A flexible connection unit for use in a spinal stabilization device, comprising a longitudinal member having first and second end portions and a flexible portion located between the end portions, wherein the flexible portion comprises at least one spacer and a flexible member located in a longitudinal axial channel of the at least one spacer, wherein the flexible member comprises a biocompatible metal material and the end portions maintain the at least one spacer in a substantially fixed longitudinal axial position with respect to the flexible member.