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( Joint Aspiration)

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Definition | Reasons for Procedure | Possible Complications | What to Expect | Call Your Doctor


This is a procedure to take joint fluid out of a joint using a sterile needle. This can be done in most of the joints in the body, but it is usually done on larger ones, such as the knee or shoulder.


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Reasons for Procedure

Arthrocentesis is done to:

  • Find out why a joint is painful, swollen, or fluid-filled
  • Drain fluid out of a swollen joint to decrease pain and increase your ability to move the joint
  • Diagnose the specific type of arthritis occurring within a joint
  • Confirm a diagnosis of infection in the joint
  • Check for crystals in the joint fluid, which could be a sign of gout

In some cases, the doctor may inject medication into the joint space after the fluid has been taken out.

Possible Complications

Problems from the procedure are rare, but all procedures have some risk. Your doctor will review potential problems, like:

  • Infection of the joint
  • Bleeding into the joint
  • Increased pain

Some factors that may increase the risk of complications include:

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

What to Expect

Your doctor may ask about your medical history. A physical exam may be done, including an examination of the joint.

Imaging tests to help view internal body structures may include:

Your doctor may give you local anesthesia. This numbs the area where the needle will enter the joint.

Your doctor will clean the area where the needle will be inserted. Next, a needle attached to a syringe will be inserted into the fluid-filled joint cavity. Your doctor will draw the fluid into the syringe. After this, the doctor may take the syringe off and inject some medicine into the joint through the needle. After the needle is removed, the doctor will put pressure on the spot over the joint. A bandage will be placed over the area.

About 5-10 minutes

You may feel stinging or burning if local anesthesia is injected into the area.

When you return home after the procedure, do the following to help ensure a smooth recovery:

  • For the first 24 hours, use an ice pack for 15-20 minutes at a time every 3-4 hours. Place a towel between your skin and the ice pack.
  • To reduce discomfort, take a pain reliever.
  • Ask your doctor when you can resume normal activities.
  • Be sure to follow your doctor's instructions .

Call Your Doctor

After arriving home, contact your doctor if any of the following occurs:

  • Signs of infection, including fever and chills
  • Redness, swelling, increasing pain, excessive bleeding, or any discharge from the site
  • Pain that is not relieved by your pain medication

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


Arthritis Foundation


National Institute of Arthritis and Musculoskeletal and Skin Diseases



The Arthritis Society


Canadian Orthopaedic Association



Injections and procedures for knee pain. Arthritis Foundation website. Available at: http://www.arthritistoday.org/where-it-hurts/knee-pain/treatment/knee-injection.php. Accessed July 23, 2013.

Questions and answers about arthritis and rheumatic diseases. National Institute of Arthritis and Musculoskeletal and Skin Diseases website. Available at: http://www.niams.nih.gov/Health_Info/Arthritis/arthritis_rheumatic_qa.asp. Updated April 2012. Accessed July 23, 2013.

Synovial fluid analysis. American Association for Clinical Chemistry Lab Tests Online website. Available at: http://labtestsonline.org/understanding/analytes/synovial/tab/glance. Updated April 10, 2012. Accessed July 23, 2013.

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

Last reviewed June 2013 by John C. Keel, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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