A bone fixation device. The bone fixation device includes a receiver having a deformable portion, a bone fastener having a head, the head insertable into the receiver from the deformable portion, and a retaining member couplable to the deformable portion. The retaining member deforms the deformable portion...http://www.google.es/patents/US7699876?utm_source=gb-gplus-sharePatente US7699876 - Multi-axial bone fixation apparatus
