Enhancing PMMA Cements With Manually Added Antimicrobial Agents

Abstract

Periprosthetic joint infection (PJI) is an infrequent yet severe complication. A fundamental aspect of PJI treatment involves the use of polymethylmethacrylate (PMMA) cement augmented with antibiotics. For therapeutic application, it is often necessary to manually mix antibiotics with commercially produced PMMA cements. However, the potential issues arising from this manual admixing have not been thoroughly documented. This study aims to elucidate the impact of additional homogenization through dry mixing of a polymer-active substance blend on the quality of manually mixed PMMA cement. In this laboratory-based investigation, four cement samples were prepared using various methods for the manual incorporation and homogenization of the antibiotic vancomycin. The reference controls were Copal G + V and Copal G + C pro (Heraeus Medical GmbH, Wehrheim, Germany), representing commercially available PMMA cements and a closed mixing system. The samples were analyzed for mechanical, microbiological, and microscopic properties. The mechanical and microbiological analyses revealed no statistically significant differences between the manually mixed samples and the references. However, microscopic examination of the mixing cartridges' inner surfaces indicated scratching and signs of abrasion during the mixing process. The manual incorporation of antibiotics into PMMA cement should be limited to specific indications, with a preference for using commercially available mixtures whenever possible.