Facet joint tropism in degenerative lumbar scoliosis: a retrospective case-control study.

Background: To investigate the association between lumbar degenerative scoliosis and the dural sac cross-sectional area (DSCA), the lumbar canal anterior-posterior (LCAP) diameter, and the neural foraminal cross-sectional area (NFCA) in relation to facet joint tropism (FJT).

Methods: In a retrospective case-control study, we analyzed data from 160 patients referred for lumbar magnetic resonance imaging (MRI) between January 2020 and December 2022. Cobb's angle on anteroposterior lumbosacral X-ray is served to identify the presence of degenerative lumbar scoliosis-Cobb's angle exceeding 10 degrees-, and axial T2W MRI is implemented to evaluate facet joint angles and tropism-defined as a difference exceeding 10 degrees between the facet joint angles at each level-, DSCA, LCAP, and NFCA.

Results: FJT was much more common in patients with degenerative lumbar scoliosis (69%) than in controls (14%). The frequency of FJT also incremented with the increasing severity of the scoliotic curve. We observed that LCAP and NFCA were significantly smaller in cases with FJT. However, no statistically significant difference was found in DSCA related to FJT. Age and gender did not exhibit significant associations with degenerative lumbar scoliosis, and no correlation was detected between different Cobb's angle groups and age.

Conclusions: These findings underscore the importance of considering FJT as a potential contributing factor to degenerative lumbar scoliosis and may have implications for clinical diagnosis and management. Prospective research with larger and more diverse cohorts is needed to further investigate this complex relationship and its impact on lumbar spinal health.