INTRODUCTION
Modic changes in adjacent endplates are frequently observed in lumbar disc herniation patients and are often associated with severe low back pain and poorer surgical outcomes, but conclusions remain unclear. This study aimed to clarify whether preoperative Modic changes and their subsequent alterations affect postoperative outcomes.
METHODS
From June 2014 to September 2020, 120 patients underwent single-level lumbar disc herniation surgery at our institution. Of these, 51 patients with over two years of follow-up data were included. All patients received lumbar MRI both preoperatively and two years postoperatively to assess Modic changes at adjacent endplates of the herniation. Based on MRI findings, patients were grouped by the presence or absence of preoperative Modic changes. Additionally, Modic type was evaluated by MRI at the two-year follow-up to determine any alterations from the preoperative MRI. Evaluations were conducted preoperatively and at 1, 3, 6 months, 1, 1.5, and 2 years postoperatively, including lumbar lordosis (LL), Oswestry Disability Index (ODI), and Visual Analogue Scale (VAS) scores for back pain, leg pain, and numbness. Statistical analyses were used to compare outcomes between groups.
RESULTS
Preoperative Modic changes were observed in 15 patients (Type 1: 3 cases, Type 2: 10 cases, Type 3: 2 cases), with no significant differences in baseline demographics between patients with and without Modic changes. Across all evaluation periods, lumbar lordosis and ODI showed no statistically significant differences between groups. For VAS scores, the presence of Modic changes was not associated with worse outcomes, except for a transient improvement in leg pain in the Modic-positive group at one month postoperatively. Among the 51 patients, alterations of Modic type were observed in 12 cases (23.5%): 9 cases newly developed Modic Type 1, and 3 cases showed a shift from Type 1 to Type 2. No significant differences were found between patients with and without Modic type alterations; however, patients with alterations showed better improvement in leg pain VAS scores at one month postoperatively.
DISCUSSION
Our study indicates that neither preoperative Modic changes nor postoperative Modic type alterations significantly influenced long-term outcomes in lumbar disc herniation surgery. Although Modic Type 1 is often associated with worse symptoms, our findings suggest that Modic changes may not reliably predict surgical outcomes. These results align with recent meta-analyses concluding that the presence or absence of Modic changes before surgery does not significantly impact postoperative clinical outcomes. This suggests that Modic changes have limited relevance in surgical indications or treatment selection. Interestingly, of the 36 patients without preoperative Modic changes, 12 showed newly developed Modic changes. This finding suggests that the adjacent endplates were adversely affected by newly developed disc herniation. However, these newly developed endplate changes did not result in poorer surgical outcomes, indicating that postoperative Modic alterations may not have clinically significant effects. Although leg pain improved at one month in patients with preoperative Modic changes or subsequent Modic alterations, this effect was not sustained, suggesting limited clinical significance. Further studies with larger cohorts are warranted to investigate potential effects on surgical outcomes.