Knee cryoneurolysis

Knee pain is a common condition caused by a multitude of factors. It can occur suddenly following an injury such as a sprain or fracture, or gradually. It can be caused by mechanical problems (e.g. knee osteoarthritis, algodystrophy) or by inflammation (e.g. rheumatoid polyarthritis, ankylosing spondylitis).

After age 50, knee osteoarthritis, also known as degenerative joint disease, is the most common cause of knee pain. In this disease, the cartilage in the knee joint gradually breaks down, becoming increasingly thin and unable to serve as a smooth gliding surface or cushion in the joint. This causes the bones to rub against each other, resulting in pain, stiffness and inflammation.

To relieve the pain associated with knee osteoarthritis, the most popular options for patients include:

• Anti-inflammatory drugs (NSAIDs) to reduce the inflammation;
• Opiates or injections of corticosteroids or hyaluronic acid to relieve the pain;
• Arthroplasty (insertion of an implant) when conservative treatments fail and/or if the pain becomes extremely debilitating (this option is only used for the most serious cases).

These treatments nevertheless carry a risk of unwanted side effects that must be taken into consideration.

Cryoneurolysis is an innovative interventional radiology technique that emerged in the 2000s. Still not widely known today, it offers a minimally invasive solution to treat pain. It is performed on an outpatient basis under local anesthesia, meaning it carries a very low risk of complications.

Cryoneurolysis is a revolutionary technique that aims to relieve knee pain by targeting the nerves that transmit pain signals. Unlike more invasive procedures such as the insertion of an implant, cryoneurolysis is a minimally invasive option that brings relief without major surgery.

The procedure is performed on an outpatient basis under local anesthesia by an experienced interventional radiologist, under ultrasound guidance.  

It consists in applying extreme cold (-70°C/-94°F) to the targeted nerves in the knee using a very thin “needle” called a cryoprobe. This exposure to an extremely low temperature damages the nerves, preventing it from sending pain signals to the brain. The nerves will regenerate in the months following the procedure.

In addition, cryoneurolysis does not harm the tissues traversed by the probe. It leaves no scars and carries an extremely low risk of complications. Patients recover within hours after the procedure.

This pain-free procedure therefore brings long-term relief for knee pain without the need for hospitalization.

Cryoneurolysis is a procedure to treat knee pain using a minimally invasive technique that shows promising outcomes. People who have undergone the procedure report a significant reduction in pain and improvement of their mobility. Because it is a minimally invasive procedure, recovery is also faster compared with other surgical procedures.

The findings of 14 studies on cryoneurolysis were analyzed in 2023. Two of the studies focused on knee oseteoarthritis, three on unspecified chronic knee pain, and nine on patients before or after undergoing a total knee replacement. The findings demonstrate significant improvements in:

• Pain
• Function
• Quality of life
• Opioid use

Moreover, most of the side effects were minor and temporary. Consequently, cryoneurolysis appears to be a promising solution to relieve knee pain, especially in patients with light to moderate knee osteoarthritis or prior to a total knee replacement. Nevertheless, the authors stress the importance of conducting additional studies to confirm its efficacy and determine the best choices in terms of the nerves targeted and the techniques used (1).

Cryoneurolysis is a safe, minimally invasive procedure performed under local anesthesia under imaging guidance by an experienced interventional radiologist, which significantly lowers the risk of unwanted side effects. Momentary swelling of the area treated can be expected, but no serious adverse effects have been recorded to date.

Considering its favorable risk-benefit ratio, cryoneurolysis for knee pain could be an effective complement to analgesic drugs for patients with osteoarthritis of the knee. 

Cryoneurolysis is performed on an outpatient basis at the American Hospital of Paris. It is a minimally invasive procedure targeting nerves in the knee in order to relieve knee pain.

After the patient is given a local anesthesia in the knee, the interventional radiologist locates the exact position of the affected nerves under ultrasound guidance. Using a cryoprobe adapted for high-precision surgery, the nerve is reached without causing damage to the tissues. This avoids scarring and reduces the risk of complication to a minimum.

Once the probe is positioned near the nerve, the coolant is introduced, which lowers the temperature of the nerves responsible for the knee pain until they freeze. This cryoablation diminishes the electrical signal to the brain, restoring balance in the nerves and procuring lasting pain relief.

At the end of the procedure, which is totally painless, the cryoprobe is removed and a compression dressing is applied. No hospitalization is required, the patient can leave the hospital on the same day.