Every joint in the human body contains synovial fluid. The synovial membrane secretes this fluid into the joint cavity. It lubricates the joints and allows for ease of movement. The synovial membrane is also the main place where inflammation occurs in joint diseases such as arthritis.

Your doctor may recommend performing a synovial biopsy if they can’t give a diagnosis based on routine measures. They might also order a biopsy if they think you might have a synovial infection. The synovial biopsy process is becoming more common when performing research on arthritis and joints.

A synovial biopsy is also known as “a biopsy of the synovial membrane that lines the joint.” This is because the process actually involves removing a piece of this membrane for examination.

Your doctor may need to perform a synovial biopsy after they’ve completed more routine exams, such as a physical examination. Your doctor may also perform the biopsy when they suspect you may have an infection or gout.

The biopsy can also help diagnose other causes of joint inflammation, such as autoimmune diseases. A synovial biopsy may also be helpful if a doctor suspects a metabolic disease, such as hemochromatosis, which involves the deposition of iron, or cancer.

A synovial biopsy is an uncomfortable test, but with proper local anesthesia, the pain is tolerable. You’ll feel a prick and burning sensation when you receive the local anesthesia to numb the area. You may feel some discomfort when your doctor removes the tissue. You may also experience some discomfort after the procedure. Your discomfort will vary based on whether you had a closed-needle procedure or an arthroscopy.

Notify your doctor before the test if you’re pregnant, if you have bleeding problems, or if you have drug allergies. In addition, list any medications or supplements you’re currently taking.

Closed-Needle Process

You might undergo the synovial biopsy process at your doctor’s office. This is known as a closed-needle process. This process doesn’t require any incisions. It’s a safe, effective way to collect tissue samples.

Your doctor will inject local anesthesia into the site to limit pain and discomfort. Your doctor will then insert an instrument called a trocar into the joint. A trocar is an instrument that is slightly larger than a needle. It’s typically used for aspiration and to clear the space of fluid. Your doctor will then thread a tissue grabber through the trocar to cut a sample of the synovial membrane.


As an alternative to a biopsy performed in your doctor’s office, your doctor may perform the procedure using arthroscopy. Arthroscopy is a surgery that’s a common method used to diagnose and treat joint disorders.

The main difference between arthroscopy and a closed-need procedure is that your surgeon will insert a tiny camera and light source into the joint via a small incision. This allows the surgeon to see inside the joint. Another small incision allows your surgeon to insert tools to remove any of the following:

  • tissue
  • cartilage
  • fluid
  • bone

Arthroscopy is more complicated and expensive than a closed-needle procedure. However, it allows your surgeon to get a larger tissue sample and to see directly into the joint.

Following the procedure, apply ice to the joint to reduce pain and swelling. You can begin to do light physical activity several days after the procedure. Limit your physical activity to light activities such as walking.

Synovial biopsy is generally a safe procedure. Although rare, the main risks include:

  • an allergic reaction to the medication or anesthesia
  • difficulty breathing
  • bleeding in the joint
  • a blood clot
  • damage to the cartilage or ligaments of the joint
  • an infection in the joint
  • an injury to a blood vessel or nerve
  • stiffness
  • soreness

An abnormal test result could indicate:

  • a fungal infection
  • gout
  • an abnormal accumulation of iron deposits in the joint
  • tuberculosis
  • synovial cancer
  • autoimmune diseases
  • rheumatoid arthritis

Your doctor will review and discuss with you the results of your synovial biopsy. If you have abnormal results, you may need further testing to diagnose your condition.