A bi-directional fixating transvertebral (BDFT) screw/cage apparatus, a posterior lumbar facet staple and a staple gun for a posterior lumbar facet staple, a posterior cervical facet joint staple, and a staple gun for a posterior cervical facet joint staple are provided. The BDFT apparatus includes an intervertebral cage including a plurality of internal angled screw guides, a plurality of screw members, and a screw locking mechanism that prevents the screw members from pulling out of the internal angled screw guides. The internal angled screw guides orient a first screw member superiorly and a second screw member inferiorly. The intervertebral cage is adapted for posterior lumbar intervertebral placement, anterior lumbar intervertebral placement, anterio-lateral thoracic intervertebral placement, or anterior cervical intervertebral placement.