Coupling device for coupling a rod to a bone anchor and system including such a coupling device and at least two bone anchors

A bone anchoring device for coupling a rod to bone, the bone anchoring device comprising:

• a bone anchor comprising a shank for anchoring to bone and a head, the head comprising an outer surface portion and a projection that extends outwardly away from the outer surface portion;
• a receiving part having a first end, an opposite second end, and a central axis extending between the first end and the second end, the receiving part comprising a rod receiving portion at the first end for receiving a rod, and a head receiving portion at the second end that defines an accommodation space for accommodating the head;
• and
• a locking member positionable at least partially around the head receiving portion, wherein when the head is in the accommodation space, the locking member is movable from a first position where the head is movable relative to the receiving part, to a second position where the head is locked relative to the receiving part;
• wherein the bone anchoring device comprises a restraining surface formed by at least one recess in the head receiving portion that is configured to cooperate with the projection on the head of the bone anchor to restrict pivoting of the bone anchor relative to the receiving part.