A vertebral rod assembly comprises first and second members (12, 14) that may rotate about a first axis (Rl). Each of the first and second members includes a base (18, 36) and a vertebral support rod (16, 34) extending from the base. An extension (24, 26) extends from the base (18) on the first member (12) into an opening (40, 74) formed in the base (36) of the second section (14). A fastener (44) extends through the base of the second member to lock the first and second members, and to prevent the rotation of the first member and second member.
