The Impact of Paravertebral Muscles on Lumbar Degeneration Based on Computed Tomography (CT): A Nationwide Multicenter Study.

Abstract

Multicenter cross-sectional study. Lumbar spine degeneration (LSD) is a prevalent clinical condition, yet the influence of paravertebral muscles on LSD remains insufficiently explored. This study investigates the effects of various paravertebral muscles and muscle parameters on lumbar degeneration. This cross-sectional analysis of 4,305 adults from the China Action on Spine and Hip (CASH) cohort utilized quantitative CT to measure psoas and paraspinal muscle parameters at L1/L3/L5 levels. Intervertebral disc degeneration (IVDD) and facet joint degeneration (FJD) were radiologically graded. Adjusted binary logistic regression models (for age/sex/BMI) evaluated muscle-degeneration associations. 3,734 participants (2,266 females, 1,468 males) were included. After adjusting for confounding factors, paraspinal muscle area (PSMA) at the L3 and L5 levels was significantly associated with IVDD and FJD. An increase in L5-PSMA significantly reduced the risk of both IVDD and FJD (OR=0.49, 95% CI 0.41-0.60, P<0.01; OR=0.71, 95% CI 0.62-0.83, P<0.01). A similar effect was observed at the L3 level (L3-PSMA: OR=0.59, 95% CI 0.48-0.72, P<0.01; OR=0.98, 95% CI 0.96-0.99, P<0.05). No significant correlation was found at L1. Stratified by sex, males had higher paravertebral muscle area and density and lower fat fraction (P<0.01). Females had higher lumbar FJD scores across all segments (P<0.05) and higher IVDD scores at L5-S1 (P<0.01). The impact of PMSA on lumbar degeneration is more significant in females compared to males. (L5-IVDD OR=0.12 (0.08, 0.19) vs. 0.71 (0.55, 0.9); L5-FJD OR=0.44 (0.34, 0.56) vs. 0.88 (0.78, 0.98)). Paravertebral muscle at L3 and L5 is associated with lumbar degeneration, with PSMA exerting the most stable effect on both IVDD and FJD. These effects were more pronounced at L5 and in females, with IVDD more susceptible to influence. Level 3.