The system has an anchoring base (112) inserted in housing of a bone structure along a direction perpendicular to bottom of the housing. An anchoring unit e.g. cam (210), projects from the base in a parallel manner to the bottom to engage with a side wall of the housing. The cam is movably mounted on an anchoring arm (230) of the base to pivot about a rotational axis parallel to the insertion direction of a cranial connection assembly in the housing. The assembly is formed of a percutaneous connector (110) and an electrical connection unit (120) i.e. subcutaneous cranial connection case.
