The fixing system to be installed on a vertebra of the spinal column in order to connect it to a rod (10) comprises a connection piece (12) located opposite the rib. A link (42) connects the connection piece and a rib. Adjustable locking means (36) integral with the connection piece are able to simultaneously hold in a fixed position the connection piece relative to the rod and a portion of the link relative to the connection piece so as to lock the relative movement of the rod and the vertebra in opposite directions to each other.
