Effect of Intraarticular Injection of Lornoxicam on the Articular Cartilage & Synovium in Rat

Abstract

Background & objectives: Intraarticular (i.a) drug application is consider to be a new therapeutic approach for the treatment of postoperative pain after arthroscopic knee surgery without any systemic adverse effects. Lornoxicam, a nonsteroid anti-inflammatory drug is a short acting agent, and its anti-inflammatory and analgesic activity may be effective in the postoperative pain management in minor surgery. In this study, the effects of intraarticular administration of lornoxicam on the synovium and articular cartilage in the rat knee joint were investigated. Methods: Lornoxicam (0.25 ml) was given as an injection into the right knee joint and 0.25 ml of 0.9 per cent saline solution by injection into the left knee joint as a control in 25 rats. Groups of five rats were sacrificed by a lethal injection of ketamine 1(st), 2(nd), 7(th), 14(th) and 21(th) days after lornoxicam administration. Knee joints were detached, fixed in 10 per cent buffered formalin and decalcified. Serial sections of 5 mu m were stained with haematoxylin-eosin and evaluated for the presence of inflammation in the articular, periarticular regions and synovium. Inflammatory changes in the joints were graded according to a five-point scale, histologically. Results: There were no significant differences in inflammation and cartilage degeneration, between control and lornoxicam applied knees. Grade 3 inflammatory changes occurred only in one knee in lornoxicam group, at 24 h after injection. No pathological changes were observed in both groups at any time point. Interpretation & conclusions: Lornoxicam did not show significant effect on inflammation on rat synovia in knee joint. Further studies including in human need to be done before any recommendations are made for La. administration of lornoxicam.