A vertebral fixation plate system and a method for its use in a surgical procedure to fuse adjacent spinal vertebrae to each other. A base member is fastened to a spinal interbody fusion device installed in place of an injured spinal disc. The base member is received within a receptacle defined in the vertebral fixation plate and mates with the plate, in a selected one of a plurality of available positions of the plate with respect to the base member, and thus with respect to the adjacent vertebrae between which the spinal interbody fusion device is installed. A locator member defined on the base member or the plate is mated in a locating cavity defined in the other one of the base member or the plate to keep the plate in the selected position.
