The arthroscopic surgery instrument includes an elongated outer sheath member having substantially fully open distal and proximal ends, and an inner hollow cylindrical cutting blade member rotatable within the sheath member. The cutting blade member has a distal end that is substantially fully open....http://www.google.fr/patents/US5112299?utm_source=gb-gplus-shareBrevet US5112299 - Arthroscopic surgical apparatus and method
