Abstract: A device to monitor penetration of an instrument in an anatomical structure including at least two electrodes, a source of current supplying the at least two electrodes, and means for measuring impedance between the electrodes, wherein the electrodes are located on the penetration instrument, wherein the first electrode has a contact surface coinciding with a distal surface of the penetration instrument and the second electrode has a contact surface coinciding with a lateral surface of the penetration instrument, and wherein the contact surfaces are dimensioned to have a coinciding and constant contact surface as a function of a degree of penetration of the penetration instrument in the anatomical structure.

Abstract: The disclosure relates an implant for placement in an anatomical structure including at least two electrodes separated by an insulator, the electrodes being flush with the surface of the implant to allow the implant to be followed up and guided during insertion in the anatomical structure.

Abstract: A connecting element for a spinal fixing system that connects at least two implantable connection assemblies including a rod including a flexible part extended at one end at least by a rigid part, the flexible part including a cable at least partly surrounded by a polymer envelope, the cable including at least one elastic strand coaxial with the envelope.