Abstract
BACKGROUND: The relationship between paraspinal muscle degeneration and low back pain (LBP), disability, and structural changes has been investigated in the literature, but it is still a matter of debate. We differentiated paraspinal muscle magnetic resonance imaging by quality and quantity, focusing on fatty infiltration (FI) and paraspinal muscles cross-sectional area (CSA) from T12 to S1 in patients with and without chronic LBP. We aimed to determine whether paraspinal muscle quantity (CSA) and quality (FI) are positively associated with LBP or degenerative/spinopelvic changes in the spine. METHODS: Between 2018 and 2021, we prospectively enrolled 205 patients aged between 18 to 65 years, of whom 153 patients had chronic back pain (back pain group) and 52 patients did not have chronic back pain (no back pain group), and collected clinicodemographic, structural, and spinopelvic data. We correlated these data with paraspinal muscle FI and CSA from T12 to S1. Multivariate models were run to highlight associations between pain, disability, or degenerative and spinopelvic parameters. RESULTS: Age was not associated with increased FI but consistently with decreased CSA values. After adjusting for age, sex, and body mass index, FI was associated with an increased risk of back pain (OR, 8.80; 95% CI, 1.9-39.79; P = 0.006) and high disability scores (OR, 3.41; 95% CI, 1.12-10.30; P = 0.030). Decreased CSA was associated with reduced disc height (P < 0.001), while FI and CSA did not associate with abnormal spinopelvic parameters. CONCLUSIONS: FI on paraspinal muscle highly correlates with back pain and disability but was not found in structural and degenerative changes in the lower back. CLINICAL RELEVANCE: Findings from this study are clinically relevant for patient counseling and rehabilitation strategies. LEVEL OF EVIDENCE: 2b.