Patent ID: 8172879
Filing Date: 2012-05-08
Classification: A61B

Abstract:
1. A spinal rod comprising: a rod tube formed of a biocompatible material; a spring rod formed of a biocompatible material and having a spring rod portion disposed in the rod tube, the spring rod portion axially movable within the rod tube whereby application of an axial force on the spring rod portion creates axial movement of the spring rod relative to the rod tube causing the spring rod and the rod tube to flex and arch; and a spacer ring radially disposed between the rod tube and the spring rod; at least two secondary spacer rings situated between the spring rod portion and the rod tube and axially adjacent each side of the spacer ring, wherein each one of the secondary spacer rings comprises a curved outer surface having a concave curvature extending inward toward a midpoint of the secondary spacer ring.