Screw head retaining device for fixing osteosynthesis plate in e.g. cervical spine, has flange cooperating with support zones, which are subjected to deformation during passage of flange, and act as stop for flange after engagement of screw

摘要

The device has a flange (2d) provided on a head of a screw and cooperating with pinpoint support zones (1c1) of an opening (1c) such as oblong hole or circular hole, formed in thickness of an osteosynthesis plate (1). The zones are subjected to a plastic deformation during passage of the flange according to engagement of the screw, and act as a stop for the flange after engagement of the screw. The zones are formed in a ring pivotably engaged in the opening.