Sheaths for implantable fixation devices have a flexible body with a perforated wall, and an interior of the body is sized and shaped to receive the fixation device. Sheaths include a plurality of flexible or inflexible tubes arranged to form a ring, where the central cavity defined by the ring is sized...http://www.google.es/patents/US6746483?utm_source=gb-gplus-sharePatente US6746483 - Sheaths for implantable fixation devices
