What is a Genicular Nerve Block?
Your knee is a large, complex joint made up of four bones: the femur, the tibia, the fibula, and the patella. These bones are stabilized by the muscles of the quadriceps, hamstrings, and calves.
There is a complex network of nerves and arteries, collectively referred to as the genicular nerves, throughout this entire joint. A genicular nerve block uses an anesthetic injected into the sides of the knee to relieve knee pain from a variety of causes. Your knee pain might be sporadic, only occurring at night, or it might be constant and interfere with every step you take.
Additionally, a genicular nerve block for knee surgery can provide lasting pain relief as you recover and rehabilitate this joint, delivering targeted relief directly where it’s needed—without the potential side effects of oral pain medications.
Genicular nerve blocks can also be used as a diagnostic tool. If a genicular nerve block relieves at least 50% of your knee pain, it indicates that you may be a candidate for a more permanent pain solution like radiofrequency ablation (RFA). This is a procedure that uses a weak electrical current to damage pain-signaling nerves in the knee. Many patients have experienced long-term pain relief and increased mobility with RFA.
A genicular nerve block for knee pain is placed in several different locations in your knee. The anesthetic blocks the pain-signaling nerves in the knee. This does not treat any underlying conditions that are causing pain, but it does allow for other treatments or rehabilitative exercise to occur, pain-free.
Sometimes a corticosteroid will be injected for inflammation, as well. But unlike other joint injections, a genicular nerve block is most frequently simply an anesthetic medication with no steroid.
Why is a Genicular Nerve Block performed?
A genicular knee block is a minimally invasive procedure with a low risk of side effects or complications that can help relieve pain safely so that you can begin other treatments, such as physical therapy.
Genicular nerve blocks can help you avoid more invasive knee surgeries when other conservative pain control methods are not working and it’s a good option for people who are not eligible for surgery but need pain control without oral medications.
A genicular nerve block does not require a steroid to be effective, making it a good option for people who are allergic to steroids or wish to avoid potential steroid side effects.
There are other benefits unique to specific causes of knee pain, too.
Osteoarthritis, one of the most common causes of chronic knee pain, can also be one of the most difficult to treat. For intractable osteoarthritis, a genicular nerve block using just an anesthetic or an anesthetic and a corticosteroid, can provide pain relief lasting for at least two weeks.
While Osteoarthritis is the most common cause of chronic knee pain, it isn’t the only one. Gout, tendinitis, and injury can cause pain and swelling that is either episodic or constant. There are a variety of treatments for each of the conditions, while used in conjunction with a genicular nerve block to relieve the pain.
Most people having total or partial knee replacement surgery, have positive results. Pain and swelling can indicate a failed total or partial knee replacement, where the implant may shift and become loose which would cause intense pain, swelling and instability in the knee, sometimes calling for a knee revision surgery. A genicular nerve block can help control the pain before and after this procedure.
Having a genicular nerve block for pain management during and after knee surgery recovered faster, had lower pain scores, and took less than half the dosages of opioids during their recovery and up to a week afterward than patients who did not receive a genicular nerve block.
How is a Genicular Nerve Block performed?
Unlike some nerve blocks that target a single nerve, a genicular nerve block is placed in at least three separate locations in the knee for best results, which are located at the top of the knee, on the inside and outside of the knee, and below the knee on the inside of the leg.
This procedure is performed on an outpatient basis with local anesthetic. It’s best to bring a friend or family member to drive you home.
Once your skin is numb, your doctor uses X-ray guidance to properly place the injections. Medications are injected outside of the joint, cutting the pain signals off where the nerves begin. Pain relief may begin within minutes. You are encouraged to take it easy for the rest of the day.
What should I expect after a Genicular Nerve Block?
It’s best to have someone drive you home the day of your knee nerve block. You may experience numbness in their leg, so it’s recommended that you refrain from driving for the first 24 hours. It’s okay to move around, but no exercising or standing for long periods of time. Take the day off and rest.
There may be mild swelling, bruising, or soreness at the injection sites. Over-the-counter, non-steroidal anti-inflammatory medications like ibuprofen and naproxen sodium can help, as directed by your doctor. You can also apply ice to ease swelling in a 20 minutes on, 20 minutes off pattern as needed.
Keep a pain diary in the days following your procedure to note when and if you feel any changes to your pain. You may feel a dramatic drop in pain right after the procedure, followed by a slight increase in the pain before the levels stabilize, which is normal.
The risks of genicular nerve blocks are rare, but can include the following:
- Drug allergy
- Heavy bleeding
- Increase in pain
- Nerve damage
- Tissue damage
- Allergic reactions
- Infection (heat, redness, or excessive swelling in the knee; oozing or bleeding at the injection site, fever, general feeling of being unwell)
Most patients experience some level of pain relief immediately after the block. Some patients experience complete pain relief for a few hours, while others experience total or partial relief for days, weeks, and even months. There is no way to predict how long the genicular nerve block will last.
This procedure works best when it’s part of a comprehensive treatment plan, including lifestyle changes like diet, exercise, and complementary therapies (like physical or biofeedback therapy).
As previously mentioned, with a successful genicular nerve block, you may also be a candidate for radiofrequency ablation, which offers the possibility of long-term pain relief that has few side effects and can be repeated as needed with no ill effects.
