The invention provides an implantable spinal distraction/fusion rod with varied
thread pitch and diameters along different portions of its length that it is capable
of distracting two or more vertebral bodies relative to each other and/or facilitating
the procedure of fusing the vertebral bodies together from within the spine. The
present invention also provides for methods of using the rod to distract and/or
fuse two or more vertebral bodies from within the spine.
