An apparatus for reduction of spondylolisthesis involving the insertion of an elongate implant which is split longitudinally into two side-by-side members, one of which is movable relative to the other, into the disk space between two misaligned vertebrae is disclosed. Each of the members is provided...http://www.google.es/patents/US5601556?utm_source=gb-gplus-sharePatente US5601556 - Apparatus for spondylolisthesis reduction
