Pièce de réception pour recevoir une tige pour coupler la tige sur un élément d'ancrage d'os et dispositif d'ancrage d'os avec une telle pièce de réception
A receiving part for receiving a rod for coupling the rod to a bone anchoring element is provided, the receiving part including a receiving part body (5) with a rod receiving portion (9) with a channel (12) for receiving the rod, and a head receiving portion (16) for accommodating a head (3) of the bone anchoring element, the head receiving portion having an open end (17) and being flexible, so as to allow introduction and clamping of the head, the head receiving portion having a first exterior surface portion (16a, 16a', 16a") and a central axis (C) extending through the open end (17)； and a locking ring (8) embracing the head receiving portion (16), the locking ring having a first interior surface portion (83, 83', 83") that engages the exterior surface portion (16a, 16a', 16a") in a first contact region to clamp the head (3)； wherein at least one of the exterior and the interior surface portion is a cylindrical surface portion (83", 16a") and the other one is either a cylindrical surface portion (83", 16a") or a ring-shaped bulge portion (16a, 83').
