A hook device for use with support rod implantation apparatus is disclosed which is positionable along the central axis of the posterior surface of the spine and has independently rotationally positionable blade and head portions. The head portion is engageable with a deflecting top cylindrical portion...http://www.google.com/patents/US5810818?utm_source=gb-gplus-sharePatent US5810818 - Spinal hook implant having a low blade and S swivel hook
