Synovial Fluid: Purpose, Procedure And Results

What is Synovial Fluid?

Synovial fluid analysis is also known as joint fluid analysis or joint fluid aspiration. Synovial fluid is found in the liquid that surrounds the joints in individuals. It prevents friction between the bones that form the joint. This helps in ease of movement in the person. It also protects the joints against any kind of external shock that may cause damage to the joint in the absence of the fluid. Synovial fluid is produced by the synovial membrane that surrounds the synovial joints.

Synovial fluid is an ultrafiltrate from plasma. It contains proteins derived from the blood plasma. It is present in the joints of the hips, hands, feet, knees and shoulders. Certain disorders of the joint can change the appearance and feel of the synovial fluid. 

Preparation For Synovial Fluid Analysis

Usually, no particular preparation is required for the synovial fluid analysis test. You must inform your doctor if you are taking medications such as aspirin, warfarin or clopidogrel. These medicines may severely affect the test results and may even affect your ability to take this test.

The Procedure of Synovial Fluid Analysis

The synovial fluid obtained is sent to the lab. The lab technician checks the colour and clearness of the drawn sample. The sample is then placed under a microscope. The red and white blood cells are counted. It is also checked for any gout crystals or bacteria that may be present.

The synovial fluid is examined for amounts of glucose, proteins, uric acid and Lactate Dehydrogenase (LDH). The concentration of various cells is measured in the synovial fluid. Then, cultures of synovial fluid are prepared to observe any bacterial growth in it.

The chemical analysis of synovial fluid consists of the following tests:

• Glucose Testing: It measures the amount of glucose present in the synovial fluid. It is seen that glucose levels are lower in certain conditions such as autoimmune disorders or septic arthritis.

• Lactate: It examines the level of lactate dehydrogenase (LDH) in the synovial fluid. High levels of lactate are seen in the case of an infection.

• Total Protein: Elevated levels of protein can point to an inflammatory disease or a bleeding disorder.

• Uric Acid testing: The amount of uric acid is analysed in the synovial fluid. High amounts of synovial fluid indicate the presence of a disease called gout.

The microscopic assessment of synovial fluid consists of the following tests:

• White Blood Cell count: In response to infection, septic arthritis, gout and pseudogout, WBCs become elevated.

• Gram Stain: The synovial fluid is stained to examine the presence and type of microbes present. If the gram stains are positive, it may indicate the presence of septic arthritis or gout.

• Bacterial Culture: Infection is indicated by the presence of certain microbes in the sample.

What to Expect For Synovial Fluid Analysis?

For this test, a sample of the synovial fluid is required. After the skin around the joints is cleaned with an antiseptic, the doctor inserts a sterile needle into the space between the joints. The synovial fluid is thus extracted into a clean syringe. 

Why is The Synovial Fluid Analysis Performed?

The synovial fluid analysis can help in the diagnosis of any pain, redness or swelling in the joints. In certain cases, removing the synovial fluid can also help relieve some of the joint pain. This test is conducted when:

• There is bleeding in the joints after a joint injury
• Gout disease which forms crystals in the joint area
• Arthritis
• If there is some kind of infection in a joint

When Should One Get Synovial Fluid Analysis?

A synovial fluid analysis may be ordered by your doctor if you have the following symptoms, especially in cases where the cause of joint problems is not known:

• Joint effusion
• Sudden pain and warmth in a joint
• Redness at a joint
• Difficulty bending a joint
• Joint discomfort accompanied by fever

The synovial fluid analysis is not quite often performed in children unless they have certain symptoms that suggest a joint infection, such as fever. Your doctor can explain the reasons and rule out or confirm the presence of a joint disorder. They can also explain that the benefits of getting this procedure done can far outweigh minor risks associated with it such as an infection or bleeding because of repeated aspiration from the joint.

What If Synovial Fluid Analysis Results are Present/Absent?

If a certain abnormality is present in the joints, the synovial fluid surrounding it may look cloudy or unusually thick. If the following are present in the sample, it may indicate an abnormality:

• Blood: there is an injury in the joint or bleeding in the entire body
• Pus: there is an infection in the joint
• Excess synovial fluid: It might be indicating a condition called osteoarthritis or even an injury in the cartilage, ligament or meniscus.

It is observed that the normal synovial fluid is :

• Clear
• Colourless or pale yellow
• Stringy
• Free of bacteria, viruses, and fungi

The results of a chemical analysis of synovial fluid are compared similarly to that of a blood test. The normal ranges are indicated and compared against the obtained results from the sample. Usually, the composition of synovial fluid is similar to that of plasma. Certain differences in the composition of the synovial fluid can indicate the presence of a disease. 

The microscopic content of synovial fluid provides evidence of different diseases and conditions in the joints. The various parameters are compared to the normal appearances and a clinical decision is made by your doctor.

What is The Cost of Synovial Fluid Analysis in India?

The average price range of synovial fluid analysis in India ranges approximately from Rs. 400 to Rs. 1200.

Synovial fluid plays an important role in the smooth movement of your joints. If affected by any infection or some form of arthritis, it can severely alter the composition of the synovial fluid. It is important to regularly monitor the synovial fluid state in a good lab. For further enquiries about this test, please contact Metropolis Healthcare at www.metropolisindia.com.