Salvage of contaminated osteochondral allografts: the effects of chlorhexidine on human articular chondrocyte viability.

Because chondrocyte viability is imperative for successful osteochondral allograft transplantation, sterilization techniques must provide antimicrobial effects with minimal cartilage toxicity. Chlorhexidine gluconate (CHG) is an effective disinfectant; however, its use with human articular cartilage requires further investigation.To determine the maximal chlorhexidine concentration that does not affect chondrocyte viability in allografts and to determine whether this concentration effectively sterilizes contaminated osteoarticular grafts.Controlled laboratory study.Osteochondral plugs were subjected to pulse lavage with 1-L solutions of 0.002\%, 0.01\%, 0.05\%, and 0.25\% CHG and cultured for 0, 1, 2, and 7 days in media of 10\% fetal bovine serum and antibiotics. Chondrocyte viability was determined via LIVE/DEAD Viability Assay. Plugs were contaminated with Staphylococcus aureus and randomized to 4 treatment groups. One group was not contaminated; the 3 others were contaminated and received no treatment, saline pulse lavage, or saline pulse lavage with 0.002\% CHG. Serial dilutions were plated and colony-forming units assessed.The control group and the 0.002\% CHG group showed similar cell viability, ranging from 67\% \ub1 4\% to 81\% \ub1 22\% (mean \ub1 SD) at all time points. In the 0.01\% CHG group, cell viability was reduced in comparison with control by 2-fold at day 2 and remained until day 7 (P 0.002\% significantly decreases chondrocyte viability within 1 to 2 days after exposure and should therefore not be used for disinfection of osteochondral allograft. Pulse lavage does not affect chondrocyte viability but cannot be used in isolation to sterilize contaminated fragments. Overall, 0.002\% CHG was shown to effectively decontaminate osteoarticular fragments.This study offers a scientific protocol for sterilizing osteochondral fragments that does not adversely affect cartilage viability