| 摘要 |
A polyaxial pedicle screw comprising: a bone screw member including a head having a threaded shaft extending from the head, the head including a first portion and a second portion; a housing positionable on the head of the bone screw, the housing having a distal opening, wherein the first head portion is configured and dimensioned to pass through the housing distal opening and the second head portion is configured and dimensioned not to pass through the housing distal opening. |
