MRI Assessments of Adjacent Disc Degeneration Following Lumbar Fusion

Abstract

Study Design: Retrospective case-control study Objective: To use MRI to assess intervertebral disc degeneration at adjacent levels after spinal fusion and after discectomy. Summary of Literature Review: Degeneration of adjacent intervertebral discs following lumbar spinal fusion is one of the principal reasons for considering motion preservation techniques, such as placement of an artificial disc. Much attention has recently been directed toward disc morphometric studies using MRI. Materials and Methods: Fifty-six patients who underwent spinal surgery for lumbar degenerative disease and who underwent a minimum of 2 years of follow-up MRIs were included in this study. Thirty-four patients were included in the lumbar fusion study group, and 22 patients were included in the discectomy control group. The MRI Thompson classification was used to grade both upper and lower adjacent disc degeneration preoperatively and at the time of last follow-up. Results: There were significant changes in Thompson degenerative grade in the upper adjacent levels for both the fusion group patients and in the discectomy group patients. However, there was no statistically significant difference between the two groups with regard to either the upper or lower adjacent levels (p=0.146 and 0.350, respectively). Conclusions: In this short-term study comparing MRI outcomes in spinal fusion and discectomy patients, no significant difference in adjacent disc degeneration was observed between the two group.