Impact of paravertebral muscular atrophy in acute work-related low back pain: a retrospective cohort study

TL;DR

This study found that muscle atrophy near the spine, seen via MRI, is not strongly linked to longer recovery times in acute work-related back pain.

Contribution

The study provides new evidence that paravertebral muscle atrophy has limited impact on short-term disability in acute low back pain.

Findings

No significant associations were found between muscle atrophy and disability duration, except for a weak link with Goutallier scores in the multifidus muscle.

Psoas cross-sectional area showed a modest correlation with follow-up and total temporary incapacity durations.

Muscle morphology appears to play a minor role in acute LBP recovery compared to chronic cases.

Abstract

This study aims to assess whether paravertebral muscle atrophy, evaluated through MRI, is associated with longer disability periods in patients with acute work-related low back pain (LBP).

This retrospective observational study reviewed cases of adult patients evaluated foracute work-related LBP who underwent lumbar MRI between January 2021 and August 2023. Exclusion criteria included pre-existing spinal disorders, major trauma, systemic conditions affecting recovery, or radicular symptoms. Disability was quantified using total temporary incapacity (TTI), absolute incapacity (AI), and follow-up (FU) durations. Paraspinal muscle morphology was assessed at the L4–L5 level using cross-sectional area (CSA) and fatty infiltration grading with Goutallier, Mercuri, and Kader scales. Associations were tested using t-tests, ANOVA, and chi-square, with significance set at p < 0.05.

A total of 87 patients (77.0% male; mean age, 36.4 ± 14.9 years) were included. The mean TTI was 30.2 ± 21.9 days. No significant associations were found between CSA or most morphological scores and disability duration. Only higher Goutallier scores in the multifidus muscle were weakly associated with longer follow-up (p = 0.037). A modest correlation was observed between psoas CSA and follow-up/TTI duration (p < 0.05).

Paravertebral muscle atrophy, as assessed by MRI, does not appear to significantly influence short-term disability in acute work-related LBP. These findings suggest that muscle morphology plays a minor role in acute LBP recovery, contrasting with its known impact in chronic cases.

Figures