Spinal implant apparatus having a single central rod and plow hooks

Abstract

A hook and rod apparatus for implantation and fixation to the centerline of the spine, wherein the rod provides for immobilization of the spine via its inherent rigidity. The hook elements are designed to be mounted at the arched portion of the lamina. In a first plow shaped variation, the blade portion of the hook is an arched surface which seats under the arched surface of the lamina. In a second claw shaped variation, the blade portion includes a bifurcated conformation having a pair of offset flat extending members which are offset so as to seat under the angled portions of the lamina which are directly laterally disposed relative to the arched center of the lamina. The rod coupling features of the hooks may further be polyaxial by virtue of separate coupling elements which may be mounted to the blade portion, for example on a semi-spherical head portion thereof. In the alternative, the blade portion may have a contractible recess formed in a top thereof, for receiving and locking to a shaft of body portion at a variety of heights. The rod receiving features of the hook may include both the polyaxial and height variability natures of both of the previous hooks by having a shaft portion which has a semi-spherical head onto which the coupling element is mounted.