Comparison of the membrane filtration of the sonication fluid technique with the habitual centrifugation of the sonication fluid technique for diagnosis of infection in orthopaedic implants biofilms

Abstract

Orthopedic implants can improve mobility and quality of life, but early or late infections can result in devastating consequences. Commonly biofilm-associated pathogens, such as Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus are difficult to treat and eradicate with antibiotics. For diagnosis, the best microbiology approach so far has been the periprosthetic tissue culture collected during surgery. Nevertheless, the sensitivity and specificity ranged from 65 to 94% [3].In order to increase the recovery of pathogens, and consequently improve treatment, further diagnostic strategies have been developed. The sonication has obtained excellent results, with increased sensitivity in the diagnosis of infections associated with orthopedic implants. Sonication uses ultrasonic low frequency and low-intensity energy applied directly on the surface of metallic implants leading to the formation of microbubbles that assist in dislodging small amounts of biofilm. The habitual sonication technique involves culturing only small aliquots of the sonicated fluid, which may result in a loss of pathogens outside these aliquots but in the sonicated fluid. The aim of this study is to evaluate if the membrane filtration of the sonication fluid technique is better than the habitual centrifugation of the sonication fluid technique for microbiological detection and identification of infections associated with orthopedic implants and analyze the risk factors for infections associated with orthopedic implants. This study will be a prospective cohort study comparing the results obtained from the cultures of the sonicated fluid (using the habitual technique) with the result of the cultures of the membrane that filtered the sonicated fluid. (AU)