A bi-directional fixating transvertebral (BDFT) screw/cage apparatus is provided. The BDFT apparatus includes an intervertebral cage including a plurality of internal angled screw guides, a plurality of screw members, and a cage indentation adjacent to the screw guides that independently or supplemented by other screw locking mechanisms 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.