The disclosure relates to a device for establishing an anatomical reference point of an intervertebral disc for the attachment of at least one instrument Intended for the implantation, through a posterior or posterolateral approach, of a disc prosthesis or osteosynthesis cage as a replacement for the intervertebral disc. The device includes at least two means for bone anchorage each intended to be attached to a vertebra adjacent to the disc, a coupling element for the instrument and elements for adjusting the position of the coupling element relative to the position of the disc.