Antimicrobial efficacy of external fixator pins coated with a lipid stabilized hydroxyapatite/chlorhexidine complex to prevent pin tract infection ina goat model

Background: Pin tract infection is a common complication of external fixati on, An antiinfective external fixator pin might help to reduce the incidenc e of pin tract infection and improve pin fixation, Methods: stainless steel and titanium external fixator pins, with and witho ut a lipid stabilized hydroxgiapatite/chlorhexidine coating, were evaluated in a goat model. Two pins contaminated with an identifiable Staphylococcus aureus strain were inserted into each tibia of 12 goats. The pin sites wer e examined daily. On day 14, the animals were killed, and the pin tips cult ured. Insertion and extraction torques were measured. Results: Infection developed in 100% of uncoated pins, whereas coated pins demonstrated 4.2% infected, 12.5% colonized, and the remainder, 83.3%, had no growth (p < 0.01). Pin coating decreased the percent loss of fixation to rque Over uncoated pins (p = 0.04), Conclusion: These results demonstrate that the lipid stabilized hydroxyapat ite/chlorhexidine coating was successful in decreasing infection and improv ing fixation of external fixator pins.