Anti-over tightening bone screw fixing arrangement

摘要

A fixing arrangement comprises a retaining element and a clamping sleeve which receives a bone screw. The bone screw has a head and a secondary thread and is pivotally mounted in the clamping sleeve. The clamping sleeve has a radially protruding section on the outer casing of the clamping sleeve and at least one track of a clamping thread, which complements the secondary thread, in the interior of the clamping sleeve. In the unclamped state, a free path is formed by a clearance on the clamping sleeve. A protruding section engages into an opening on the receiving seat in a formfitting manner, and the thickened section is shaped to expand towards the rear in the form of a cone. The cone angle is selected such that the free path divided by the tangent of the half-cone angle corresponds to 0.5 to 2.5 times the thread pitch of the secondary thread.