Antimicrobial Efficacy of Five Wound Irrigation Solutions in the Periprosthetic Joint Infection Microenvironment In Vitro and Ex Vivo.

Abstract

Background/Objectives: Periprosthetic joint infections (PJI) are difficult to treat due to biofilm formation on implant surfaces and the surrounding tissue, often requiring removal or exchange of prostheses along with long-lasting antibiotic treatment. Antiseptic irrigation during revision surgery might decrease bacterial biofilm load and thereby improve treatment success. This in vitro study investigated and compared the effect of five advanced wound irrigation solutions to reduce bacterial burden in the PJI microenvironment. Methods: We treated in vitro biofilms grown on titanium alloy implant discs with clinical bacterial strains isolated from patients with PJIs, as well as abscess communities in a plasma-supplemented collagen matrix. The biofilms were exposed for 1 min to the following wound irrigation solutions: Preventia^®, Prontosan^®, Granudacyn^®, ActiMaris^® forte ('Actimaris'), and Octenilin^®. We measured the bacterial reduction of these irrigation solutions compared to Ringer-Lactate and to the strong bactericidal but not approved Betaseptic solution. Additionally, ex vivo free-floating bacteria isolated directly from clinical sonication fluids were treated in the same way, and regrowth or lack of regrowth was recorded as the outcome. Results: Irrigation solutions demonstrated variable efficacy. The mean CFU log₁₀ reduction was as follows: Octenilin, 3.07, Preventia, 1.17, Actimaris, 1.11, Prontosan, 1.03, and Granudacyn, 0.61. For SACs, the reduction was: Actimaris, 8.27, Octenilin, 0.58, Prontosan, 0.56, Preventia, 0.35, and Granudacyn, 0.24. Conclusions: All solutions achieved complete bacterial eradication in all tested ex vivo sonication fluids, except Granudacyn, which was ineffective in 33% of the samples (2 out of 6). Advanced wound irrigation solutions have the potential to reduce bacterial burden in the PJI microenvironment during revision surgery. However, their efficacy varies depending on bacterial species, growth state, and the composition of the irrigation solution. This underscores the importance of considering these factors when developing future PJI-specific irrigation solutions.