Medically Reviewed By William C. Lloyd III, MD, FACS

What is arthrocentesis?

Arthrocentesis is the removal of the synovial fluid that lubricates your joints. Doctors perform arthrocentesis using a needle and syringe. The fluid is removed and tested to diagnose the cause of a buildup of fluid. Causes include infection, arthritis, and joint injury. Doctors also use arthrocentesis to treat joint pain by removing excessive or infected fluid. Arthrocentesis is performed in many joints, including the elbow, knee, hip and jaw. 

Arthrocentesis is only one method used to diagnose or treat a variety of joint conditions, most often of the knee. Consider getting a second opinion about all of your treatment choices before having an arthrocentesis.

Other procedures that may be performed

Your doctor may perform other procedures in addition to arthrocentesis to diagnose or treat certain conditions. These include: 

  • Medication injection, which involves injecting medication, such as an anesthetic or a steroid, into the joint. Medications are injected to help relieve pain, swelling and/or inflammation.

  • Synovial fluid biopsy, which involves examining the synovial fluid removed for infection and other disease

Why is arthrocentesis performed? 

Your doctor may recommend an arthrocentesis to diagnose and possibly treat the following diseases and conditions of the joints:

  • Arthritis, or inflammation of the joint. Both osteoarthritis and rheumatoid arthritis can lead to pain, swelling and destruction of the joint.

  • Autoimmune disorders, such as lupus, which often leads to joint pain and swelling in some cases

  • Bleeding into the joint (hemarthrosis), such as bleeding caused by a torn ligament or a bleeding disorder

  • Crystal-induced arthritis, such as gout 

  • Cysts filled with synovial fluid. Cysts can form as a complication of arthritis and breakdown of the joint.

  • Injury to the joint, such as a fracture or a torn ligament or cartilage

  • Joint infection, which is also called septic arthritis

  • Unexplained joint effusion, which is a buildup of synovial fluid with swelling of the joint. Arthrocentesis is used to remove the excess fluid.

Ask your doctor about all of your treatment options and consider getting a second opinion before deciding on arthrocentesis.

Who performs arthrocentesis?

Orthopedic surgeons often perform arthrocentesis procedures. Orthopedic surgeons specialize in the medical and surgical treatment of conditions of the bones, joints, and connective tissues. 

Other specialists who perform arthrocentesis include:

  • Oral and maxillofacial surgeons are surgeons who diagnosis and treat diseases, injuries, and defects involving functional and aesthetic aspects of the mouth, teeth, jaws and face. Oral surgeons perform arthrocentesis of the jaw.

  • Sports medicine and pediatric sports medicine doctors are family practice, internal medicine, emergency medicine, or pediatric doctors who have additional training in sports medicine.

How is arthrocentesis performed?

Your arthrocentesis will be performed a doctor’s office, outpatient setting or hospital. The procedure takes less than 30 minutes and generally includes these steps:

  1. You remove clothing from the affected joint or you dress in a patient gown.

  2. You lie on the examination table to allow access to the joint. 

  3. You may have sedation to make you drowsy and relaxed, and possibly a pain medication. This is common for infants and children. You may have general anesthesia for arthrocentesis of the jaw. Your care team uses monitoring devices to watch your vital signs if you have sedation or general anesthesia.

  4. Your doctor cleans and numbs the joint and surrounding area with a local anesthetic.

  5. Your doctor inserts a needle into the joint space and withdraws a portion of synovial fluid into a syringe. The needle may be guided to the proper position using imaging technology if the joint is difficult to access, such as a hip joint.

  6. Your doctor detaches the syringe of synovial fluid from the needle and replaces it with a syringe of medication, if needed. The medication is injected into the joint. 

  7. Your doctor removes the needle and cleans and bandages the area.

  8. The synovial fluid is sent to the laboratory for testing. Your doctor will discuss the results with you at a later time.

Will I feel pain?

Your comfort and relaxation is important to you and your care team. You may feel a pinch, discomfort or stinging when the area is numbed and pressure during the procedure. Your care team will give you pain and sedative medications as needed to keep you comfortable. Tell your doctor if you have pain or are uncomfortable.

