Patent ID: 7744649

Claim:
An implant for changing an alignment between two vertebrae and maintaining the alignment comprising: a first half having a first body with a first longitudinal axis, a first collar, a first chamber, a first joint, a first longitudinal side and a first set of radial anchors; the first set of radial anchors radially extending generally perpendicularly from the first body; a second half having a second body with a second longitudinal axis, a second collar, a second chamber, a second joint, a second longitudinal side and a second set of radial anchors; the second set of radial anchors radially extending generally perpendicularly from the second body; the first half and the second half slidingly connected by the first joint and the second joint along the first longitudinal side and the second longitudinal side; the first body and the second body connected form an implant body; the first collar and the second collar connected form an implant collar; the first chamber and the second chamber connected form an implant chamber; the first chamber being threaded with a first set of threads; a drive screw having an outside perimeter and a spanner head; the outside perimeter being threaded with a second with a set of threads; the drive screw located in the implant chamber; the first set of threads in engagement with the second set of threads; the first set of threads and the second set of threads having a pre-determined relationship to allow the first half to move a pre-determined distance in relation to the second half when the drive screw is rotated a pre-determined angle of rotation; the first set of radial anchors and the second set of radial anchors being generally parallel; the first set of radial anchors having a first set of corners and a second set of corners; and, the second set of radial anchors having a third set of corners and a fourth set of corners.