A surgical instrument extendable through a cannula for moving a first bone portion relative to a second bone portion includes a first portion having a longitudinal axis engageable with a first member connected with to the first bone portion. A second portion is engageable with a second member connected...http://www.google.fr/patents/US7341594?utm_source=gb-gplus-shareBrevet US7341594 - Surgical instrument for moving vertebrae
