Although rates of total joint prosthetic
infections remain relatively constant at 1-3%, an increasing number of
orthopedic procedures and a corresponding rise in the absolute number of infectious complications mandate distinctly new solutions. In order to combat the implant
infection threat, an
antibiotic-releasing bone void filler (BVF), commercial tradename, ElutiBone, has been developed using a combination of commercially available ceramic-based BVF plus clinically familiar biocompatible
polymers, and a variety of select, dispersed
antibiotics. While several traditional
antibiotics have been successfully released for an extended duration, a more versatile strategy, releasing multiple
antibiotics simultaneously, may be possible. In this study, the
antiseptic chlorhexidine and a variety of bacteriostatic
silver compounds were incorporated to provide synergistic antimicrobial activity upon release in combination formulations from ElutiBone matrices.
Silver chloride was the most effective bacteriostatic tested (p=0.05), showing a measurable zone of inhibition at spiked concentrations as low as 31µg/ml. Subsequently,
silver chloride was used in combination with the
antiseptic chlorhexidine to test for enhanced antimicrobial bioactivity against S. aureus. Measurable synergy between the two compounds confirmed the suitability of ElutiBone to locally deliver this multidrug antimicrobial cocktail. A myriad of other drug interactions could and should be tested in this novel system in order to expand the utility and combat the increasing prevalence of
polymicrobial infections.