Intra-Articular Injection of 0.5% Buprenorphine in Early Osteoarthritis of Knee Joint: A Study of 50 Cases

Abstract

Abstract Background: Osteoarthritis (OA) of the knee is a disabling disease. Recently, relatively younger patients with early OA and knee pain are increasing. Intra-articular (IA) therapies need to address the inflammation associated with OA along with pain relief. Recent reports suggest the presence of opioid receptors in peripheral locations and presence of their anti-inflammatory actions of IA opioid injections. Aim: To study the role of IA buprenorphine injection in the management of early OA of the knee joint. Materials and Methods: A prospective study of 50 patients with early OA was carried out. Patients were administered 2 ml IA 0.5% buprenorphine on days 1 and 7. The results were assessed with Oxford Knee Score (OKS) and Visual Analog Scale (VAS) on days 1, 7, 15, 30, and 90. Results: There was a significant improvement in mean OKS till day 30 (P < 0.0001) with values at day 90 showing similar results to day 1. The mean VAS values also showed a significant improvement till day 30 (P < 0.0001). There was no significant change in total neutrophil counts in synovial fluid on day 7. The most common adverse effect reported was nausea and vomiting (24%), pointing to systemic absorption. Conclusion: IA injection of buprenorphine showed no reduction in neutrophil counts in synovial fluid in this study and the pain relief resulting may in part be attributable to systemic absorption of the drug. Better depot preparations and further research into chondroprotective action of IA opioid injections are still needed to recommend it as a viable therapeutic option in early OA of the knee.