US Patent 8679117 Bolt and tool with anti-torque features

A system for fixing a wire to a surface of an external fixator having a wire adapted to extend through bony structure fastened with respect to the surface. A bolt having a shaft which comprises a threaded section, a head section and at least one clamping element is provided wherein the bolt is adapted to extend through an opening in the external fixation element with a nut, and clamps the wire to the surface. A counter torque tool is used to provide a counter torque while fastening the wire with the bolt and the nut. The bolt comprises a counter torque opening and wherein the counter torque tool comprises a section which is adapted to engage into the counter torque opening of the bolt to apply the counter torque.