Q: I saw an advertisement on TV for Coolief to treat arthritis. It looked encouraging. What is it and does it work?
A: Coolief is a procedure used to reduce pain for people with knee osteoarthritis. A doctor inserts electrodes through the skin, placing them near nerves in several locations around the knee. Electric current applied through the electrodes then delivers heat to the nerve. This impairs its ability to send pain signals to the brain.
Standard nerve blocks use a similar method to block pain signals. But Coolief doesn’t just heat up the electrodes, they also get cooled down — a technique called cooled radiofrequency ablation. The idea is to deliver more energy where it’s supposed to go with less collateral damage.
The procedure is considered minimally invasive. However, it requires several injections and X-ray guidance to be sure of the proper location. By comparison, a cortisone shot in the knee to relieve pain is usually only one injection, and X-ray guidance is rarely needed.
Does Coolief work? A number of studies have tried to answer this question, but the evidence is iffy. The evidence supporting cooled radiofrequency ablation as a reliable and long-lasting way to relieve pain from knee osteoarthritis is quite limited. Many studies included only a few patients and did not assess responses after more than a few weeks.
Most studies found few or no side effects associated with the Coolief procedure. Even so, the manufacturer warns of potential risks that include infection, nerve damage, increased pain — even paralysis and death. In part, this may be based on reports of cooled radiofrequency ablation in other areas of the body.
Coolief was “cleared” by the FDA. This might lead you to assume the FDA evaluated the evidence and concluded this procedure is safe and effective. In fact, Coolief did not require specific FDA approval because the FDA concluded it was similar enough to other legally marketed devices.
Coolief might be helpful for some people with osteoarthritis of the knee. Or it might not. Also, it’s expensive and may not be covered by insurance. Before I recommend the procedure, I’d like to see more and better studies.
If you have osteoarthritis of the knee, talk to your doctor about all the options, including cooled radiofrequency ablation.