Lumbar Anatomical Parameters Correlating With Spinal Epidural Lipomatosis of Patients With Lumbar Spinal Stenosis.

STUDY

DESIGN

Retrospective study.

OBJECTIVES

To investigate the correlation between lumbar anatomical parameters and spinal epidural lipomatosis (SEL) in patients with lumbar spinal stenosis (LSS).

METHODS

A total of 397 patients with LSS who underwent surgical treatment were enrolled and divided into SEL and No-SEL groups. Clinical and radiological data were collected for all participants. Correlation analysis was performed to evaluate the relationships between various parameters and epidural fat thickness. Variance inflation factor (VIF) was calculated to assess multicollinearity among the covariates. Univariate and multivariate analyses were employed to investigate factors associated with SEL in patients with LSS. Furthermore, to eliminate the confounding effect of segmental differences on other risk factors, separate univariate and multivariate analyses were conducted specifically for the L3/4 and L4/5 levels.

RESULTS

Correlation analysis showed facet angle (FA), intervertebral angle (IA), the ratio of bony spinal canal/intervertebral space spinal canal (BSC/ISSC), BMI, and endocrine disorders all showed weak to moderate correlations with fat thickness. Univariate analysis showed significant differences in FA, IA, endocrine disorders, BSC/ISSC and segment between SEL group and NO SEL group. Binary logistic regression analysis showed lesser BSC/ISSC and segment (upper lumbar spine) were independent factor associated with the imaging presence of SEL. The Youden index shows the cut-off value of BSC/ISSC is 0.735.The univariate and multivariate analyses showed that, for the data obtained from L3/4 and L4/5, there was a statistically significant difference in BSC/ISSC, whereas no such difference was observed for FA or IA.

CONCLUSIONS

Lesser BSC/ISSC and upper lumbar spine were independent anatomical factor associated with the imaging presence of SEL. Spinal stenosis leads to compression of the dorsal epidural adipose tissue, and the change in its distribution pattern may uncover the key mechanism underlying the development of SEL in LSS patients.