In vitro comparison between commercially and manually mixed antibiotic-loaded bone cements.

Abstract

Purpose: The purpose of this study is the evaluation of the differences and, eventually, of the advantages or disadvantages of manual formulations with respect to industrial ones.

Methods: Medical-grade bone cements (Palacos R® and Palacos LV®), based on poly-methyl methacrylate (PMMA) and used clinically in several cemented prosthetic devices were manually enriched with gentamicin sulphate during preparation and then compared with a commercially-available, antibiotic-loaded cement (Palacos R+G®) by means of an in vitro antibacterial test (inhibition zone evaluation). The purpose of this study was to evaluate the differences and advantages or disadvantages, if any, of manual formulations compared to commercial ones. The use of a different antibiotic (vancomycin) alone or in addition to gentamicin-containing bone cements was also considered.

Results and conclusion: The commercial formulation produces an inhibition zone that is a bit larger and more regular than the manually mixed preparation. The vancomycin halo is smaller but clearer than the gentamicin halo. The addition of vancomycin to gentamicin-containing bone cements does not significantly increase the halo dimensions but could be an interesting strategy in the prevention of multiple and resistant infections.