The invention describes an external fixator formed by a curved elastic bar with an essentially C shape which serves to immobilize pelvic fractures. It also describes a turnbuckle for opening said external fixator comprising two side support elements for the ends of the external fixator and a central support element for the central part of the external fixator, where the central support element is longitudinally movable along a line perpendicular to the line joining said side support elements.
