Introduction: Low back pain (LBP) is a globally prevalent musculoskeletal condition that poses significant public health challenges due to its impact on quality of life and socioeconomic burden. While magnetic resonance imaging (MRI) findings such as disc degeneration (DD), Modic changes (MC), and Schmorl's nodes (SN) have been suggested as potential contributors to LBP, their longitudinal relationship remains unclear.
The purpose of this study was to examine the seven-year changes in LBP status and their association with MRI findings (DD, MC, and SN) in a large population-based cohort.
Methods: The Wakayama Spine Study followed 520 participants (mean age 60.3 years, 63.7% follow-up rate) over seven years, starting from 2009. LBP was defined as pain lasting for one month or longer. MRI phenotyping was performed by assessment of DD (using Pfirrmann's system) between L1/2 and L5/S1, MC (identified by diffuse high-intensity signal changes on endplates), and SN (defined as herniation pits with hypointense signals). Multivariate logistic regression analysis examined the relationship between newly developed LBP (71 participants) and baseline DD, MC, and SN, compared to 241 participants without LBP changes, adjusting for sex and age.
Results: After seven years, 46.3% of participants remained pain-free, 13.7% developed new LBP, 25.0% had persistent LBP, and 15.0% had resolved LBP. The prevalence of DD showed minimal increase (89.6% to 92.1%), MC remained stable (47.7% to 46.5%), while SN prevalence notably increased (27.1% to 50.4%). Multivariate analysis revealed no significant associations between newly developed LBP and baseline DD, MC, or SN.
Conclusions: Despite considerable variation in LBP status over seven years, most MRI findings remained relatively stable, except for a marked increase in SN prevalence. The lack of association between baseline MRI findings and new-onset LBP suggests that these structural changes may not be strongly predictive of LBP development in subjects with advanced age. These findings highlight the complex nature of LBP and support the notion that clinical decisions should not be based solely on MRI findings.