Indications of a synovial biopsy
The main indication for a synovial biopsy is chronic (>6–8 weeks), nontraumatic, inflammatory (synovial fluid white blood cell count >2000 cells/mm 3 ) arthritis limited to one or two joints in which the diagnosis has not been made by history, physical examination, laboratory studies, or synovial fluid analysis with culture (including both fungi and mycobacteria). Synovial biopsies are also important for research purposes to assess the pathophysiology of various arthritides and response to various treatments.
