Bone screw

摘要

A bone screw having a screw member possessing a threaded section and a head and a receiving part at the head end for receiving a rod to be connected to the bone screw is provided. The receiving part has on open first bore and a substantially U-shaped cross-section having two free legs provided with a thread. Furthermore, the receiving part has a second bore on the end opposite to the first bore whose diameter is greater than that of the threaded section and smaller than that of the head. On the bottom of the first bore a seat for the head is provided. In order that the screw member can be pivoted to at least one side by an enlarged angle, the edge bounding the free end of the second bore viewed relative to the axis of the first bore is of asymmetric construction.

主权项

1. A bone fixation assembly comprising:
a coupling element for coupling a rod to the bone fixation assembly, the coupling element having an upper end and a lower end and defining a first bore coaxial with a first longitudinal axis and a second bore communicating with the first bore, said coupling element having a U-shaped opening that extends from the upper end toward the lower end, and wherein the U-shaped opening is configured to receive the rod; and an anchoring element having a first end for insertion into bone and a second end positionable within the second bore and configured to engage a seat of the coupling element, wherein the anchoring element, when engaging the seat of the coupling element, is movable relative to the seat of the coupling element in at least a first direction at a first angle relative to the first longitudinal axis and in at least a second direction at a second angle relative to the first longitudinal axis, the second angle being greater than the first angle.