title: Salvage of contaminated osteochondral allografts: the effects of chlorhexidine on human articular chondrocyte viability.
abstract: BACKGROUND
  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.
  
  
  OBJECTIVE
  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.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  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.
  
  
  RESULTS
  The control group and the 0.002% CHG group showed similar cell viability, ranging from 67% ± 4% to 81% ± 22% (mean ± 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 < .01). The 0.05% and 0.25% CHG groups showed a 2-fold reduction in cell viability at day 1 (P < .01). At day 7, cell viability was reduced to 15% ± 18% (4-fold decrease) for the 0.05% CHG group and 10% ± 19% (6-fold decrease) for the 0.25% CHG group (P < .01). Contaminated grafts treated with 0.002% CHG demonstrated no colony-forming units.
  
  
  CONCLUSIONS
  Pulse lavage with 0.002% CHG does not cause significant cell death within 7 days after exposure, while CHG at concentrations >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.
  
  
  CONCLUSIONS
  This study offers a scientific protocol for sterilizing osteochondral fragments that does not adversely affect cartilage viability.
authors: Brian Cole, Department of Orthopedics, Anatomy and Cell Biology, Rush University Medical Center, 1611 West Harrison Avenue, Suite 300, Chicago, IL 60612, USA. bcole@rushortho.com.
authors: Joel
authors: J
authors: Campbell
authors: Giuseppe
authors: G
authors: Filardo
authors: Benjamin
authors: B
authors: Bruce
authors: Sarvottam
authors: S
authors: Bajaj
authors: Nicole
authors: N
authors: Friel
authors: Arnavaz
authors: A
authors: Hakimiyan
authors: Stephen
authors: S
authors: Wood
authors: Robert
authors: R
authors: Grumet
authors: Sasha
authors: S
authors: Shafikhani
authors: Susan
authors: S
authors: Chubinskaya
authors: Brian J
authors: BJ
authors: Cole
mesh_terms: D064591:Allografts; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D002356:Cartilage / Q000187:drug effects* / Q000637:transplantation; D002358:Cartilage, Articular / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D019902:Chondrocytes / Q000187:drug effects* / Q000637:transplantation; D005269:Femur / Q000637:transplantation; D006801:Humans; D013242:Sterilization / Q000379:methods*
chemical_list: D000891:Anti-Infective Agents, Local; C010882:chlorhexidine gluconate; D002710:Chlorhexidine
keywords: contamination; decontamination; dropped; osteochondral graft