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(Joint Aspiration)


Arthrocentesis takes joint fluid out using a needle. It can be done in most of the joints in the body. It is usually done on large joints like the knee or shoulder.

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Reasons for Procedure

It is done to:

  • Find out why a joint is painful, swollen, or is filled with fluid
  • Drain fluid to reduce pain and allow you to move the joint better
  • Diagnose the type of arthritis in a joint
  • Confirm a diagnosis of infection
  • Check for crystals in the joint fluid, which could be a sign of gout

In some cases, medicine may be injected in the joint space after the fluid has been taken out.

Possible Complications

Problems are rare, but all procedures have some risk. Your doctor will go over some problems, like:

  • Infection
  • Bleeding
  • Increased pain

Things that may raise the risk of problems are:

  • Infections on the skin
  • Recent fever or infection
  • Bleeding problems
  • Use of blood thinners

What to Expect

Prior to Procedure

Before your procedure:

  • Talk to your doctor about your medicines. You may be asked to stop taking some medicines up to one week before the graft.
  • Talk to your doctor about any herbs or supplements you take. You may be asked to stop taking some.


You may be given local anesthesia. This numbs the site where the needle will enter the joint.

Description of the Procedure

The needle site will be cleaned. Next, a needle attached to a syringe will be inserted into the joint. Fluid will be pulled into the syringe. After this, medicine may be injected into the joint through the needle. After the needle is taken out, pressure will be put on the spot. A bandage will be put on the site.

How Long Will It Take?

About 5-10 minutes

How Much Will It Hurt?

You may feel stinging or burning if local anesthesia is used.

Post-procedure Care

Follow your doctor’s instructions when you return home.

Call Your Doctor

Call your doctor if you have:

  • Signs of infection, such as fever and chills
  • Redness, swelling, increasing pain, excessive bleeding, or any discharge from the site
  • Pain that isn't relieved by the medicine you've been given

If you think you have an emergency, call for emergency medical services right away.


Arthritis Foundation  http://www.arthritis.org 

National Institute of Arthritis and Musculoskeletal and Skin Diseases  http://www.niams.nih.gov 


The Arthritis Society  http://www.arthritis.ca 

Canadian Orthopaedic Association  http://www.coa-aco.org 


Arthritis. National Institute of Arthritis and Musculoskeletal and Skin Diseases website. Available at: http://www.niams.nih.gov/health%5Finfo/Arthritis/arthritis%5Frheumatic.asp. Updated April 30, 2017. Accessed May 29, 2018.

Knee pain treatment. Arthritis Foundation website. Available at: http://www.arthritistoday.org/where-it-hurts/knee-pain/treatment/knee-injection.php. Accessed May 29, 2018.

Synovial fluid analysis. Lab Tests Online—American Association for Clinical Chemistry website. Available at: http://labtestsonline.org/understanding/analytes/synovial/tab/glance. Updated May 29, 2018. Accessed May 29, 2018.

Zuber TJ. Knee joint aspiration and injection. Am Fam Physician. 2002;66(8):1497-1501.

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