Experimental septic arthritis in rabbits treated by a combination of antibiotic and steroid drugs

Intraarticular steroid injection is traditionally contraindicated during acute septic arthritis. However, there is abundant evidence which proves that the damage to the joint is not only due to the direct effect of bacteria, but also to the local protective mechanisms evoked by the organism. There is, therefore, theoretical justification for a combined therapy of systemic antibiotics and intraarticular corticostertoids in septic arthritis.

Experimental arthritis was induced by the intraarticular injection of Staphylococcus epidermidis in rabbits. The experimental scheme included three groups of animals: animals that were infected but not treated (group 1); animals treated with systemic antibiotics (group 2); and animals treated with systemic antibiotics and intraarticular steroids (group 3). Nine days later the animals were sacrificed and joint histopathological-histochemical indices were calculated.

Animals from groups 2 and 3 had a smaller pannus, reduced proteoglycan loss, no loss of cartilage height and diminished synovial inflammation in comparison to the animals from group 1. The animals from groups 2 and 3 were identical in terms of cartilage cellularity, surface erosion, chondrocyte cloning, pannus formation and proteoglycan loss. Synovial inflammation appeared to be less pronounced in group 3 animals when compared to animals of group 2.

Concomitant antibiotic-steroid treatment of septic arthritis seems to be harmless in this experimental setting.