| 摘要 |
A limited angulation bone screw assembly adapted to couple a spinal rod with a vertebra including a bone screw, a bushing and a housing. The pedicle screw having a shaft and an upper head portion, the upper head portion comprising a spherical surface with flats disposed on opposite sides of the upper head portion. The bushing comprising a lower rounded surface for mating with the spherical surface and flats of the upper head portion to restrict the angular movement of the bone screw. The coupled bone screw and bushing are inserted into the housing in a first orientation and then rotated to a second orientation to secure the coupled bone screw and bushing to complete the housing.
|
