Needle biopsy of the synovium of children.

While the diagnosis of juvenile rheumatoid arthritis is based on clinical criteria and does not require confirmation by synovial biopsy, biopsy is occasionally desired to exclude other diagnoses. Needle synovial biopsy of the knee may be performed on young children as an office procedure and generally provides adequate tissue for examination. In the author's clinic this procedure has replaced open biopsy of the knee of children.