Bisphosphonates and Antibiotics Combination Therapy for Chronic Low Back Pain Associated with Modic Change: A Quasi-Experimental Study

Background: Although effective treatments are still lacking for chronic low back pain (CLBP) associated with Modic changes (MC), in recent years, the efficacy of bisphosphonate and antibiotic treatment has been tested separately with variable success. This study aimed to compare the effectiveness of combined therapy of bisphosphonate and antibiotics versus single-drug therapy in CLBP patients with MC.Methods: This quasi-experimental study was carried out from October 2019 to September 2020 according to 1964 Helsinki declaration among 60 adult CLBP patients with MC (confirmed by magnetic resonant imaging) and randomly allocated in Group-A (n=20): Zoledronic acid (ZA) only, Group-B (n=20): amoxicillin-clavulanate only, and Group-C (n=20): both ZA and amoxicillin-clavulanate. The primary outcomes were measured by the visual analog scale (VAS) and Roland Morris disability questionnaire (RMDQ) at follow-ups after 1 month, 100 days, and 6 months. Per-protocol analysis was performed using SPSS 24.Results: Out of the 60 patients, 43 patients (72%) completed all three follow-ups. The VAS score gradually decreased in all groups after treatment, wherein Group-C patients had the significantly lowest score at the 2nd and 3rd follow-ups (2.87±0.80 and 1.68±0.70, respectively) compared to Group-A (3.40±0.63 and 2.20±0.67, respectively) and Group-B (3.50±0.52 and 2.41±0.66,respectively). In addition, RMDQ also decreased significantly after 1 month compared to pretreatment (p<0.05) in all 3 groups, and this gradual decrement was continued until 6 months of treatment. However, it was reduced more in Group-C (6.26±0.70) than in group-A (6.69±1.40) and Group-B (7.75±1.21) at the end of the 3rd follow-up. Moreover, Group-C patients had the highest satisfaction level and lowest number of days with absence from work score compared to A and B (p<0.05). However, adverse effects were relatively higher in Group-C than A and B (p>0.05).Conclusion: Bisphosphonates and antibiotics combination therapy is more effective than single-drug therapy for CLBP associated with MC.