Chronic knee pain can have many causes. The genicular nerves are a set of nerves that transmit the pain signal or sensations from the knee to the brain. A genicular nerve block blocks and radiofrequency ablation is a set of procedures used to diagnose and treat chronic knee pain.
Step 1 - Genicular Nerve Block:
First a diagnostic genicular block is performed. During this procedure the nerves that are believed to be causing the pain are blocked or numbed temporarily. This is meant to determine and confirm if these nerves are responsible for the pain. This relief is only intended to last approximately 5-8 hours.
Step 2- Repeat Genicular Nerve Block:
The initial procedure is repeated. Two sets of diagnostic (test) injections are completed on two different occasions to confirm the underlying cause of the pain. If two blocks (step 1 and step 2) are successful in temporarily alleviating a large percentage of your pain, this is a positive test. At this point radiofrequency ablation can be considered.
Step 3 – Genicular Nerve Radiofrequency Ablation:
Radiofrequency (RFA) Ablation can be performed, which provides long lasting relief. Radiofrequency ablations involve using a special needle which heats up. This needle then burns or stuns the nerves going to the joints. The ablation interrupts the pain sensations originating from nerves for typically greater than 6 months.
What conditions are treated with Genicular Nerve Radiofrequency Ablation (RFA)?
Genicular nerve block is to treat the symptoms of chronic knee pain from osteoarthritis, failed knee replacement, patients medically unstable for knee replacements and patients who want to avoid knee replacements.
How is the procedure performed?
Our team will help position you to make sure the procedure can be completed with the least amount of discomfort for you. The skin is cleansed with a sterilizing solution (chlorhexidine) and a sterile drape is placed. A local anesthetic medication typically (Lidocaine) is given to numb the skin. Next, fluoroscopy (x-ray) or ultrasound is used to find the target. Next the needle(s) is directed to the desired location. Contrast dye may then be injected to confirm the correct placement of the needle. A local anesthetic for numbing and /or steroids for reducing inflammation are then injected. During the entire procedure you will be constantly monitored by the physician. After the injection a small bandage is placed on your skin. You will be given time after the procedure to make sure you feel good and are not having side-effects before leaving the clinic.
What medication is injected?
The injection includes a combination of anesthetic (lidocaine or bupivacaine) and sometimes steroid (cortisone, Kenalog or dexamethasone).
Does the procedure hurt?
The procedure is typically well tolerated. A localized burning sensation from the anesthetic is commonly felt and is usually the most uncomfortable part of the process. During the procedure a pressure sensation is often experienced this typically resolves within a few minutes. Minor soreness for a week after the procedure is normal.
How long does the procedure take?
The procedure typically takes about 15 minutes to perform. Please plan on being at the clinic for about 1 hour to allow for pre and post-procedural safety protocols.
How quickly will I get relief?
The genicular nerve block will result in quick relief that only is intended to last 8 hours. The ablation procedure may take 10-14 days to reach maximal effectiveness. Our clinical nurse should call you on the following day to check on you. Future planned injections can be scheduled at that time.
How long can I expect the relief to last?
The radiofrequency ablation is intended to last 6-12 months. Some patients can get relief lasting greater than a year. Unfortunately, some patients get no relief.
How often can the procedure be repeated?
Depending on results and providers discretion the injections may be repeated every 6-12 months.
Can I have the injection if I have diabetes?
Yes. It is important to control your blood sugar before and after the injection. Diabetic patients may experience a small temporary increase in blood sugar lasting no more than 2-3 days.
What are the risks and side effects?
Risks and side effects are minimal and serious complications are rare. We take every precaution to ensure safety. Potential risks may include but are not limited to: vasovagal response (passing out), new or increased pain, infection, bleeding, permanent skin changes, allergic or unexpected drug reaction with minor or major consequences, and unintended nerve injury.
Please let us know if you have an active infection, are using antibiotics, or are using blood thinners.
Should I take my normal medications as scheduled?
Yes. Continue prescribed medications as you typically take prior to procedure.
What if I am on a blood thinner or Aspirin?
Anti-coagulation is often stopped for a short period of time prior to injection. Please speak with your primary physician if you take blood thinners to make sure that you can safely stop taking these medications.
Do I need a driver?
Yes. For your safety we require a driver to take you home.
Can I eat the day of the procedure?
It depends on the location. We recommend eating a light meal if the injection is done in our clinic. If the procedure is done at the surgery center, then you must fast for at least 8 hours prior to the procedure.
Can I get sedation or anesthesia?
Most patients do well without sedation. Light sedation with oral medications is sometimes provided at the physician’s discretion.
What if I am pregnant?
There are serious potential risks to an unborn fetus when exposed to imaging studies, including x-ray and fluoroscopy. If there is any chance you may be pregnant, please postpone this procedure until it can be confirmed that you are not pregnant as it is not safe to do during pregnancy.
What should I wear?
We recommend light loose-fitting clothes. Sometimes we will ask you to change into a gown.
When can I drive after the procedure?
We recommend resuming driving the next day.
What can I do if I am sore or have pain after the procedure?
Ice packs can be applied to the area for 20 minutes per hour. Over the counter Tylenol and Motrin can be used to aid with any discomfort.
What are my restrictions after the procedure?
Typically, you may resume light activities on the same day following your procedure. Physical therapy can be re-started within 24 hours. We recommend returning to work the day after the procedure.
When can I shower?
Showering the day of the procedure is allowed. For 24 hours you are asked to refrain from submerging or swimming in water. Keep the bandage on for one day.
When do I come back for a follow-up visit?
We follow-up with all of our patients after their procedures. We typically see patients back in 2-4 weeks.