A method and a system for a spinal fixation incorporate a plurality of polydirectional fixation screws and a plurality of linkages. The polydirectional fixation screws include an upper member and a lower member. The upper member is attached to the linkage. The upper member includes a first hemispherical...http://www.google.com/patents/US20010034521?utm_source=gb-gplus-sharePatent US20010034521 - Method and system for spinal fixation
