Prevention of pin tract infection with titanium‐copper alloys

The most frequent complication in external fixation is pin tract infection. To reduce the incidence of implant‐associated infection, many published reports have looked at preventing bacterial adhesion by treating the pin surface. This study aimed to evaluate the antibacterial activity of a Titanium‐Copper (Ti‐Cu) alloy on implant infection, and to determine the potential use of the Ti‐Cu alloy as a biomaterial. Two forms of Ti‐Cu alloys were synthesized: one with 1% Cu and the other with 5% Cu. For analyzing infectious behavior, the implants were exposed to Staphylococcus aureus and Escherichia coli . The reaction of pathogens to the Ti‐Cu alloys was compared with their reaction to stainless steel and pure titanium as controls. Both Ti‐Cu alloys evidently inhibited colonization by both bacteria. Conversely, cytocompatibility studies were performed using fibroblasts and colony formation on the metals was assessed by counting the number of colonies. Ti‐1% Cu alloy showed no difference in the number of colonies compared with the control. External fixator pins made of Ti‐Cu alloys were evaluated in a rabbit model. The tissue‐implant interactions were analyzed for the presence of infection, inflammatory changes and osteoid‐formation. Ti‐1% Cu alloy significantly inhibited inflammation and infection, and had excellent osteoid‐formation. Copper blood levels were measured before surgery and at 14 days postoperatively. Preoperative and postoperative blood copper values were not statistically different. Overall, it was concluded that Ti‐Cu alloys have antimicrobial activity and substantially reduce the incidence of pin tract infection. Ti‐1% Cu alloy shows particular promise as a biomaterial. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009