The American College of Rheumatology (ACR) diagnostic criteria incorporate four main areas – joint involvement, RA related blood tests, general inflammation blood tests, and duration of symptoms.1According the ACR,
“Joint involvement refers to any swollen or tender joint on examination, which may be confirmed by imaging evidence of synovitis.”2
Physical examination is the starting point for identifying joint involvement. But confirmation by actually looking inside the joint with imaging techniques remains a critical part of confirmation.The synovium is a sac-like lining around certain joints. It provides nutrients and lubrication for joint soft tissues. During the disease processes involved with RA, the synovium swells and thickens, becoming permeated with inflammatory cells and chemicals. Ultimately, cartilage and bone tissue erodes leading to the classic joint damage associated with RA.3 The synovial fluid can be taken from a joint and analyzed for chemicals and cells associated with RA.4 This can be done via needle biopsy or surgery. During an ankle surgery I had several years ago, the orthopedic surgeon sent a sample of tissue to a laboratory for analysis – the results came back positive for RA related synovitis. Medical imaging procedures can be used in as a noninvasive technique for examining a joint.
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