Abstract
Spinal fusion had become a standard surgical procedure which was now more predictable and reproducible. Soon it was used for the treatment of degenerative or post-operative changes of the spine.1420 Although there is still controversy about its benefit,2127 lumbar spinal fusion became accepted worldwide as a treatment option for symptomatic degenerative disease, degenerative spondylolisthesis, degenerative lumbar scoliosis, post-discectomy-syndromes or segmental instability adjacent to a previous fusion.2832