Apparatus and a method of inserting spinal implants is disclosed in which an intervertebral space is first distracted, a hollow sleeve having teeth at one end is then driven into the vertebrae adjacent that disc space. A drill is then passed through the hollow sleeve removing disc and bone in preparation...http://www.google.de/patents/US7686805?utm_source=gb-gplus-sharePatent US7686805 - Methods for distraction of a disc space
