Microbiological diagnostics of prosthetic hip joint infections

A prosthetic hip joint loosening - septic or aseptic, is a consequence of a host defence against a foreign body material. Aseptic loosening is connected with small wear debris peeling of from material the implant is composed of. Prosthetic hip joint infection is one of the most serious complications of hip arthroplasty, which is associated with biofilm growing on the implant's surface and the presence of small colony variants (SCV) of microorganisms. Culture of microorganisms from removed orthopedic implants combined with sonication is simple and useful method to differentiate aseptic type of loosening from bacterial infection. Another simple way is to estimate synovial fluid leukocyte count and percentage of neutrophils. All the mentioned methods, distinguishing two types of implant loosening, are very important in order to administer the appropriate antimicrobial treatment.