Comparison of the efficiency of different antibiotic irrigation solutions in decontamination of allografts contaminated with Staphylococcus aureus

Abstract

The purpose of this study was to investigate the local antibacterial efficacy of saline, rifampicin, gentamicin, high-concentration fusidic acid and low-concentration fusidic acid in the decontamination of allografts contaminated with Staphylococcus aureus. Fifty-five sterile, fresh-frozen femoral heads obtained from the bone bank were contaminated with methicillin-sensitive ATCC 25923 Staphylococcus aureus. Samples were divided into groups and debrided with high-pressure (80 psi) pulse lavage using a saline, rifampicin irrigation solution (50 mg/l), gentamicin irrigation solution (50 mg/l) and low- (50 mg/l) or high-concentration (500 mg/l) fusidic acid irrigation solution for 30 seconds from a distance of 10 cm. After irrigation, allografts were incubated in the culture and developed colonies were counted. Mean±standard deviation (min-max) values were calculated. The differences between the four irrigation groups were evaluated using the Kruskal-Wallis variance analysis and groups were compared two at a time using the post-hoc Mann-Whitney U test. No colonization was detected with the exception of one allograft in the rifampicin irrigation group. The gentamicin irrigation group had similar results as the high-concentration fusidic acid irrigation group and both results were superior to those of the saline and low-concentration fusidic acid irrigation groups (p=0.010 and 0.004, respectively). The low- and high-concentration fusidic acid irrigation groups were similar and were not shown to have superior results than saline irrigation group. Rifampicin irrigation solution was the most effective in the decontamination of allografts previously contaminated with Staphylococcus aureus. Gentamicin, high-concentration fusidic acid, low-concentration fusidic and saline irrigation solutions may also be used respectively, according to their effectiveness.