Quantitative assessment of the effect of 0.05% chlorhexidine on rat articular cartilage metabolism in vitro and in vivo.

Wound infection remains a problem. Syringe and needle jet lavage of chlorhexidine gluconate 0.05% removed or killed 99.8% of contaminating bacteria within 1 minute in a wound model. In clinical use, however, possible toxicity to articular cartilage is a concern. In an established intact rat patella model in vitro, 1 minute of exposure to chlorhexidine 0.05% and chlorhexidine jet lavage did not significantly alter cartilage metabolism. A 1-hour exposure decreased metabolic activity. In vivo, a 30-minute exposure with or without rinsing produced no impairment of metabolic activity 6 weeks later, suggesting that cartilage has the potential for biological recovery. However, injecting and leaving chlorhexidine 0.05% in the joints was detrimental to the metabolic activity of the articular cartilage as assessed 6 weeks later. Thus, chlorhexidine gluconate 0.05% could be used on normal articular cartilage. Any potential damage from prolonged exposure can be avoided by rinsing after 1 minute.