… Continued …
It is usually used to help rule out other possible causes /health conditions, particularly such as rheumatoid arthritis (another common form of arthritis, this is usually associated with the abnormality of immune system).
In people with rheumatoid arthritis, they usually have high levels of rheumatoid factors or RF (protein made by the body immune system that mistakenly attacks the wrong targets such as healthy tissues). High levels of RF are also associated with other autoimmune disorders such as and Sjogren’s syndrome.
This blood test may be combined with other laboratory test such as biochemistries, ESR (sedimentation rate), and urinalysis tests.
In diagnosing osteoarthritis, laboratory tests are usually not used alone. Instead, they are more purposed to confirm the clinical picture.
Joint fluid analysis
Your joint has fluid called synovial fluid. This liquid is normally found in a normal joint. Its function is to help nourish the cells in the joints and can act as a lubricant.
But when the joint is affected by arthritis, synovial fluid can change in amount and character. For this reason, joint fluid analysis may also be required to help diagnose osteoarthritis.
In this procedure, your doctor can use an appropriate needle to take a small sample of this liquid in the affected joint. Then it will be closely examined to determine whether the joint pain and inflammation are triggered by infection or the presence of uric acid crystals (the main reason behind gouty arthritis).
Last accessed on September 2014. Image credit to the Hospital for Special Surgery!