The invention relates to a bone anchoring device, in particular to a polyaxial bone screw which is connected to two stabilization rods and to a stabilization device having such a bone anchoring device, in particular for the stabilization of the spinal column.
A dynamic stabilization device for bones, in particular for vertebrae, is described in US 2004/0049190 A1. The stabilization device includes two bone anchoring elements, at least one of which is a polyaxial bone screw and a rigid rod with a longitudinal axis connecting them. An elastic element is inserted between the two bone anchoring elements. The elastic element acts on the bone anchoring elements to exert a force in a direction of the longitudinal axis. One of the bone anchoring elements is fixedly connected to the rod to prevent translational movement of the rod and the other bone anchoring element is slidably connected to the rod.
EP 1 800 614 A1 describes a dynamic stabilization device for bones or for vertebrae having at least two bone anchoring elements and at least one connection element in the form of an elastic loop connecting the bone anchoring elements. In one embodiment, the bone anchoring element is in the form of a polyaxial bone screw having a receiving part which accommodates to two elastic loops each of which can be connected to a second bone anchoring element.
Based on the foregoing, there is a need to provide a bone anchoring device and a stabilization device comprising such a bone anchoring device which allows the dynamic stabilization of bone parts or vertebrae and which allows a variable design of elastic properties of the dynamic stabilization device.