US Patent 9445844 Composite material posterior dynamic stabilization spring rod

The present invention provides a Posterior Dynamic Stabilization (PDS) device that allows elongation, which is a critical requirement for a PDS device as it allows pedicles to travel naturally in flexion, extension, and lateral bending of the spine. This interpedicular travel preserves a more natural center of rotation unlike other PDS devices that simply allow bending. In particular, the invention involves a PDS spring rod, wherein the helix is created with composite flow molding (CFM) technology and comprises a polymer matrix reinforced with continuous carbon fibers, wherein the fibers are oriented substantially parallel to the centerline of the helix, thereby creating a high strength spring.