Patent ID: 7601171

Claim:
A spinal motion preservation assembly adapted for assembly in a spinal motion segment the spinal motion preservation assembly comprising: a distal bone anchor comprising: a distal end; a proximal end; a cavity in an interior of the distal bone anchor accessible from the proximal end, the cavity adapted for receipt of a distal pivot cup inserted into the proximal end of the distal bone anchor; and a set of threads on an exterior of the distal bone anchor, the set of threads adapted to engage a distal vertebral body in the spinal motion segment; a pivot comprising: a distal end; a proximal end; and a middle between the distal end and the proximal end; the distal pivot cup comprising: an exterior corresponding to a portion of the cavity in the interior of the distal bone anchor; and a cavity at the proximal end of the distal pivot cup for receiving the distal end of the pivot; a proximal bone anchor comprising: a distal end; a proximal end; a cavity that runs through an interior of the proximal bone anchor from the distal end to the proximal end, the cavity adapted for receipt of a proximal pivot cup inserted into the proximal end of the proximal bone anchor; and a set of threads on the exterior of the proximal bone anchor adapted to engage a proximal vertebral body in the spinal motion segment; a proximal pivot cup comprising: a distal end; a proximal end; and a cavity at the distal end of the proximal pivot cup for receiving the proximal end of the pivot; at least one component located between the distal end of the distal bone anchor and the proximal end of the proximal bone anchor that is elastically deformable; and the distal bone anchor, distal pivot cup, pivot, proximal pivot cup, and proximal bone anchor all adapted for insertion from a bore in the proximal vertebral body in the motion segment such that the spinal motion preservation assembly may be inserted and assembled in the spinal motion segment through use of just the bore in the proximal vertebral body.