Compression osteosynthesis screw, and an ancillary device for use therewith

摘要

An osteosynthesis screw comprising both a screw shank, having a thread with a distal zone and a proximal zone, and a screw head for threading on the screw shank and for co-operating with its proximal zone via internal tapping complementary to the thread of the shank is suitable for applying compression to bone fragments. The screw head also has an outside thread at a pitch that is smaller than the pitch of the screw shank, wherein the distal zone and the proximal zone are separated by a central zone shaped to be inactive during screwing so as to form a sliding zone for the bone fragments to be put into compression.