Association between MRI findings and inflammatory symptoms in non-specific chronic low back pain

Non-specific chronic low back pain (nsCLBP) likely constitutes a heterogeneous group of conditions, and identifying an inflammatory phenotype may improve treatment stratification. The objective of this study was to determine associations between inflammatory back pain (IBP) features and MRI findings in subjects with nsCLBP. Participants were selected from the longitudinal Clinical Cohort for Comprehensive Deep Phenotyping of Chronic Low-Back Pain Adults Study (comeBACK), a cohort of adults with nsCLBP. IBP features (morning stiffness, nocturnal LBP, symptom improvement with exercise / worsening with rest, insidious onset, onset < 40 years) were assessed via questionnaire. MRI scans of the lumbar spine were interpreted by a radiologist, using a comprehensive scoring system: Modic changes (MC), endplate erosion, facet joint arthritis, central canal stenosis and degeneration of the sacroiliac joints (SIJ). Logistic regression was performed (presence IBP feature as dependent variable and MRI findings as independent variables). A total of 290 individuals (159 female) were included. Both endplate erosion and MC1 changes were positively associated with overall IBP (erosion: OR 2.1, 95%CI 1.3–3.3; MC1: OR 2.2, 95%CI 1.4–3.4), and specifically morning stiffness and worsening with rest. Negative association with overall IBP symptoms was found for SIJ degeneration (OR 0.6, 95%CI 0.4-1.0) and no association for facet arthropathy, MC2 and central canal stenosis. Our exploratory analysis supports the notion of an inflammatory nsCLBP phenotype with distinguishing imaging features, by establishing associations between endplate erosion and Modic type 1 changes with select IBP features.