Provided is a bone fixator capable of reducing risks to a human body and having a simple structure. This fixator (10) is provided with: pedicle screws (12, 14) fixed to first and second mounted portions (24, 26) of a bone, respectively； first and second vibration members (16, 18)； and a rod (20). The first vibration member (16) is provided with a first screw (16a) comprising a right-hand thread, and fixed to the pedicle screw (12) so as to be able to vibrate. The second vibration member (18) is provided with a second screw (18a) comprising a left-hand thread, and fixed to the pedicle screw (14) so as to be able to vibrate. The rod (20) has a third screw (20a) at one end and a fourth screw (20b) at the other end. The third screw (20a) engages with the first screw (16a) and the fourth screw (20b) engages with the second screw (18a). The second vibration member (18), when receiving ultrasonic waves oscillated from the outside of the body, deforms while vibrating, and the rod (20) rotates while being pressed against by the second vibration member (18)； accordingly, the distance between the pedicle screws (12, 14), that is, the distance between the first and second mounted parts (24, 26) is increased or decreased.La présente invention concerne un fixateur d'os apte à réduire les risques au niveau d'un corps humain et présentant une structure simple. Ledit fixateur (10) comprend : des vis pédiculaires (12, 14) fixées respectivement aux premières et secondes parties montées (24, 26) d'un os ； de premiers et seconds éléments de vibration (16, 18) ； et une tige (20). Le premier élément de vibration (16) est muni d'une première vis (16a) comprenant un filetage droit, et fixé à la vis pédiculaire (12) afin de pouvoir vibrer. Le second élément de vibration (18) est muni d'une deuxième vis (18a) comprenant un filetage gauche, et fixé à la vis pédiculaire (14) afin de pouvoir vibrer. La tige (20) présente une troisième vis (20a) à une extrémité et une quatrième vis (20b) à l'autr
