Pathoanatomical contributors to lumbar spinal stenosis
Abstract
Objective: To investigate the association and relative contribution of facet joint hypertrophy and disc degeneration, particularly posterior disc bulging, with dural sac cross-sectional area and the prevalence and severity of lumbar central canal stenosis in a general adult male population.
Methods: 197 adult males from the Twin Spine Study were included in the study. Using axial MRI scans of the lumbar spine, central canal stenosis, facet joint hypertrophy, and posterior disc bulging were assessed at the L2/3 through L5/S1 spinal levels. Previously established measurement techniques and grading criteria were used to assess the structures of interest.
Results: Facet joint hypertrophy and posterior disc bulging were inconsistently associated with central canal stenosis when analyzed by spinal level, except for a consistent association of posterior disc bulging with qualitatively assessed LSS across all levels. Posterior disc bulging was also associated with both canal capacity and qualitatively assessed central canal stenosis when considering the combined levels of L3/4 and L4/5.
Conclusion and significance: Posterior disc bulging appears to play a more significant role in central canal stenosis than facet joint hypertrophy. However, both structures explained little of the variance in canal capacity or the odds of having stenosis, suggesting that other factors may be of greater importance. Further research using larger samples that can support more refined measures of facet joint hypertrophy, disc degeneration, and stenosis is needed to clarify their associations and confirm and expand our study findings.