US Patent 9848892 Bone anchoring element

An anchoring element includes a screw having a shank with a bone thread portion and a head. The anchoring element also includes a receiving part for connecting the screw to a rod-shaped element, the screw and the receiving part being connected to one another in a polyaxial or monoaxial manner, and the shank of the screw being of tubular design and its wall having a plurality of recesses. The bone anchoring element provides for the bone screw to fuse with the surrounding bone substance, and at the same time bone portions or vertebrae can be positioned relative to one another and fixed. Moreover, a substance to be introduced into the bone can be introduced precisely at the desired site.