| 摘要 |
<p>A bone anchoring device is provided comprising an anchoring element (1) a shank (2) to be anchored in a bone or a vertebra and a head (3), a receiving portion (5) comprising a first end (6) and a second end (7) opposite to the first end, a longitudinal axis (8) passing through the two ends, a bore (5) coaxial with the longitudinal axis, a first region (11) adjacent to the second end (7) for receiving aid head and a recess (12) which is opened towards the first end (6) and which forms two free legs (15, 16) for receiving a rod (14), a pressure element (20) which exerts a pressure on said head (3) to lock said head in the receiving portion (5), and a closure element (30; 40, 45) cooperating with said legs (15, 16) to secure the rod in said recess (12), wherein said pressure element (17) has a first end (21) and a second end (22) opposite to the first end (21) and a recess (24) which is open towards the first end (21) to receive the rod, the depth of the recess (24) being larger than the diameter of the rod and wherein in a pre-assembled state the bottom (27) of the recess (24) of the pressure element (17) projects over the bottom (13) of the recess (12) of the receiving portion in a direction towards the first end (6) of the receiving portion (5).</p> |
