Is the development of Modic changes associated with clinical symptoms? A 14-month cohort study with MRI
Modic changes (MCs) have been suggested to be a diagnostic subgroup of low back pain (LBP). However, the clinical implications of MCs remain unclear. For this reason, the aims of this study were to investigate how MCs developed over a 14-month period and if changes in the size and/or the pathological type of MCs were associated with changes in clinical symptoms in a cohort of patients with persistent LBP and MCs. Information on LBP intensity and detailed information from MRI on the presence, type and size of MCs was collected at baseline and follow-up. Changes in type (Type I, II, III and mixed types) and size of MCs were quantified at both time points according to a standardised evaluation protocol. The associations between change in type, change in size and change in LBP intensity were calculated using odds ratios (ORs). Approximately 40 % of the MCs followed the expected developmental path from Type I (here Type I or I/II) to Type II (here Type II or II/III) or Type I to Type I/II. In general, the bigger the size of the MC at baseline, the more likely it was that it remained unchanged in size after 14 months. Patients who had MC Type I at both baseline and 14-month follow-up were less likely to experience an improvement in their LBP intensity as compared to patients who did not have Type I changes at both time points (OR 7.2, CI 1.3–37). There was no association between change in size of MCs Type I and change in LBP intensity. The presence of MCs Type I at both baseline and follow-up is associated with a poor outcome in patients with persistent LBP and MCs.