Spinal degeneration and lumbar multifidus muscle quality may independently affect clinical outcomes in patients conservatively managed for low back or leg pain

• Published in: Scientific reports Vol. 14; no. 1; p. 9777
• Main Authors: Cooley, Jeffrey R., Jensen, Tue S., Kjaer, Per, Jacques, Angela, Theroux, Jean, Hebert, Jeffrey J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 29.04.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 692/4023/1671; 692/698/1671/1668/1973; 692/699/1670/407; 692/700/1421/1628; Adult; Aged; Back pain; Clinical outcomes; Conservative Treatment - methods; Degeneration; Female; Generalized linear models; Humanities and Social Sciences; Humans; Intervertebral Disc Degeneration - diagnostic imaging; Intervertebral Disc Degeneration - pathology; Intervertebral Disc Degeneration - therapy; Leg; Leg - pathology; Longitudinal studies; Low Back Pain - therapy; Lumbar Vertebrae - diagnostic imaging; Lumbar Vertebrae - pathology; Magnetic Resonance Imaging; Male; Middle Aged; multidisciplinary; Pain; Pain Measurement; Paraspinal Muscles - diagnostic imaging; Paraspinal Muscles - pathology; Pathology; Prospective Studies; Science; Science (multidisciplinary); Treatment Outcome
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-60570-0

Few non-surgical, longitudinal studies have evaluated the relations between spinal degeneration, lumbar multifidus muscle (LMM) quality, and clinical outcomes. None have assessed the potential mediating role of the LMM between degenerative pathology and 12-month clinical outcomes. This prospective cohort study used baseline and 12-month follow-up data from 569 patients conservatively managed for low back or back-related leg pain to estimate the effects of aggregate degenerative lumbar MRI findings and LMM quality on 12-month low back and leg pain intensity (0–10) and disability (0–23) outcomes, and explored the mediating role of LMM quality between degenerative findings and 12-month clinical outcomes. Adjusted mixed effects generalized linear models separately estimated the effect of aggregate spinal pathology and LMM quality. Mediation models estimated the direct and indirect effects of pathology on leg pain, and pathology and LMM quality on leg pain, respectively. Multivariable analysis identified a leg pain rating change of 0.99 [0.14; 1.84] (unstandardized beta coefficients [95% CI]) in the presence of ≥ 4 pathologies, and a disability rating change of − 0.65 [− 0.14; − 1.16] for each 10% increase in muscle quality, but no effect on back pain intensity. Muscle quality had a non-significant mediating role (13.4%) between pathology and leg pain intensity. The number of different pathologies present demonstrated a small effect on 12-month leg pain intensity outcomes, while higher LMM quality had a direct effect on 12-month disability ratings but no mediating effect between pathology and leg pain. The relations between degenerative pathology, LMM quality, and pain-related outcomes appear complex and may include independent pathways.