Synovial Cyst Decompression

With the guidance of ultrasound imaging (a painless exam that uses high-frequency sound waves to produce real-time images), your doctor will insert a tiny needle to draw fluid out from behind your knee and shrink or remove the synovial cyst. This procedure can help relieve pressure on the nerves caused by the cyst, which is often a result of degeneration in the facet joints of the lumbar spine.

You will lie on your stomach on the exam table for this procedure. Your doctor will then give you a shot of local anesthesia to numb the area. You will feel a small pinch as the anesthesia is administered.

The target lesion is precisely localized by advancing the needle under CT image guidance and confirmed with a test injection of contrast material. Only after the location is precisely identified is the lesion aspirated/decompressed. Steroid injection and lidocaine are also administered to treat associated inflammation. The needle is removed, the skin is cleaned, and a standard band-aid is applied.

There are things you can do to make your experience more comfortable, and many of these will depend on your individual preferences. You might like to keep a list of questions or—as you’re doing now—educate yourself about the procedure.

Some other things to keep in mind in planning for this procedure include:

• You will need a driver to bring you and take you home.
• Your doctor may ask you to stop taking aspirin, non-steroidal anti-inflammatory drugs (NSAIDs), or blood thinners (such as Coumadin or warfarin) for a time before the procedure.

On the day of your procedure you should:

• Wear comfortable, loose-fitting clothes.
• Wear comfortable shoes.
• Avoid bringing jewelry or valuables.

The benefits of a synovial cyst decompression could be:

• Relief of pain.
• Reduced inflammation, which may lead to healing.

Some risks you should be aware of include:

• As with any procedure, there is a slight risk of infection.
• Rarely, this procedure can cause a temporary increase in pain.
• Rarely, there are reactions to the medication such as rash or hot flashes.
• There is a slight risk of nerve damage at the injection site.
• There is a slight risk of bleeding.

Keep in mind that this information is general. Your radiologist is the best source of information about how these risks and benefits may apply to you.