Bacterial adhesion to femoral ballhead surfaces of artificial hipjoints in vitro

Abstract

In orthopedic surgery one of the most significant complications is the infection of implants by microorganisms. The purpose of this study was to investigate whether an adhesion of microbes to femoral ballheads consisting of aluminium oxide, zirconium oxide and CoCrMo-alloy is possible, especially to the smoothly polished surface, and whether this implant component might play a role in respect of the mode of infection. The femoral ballheads were contaminated with strains of Staphylococcus aureus and exopolysaccharide producing Staphylococcus epidermidis and incubated in two fractions for 36 and 72 hours. The present experiment documents that the strains of microorganisms tested adhere well to all ballheads used. However, the surfaces of the zirconium oxide ballheads manifest the most pronounced bacterial lawn with the strains investigated.In comparison to aluminium oxide ballheads which also show several layers of colonisation over large areas, these are overgrown with plate-like microbial lawns. Due to the surface tension and surface energy the microbial adhesion is found on metal (CoCrMo-alloy) ballheads initially in small rounded areas with tendency to confluence.