Posterior dynamic stabilization device having a mobile anchor

摘要

A posterior dynamic spinal stabilization device utilizing a spinal rod, a fixed anchor, a mobile anchor adapted for both translation and pivoting, a mobile anchor-limiting stop affixed to the rod and an optional bumper-type, a rod with at least one limiting stop. It allows predetermined and prescribed interpedicular motion. It allows the use of traditional pedicle screw-rod placement techniques in a flexible system possessing many treatment options using familiar components that are familiar to the surgeon, and can be used on multiple levels (especially to top off) and can transition loads by limiting displacements.

主权项

1. A posterior dynamic spinal stabilization system comprising:
a) a rod having a first end and a second end, b) a mobile anchor having i) a shank and ii) a rod-receiving portion mated to the first end of the rod, wherein the rod-receiving portion is adapted to translate along the rod and pivot about the shank, the mobile anchor adapted for translation and pivoting along the rod after implantation,
c) a fixed anchor having i) a shank and ii) a rod-receiving portion locked to the second end of the rod, the fixed anchor adapted to lock to the second end of the rod after implantation, andd) a first motion limiting stop positioned on the rod at a location cranial to the mobile anchor, e) a set screw adapted to seat in the rod-receiving portion of the mobile anchor, the set screw comprising a low friction, upper bearing surface for bearing upon the rod and reducing wear generation, and f) lower bearing seated within the rod-receiving portion of the mobile anchor and having a surface adapted for receiving a rod, the surface possessing a low friction face that reduces wear generation,wherein the low friction surface of the lower bearing has an arcuate contact surface adapted for contacting the rod.