Influence of Lumbar Posterior Fusion on Adjacent Segments to the Fusion Site

Lumbar posterior fusion is an established method of treating spondylosis, however there have been controversial views with regard to the degenerative change of adjacent segments to the fusion site.Thirty patients who underwent lumbar posterior fusion with about five years postoperative observation were included in this study. Intervertebral disc height, spondylolisthesis in adjacent segment to the fusion site and the Japanese Orthopedic Association (JOA) score were evaluated before and after surgery. Fifteen cases showed degenerative changes including decreased intervertebral disc height or spondylolisthesis to adjacent segments. However, no significant correlation was seen between the clinical status and degeneration adjacent to the fusion. As a result of estimating ages, sex, disc angle, % slip, lumbosacral joint angle, and lumbar lordosis, no significant difference was found between cases affecting degeneration adjacent to the fusion or those not.