摘要 |
A method and a system for a spinal fixation incorporate a plurality of polydirectional fixation screws and a plurality of linkages. The polydirectional fixation screws include an upper member and a lower member. The upper member is attached to the linkage. The upper member includes a first hemispherical portion. The lower member engages the bone and includes a second hemispherical portion which cooperates with the first hemispherical portion to define a sphere. The second hemispherical portion is coupled to the first hemispherical portion for relative pivotal movement about an axis. Relative movement between the first and second hemispherical portions readily permits sagittal plane adjustments. The polydirectional fixation screw further includes a biasing member for biasing the first member away from the second member in a direction substantially parallel to the axis. The linkages are provided with various vertical offsets to readily permit coronal plane adjustment. |