| 摘要 |
A polyaxial bone anchoring device is provided comprising a bone anchoring element (1) having a shank (2) to be anchored in the bone and a head (3); a receiving part (5) coupled to the shank and configured to pivotably receive the head, and having a channel (56) for receiving a rod (6) and a central axis (C); a pressure member (7, 7') arranged in the receiving part and configured to exert pressure onto the head to lock the head in the receiving part; a locking member (8, 8') that is insertable into the channel, the locking member comprising a top end (81) and a bottom (82) end facing the pressure member; wherein the pressure member (7, 7') has a deformable portion (77, 78; 76', 107a, 107b); and wherein, when the locking member (8, 8') is advanced into the channel in the direction of the central axis (C), first the locking member (8, 8') contacts the pressure member (7, 7') resulting in a load applied to the pressure member that clamps the head (3), and thereafter the locking member (8, 8') contacts the pressure member (7, 7') such that the deformable portion (77, 78; 76', 107a, 107b) is deformed and the locking member comes into contact with the rod and clamps the rod (6). |
