COUPLING ASSEMBLY FOR COUPLING A ROD TO A BONE ANCHORING ELEMENT, KIT OF SUCH A COUPLING ASSEMBLY DIFFERENT ROD RECEIVING ELEMENTS AND BONE ANCHORING DEVICE
An instrument for inserting a bone anchoring element into a bone is provided, the instrument including a shaft (2) having an end portion (23, 23′) for engaging the bone anchoring element and for transferring torque to the bone anchoring element (1, 1′) and a longitudinal axis defining an axis of rotation (R)a cutting member (4, 4′) connected to the shaft (2) with cutting portions (45) that are configured to cut bone materialwherein the cutting member (4, 4′) has an outer diameter (D) defined by the cutting portions (45) that is substantially the same or larger than an outer diameter (dd) of a receiving part (500) of the polyaxial bone anchor in a region at a bottom end (500b) of the receiving part.
