Correlation Between Clinical Result and Adjacent Segment Degeneration After Lumbar Spinal Fusion

Abstract

Study Design: Retrospective study Objectives: To determine the relationship between clinical outcome and adjacent segment degeneration (ASD) after lumbar fusion. Summary of Literature Review: Few studies have analyzed the correlation between clinical outcomes and ASD. Materials and Methods: Between January 2000 and December 2004, 217 patients who underwent lumbar spinal fusion (�2 years of follow-up) were evaluated. The patients were divided into 2 groups: one-segment (A) and two-segment (B). The UCLA grading scale was used to evaluate the prevalence of ASD on radiography. The association between clinical outcome and ASD was evaluated by Spearman’s correlation. Results: ASD occurred in 11.6% (13/112) of patients in group A and 15.2% (16/105) of patients in group B. The number of cases which progressed to more than 2 levels of the degenerative grade were 0 cases in group A and 13 cases (81.3%) in group B. In A, 5 out of 13 ASD cases downgraded one level in their clinical outcomes. In B, all 16 ASD cases downgraded more than one level in their clinical outcomes. Worsening in degenerative grade, was correlated with worse clinical outcome (Spearman’s rho = 0.829, P �0.05). Conclusions: The association of clinical outcomes with ASD after fusion showed a significant correlation, especially association with ASD after multiple segment fusion.