How is osteoarthritis diagnosed?
There is no blood test for the diagnosis of osteoarthritis. Blood tests are performed to exclude diseases that can cause secondary osteoarthritis, as well as to exclude other arthritis conditions that can mimic osteoarthritis.
X-rays of the affected joints are the main way osteoarthritis is identified. The common X-ray findings of osteoarthritis include loss of joint cartilage, narrowing of the joint space between adjacent bones, and bone spur formation. Simple X-ray testing can be very helpful to exclude other causes of pain in a particular joint as well as assist the decision-making as to when surgical intervention should be considered.
Arthrocentesis is often performed in the doctor's office. During arthrocentesis, a sterile needle is used to remove joint fluid for analysis. Joint fluid analysis is useful in excluding gout, infection, and other causes of inflammatory arthritis. Removal of joint fluid and injection of corticosteroids into the joints during arthrocentesis may help relieve pain, swelling, and inflammation.
Arthroscopy is a surgical technique whereby a doctor inserts a viewing tube into the joint space. Abnormalities of and damage to the cartilage and ligaments can be detected and sometimes repaired through the arthroscope. If successful, patients can recover from the arthroscopic surgery much more quickly than from open joint surgery.
Finally, a careful analysis of the location, duration, and character of the joint symptoms and the appearance of the joints helps the doctor in diagnosing osteoarthritis. Bony enlargement of the joints from spur formations is characteristic of osteoarthritis. Therefore, Heberden's nodes and Bouchard's nodes of the fingers and bunions of the feet can help the doctor make a diagnosis of osteoarthritis.