Lactate UV-system: a rapid method for diagnosis of septic arthritis.

The concentration of lactic acid in synovial fluid was estimated in 43 specimens from patients with an acute monoarthritis by a simple enzyme method. In 9 patients with 10 episodes of septic arthritis concentrations of synovial fluid lactic acid were significantly higher (mean 10.8 mmol/l) than in 33 patients with nonseptic effusions (mean 3.1 mmol/l). With this method concentrations of synovial fluid lactic acid provide a rapid diagnostic guide in the separation of septic from nonseptic arthritis.