Bacterial growth on antibiotic-loaded acrylic cement. A prospective in vivo retrieval study.

Twenty-three patients with intraoperative culture-proven periprosthetic infection of the hip or knee were enrolled in a prospective cement retrieval study. All were treated with a two-stage technique using antibiotic-loaded acrylic cement as an antibiotic depot. Staphylococcus epidermidis was the most commonly isolated organism (19 of 23 cases). Cement and tissue were examined at second-stage revision for the presence of viable organisms. In this series, no organisms were isolated from the surface of the cement, a 100% concordance with the tissue cultures. A subsequent failure rate of 4.4% (1 case) was seen in this series. Investigation suggests this may represent reinfection from a new strain of organism rather than failure of eradication of the original infection.