Microbiology of periprosthetic joint infection

Abstract

Periprosthetic joint infections (PJIs) are expected to become more common in the future as total joint arthroplasties increase in frequency. PJIs are difficult to differentiate from mechanical failure. The diagnosis and treatment of PJIs is often dependent on the results of cultures obtained from the joint or periprosthetic space. Criteria for diagnosis of periprosthetic joint infection vary, but usually include one or more of the following: presence of a sinus tract, recovery of a typical organism from multiple joint fluid or tissue cultures, elevated joint fluid white cell count with neutrophil predominance, presence of pus at the time of surgery, histopathology consistent with acute inflammation and high erythrocyte sedimentation rate and C reactive protein. Staphylococcus aureus and coagulase-negative staphylococci are the most common organisms associated with PJIs. Streptococci, gram-negative bacteria and anaerobes are seen less frequently. Mycobacterium tuberculosis, fungi, and other unusual organisms are rare but may be seen in cases where the routine bacterial cultures are negative.