Radiofrequency: Electrical heat production
Denervation: Interruption of nerve conduction
Frequency: Usually performed after a patient has successfully completed lumbar medial branch blocks with at least 50% pain relief for the duration of the local anesthetic.
Anesthetic: Local +/- IV sedation
Radiofrequency ablation of the genicular nerves around the knee can help with any type of chronic knee pain most commonly performed secondary to arthritis of the knee or continued pain after knee replacement. After conservative measures fail to help alleviate chronic knee pain, this can be a great option to help control your pain without the use of chronic medications and/or steroid injections.
In the normal course of treatment for chronic pain from arthritis of the knee joint, typically steroid injections are performed. If these fail and/or give side effects, the next step is viscosupplementation i.e. injecting a gel-like substance into the knee joint to help “lubricate” the joint and provide some pain relief. This is normally done in a series of 3 and possibly even 4 times and can be repeated every 6 months.
If these measures fail to give you adequate pain relief, a relatively knee therapy can be performed. This initially involves numbing 3 nerves around your knee joint (genicular nerve blocks). If numbing these nerves gives you at least 50% pain relief (makes your pain numb) for at least 4 hours, then you would be a candidate for cauterizing these nerves ie knee ablation.
Add the Contraindications and Side effects of lumbar radiofrequency denervation
During the procedure, you will be lying on your back. An IV may be placed for sedation. An x-ray machine is used to locate the specific locations of the nerves in your knee. After your skin is cleaned with an antiseptic solution, normally betadine unless you are allergic, a series of x-rays will be taken to guide the needle placement. The skin is localized with a local anesthetic which is typically the most painful part of the procedure as this medicine has a tendency to burn when it is injected. Another needle is then placed through the numb area of your skin and guided by the x-ray machine to the location of where the nerve sits. This is done 2 more times in around your knee until all needles are in place. The needles will then be connected to a radiofrequency generator and the nerves that are to be disrupted are stimulated. This will likely produce an unpleasant sensation in your knee. If any pain/twitching travels to your ankle/foot at any time during the procedure, please notify your physician. When satisfactory stimulation is achieved, additional local anesthestic is placed on the nerves. Finally, lesioning of these nerves begins. You may experience increased pressure/pain in your knee which is normal. However, if at any time the pain is too intense, please tell your physician who can provide more local anesthetic. After the lesioning is complete, the needles are removed and the procedure is completed.
Typical length of the procedure:
15 minutes. Expect to be at the clinic no more than 20 minutes after you have been checked in by the medical assistant into the preoperative area. If this is your first injection and/or you have had sedation, you will likely be at the clinic for at least one hour. Please plan accordingly.
How long do you expect pain relief:
On average, patients will gain at least 50% pain relief for 6 months. This relief may not be immediate and can take several weeks before adequate pain relief is achieved. If the pain returns after this time frame, the procedure can be repeated.