Tulip head screw for repositioning vertebral body with e.g. various indications, has tulip head thread whose diameter in region of outer circumferential predetermined breaking edge is greater than diameter of remaining of thread

摘要

The screw has a U-shaped tulip head (3) accommodating a correction rod (4), and an internal thread (5) comprising legs for inserting a set screw (7) into left and right elongated legs (9, 10). The elongated legs are divided into left and right head flanks (11, 12) and left and right elongated head flanks (13, 14). A radially circumferential predetermined breaking edge has height offset between the elongated legs at an outer side of the head. Diameter of thread of the head in a region of an outer circumferential predetermined breaking edge is greater than diameter of remaining of the thread.