Bone screw has holder element joined to shaft and possessing two free arms , with inner screw, slot, external nut, cavity and shoulder cooperating with attachment

摘要

An element (40) with cylindrical external surface has an external diameter such that it slides between two free arms (9,10) of the holder element. An inner screw (60) fits in an internally threaded (43) central hole. At least one slot (47) extends from one end over a pre-set length long the cylinder wall. An external nut (50) cooperates with the external thread (12) on the free arms, and holds the element between the arms when screwed up. One end (42) of the element has a cavity (44) formed by a shoulder (45) cooperating with an attachment (52) on the external nut. A rod-shaped element (100) is positioned in a holder element (3) joined to a shaft (1).