Compression screw for osteo-synthesis of mini bone fragments, has four-lobed track, defined at screw head, which forms threaded orifice for fixation to threaded inner rod of screwdriver

摘要

A compression screw includes two notches extending from a sharpened, spiral distal end to a conical proximal end, and a head defining a four-lobed track. The track defines a threaded orifice extending into the screw interior. The threaded inner rod of a screwdriver is inserted and fixed into the screw interior via the orifice. The screw also defines two threaded zones of different passes for inter-fragmentary compression.