SYNOVIAL-FLUID L-LACTIC ACID IN ACUTE ARTHRITIS OF THE ADULT KNEE-JOINT

Determination of synovial fluid (SF) lactic acid has been suggested to be an unspecific indicator of SF leukocytosis, and it is not recommen ded for differential diagnosis of bacterial arthritis. We analyzed the L-lactic acid content by enzymatic UV-method in 65 SF samples obtaine d from adult patients with acute knee arthritides. The concentration o f L-lactic acid was not high in any SFs with intensive leukocytosis, T he mean concentration of L-lactic acid was 13.5 mmol/l (95% confidence intervals 9.4;17,6 mmol/l) in the synovial-fluid samples from culture -positive arthritis and 5.5 mmol/l (4.9;6.2 mmol/l) in the synovial-fl uid samples from culture-negative arthritis. Determination of SF L-lac tic acid is an important part of the diagnostic setup for acute arthri tis. Values >9 mmol/l strongly support occurrence of bacterial arthrit is and indicates an immediate onset of the treatment.