Synovial fluid analysis

What is synovial fluid analysis?

Synovial fluid analysis is a diagnostic test used to diagnose joint conditions, such as arthritis and lupus. It involves taking a sample of the fluid that surrounds and cushions a joint, checking for inflammation, and identifying infection-causing organisms.

Preparation

Your doctor will give you instructions on how to prepare for the test, which may include fasting for several hours before. There are no restrictions on drinking water, and you may be advised to take any medication as normal on the day of the test.

Types of Synovial Fluid Analysis

Synovial fluid analysis includes the following tests:

• Gram Stain Test – This test looks for bacteria that can cause infection in the joint. It can also help diagnose lupus.
• Cell Count – This test checks the number and types of white blood cells in the joint. It can help diagnose conditions such as rheumatoid arthritis and gout.
• Crystal analysis - This test looks for tiny crystals in the synovial fluid. This can indicate gout or pseudogout.
• Glucose test – This test looks at the level of sugar in the joint. It can indicate an infection.
• Total Protein test – This test looks at the amount of protein in the joint fluid. It is a sign of inflammation.
• Cytology test: This test looks for cells related to joint inflammation. It can help diagnose lupus.

Procedure

The test is usually done in a hospital or doctor’s office. You may be asked to lie on your back or sit during the procedure. X-rays will be taken to check the joint before any fluid is removed. The procedure itself involves using a thin needle to draw out a sample of synovial fluid from the joint. You may feel a slight pinch when the needle enters the joint. The sample is then sent to a laboratory for analysis.

Uses of Synovial Fluid Analysis

Synovial fluid analysis can be used to diagnose and/or monitor the following conditions:

• Arthritis – Synovial fluid analysis can help differentiate between types of arthritis, such as rheumatoid and osteoarthritis.
• Infection – Bacterial infection can cause inflammation in the joint, so the Gram Stain test is used to look for the presence of bacteria.
• Lupus – The cytology test can help to diagnose lupus.
• Gout – The crystal analysis test can help diagnose gout or pseudogout.

Risks

Synovial fluid analysis is a safe procedure with few risks. You may feel a slight pinch when the needle enters your joint, as well as some discomfort during the procedure. You may also experience some slight bruising at the site of the injection.

Why is Synovial Fluid Analysis Done?

Synovial fluid analysis is used to diagnose and monitor conditions that can cause joint inflammation and pain. It is a useful tool in diagnosing and monitoring conditions such as arthritis, lupus, and gout.

When is Synovial Fluid Analysis Done?

Synovial fluid analysis is usually recommended if there is evidence of joint inflammation or if a joint infection is suspected. Your doctor will advise you on when the test should be done.