Differences in Diagnostic Properties Between Standard and Enrichment Culture Techniques Used in Periprosthetic Joint Infections.

Abstract

Culture-negative infections can complicate the diagnosis and management of orthopedic infections, particularly periprosthetic joint infections (PJIs). This study aimed to identify differences in rate of detection of infection and organisms between cultured using standard and enriched methods. This retrospective, cross-sectional study evaluated PJI samples obtained between January 2013 and December 2017 at Yokohama City University Hospital. Samples were assessed using standard and enrichment culture techniques. White blood cell counts, C-reactive protein levels, type of microorganism (coagulase-positive or coagulase-negative), and methicillin-resistant Staphylococcus were investigated. A total of 151 PJI samples were included in the analysis; of these, 68 (45.0%) were positive after standard culture while 83 (55.0%) were positive only after enrichment culture. The mean white blood cell counts and C-reactive protein levels were significantly lower in the enrichment culture group than in the standard culture group (P < .01). The rate of methicillin-resistant Staphylococcus and coagulase-negative Staphylococci was significantly higher in the enrichment culture group than in the standard culture group (P < .01). The enrichment culture method has a higher rate of detection of infection than standard culture techniques and should, therefore, be considered when diagnosing orthopedic infections, particularly PJI.