Knee Arthrocentesis

Arthrocentesis is a procedure for removing fluid from a joint. 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.

LET YOUR CAREGIVER KNOW ABOUT:

  • Allergies.

  • Medications taken including herbs, eye drops, over the counter medications, and creams.

  • Use of steroids (by mouth or creams).

  • Previous problems with anesthetics or Novocaine.

  • History of blood clots (thrombophlebitis).

  • History of bleeding or blood problems.

  • Previous surgery.

  • Other health problems.

RISKS AND COMPLICATIONS

  • A local anesthetic may not numb the area well enough and you may feel some minor discomfort. In rare cases, you may have an allergic reaction to the drug used to numb the skin.

  • More fluid may form in the joint.

  • You may develop infection or bleeding.

BEFORE THE PROCEDURE

Wash all of the skin around the entire knee area. Try to remove any loose, scaling skin. There is no other specific preparation necessary unless advised otherwise by your caregiver.

AFTER THE PROCEDURE

  • You can go home after the procedure.

  • You may need to put ice on the joint 15 to 20 minutes, 3 to 4 times a day until pain goes away.

  • You may need to put an elastic bandage on the joint.

HOME CARE INSTRUCTIONS

  • Only take over-the-counter or prescription medicines for pain, discomfort, or fever as directed by your caregiver.

  • You should avoid stressing the joint. Unless advised otherwise, this includes jogging, bicycling, recreational climbing, hiking, and other activities that would put a lot of pressure on a knee joint.

  • Laying down and elevating the leg/knee above the level of your heart can help to minimize return of swelling.

SEEK MEDICAL CARE IF:

  • You have repeated or worsening swelling.

  • There is drainage from the puncture area.

  • You develop red streaking that extends above or below the site where the needle had been placed.

SEEK IMMEDIATE MEDICAL CARE IF:

  • You develop a fever.

  • You have pain that gets worse even though you are taking pain medicine.

  • The area is red and warm and you have trouble moving the joint.

MAKE SURE YOU:

  • Understand these instructions.

  • Will watch your condition.

  • Will get help right away if you are not doing well or get worse.