| abstract |
A coupling assembly is provided for coupling a rod to a bone anchoring element, the coupling assembly ( 4, 4′, 4 ″) comprisingn a receiving part ( 5, 5 ″) having a first end ( 5 a ), a second end ( 5 b ) and a central axis (C) extending through the first end ( 5 a ) and second end ( 5 b ), a recess ( 52 ) for receiving a rod ( 100 ), and an accommodation space ( 54 ) for accommodating a head ( 3, 3 ′) of an anchoring element ( 1 ), the accommodation space having an opening ( 55 ) at the second end ( 5 b ) sized so as to permit the insertion of the head ( 3, 3 ′) and a bore ( 51 ) extending from the accommodation space to the first end ( 5 a ), a retainer element ( 6, 6′, 6 ″) configured to be positioned at least partially in the accommodation space ( 54 ) and sized so as to at least partially encompass an inserted head ( 3, 3 ′); a spring element ( 7, 7 ″), separate from the retainer element ( 6, 6′, 6 ″), configured to be arranged at least partially in the accommodation space ( 54 ), wherein the spring element ( 7, 7 ″) is configured to be compressed in the axial direction and wherein the spring element ( 7, 7 ″) has such a length in the axial direction that it can be engaged by an inserted rod when the retainer element ( 6, 6′, 6 ″) and the spring element are arranged in the accommodation space ( 54 ). |