Investigation of the efficacy of intra-articular botulinum toxin type A application in the treatment of experimentally induced osteoarthritis in rats

This study aimed to evaluate the effectiveness of botulinum toxin type A in rat model of experimentally induced osteoarthritis. The experiment was conducted on 30 male Sprague-Dawley rats. Osteoarthritis was induced via intra-articular injection of MIA at a dose of 3 mg per rat. The efficacy of intra-articular injections of 10 U BoNT-A and 20 U BoNT-A was assessed through body weight monitoring, knee circumference measurements, leg posture scoring, as well as X-ray, µCT and histopathological examination. Data were analysed using repeated measures ANOVA, generalised linear model, Kruskal-Wallis test, independent samples T test and Mann-Whitney U test. BoNT-A administration led to a significant decrease in body weight and a significant increase in lameness scoring. No significant change was observed in knee circumference measurements by the end of the study. While X-ray evaluations showed no significant differences, micro-CT analyses revealed statistically significant changes. In conclusion, BoNT-A produced statistically significant yet clinically negligible effects on pain and bone parameters. Additionally, higher doses (20U) of BoNT-A were associated with adverse effects.