Anesthesiology | Interventional Pain Medicine
Assistant Professor — University of Toronto
Interventional Pain Physician — Afiya Spine & Pain Institute
Staff Anesthesiologist — Scarborough Health Network
Knee radiofrequency ablation is a procedure used to reduce pain signals carried by small sensory nerves around the knee.
These nerves are called genicular nerves. Radiofrequency ablation uses heat generated by specialized needles to disrupt the ability of these nerves to carry pain signals from the knee region toward the brain.
The procedure does not replace the knee joint, remove arthritis, rebuild cartilage, or correct the underlying joint damage. It is designed to reduce pain so that walking, activity, sleep, physiotherapy, strengthening, or daily function may be easier.
This procedure is most commonly considered for chronic knee pain from osteoarthritis when pain remains significant despite medication, physiotherapy, exercise, bracing, weight management, or injections.
It is usually considered after a positive genicular nerve block. A positive block suggests that the genicular nerves are carrying a meaningful part of your knee pain.
Patients who may be good candidates include people who are not candidates for knee replacement surgery, people who do not want knee replacement surgery, and people using the procedure as a bridge while waiting for knee replacement.
For some patients who already have a knee replacement, genicular radiofrequency ablation may be considered for persistent knee pain only after the surgeon has assessed the knee replacement and ruled out problems such as infection, loosening, fracture, or other surgical complications.
Tell us if you have a knee replacement booked within the next 6 months. Knee radiofrequency ablation itself does not inject steroid into the knee joint, but this information is important if any knee joint steroid injection is being considered at the same visit or nearby in time.
Tell us if you already have a knee replacement, have had recent knee surgery, have an active infection, are taking antibiotics, or have had a recent major change in your health.
You usually do not need to fast for this procedure unless you are specifically told otherwise.
The procedure is usually quick, but the full visit includes check-in, assessment, preparation, and recovery.
Most patients should expect the full appointment to take approximately 60 to 90 minutes, although this can vary depending on clinic flow that day.
The exact number and location of targets depends on your pain pattern, anatomy, imaging, and the treatment plan.
Most patients describe:
Local anesthetic is used to reduce discomfort. The procedure is usually brief.
You may walk and do normal light activity after the procedure. Avoid unusually strenuous activity for the rest of the day.
Do not drive until any numbness, weakness, heaviness, or altered sensation has fully resolved. If you feel lightheaded or weak after the procedure, do not drive.
Knee radiofrequency ablation is not judged only by the first few hours afterward. The effect can take time to develop.
Some patients notice improvement within 1 to 2 weeks. For others, improvement may take 4 to 6 weeks.
It is common to have temporary soreness or a pain flare before the benefit becomes clear.
The amount and duration of relief varies from person to person. Some patients have substantial relief, some have partial relief, and some do not improve.
When it works, relief may last several months. Studies of genicular radiofrequency ablation commonly report benefit in the 3 to 12 month range, although individual results vary.
The next step depends on how much relief you have after the procedure and how long that relief lasts.
If your knee pain improves significantly, we may continue to monitor your response and focus on rehabilitation, walking tolerance, strengthening, weight management, or other conservative measures.
If your pain returns after a period of meaningful relief, repeat treatment may be considered depending on your response, goals, and overall treatment plan.
If your pain does not improve, or only partially improves, we would usually reassess. This may mean reviewing imaging, reconsidering the pain source, discussing knee joint injection options, or recommending orthopedic review.
If you have not already had diagnostic testing, genicular nerve blocks are often used to help assess whether knee radiofrequency ablation is likely to help.
Keep the needle sites dry for 24 hours. Remove bandages after 24 hours.
If you develop a pain flare, this usually improves with time. Ice packs and over-the-counter pain relievers may help if you are allowed to use them. Avoid unusually strenuous activity for the rest of the day.
Knee radiofrequency ablation is generally a low-risk procedure when performed with image guidance and sterile technique.
The most common issues are temporary soreness, bruising, lightheadedness, temporary increase in pain, or temporary irritated-nerve discomfort.
Uncommon risks include bleeding, infection, allergic reaction, medication entering a blood vessel, temporary numbness, skin burn, or worsening pain.
Serious complications are very rare, but can occur with any procedure performed near nerves and blood vessels.
Tell us if you have a knee replacement booked within the next 6 months. We generally do not want to inject steroid into the knee joint if this could delay your surgery.
Seek medical attention if you develop fever, worsening redness or swelling at the needle site, drainage from the needle site, severe worsening pain, or a hot swollen knee that does not settle.
The procedure itself, including the clinic visit and use of X-ray guidance, is covered by OHIP.
OHIP does not cover the cost of medications used or prescribed, such as local anesthetic, contrast dye, or other medications. These costs may be covered by private insurance.
The medication cost is usually in the range of $25 to $100, depending on the extensiveness of the procedure, but this may vary.
Unless you are told otherwise, you may usually take your regular medications. Blood thinners require separate review.
Tell us before the procedure if you take blood thinners or antiplatelet medications. Do not stop them on your own. We will give you specific instructions based on the medication and your medical history.
Tell us before the procedure if you have ever had an allergy or serious reaction to contrast dye, local anesthetic, or antiseptic skin-cleaning solution.
Tell us if you have diabetes, an active infection, are taking antibiotics, are pregnant or may be pregnant, have a knee replacement booked within the next 6 months, or have had a recent major change in your health.
Afiya Spine & Pain Institute
301 - 15 Wellesley St W, Toronto, ON M4Y 1G1
Phone: 416-413-7999 | E-Fax: 416-641-4520
For questions or concerns after your procedure, contact the clinic.