Chronic Knee Pain? It could be nerve related.
by Hanna Logsdon, MS IV
For some patients with chronic knee pain, directly addressing the nerves which supply the knee may be an effective treatment option. There are several nerves which are responsible for sensation in and around the knee; the medial genicular nerve, lateral genicular nerve, and infrapatellar nerve. Pain originating from these nerves can be treated with nerve blocks or radiofrequency ablation (RFA) depending on the location and quality of the pain. Nerve pain (neuralgia) tends to be described as sharp, shooting, burning, electric, and pins/needles sensation.
Genicular Nerve Blocks
The nerves around the knee can be injected “blocked” using a small needle to spread a combination of local anesthetic and steroid around these nerves. If these nerves are the cause of your pain, rapid temporary pain relief is expected for the day of the injection from the local anesthetic. Following the injections you may experience some soreness in the area. A few days later, pain relief from the steroid will typically begin and may last for a few weeks or months. These nerve blocks can also help to diagnose the cause of your pain (i.e. significant pain relief from the injection supports the diagnosis of nerve related pain).
If you do experience temporary pain relief from a nerve block, a longer-lasting procedure may be performed: radiofrequency ablation (RFA). In RFA, the affected nerves are located through stimulation with a small probe and an injection of local anesthetic is performed to provide anesthesia. The nerves are then ablated (heated) with a small electrode which reaches high temperatures essentially burning the nerve and cutting off its ability to transmit pain sensations to the brain. This procedure is performed for each of the affected genicular nerves during one session in the office. Following this procedure, soreness may occur for a few days. It is also possible to ablate the nerves using cold temperatures rather than heat, this is known as cooled RFA. This procedure can be performed in an office or outpatient surgery center and may provide pain relief for months to years.
Who should consider these procedures?
- Patients who may need a knee replacement but are not good surgical candidates
- Patients who have persistent pain despite successful knee joint replacement surgery
- Patients with nerve related pain who are avoiding or postponing surgery
- Patients who have had trauma or injury to the genicular nerves
What are the risks?
These procedures are generally low risk but there are potential complications to keep in mind. Altered sensation such as numbness/tingling may occur around the knee following genicular nerve treatment but this is uncommon. Infection is also an uncommon complication, since these injections do not actually enter the knee joint itself and sterile technique is used. You may experience temporary increased pain and soreness around the injection sites for up to a few days following either procedure.
If you are experiencing chronic knee pain, addressing the genicular nerves through either a nerve block or RFA may be an effective option to relieve pain.
Dr. Martin Taylor, Neurologist here at OrthoNeuro performs genicular nerve blocks and RFA in appropriate patients