Joint Aspiration (Arthrocentesis)

What is arthrocentesis?

Arthrocentesis is a procedure for removing fluid from a joint.

When is it used?

The procedure is used to remove uncomfortable amounts of fluid from a joint or to get a sample of joint fluid for testing. Testing joint fluid can help your health care provider figure out the cause of the pain or swelling you are having in your joint. Infection or gout, among other conditions, can cause fluid to form in joints, resulting in pain or swelling.

How do I prepare for arthrocentesis?

Follow any instructions your health care provider gives you.

What happens during the procedure?

Your health care provider will clean the area around the joint and may give you a local anesthetic to numb the area. Your provider will insert a needle into the joint cavity and withdraw fluid. After removing the needle, your provider will put pressure on the place where the needle was inserted and may put a bandage on it. He or she will send the fluid sample to a lab for tests. You may be given shots into the joint that prevent inflammation, with or without pain medicine.

What happens after the procedure?

• You can go home after the procedure.
• You may need to put ice on the joint 20 to 30 minutes every 3 or 4 hours until the pain goes away.
• You may need to put an elastic bandage on the joint.
• For pain you may take acetaminophen, aspirin, or medicine given to you by your health care provider.
• You should avoid stressing the joint.

Ask your health care provider what other steps you should take and when you should come back for a checkup.

What are the benefits of this procedure?

Removing fluid may help your joint feel better. The procedure may also help your health care provider make a better diagnosis.

What are the risks associated with this procedure?

• A local anesthetic may not numb the area quite enough and you may feel some minor discomfort. Also, in rare cases, you may have an allergic reaction to the drug used in this type of anesthesia.
• More fluid may form in the joint.
• You may have infection or bleeding.

You should ask your health care provider how these risks apply to you.

When should I call my health care provider?

Call your provider if:

• You have swelling.
• There is drainage from the puncture area.
• You develop a fever.
• You have pain that gets worse even though you are taking pain medicine.
• The area is red and warm.

Call during office hours if:

• You have questions about the procedure or its result.
• You want to make another appointment.