US Patent 7591839 Bone anchoring element for anchoring in a bone or vertebra, and stabilization device with such a bone anchoring element

A bone anchoring element comprises a bone anchoring element and a receiving member. The bone anchoring element can be in the form of a screw with a shaft and a first head. A second head is elastically connected to the first head. The second head is arranged in the receiving member such that the second head can swivel. The second head is fixed in the receiving member in an angular resting position. The screw is deflectable from the angular resting position relative to the second head. The second head is elastically connected to the first head such that a restoring force returns the screw to the angular resting position.