evaluation of delayed effect of intra-articular injection of cefazolin, gentamicin and vancomycin on articular cartilage: an experimental study in rabbits

background: antibiotics are the most common additives used in irrigation solutions for open fractures. none-the less, there have been few studies exploring the effects of antibiotics on articular cartilage. the purpose of this study was to evaluate the delayed effect of intra-articular injection of cefazolin, gentamicin and vancomycin on articular cartilage.objectives: we proposed they may have potential toxicity on articular cartilage and this effect may be manifested as a delayed phenomenon due to changes in matrix and cell viability.materials and methods: a sample of 20 rabbits was chosen and assigned into 4 groups (each containing 5 animals). a course of antibiotics including gentamicin, vancomycin and cefazolin was injected in both knees of test rabbits. normal saline was injected to controls. after 8 weeks, articular cartilage of distal femurs was harvested and analyzed using confocal microscopy and real time pcr.results: according to confocal microscopy results, gentamicin and vancomycin had significant decrease in live chondrocyte cell number; however, cefazolin had no effect.conclusions: quantitative analysis showed no significant difference between antibiotics and control group. we found that cefazolin can be safely used for intra-articular injections, but vancomycin and gentamicin should be used cautiously.