Letters Section Editor: Robert M. Golub, MD, Senior Editor.
In Reply: Our search of the literature identified 6 studies1- 5 that address synovial fluid lactic acid as a clinical test for septic arthritis. Previous studies6 suggest that although synovial lactic acid dehydrogenase (LDH) by enzymatic analysis may be sensitive for detecting bacterial infection, it is not specific, and elevated synovial LDH levels may be observed in noninfectious inflammatory and crystal-induced arthropathies, such as rheumatoid arthritis and gout.
Margaretten ME, Kohlwes J, Bent S. Synovial Lactic Acid and Septic Arthritis—Reply. JAMA. 2007;298(1):40. doi:10.1001/jama.298.1.40-b