A specially-shaped tube for gaining access to and removing mechanical fasteners such as pedicle screws. A small arthroscopic incision is made over the location of the fastener. A guide wire is then placed into the incision and attached to the fastener. A series of progressively enlarging dilator tubes...http://www.google.fr/patents/US20040158257?utm_source=gb-gplus-shareBrevet US20040158257 - Extractor tube for removing orthopaedic hardware
