both pre-sacral anterior and posterior approaches and subsequent trans-sacral axial stabilization methods and devices afford significant advantages over current practice, including: the patient is in a prone position that is easily adaptable to other posterior instrumentation; blood loss is minimal; soft tissue structures, e.g., veins, arteries, nerves are preserved, and substantially less surgical and anesthesia time is required compared with conventional procedures; the implants of the present disclosure are intended to preserve or restore function, not merely alleviate pain.The spinal therapies include fusion and dynamic stabilization with and without a distraction of the most cephalad motion segment of the two or more... The objects, advantages and features of the present disclosure presented above are merely exemplary of some of the ways the disclosure overcomes difficulties presented in the prior art, and are not intended to operate in any manner as a limitation on the interpretation of the disclosure. Applicants believe the advantage of adjusting distraction between and among successive adjacent vertebral bodies within multiple motion segments at various spinal levels, as just described, of the inventive multi-level axial stabilization assembly systems described herein to be unique, i.e., that no other (known) current spinal therapies are able to achieve across a plurality of adjacent motion segments distraction/decompression and stabilization/motion management, including combinations of progression-of-treatment options, leading to discogenic pain relief. Transition syndrome refers to altered biomechanics and kinematics of contiguous vertebral levels and concomitant risk of adjacent motion segment instability that may occur as a result of spinal therapeutic procedures that are suboptimal in terms of their ability to restore physiological function and properties, and thus risk a cascading deleterious effect on surrounding otherwise healthy tissue.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. 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).
wherein the first assembly comprises a first set of male threads for engagement with a distal vertebral body and a second set of male threads with the same handedness for engagement with a less distal vertebral body. The previously unfulfilled needs to provide therapy to two or more adjacent motion segments accessed through a trans-sacral approach are addressed by the present disclosure. 6,921,403 “Method and Apparatus for Spinal Distraction and Fusion” issued on Jul. The PNDs of the present disclosure do not adversely impact the stiffness of the motion segment being treated. Moreover, in one aspect, the PND provides anterior-posterior translation and has a mobile ICOR. It is a further object of the present disclosure to provide axial spinal devices and assemblies, as well as instrumentation and methods for their deployment, which collectively comprise an axial spinal stabilization system, in particular, for the anterior lumbar spine, capable of distracting and treating multiple vertebral bodies and adjacent motion segments at multiple levels of the spine via fixation; motion management; or both static and dynamic stabilization, by means of a minimally invasive, pre-sacral surgical approach and trans-sacral deployment and axial orientation of the spinal devices and assemblies through the vertebral bodies, in a manner that does not compromise the annulus and adjacent tissues. 22, 2004 incorporated herein in their entirety into this disclosure by reference, as alternative options to or together with fixation rods facilitating fusion of the vertebral bodies, to selectively achieve motion management rather than elimination of motion with respect to a targeted plurality of motion segments within multiple spinal levels. It is another object of the present disclosure to preserve biomechanical function and eliminate chronic pain by facilitating successful fusion of motion segments within multiple levels of the spine by means of axially-deployed, differentially threaded (anchored) spinal fixation assemblies that provide adjustable distraction to restore normal intervertebral disc height among a plurality of adjacent motion segments and that achieve stabilization in closer proximity to the instantaneous center of rotation around the vertical axis of the spine, advantages not afforded by other current spinal fusion systems. 10/972,184, 10/972,039, 10/972,040, and 10/972,176, all of which were filed on Oct.
Additionally, due to the axial delivery of the implant via a protected channel, there is no retraction of muscles and no exposure to major vessels or soft tissue as with the delivery system for systems delivered from other surgical approaches.