Radiofrequency Neurotomy (RFN) for Knee Pain

Why am I having a Radiofrequency Neurotomy?

Radiofrequency neurotomy (RFN) is a needle-based treatment used to treat pain originating from the genicular nerves in and around the knee. The procedure is used to treat pain that is caused by arthritis, after knee replacement surgery, if you are unable to have knee replacement surgery, or if you are wishing to avoid surgery.

How is the procedure performed and does it hurt?

During this procedure an Anaesthetist will be present to ensure you are you feel as comfortable as possible.

Before the procedure starts you will have a small needle (cannula) placed in a vein in your hand or arm so that sedation can be given as necessary. You will be positioned on your back with the affected knee raised on a small pillow. Once the area has been cleaned with antiseptic solution your knee will be covered with sterile drapes. You may feel a sharp sting as local anaesthetic is injected to make the skin area numb. An x-ray machine is used to help guide the needle into the right place. Once the needle is in the correct position an electrode is inserted via the needle and a low radiofrequency current is passed through the electrodes. This results in localized heat to the nerve which provides long lasting relief of your knee pain Your Pain Specialist will finish the procedure by putting some local anaesthetic down the needle to the effected nerve.

After the procedure you will return to the recovery area where the nursing team will carry out observations, give you something to eat and drink and make sure you are safe to go home.

How long will the relief last?

With time the genicular nerves will regain function, and your pain may recur. The average duration of benefit is 9 months, but this is variable. If the procedure needs to be repeated in the future, the success rate is closer to 90%.

What are the risks?

All procedures carry a risk of side effects and possible complications.

Common risks and complications:

• Bleeding or bruising
• Knee pain due to the muscle being aggravated by the needle
• Temporary leg weakness due to the local anaesthetic
• The skin may feel extra sensitive to normal touch, or you may experience numbness at the site of the procedure

Less common risks and complications:

• Not able to perform the procedure due to medical and/or technical reasons
• Infection requiring further medical treatment
• Allergies
• Damage to surrounding structure needing further treatment

Preparing for your procedure

Please advise your pain specialist at least two weeks before your procedure if you:

• Are taking blood thinners including fish oils or aspirin
• Are diabetic
• May possibly be pregnant
• Are allergic to iodine, betadine, chlorhexadine, shellfish, local anaesthetics or steroids
• Have a temperature, feel unwell or possibly have an infection

You must have a responsible adult (over the age of 18) to pick you up after the procedure and stay with you overnight.

Please make arrangements to ensure you do not drive or make important decisions for the first 24 hours following your procedure.

Day of procedure

• No food within 6 hours prior to your procedure. However, you may take water up to 2 hours prior, but no more that 200mls per hour.
• Take your regular medication with a small sip of water.
• Shower the morning or your procedure

What to do after the procedure

• Take it easy for 24 hours.
• Resume your usual diet and drink plenty of fluids
• For procedural pain use cold packs and simple analgesics such as paracetamol
• Usual activity may be recommenced the day after the procedure
• Avoid bathing/soaking until the injection sites have healed

It may take two to three weeks before you start to notice an improvement in your pain.

After discharge, if you notice:

• Swelling
• Bleeding from the site
• Changes in sensation
• Difficulty with movement of legs
• New symptoms or difficulty passing urine

Please contact Interventus Pain Specialists during office hours, your general practitioner or your nearest Emergency Department.

What happens next?

You will need to return to the clinic to determine if the pain relief provided by the RFN was meaningful.

This information will help us to guide you with a comprehensive pain management plan and enhance the outcomes of the procedure.