| 摘要 |
A coupling assembly for coupling a rod to a bone anchoring element is provided, the coupling assembly (5) comprising
a receiving part (6) having a first end (6a), a second end (6b) and a central axis (C) extending though the first end (6a) and the second end (6b),
a recess (61) for receiving a rod, and
an accommodation space for accommodating a head (3) of a bone anchor (1), the accommodation space having an opening at the second end (6b) for inserting the head (3);
a pressure element (7) configured to be positioned at least partly in the accommodation space , the pressure element (7) having a first end comprising a first end surface (7a) and a second end (7b) facing towards the second end (6b) of the receiving part (6), a central axis coaxial with the central axis (C) of the receiving part (6), and a flexible portion (71) to clamp an inserted head (3),
a rod receiving element (8) that is a separate part comprising a first end comprising a first end surface (8a) and a channel (81) for inserting a rod (100) adjacent to the first end and a second end having a second end surface (8b) facing towards the second end (6b) of the receiving part (6), wherein the first end surface (8a) projects over an upper surface of an inserted rod (100);
wherein the first end surface (7a) of the pressure element (7) is configured to extend into the channel (81) of the rod receiving element (8); and
wherein the pressure element (7) comprises a portion (79) that is configured to cooperate with a portion (8b) of the rod receiving element (8) under axial load such that either the portion (79) of the pressure element (7) or the portion (8b) of the rod receiving element (8) deformed so as to move the first end surface (7a) of the pressure element (7) further into the channel (81) of the rod receiving element (8) in an axial direction. |
