Antimicrobial Therapy in One-Stage Revision Surgery

Unlike antibiotic therapy of acute infections caused by rapidly dividing bacteria, anti-infective strategies in PJI have to take into consideration that device-associated infections are associated with specific bacterial phenotypes, i.e., multicellular biofilm formation and intracellular persistence [1, 2]. Generally, biofilm formation is associated with significant changes in bacterial metabolism, ultimately leading to a broadly reduced susceptibility (i.e., increased MICs) against a broad range of antibiotics. Resistance emerging from biofilm formation is unrelated to commonly known specific resistance mechanisms (i.e., expression of defined resistance determinants) and is referred to as phenotypic resistance [3]. Phenotypic resistance, in combination with complex pharmacokinetics present in infected bone and soft tissues and local immune dysfunctions related to the implanted device, demand high doses of systemic as well as topical antibiotics, prolonged therapy courses, and, in some cases, combination therapies.