A coupling assembly is provided comprisinga receiving part (5, 5′) having a first end (5a), a second end (5b) and a central axis (C) extending through the first end (5a) and second end (5b), a recess (52) for receiving a rod (100), the recess having a bottom, andan accommodation space (54, 54′) for accommodating a head (3) of an anchoring element (1), the accommodation space having an opening (55, 55′) at the second end (5b) sized so as to permit the insertion of the head (3) and a bore extending from the accommodation space to the first end (5a),a retainer element (6, 6′) configured to be positioned at least partially in the accommodation space (54, 54′) and sized so as to at least partially encompass an inserted head (3)wherein the retainer element (6, 6′) comprises at least one spring portion (66a, 66b 66′) that is compressible in an axial direction and that extends in an axial direction at least up to a position toward the first end (5a) of the receiving part that is higher than the bottom of the channel (52) for the rod.
