Genicular Nerve Block for Knee Pain

Introduction

Knee pain is traditionally treated with physical therapy, steroid injections, viscous supplementation injections (rooster comb), joint replacement, and medications. When these methods are ineffective at treating knee pain, a procedure to block the pain signal coming from the knee itself can be used. This procedure is called a genicular nerve block.

Knee pain is transmitted to the brain by several nerve pathways. The genicular nerves are small branches of larger nerves that are located close to the knee joint itself. Blocking these small genicular nerves can help to temporarily alleviate a significant portion of the pain coming from the knee.

This is a step in the process of identifying your pain, and identifying patients who may be eligible for radiofrequency ablation (neurolysis), which is a procedure that provides longer lasting relief, often 6-12 months duration.

Goal of the injection

In order to determine if pain in the knee can be reduced, we use a diagnostic procedure called genicular nerve block. The goal of this procedure is to place a small amount of local anesthetic on three to four small genicular nerve branches, which are located near the knee joint. While the genicular nerves are anesthetized, the pain transmitted from the knee should be significantly improved – helping us to localize the source of your knee pain.

The procedure

You will be brought into a sterile procedure suite, and asked to lie on the exam table. Using X-ray guidance, the skin is anesthetized and a small needle is inserted over each genicular nerve location. Once the needle is in proper position, a small amount of anesthetic is injected.

Following injection, the patient is cared for in the recovery area for a brief amount of time, and then discharged home.

After the procedure

Follow the specific instructions given to you by the nurses at the time of discharge from the recovery area:

• Resume activity as tolerated
• Patients are encouraged to perform activities that typically cause an increase in their normal pain. This is used to “test” whether the diagnostic procedure is helpful in reducing your pain.
• Keep a record of your pain and symptoms in the immediate hours after your injection
• Do NOT soak in a bathtub or lake for 24 hours after the procedure. You may shower.
• You will receive a phone call from a clinic  nurse, asking about the relief of symptoms you experienced after your injection. If you meet specific criteria designated by the insurance companies, you may be scheduled for a second diagnostic block – or you may be scheduled for radiofrequency ablation as the next step.

If your procedure includes sedation

• You should have no solid foods for 8 hours before the procedure.
• You may have clear liquids up to 2 hours before your procedure. Examples of these clear liquids are:  water, broth, clear juices with NO pulp, tea, coffee WITHOUT cream. Carbonated beverages are NOT allowed.
• No gum chewing for 2 hours before your procedure.
• No candy, throat lozenges, or mints.
• A nurse will call you before your procedure to review your medications and make recommendations as to what medicines you should take before your procedure.

Failure to comply with these instructions may result in cancellation and rescheduling of your procedure.

Potential risks of the procedure

Genicular nerve block procedures are considered safe, non-surgical, minimally invasive treatments. As with all medical procedures, there associated risks and side-effects that may vary between each patient. These rare but potential risks are:

• Pain at the injection site
• In very rare instances (less than 1%), minor infections can occur
• Increased pain or worsening symptoms.
• Bleeding. Youmay suffer bleeding from undergoing procedures, especially while on blood thinning medications. Please notify us if you are taking any of the following blood thinning medications: Warfarin (Coumadin), Plavix (Clopidogrel), Aspirin, Xarelto (Rivaroxaban), Heparin, Lovenox (Enoxaparin), Brilinta (Ticagrelor), or any others not listed.
• Allergic reactions to medications. The commonly used medications in this procedure include: Lidocaine, Bupivacaine, Ropivacaine, IV contrast dye, and corticosteroid (cortisone).
• Inability to complete the injection due to technical or anatomic difficulty.

Insurance requirements

Insurance companies may require two genicular nerve diagnostic block procedures, demonstrating relief of symptoms for a specific amount of time, prior to approving the radiofrequency ablation procedure.