Abstract: A rod, such as that used for spinal stabilization, made of both metal material and elastomeric material. The rod may have a metal infrastructure, which may be non-cylindrical, to provide a desired stiffness for bending in at least one direction and may also have metal exterior surfaces for engaging metal components of spinal fixation locking mechanisms. In addition, the elastomeric material may only partially circumferentially encapsulate the metal material so that the metal material forms part of the surface of the rod.