Some biological tests may be requested by your doctor to confirm the diagnosis of osteoarthritis.
There are no specific biological signs of osteoarthritis
For several years, some research teams have been looking for products of the metabolism of articular cartilage (found in synovial fluid, urine or blood of people with osteoarthritis), which could be biological indicators of osteoarthritis. Currently, research has not yet been completed, but the findings are promising.
They are of little interest in osteoarthritis. They may simply provide additional information to rule out an alternative diagnosis, like another joint disease.
Synovial fluid tests:
The appearance of the synovial fluid or joint fluid, is called "mechanical" (aspect of cooking oil), that is to say clear, viscous, containing less than 1,000 white blood cells/mm3, with < 50% of polynuclear cells.
However, it is not uncommon during the inflammatory flare-ups to see an increase in white blood cells up to 2,000/mm3.
A synovial biopsy may be requested by your doctor. It has the sole purpose of eliminating the possibility of an associated pathology, especially when the osteoarthritis affects only a single joint.