A method for osteosynthesis of a spinal column using an assembly including at least a bone anchor, a ring, a connecting member, and a connector, the method including assembling the bone anchor and ring in the connector positioning an anchoring part of the bone anchor in bone assembling the connecting member in the connector such that the bone anchor, ring and connecting member are arranged to be tightened against each other in the connector and tightening of the assembly by applying a force on the connecting member such that the connecting member contacts the ring and a head of the bone anchor.
