Disinfecting agents for removing adherent bacteria from orthopaedic hardware.

This investigation seeks to determine whether surfactants or detergents can be used to clean and disinfect orthopaedic wounds with implanted hardware. Thus, a stepwise investigation of biocompatible surfactants and detergents was performed to identify an irrigation agent for disinfecting orthopaedic wounds. Bacterial adhesions assays, irrigation studies, and bactericidal assays determined that benzalkonium chloride showed the greatest efficacy. Testing involved stainless steel screws colonized with a preformed biofilm of Staphylococcus epidermidis, Staphylococcus aureus, or Pseudomonas aeruginosa, which were immersed in benzalkonium chloride solutions for various time intervals under static conditions. After 10 minutes, benzalkonium chloride achieved a minimum 4 log kill (10,000-fold) for all 3 strains of bacteria. Additional studies demonstrated that the high mechanical energy of jet irrigation improved the disinfecting properties of this agent. With jet lavage, both 1:1000 and 1:5000 concentrations of benzalkonium chloride achieved a minimum 2 log kill (100-fold) for all 3 bacteria. The results or this study suggest that at tissue compatible concentrations, benzalkonium chloride has significant disinfection properties for in vitro colonized orthopaedic devices, and these properties may be enhanced via jet lavage.