Correlation between paraspinal muscle changes and lumbar lordosis, intervertebral disc degeneration in young adults with low back pain: a retrospective cohort study

Abstract

Abstract Background: Previous studies have showed that intervertebral disc degeneration was significantly associated with low back pain, and there was a significantly greater proportion of chronic low back pain patients with lower lumbar lordosis. Paraspinal muscles have gained more attention because of their relationship with the spinal degenerative disease in elder patients. The objective of this study was to investigate the correlation between the degree of paraspinal muscle degeneration and decreased lumbar lordosis and lumbar intervertebral disc degeneration in younger patients with low back pain. Methods: Seventy patients with chronic low back pain (39 males, 31 females) and seventy-five healthy controls (36 males, 39 females) were enrolled. The correlation of the degree of multifidus muscle degeneration with lumbar intervertebral disc degeneration and lumbar lordosis was analyzed. Results: Disc degeneration at L3-4 showed no significant difference between the low back pain group and the control group (p > 0.05). However, there was a significant difference between the two groups at both L4-5 and L5-S1 (P < 0.05). At L4-5, the degree of fat infiltration showed significantly greater in the low back pain group (0.23 ± 0.035) than that in the control group (0.18 ± 0.037) (p < 0.05). At L5-S1, both relative multifidus muscle cross-sectional area and the degree of fat infiltration demonstrated significant differences between the two groups (p < 0.05). A significant correlation was observed between lumbar intervertebral disc degeneration and the degree of fat infiltration at L4-5 (r = 0.405, p < 0.05) and L5-S1 (r = 0.397, p < 0.05), respectively. Additionally, lumbar lordosis was found significantly decreased in the low back pain group (18.5°±4.3) compared with that in the control group (37.4 ± 8.5) (p < 0.05) and also significantly correlated with the degree of fat infiltration at L5-S1 (r= -0.422, P < 0.05). Conclusions: Multifidus atrophy and fatty infiltration showed significantly correlated with lumbar lordosis and lumbar intervertebral disc degeneration in younger populations. Enhanced function in paraspinal muscles might contribute to improving the symptoms of low back pain and spinal degeneration.