Joint Aspiration

What is joint fluid analysis?

It is the removal of fluid from one of your joints, usually your knee or elbow, by using a needle. Other names for it are arthrocentesis, joint tap, synovial fluid analysis, and joint fluid analysis.

Why would I need a joint fluid analysis?

The reason a joint aspiration is done is to:

• Find a cause for swelling in your joint
• Help get rid of your pain
• Help diagnose certain kinds of arthritis and inflammatory joint problems (gout)
• See if there is bacteria or fungus growing in the fluid

How is a joint aspiration done?

Normally, you have clear or pale-yellow fluid in your joints to help you move your knees, elbows, and other joints more easily. The doctor will put local freezing in around the spot where they plan to remove some fluid. After the area is frozen, a needle is put through your skin into your joint space and the doctor pulls back on the plunger of the syringe to get a sample of the fluid (aspirates the fluid). A few samples will be sent to the lab where it will be looked at for color, how clear it is, and what type of cells are found.

What will I have to do after the test?

• You may have some pain after the test.
• What kind of treatment you will need will depend on what the results of the test are.
• Usually, you will need to wait for some of the results to come back before you can go home.

Will I have to stay in the hospital?

Most times you will be able to go home but if a bacterial or fungal infection is found, you may need to stay in the hospital for antibiotic treatment.

Home Treatment:

• Rest for 12 hours after the aspiration is done
• Slowly return to your normal activities
• Keep injection site clean
• You may need to take acetaminophen or ibuprofen, as directed by the doctor, for the pain
• Watch for signs of infection:
• Redness
• Heat
• Swelling
• Increased pain

Return to the Emergency Department IF:

• You have redness, pain, swelling, warmth
• You are unable to use of your arm or leg because of the pain.
• You have a fever with any of the other symptoms.