Association of Modic Changes, Schmorl's Nodes, Spondylolytic Defects, High-Intensity Zone Lesions, Disc Herniations, and Radial Tears With Low Back Symptom Severity Among Young Finnish Adults

Study Design. A cross-sectional magnetic resonance imaging (MRI) study. Objective. We investigated the association among Modic changes, Schmorl's nodes, spondylolytic defects, high-intensity zone lesions, radial tears, herniations, and low back symptom severity. Summary of Background Data. Disc degeneration is associated with low back pain in early adulthood, but the associations between other MRI findings and low back pain are not well known. Methods. Questionnaire data and MRI scans (1.5-T) were available for 554 subjects derived from a birth cohort at 21 years of age. Data on low back pain and back-related functional limitations at 18, 19, and 21 years of age were used for clustering of subjects, using latent class analysis. We used logistic regression with adjustment for the degree of disc degeneration to evaluate the associations between specific imaging findings and low back symptom severity. Results. The prevalence of herniations was 20%, Schmorl's nodes 17%, radial tears 9.9%, high-intensity zone lesions 3.2%, spondylolytic defects 5.8%, and Modic changes 0.7%. Latent class analysis produced 5 clusters: Always Painful (n = 65) meant painful at all time points and Recent Onset Pain (n = 56) meant increasing symptom severity, whereas subjects in the Moderately Painful (n = 73), Minor Pain (n = 193), and No Pain (n = 167) clusters had fewer symptoms. Compared with the No Pain cluster, Schmorl's nodes were more likely to occur in the Always Painful cluster (P = 0.017) and herniations in the 3 most painful clusters (P < 0.001). Herniations were associated with low back symptom severity (odds ratio, 2.5; 95% confidence interval, 1.4-4.4). Schmorl's nodes and radial tears were associated with symptoms in crude analyses only, whereas high-intensity zone lesions and spondylolytic defects occurred in similar frequencies in all clusters. Conclusion. Herniations were most likely in the subjects with recent onset or persistent (3-yr period) low back symptoms, although they were also detected in subjects with no symptoms. The clinical relevance of herniations on MRI remains to be evaluated in the context of symptoms.