Disclosed are spinal fusion assemblies for use in skeletal systems. The assembly includes a coupling element that can be coupled to a fixation element, such as, for example, a screw with a head that removably mates with the coupling element. The coupling element and fixation element are configured to...http://www.google.fr/patents/US7678139?utm_source=gb-gplus-shareBrevet US7678139 - Pedicle screw assembly
