Radiofrequency Ablation for Knee Pain
A radiofrequency ablation (RFA) is a type of injection procedure in which a heat lesion is created on certain nerves with the goal of interrupting the pain signals to the brain, thus eliminating or reducing pain.
Patients with persistent knee pain after knee replacement or arthritis patients who are not surgical candidates may benefit from RFA treatment. RFA procedures has been used for decades to treat low back pain, but with improved medical technology, it’s increasingly used for knee pain. RFA targets and destroys nerves in the knee that send pain signals to the brain.
Most patients with knee arthritis benefit from weight loss, physical therapy, pain medications such as acetaminophen (Tylenol) and nonsteroidal anti-inflammatories including Ibuprofen (Advil, Motrin) and naproxen (Aleve) and possibly a knee brace. Injections with hyaluronic treatments may reduce the rate of arthritis and provide some pain relief. Steroids may also be useful to reduce acute knee pain, but is not recommended more than 2-3 times per year.
Before this procedure is undertaken, the joints and branch nerves will have already been proven to be painful by a diagnostic block. If effective, the neurotomy should provide pain relief lasting at least three to fourteen months and sometimes much longer. After this period of time, however, the nerve will regenerate and the pain may return.
Radiofrequency abalation procedure:
As with many spinal injections, radiofrequency ablation is best performed under fluoroscopy (live x-ray) for guidance in properly targeting and placing the needle. On the day of the injection, patients are advised to avoid driving and avoid doing any strenuous activities. Patients may continue to take any normal medications except aspirin or any other blood-thinning medications, such as Coumadin. If you have already undergone any spinal injections with Dr.Suthar, you may already know that a generous amount of local anesthetic is provided. In addition, we will continue to monitor your comfort and facilitate steps to make your experience a good one. The entire procedure usually takes between 20 and 45 minutes. Additional time is required for paper-work and post-injection care.
Radiofrequency ablation results and follow-up:
On the day after the procedure, you may cautiously return to regular activities. The area of treatment will usually be very sore during the next one to four days. This pain is usually caused by muscle spasms and irritability while the targeted nerves are dying from the heat lesion over the next seven to fourteen days. You may continue with previous medications for pain to treat the expected soreness, and may also apply ice (or heat or warm towels) to the sore area to alleviate discomfort. Patients usually will want to rest for several days before returning to normal activities.
If pain relief is going to occur, full pain relief will typically not be experienced until about two to three weeks after the procedure when the nerves have completely died. On occasion, the back or neck may feel odd or slightly weak for several weeks after the procedure.
The nerves will eventually grow back (regenerate), but the patient’s pain may or may not recur. If the pain does recur, a second neurotomy can be performed, and similar results will usually be achieved. Some patients will not have a recurrence of pain.
Common concerns about RFA:
- Patients are frequently concerned that, without the ability to feel sensation through these nerves, they may cause an injury to either the joints or the back. There is no scientific evidence to support this happening. In the many years that RFA have been performed, this has not been found to occur.
- Another concern is that by damaging nerves, pain will be caused rather than relieved. There is a small chance (less than 5%) that the pain will worsen after the procedure. This is believed to be from increased irritation of a nerve that was only partially damaged, not completely destroyed. This can be treated with medication and usually goes away in several months. It is less common in the mid and low back than in the neck, and is most common at higher levels of the neck.
Potential complications of RFA:
As with all medical procedures, there are certain risks and potential complications associated with a radiofrequency neurotomy. Complications are rare with this procedure, but can occur, and include:
- Pain or discomfort around the injection site
- Numbness of skin covering the injection site
- Worsened pain due to muscle spasm in the area of the injection
- Permanent nerve pain
- Allergies or reactions to medications used