What are the risks and potential complications of arthrocentesis?  

Complications of arthrocentesis are uncommon but can occur and become serious in some cases. Complications can occur during the procedure or recovery. 

Risks and potential complications of arthrocentesis include: 

  • Adverse reaction or problems related to sedation or medications, such as an allergic reaction and problems with breathing

  • Bleeding

  • Infection

  • Nerve injury

  • Return of pain or worsening pain

Reducing your risk of complications

You can reduce the risk of some complications by following your treatment plan and: 

  • Following activity, dietary and lifestyle restrictions and recommendations before your procedure and during recovery

  • Notifying your doctor right away of any concerns, such as more swelling, bleeding, fever, or increase in pain

  • Taking your medications exactly as directed

  • Telling all members of your care team if you have any allergies 

How do I prepare for my arthrocentesis?

You are an important member of your own healthcare team. The steps you take before your procedure can improve your comfort and outcome. 

You can prepare for arthrocentesis by:

  • Answering all questions about your medical history and medications. This includes prescriptions, over-the-counter drugs, herbal treatments, and vitamins. It is a good idea to carry a current list of your medical conditions, medications, and allergies at all times.

  • Learning about the procedure and asking any questions you may have

  • Taking or stopping medications exactly as directed. This may include not taking aspirin, ibuprofen (Advil, Motrin), and blood thinners.

  • Telling all members of your care team if you have any allergies 

Questions to ask your doctor

Having an arthrocentesis can be stressful. It is common for patients to forget some of their questions during a doctor’s office visit. You may also think of other questions after your appointment. Contact your doctor with concerns and questions before arthrocentesis and between appointments.  

It is a good idea to bring a list of questions to your appointment. Common questions include:

  • Why do I need arthrocentesis? Are there any other options for diagnosing or treating my condition?

  • How long will the procedure take? When can I go home?

  • What restrictions will I have after the procedure? When can I return to work and other activities?

  • What kind of assistance will I need at home? Will I need a ride home?

  • How should I take my medications? 

  • How will you treat my pain?

  • When and how will I get the results of my test?

  • What other tests might I need?

  • When should I follow-up with you?

  • When and how should I contact you? Ask for numbers to call during and after regular hours.

What can I expect after my arthrocentesis?

Knowing what to expect after arthrocentesis can help you get back to your everyday life as soon as possible.

How will I feel after the arthrocentesis?

You may have mild soreness, tenderness or joint pain after arthrocentesis. Apply ice packs and elevate the affected joint to reduce discomfort and swelling. Use nonsteroidal anti-inflammatory drugs (NSAIDS) only as directed by your doctor. 

You might feel a little drowsy if you had sedative and pain medications. If anesthetic was injected into the joint, you may need to limit use of the joint for four to eight hours after the procedure in order to avoid injury. You may also need to limit activity if other medication was injected into the joint.

When can I go home?

Arthrocentesis is often an outpatient procedure. You will be discharged home when you are fully alert, breathing effectively, and your vital signs are stable. This generally takes less than an hour, depending on the type of sedation you receive. 

You cannot drive for 24 hours after sedation because you may still be drowsy. You will need a ride home from your procedure, and someone should stay with you for the first day.

When should I call my doctor?

It is important to keep your follow-up appointments after an arthrocentesis. Contact your doctor for questions and concerns between appointments. Call your doctor right away or seek immediate medical care if you have:

  • Bleeding

  • Drainage from the site

  • Fever (you should not have any fever after a minor testing procedure)

  • New or unexplained symptoms

  • Pain that is not controlled by your pain medication

  • Rash or skin irritation

  • Swelling, warmth or redness of the joint

Was this helpful?
  1. Arthrocentesis. Memorial Sloan-Kettering Cancer Center.
  2. Evaluation of the Patient with Joint Disorders. The Merck Manual for Health Care Professionals.
  3. Evaluating postoperative fever: A focused approach. Cleveland Clinic Journal of Medicine.
  4. Joint Aspiration (Arthrocentesis). Kids Health from Nemours Foundation.
  5. Knee Joint Aspiration and Injection. American Academy of Family Physicians.
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Nov 13
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