Radiofrequency Neurotomy Genicular Nerve Block
What is Genicular Neurotomy?
Genicular neurotomy or genicular radiofrequency ablation is a procedure to relieve knee pain from osteoarthritis by treating the genicular nerves in the knee with radiofrequency waves to prevent transmission of pain signals to the brain.
Osteoarthritis is a common degenerative disease mostly associated with advancing age. It involves the deterioration of the smooth cartilage that lines the bones in the joint leading to friction, pain and limited function. The knees, which are commonly affected by osteoarthritis, are innervated by several branches of the genicular nerve that supply the knee joint with sensation. Important genicular nerves include the:
- Superior lateral nerve
- Superior medial nerve
- Inferior medial nerve
These are the nerves targeted during a genicular neurotomy.
Indications for Genicular Neurotomy
Genicular neurotomy is indicated for chronic knee pain when conservative treatments such as medication, physical therapy or steroid injections does not provide sufficient pain relief. Those who cannot undergo surgery for various reasons will also benefit from this procedure. It can also relieve knee pain that persists after surgery and may be used before or after knee replacement surgery to speed up recovery.
Genicular neurotomy is an outpatient procedure performed in 2 steps.
A diagnostic nerve block is first performed to see if you would benefit from a genicular neurotomy. If you experience sufficient pain relief from the block, the actual neurotomy is then carried out. Both steps are performed under local or regional anesthesia to keep you comfortable
For the diagnostic block, the skin over the knee is thoroughly cleansed and the region of the 3 genicular nerves are identified by fluoroscopic or live X-ray imaging using your bony anatomy. The areas are marked on the skin and 3 needles inserted to reach the genicular nerves. Contrast dye is passed through the needles to confirm their positions on imaging. Local anesthetic is then administered through the needles to numb the genicular nerves. If you have significant pain relief several hours after this procedure, you are considered a good candidate for a genicular neurotomy.
For the procedure, the genicular nerve sites are identified once again and 3 needle-like cannulas inserted to reach these sites. Fine electrodes are passed through the cannulas and specific signals are transmitted to perform sensory and motor tests. This is done to ensure that no important sensations or functions in the limb are affected by the procedure. Once testing is complete, radiofrequency waves are transmitted through the electrodes for 90-180 seconds to create nerve lesions that block pain signals. The electrodes and cannulas are then removed and dressings placed. The entire procedure takes about 30 minutes to complete.
You may experience some soreness or spasm at the treatment sites which is easily relieved by medications prescribed by your doctor.
Satisfactory pain relief is usually experienced in a few days or weeks and can continue for 6-12 months or even longer depending on the location and cause of your pain.
Advantages of Genicular Neurotomy
Genicular neurotomy has several advantages over traditional knee surgery including:
- It is an outpatient procedure
- It is less expensive
- It can be performed under local anesthesia
- Postoperative pain is minimal
- Recovery is quick
Risks and Complications
Genicular neurotomy rarely causes complications. You may experience some skin irritation or sensitivity at the injection sites. As the procedure involves injections, potential complications include
- Nerve damage
- Vascular injury
Since nerves can repair themselves, the pain may return eventually and you may need to undergo the procedure again.