Definition

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.

Arthrocentesis Copyright © Nucleus Medical Media, Inc.

Reasons for Procedure

It is done to:

• Find out why a joint is painful, swollen, or is filled with fluid
• Ease pain and allow the joint to move 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

Some people may have medicine injected in the joint space after the fluid has been taken out.

Possible Complications

Problems are rare, but all procedures have some risk. The doctor will go over some problems that could happen, such as

• Excess bleeding
• Problems from anesthesia, such as wheezing
• Infection
• Increased pain
• Damage to nearby structures

Things that may raise the risk of problems are:

• An infection in the body
• Bleeding problems
• Use of blood thinners

What to Expect

Call Your Doctor

Call the doctor if you are not getting better or you have:

• Signs of infection, such as fever and chills
• Redness, swelling, increasing pain, excessive bleeding, or any discharge from the site
• Pain that does not get better with medicine

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