| 摘要 |
A receiving part for coupling a rod to a bone anchoring element includes: a receiving part body with a rod receiving portion and a head receiving portion having an open end for introducing a head of a bone anchoring element, and a locking ring, wherein the head receiving portion includes a plurality of flexible wall portions, the flexible wall portions and the locking ring being configured to engage each other at circumferentially distinct pressure areas having positions corresponding to circumferentially separated projections on at least one of the flexible wall portions or the locking ring, and wherein the locking ring exerts a first force on at least one of the flexible wall portions at a corresponding pressure area, and exerts a second force less than the first force on the at least one flexible wall portion in a region circumferentially adjacent to the corresponding pressure area. |
