In one embodiment, a spinal stabilization apparatus includes a vertebral anchor having a head portion and a bone attachment portion. An elongate, flexible guide is removably coupled to the head portion of the vertebral anchor and has a channel extending longitudinally thereof and communicating with a slot in the head portion of the anchor. An elongate cord may be received within the channel to facilitate inserting and securing a spacer between pairs of anchors installed into adjacent vertebrae of a person's spine.