Minimally Invasive Procedures Offer Relief From Knee Arthritis Pain Without Surgery.

Knee replacement surgery is a daunting prospect for many of the 32.5 million adults in the U.S. who have osteoarthritis (OA), the most common type of arthritis. Over time, cartilage in the knee joint breaks down and the bones change, causing pain, swelling, and stiffness that reduce mobility and can make common tasks more difficult.

While knee replacement can give patients better mobility, initial recovery takes six to eight weeks, and often continues for a full year. Some patients can’t commit to surgery due to family obligations or cannot have it because of other health conditions. Additionally, some patients may experience continued pain even after a knee replacement.

But patients who can’t have or don’t want knee replacement, or who have had prior surgery, don’t have to simply suffer with pain. MedStar Washington Hospital Center offers two minimally invasive interventional radiology procedures to help reduce pain: genicular artery embolization (GAE) and genicular nerve ablation (GNA) 

Genicular artery embolization.

Originally developed to help control bleeding after knee replacement surgery, GAE has been proven to help reduce pain in patients with OA who have not had joint replacement. GAE reduces blood flow to the knee’s lining, called the synovium, which is often inflamed due to OA. 

An interventional radiologist inserts a small tube into an artery in the patient’s thigh. Guided by live X-rays, they maneuver this tube through the arteries to the specific vessels that supply blood to the inflamed knee joint capsule. They then inject small particles into three or four of these arteries, which limits the amount of blood that can reach the synovium. This reduces inflammation and lessens pain while preserving the normal healthy blood flow to the knee. The procedure is performed under sedation, and patients return home the same day. 

Side effects can include numbness, bruising, and discoloration around the knee, but these clear up on their own. Pain relief begins within two weeks as inflammation subsides and can last six months to two years. The average patient is pain free for about a year following GAE.

Genicular nerve ablation.

GNA offers similar benefits to GAE. Instead of treating blood vessels, GNA focuses on three to four nerves that control pain of the joint to provide relief. Our research has shown that GNA is particularly helpful at reducing pain in patients over age 50, suggesting it is an effective treatment for chronic pain conditions like osteoarthritis. In addition, our research has demonstrated that this is an effective treatment for pain in patients who have already undergone knee replacement surgery.

Interventional radiologists use live X-ray guidance to position the instruments in a two-step process for GNA. First, the interventional radiologist performs a test nerve block to learn whether the full GNA will be effective. Small needles are inserted at the site of the knee nerves and a small amount of anesthetic is deposited. After 30 minutes, if the patient reports a 50% or greater reduction in pain, we schedule the full GNA.

The ablation procedure is similar to the test, except you will be under sedation. With the guidance of live X-rays, we insert ablations needles at the site of the knee nerves and use heat to destroy the nerves that cause pain. 

This results in substantial pain relief, but it doesn’t last forever. Nerves can regrow after about a year, causing pain to return. However, we can safely repeat the ablation procedure after a minimum of six months and unlike a steroid injection, it does not affect any future surgery or other pain intervention.

Benefits of GAE and GNA for patients.

GAE and GNA are both safe procedures, so there is little downside to attempting these techniques and neither interferes with any future joint replacement surgery. We usually try GNA first. If patients’ pain returns within six months or less, GAE can be a great option.

While not a substitute for knee replacement, GNA and GAE provide:

• Increased accuracy and few complications
• Less pain
• Less scarring
• Quicker recovery
• Outpatient same-day procedure
• No stitches or sutures

For many patients, controlling knee pain allows them to start physical therapy, which can help with joint stability, muscle strength, and weight loss. In fact, PT is sometimes necessary before joint replacement surgery and these minimally invasive options allow patients to get there prior to a joint replacement.

MedStar Health interventional radiologists and orthopedic surgeons provide a team-based approach to OA pain relief. We collect data on these procedures and conduct research, looking for ways to improve results. 

For example, we are studying how using artificial intelligence to analyze patient data can help us identify which patients might benefit most from GNA or GAE. 

Osteoarthritis of the knee is common and debilitating, and joint replacement surgery is an effective treatment. For patients seeking to restore mobility and their quality of life without open surgery, GAE and GNA can be minimally invasive procedures to reduce pain.