Antibiotic Treatment in Patients with Chronic Low Back Pain and Vertebral Bone Edema, a Double-Blind RCT of Efficacy

Background Modic type 1 changes (bone edema) in the vertebrae are present in 6% of the general population and in 35 to 40% of the low back pain population. It is strongly associated with low back pain (LBP). The aim was to test the efficacy of antibiotic treatment in patients with chronic LBP (> 6 months) and Modic type 1 changes (bone edema). Methods The study was a double-blind RCT with 162 patients whose only known illness was chronic LBP of greater than 6 months duration occurring after a previous disc herniation and who also had bone edema demonstrated as Modic type 1 changes in the vertebrae adjacent to the previous herniation. Patients were randomized to either 100 days of antibiotic treatment or placebo and were blindly evaluated at baseline; end of treatment and at 1-year follow-up. As primary outcome measures were disease-specific disability and lumbar pain. Secondary outcome leg pain, number of hours with pain last 4 weeks, global perceived health, EQ-5D thermometer, days with sick leave, bothersomeness, and constant pain. Results Of the 162 original patients, 144 were evaluated at 1-year follow-up. The two groups were similar at baseline. The antibiotic group improved highly statistically significant on all outcome measures and improvement progressed from 100 days follow-up until 1-year follow-up. At baseline, 100 days follow-up, and 1-year follow-up the disease-specific disability RMDQ changed; antibiotic 15, 11, 5.7, placebo 15, 14, 14. Leg pain; antibiotics 5.3, 3.0, 1.4, placebo 4.0, 4.3, 4.3. Lumbar pain; antibiotics 6.7, 5.0, 3.7, placebo 6.3, 6.3, 6.3 For the outcome measures, where a clinically important effect size was defined, improvements exceeded the thresholds, and a trend toward a dose-response relationship with double dose antibiotics being more efficacious. Conclusions The antibiotic protocol in this study was significantly more effective for this group of patients, (CLBP associated with Modic type I), than placebo in all the primary and secondary outcomes. Disclosure of Interest None declared