Diagnosis without MRI and X-ray by Matthias

According to the American College of Rheumatology guidelines,
Hip pain plus at least two of the following:

• ESR of less than 20 mm per hour

• Femoral or acetabular osteophytes on radiographs

• Joint space narrowing on radiographs

Laboratory Tests
There is no specific laboratory test to diagnose OA. It is diagnosed by a doctor using a patient’s medical history, a physical exam, X-rays, and in some cases with an examination of synovial fluid from an affected joint. Tests that may be ordered to rule out other conditions and to evaluate the patient’s health include:

• Rheumatoid factor (RF) and Cyclic Citrullinated Peptide Antibody (CCP) – used to help diagnose rheumatoid arthritis and differentiate it from osteoarthritis.
• Synovial fluid analysis – to detect crystals that may be present in the joint and to look for signs of joint infection.
• Erythrocyte sedimentation rate (sed rate or ESR) – this test shows the presence of inflammation in the body. ESR will be increased in RA but not in osteoarthritis.
• C-reactive protein test (CRP) —this test also indicates inflammation and tests for the activity of the disease. It may be used to help differentiate osteoarthritis and RA. An increased level of CRP occurs in RA but not in osteoarthritis.
• Complete Blood Count (CBC) – this is a group of tests that are used to help evaluate the patient’s red and white blood cells and hemoglobin. It may be ordered to monitor the side effects of some OA treatments.
• Comprehensive Metabolic Panel (CMP) – this is a group of tests that may be used to help evaluate and monitor the patient’s kidney and liver function.

These are all the tests. Click on the links to read if you want. But, I'll do up a powerpoint to summarize all these on Friday.

Blood Tests

Blood test results may help identify other causes of arthritis (if present) besides osteoarthritis. Some examples include:

• Elevated levels of rheumatoid factor (specific antibodies in the synovium) are usually found in patients with rheumatoid arthritis
• The erythrocyte sedimentation rates (ESR, or "sed rate") indicates inflammatory arthritis or related conditions, such as rheumatoid arthritis or systemic lupus erythematosus.
• Elevated uric acid levels in the blood may indicate gout.

A number of other blood tests may help identify other rheumatological illnesses.

Tests of the Synovial Fluid

If the diagnosis is uncertain or infection is suspected, a doctor may attempt to withdraw synovial fluid from the joint using a needle. There will not be enough fluid to withdraw if the joint is normal. If the doctor can withdraw fluid, problems are likely, and the fluid will be tested for factors that might confirm or rule out osteoarthritis:

• Cartilage cells in the fluid are signs of osteoarthritis.
• A high white blood cell count is a sign of infection, gout, pseudogout, or rheumatoid arthritis.
• Uric acid crystals in the fluid are an indication of gout.

So, what is ESR ?

Sedimentation Rate
(Erythrocyte Sedimentation Rate or ESR)

What is a sedimentation rate?

A sedimentation rate is common blood test that is used to detect and monitor inflammation in the body. The sedimentation rate is also called the erythrocyte sedimentation rate because it is a measure of the red blood cells (erythrocytes) sedimenting in a tube over a given period of time.

How is a sedimentation rate performed?

A sedimentation rate is performed by measuring the rate at which red blood cells (RBCs) settle in a test tube. The RBCs become sediment in the bottom of the test tube over time, leaving the blood serum visible above. The classic sedimentation rate is simply how far the top of the RBC layer has fallen (in millimeters) in one hour. The sedimentation rate increases with more inflammation.

Normal Results

Adults (Westergren method):

• Men under 50 years old: less than 15 mm/hr
• Men over 50 years old: less than 20 mm/hr
• Women under 50 years old: less than 20 mm/hr
• Women over 50 years old: less than 30 mm/hr

Children (Westergren method):

• Newborn: 0 to 2 mm/hr
• Neonatal to puberty: 3 to 13 mm/hr

This test can be used to monitor inflammatory or cancerous diseases. It is a screening test, which means it cannot be used to diagnose a specific disorder.

However, it is useful in detecting and monitoring tuberculosis, tissue death, certain forms of arthritis, autoimmune disorders, and inflammatory diseases that cause vague symptoms.