Most of these operations are done because of neck and arm pain and instability that occurs from degenerative disc disease. Just about half of these fusions are done at one single level. Some of these numbers may be patients who had a previous fusion and are back for a second one.
Whenever spinal fusion is done, stress and load are increased on the segments above and below the fusion. Increased motion at these levels causes accelerated degeneration. Areas affected include the disc between the vertebrae, the vertebral bones, and the joints between the fused and nonfused vertebrae.
Many studies are being done to find ways to help patients recover from disc problems without fusion. Preserving or maintaining motion is a key goal. But for now, surgical fusion is a widely accepted way to treat this problem.