POLYAXIAL BONE ANCHORING DEVICE

摘要

A polyaxial bone anchoring device is provided including
a bone anchoring element (1) comprising a head (3) and a shank (2);a receiving part (4, 4′) for receiving a rod (100) for coupling the rod to the bone anchoring element, the receiving part comprising a first end (4a), an opposite second end (4b) and a central axis (C) extending through the first end and the second end, anda channel (9) for receiving the rod and an accommodation space (11) for receiving the head;a pressure element (6, 6′) arranged in the receiving part and configured to exert pressure onto the head;

wherein the pressure element (6) comprises flexible sections (66a, 66b) facing away from the head (3), characterized in that the flexible sections (66a, 66b) comprise a free end portion (69a, 69b) with respect to the central axis (C) that cooperates with an inclined surface portion (15a, 15b) of the receiving part (4) such as to hold the pressure element (6) in a position in which it exerts a pre-load onto the head before the head is locked.

主权项

1. A polyaxial bone anchoring device comprising:
a bone anchoring element comprising a head and a shank; a receiving part for receiving a rod for coupling the rod to the bone anchoring element, the receiving part comprising a first end, an opposite second end and a central axis extending through the first end and the second end, and a channel for receiving the rod and an accommodation space for receiving the head; a pressure element arranged in the receiving part and configured to exert pressure onto the head; wherein the pressure element comprises at least one flexible section, characterized in that the at least one flexible section has a free end portion that cooperates with an inclined surface portion or with a protruding edge of the receiving part such as to hold the pressure element in a position in which it exerts a pre-load onto the head before the head is locked.