A synovial biopsy is the removal of a piece of tissue lining a joint for examination. The tissue is called the synovial membrane.
How the Test is Performed
The test is done in the operating room, often during an arthroscopy. During this procedure:
- You will receive general anesthesia. This means you’ll be pain-free and asleep during the procedure.
- The surgeon makes a tiny cut in the skin near the joint.
- An instrument called a trocar is inserted through the cut into the joint.
- A tiny camera with a light is used to look inside the joint.
- A tool called a biopsy grasper is then inserted through the trocar. The grasper is used to cut a small piece of tissue.
- The surgeon removes the grasper along with the tissue. The trocar and any other instruments are removed. The skin cut is closed and a bandage is applied.
- The sample is sent to a lab for examination.
How to Prepare for the Test
Follow your health care provider’s instructions on how to prepare. This may include not eating and drinking anything for several hours before the procedure.
How the Test will Feel
With the local anesthetic, you will feel a prick and a burning sensation. As the trocar is inserted, there will be some discomfort. If the surgery is performed under regional or general anesthesia, you will not feel the procedure.
Why the Test is Performed
A synovial biopsy helps diagnose gout and bacterial infections or rule out other infections. It can be used to diagnose autoimmune disorders such as rheumatoid arthritis, or uncommon infections like tuberculosis.
Normal Results
The synovial membrane structure is normal.
What Abnormal Results Mean
A synovial biopsy may identify the following conditions:
- Chronic synovitis (inflammation of the synovial membrane)
- Coccidioidomycosis (a fungal infection)
- Fungal arthritis
- Gout
- Hemochromatosis (abnormal buildup of iron deposits)
- Systemic lupus erythematosus (an autoimmune disease that affects the skin, joints, and other organs)
- Tuberculosis
- Synovial cancer (a very rare type of soft tissue cancer)
- Rheumatoid arthritis
Risks
There is a very slight chance of infection and bleeding.
Considerations
Follow instructions for keeping the wound clean and dry until your provider says it is OK to get it wet.
