How important is synovial fluid white cell count?
Dr. Mathews notes that total and differential white cell counts (WCCs) have been recommended as a way to distinguish infected and noninfected joints, although the systematic review did not provide clear support for this approach. “We conclude that the synovial fluid WCC is not sufficiently reliable a measure to exclude or confirm a diagnosis of septic arthritis,” she says. Techniques for microbiological examination of the synovial fluid are similarly controversial. Inoculation of synovial fluid into blood culture bottles may improve the yield from synovial fluid. However, polymerase chain reaction (PCR) was no better than bacterial culture for diagnosis staphylococcal or streptococcal joint infection. “Blood cultures may identify the causative organism even where synovial fluid culture is unrewarding,” Dr. Mathews comments. The standard two-pronged treatment of septic arthritis requires prompt use of antibiotics and removal of purulent material from the joint. Antibiotic choice and tre
