Embodiments disclosed herein provide a method of placing a vertebral fixing system on a vertebra. The vertebral fixing system comprises a connecting part with members forming a space into which a rod may be inserted. The members are moveable relative to each other. A portion of a ligature may be passed through the connecting part to form a loop extending from the connecting part. When the rod is inserted in the space between the members, the ligature may be tensioned against the rod. The members of the connecting part may be driven together to hold the ligature in place. An adjustable locking means may be utilized to fix simultaneously in position the connecting part relative to the rod and at least one portion of the ligature relative to the connecting part, so as to prevent relative displacement of the rod and the vertebra in opposite directions.