Abstract: An intervertebral implant and associated method. The intervertebral implant can include a first component having a first articulating surface and a first bone engagement surface for engaging a first vertebra, and a second component having a second articulating surface and a second bone engagement surface for engaging a second vertebra adjacent to the first vertebra. The first and second articulating surfaces articulate with each other for substantially replicating a natural spinal movement including torsion, extension/flexion, and lateral bending. The first and second bone engagement surfaces define an outer surface substantially shaped as an envelope of two intersecting cylinders.

Abstract: An intervertebral implant. The intervertebral implant includes a hollow body formed by first and second side walls and first and second end walls. The first side wall defines an engagement groove adjacent the first end wall for engaging an arm of an implant tool.

Abstract: 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.

Abstract: 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.