The present invention relates to a medical fastening system for fastening a medical marker device to an anatomical body part, the fastening system comprising:a) a base part comprising a holding unit for holding the marker device andb) a connecting part (5) for connecting the base part to the anatomical body part, characterized in thatc) the base part comprises a fastening unit for fastening the connecting part to the base part so that the base part remains rotatable relative to the connecting part.
