| 摘要 |
A polyaxial bone anchoring device includes an anchoring element having a shaft and a head, a receiving part having a seat for receiving the head, a pressure element to exert pressure onto the head, wherein the head is pivotable and can be locked at an angle relative to the receiving part, wherein an outer wall of the pressure element has a recess or a deformable portion, and an inner wall of the receiving part has a deformable portion or a recess, wherein the pressure element is movable from a first position wherein the deformable portion protrudes a first distance into the recess while the head is pivotable relative to the receiving part, to a second position wherein the deformable portion protrudes a second distance into the recess, such that a force holds the head at one of a plurality of releasable angular positions before locking the head. |
