Acute monoarthritis: a practical approach to assessment and treatment.

A basic approach to the patient presenting with acute monoarthritis includes a careful history, a physical examination and a selected battery of laboratory tests and radiographs. Because of the possibility of septic joint, rapid assessment and treatment are required. The most common causes of acute monoarthritis are trauma, crystals (gout and pseudogout) and infection. The most important cause of acute monoarthritis is infection, which must be excluded through the use of diagnostic joint aspiration and culture of synovial fluid.