An orthopedic device set, including: a plurality of intervertebral spacers elements, each spacer element having a cylindrical shape and an annular groove formed therein, each spacer element further having a different axial thickness from each other spacer; and an instrument for holding each of the intervertebral...http://www.google.com/patents/US20030014114?utm_source=gb-gplus-sharePatent US20030014114 - Vertebral bone distraction instruments
