Genicular Radiofrequency Ablation in St. Louis

Radiofrequency ablation uses a small electrode that heats the tip of a needle set right against a nerve. The heat shuts that nerve down so it stops carrying pain signals from the knee. The joint itself is not touched. Nothing is removed, replaced or rebuilt. What changes is the message the knee sends. That is why it suits people whose scans show arthritis they are not ready to have surgery on.

We do not burn a nerve without proof it is the right nerve. A diagnostic genicular nerve block comes first. Only a clear, real response qualifies you for ablation. We hold the spine to the same rule, where facet joint injections precede facet radiofrequency ablation. Skipping the diagnostic step is how patients end up with procedures that were never going to work.

Using live imaging, we place needles at the superior medial, superior lateral and inferior medial genicular nerves. Sensory and motor testing confirms the tip is next to the right nerve and away from anything that moves the leg. Then each nerve is treated in turn. The whole thing takes about thirty to forty-five minutes. You go home the same day. It is done under local anesthetic (numbing medicine) with no sedation.

Soreness at the needle sites for a few days is normal. The full benefit usually builds over two to three weeks as the treated nerves go quiet. Relief lasts months, not weeks. Nerves do grow back over time, so the procedure can be repeated when the pain returns. The knee joint is not changed. So ablation does not block a knee replacement later if you choose one.

The trial that proved this procedure is Choi and colleagues, published in Pain in 2011. Thirty-eight patients with severe knee osteoarthritis were randomized to genicular radiofrequency or a sham procedure, double-blinded. At twelve weeks, 59 percent of the treated group reported at least 50 percent pain relief. In the sham group, none did. That gap from placebo sets this apart from treatments with shaky evidence. It is also why a diagnostic block is required first. The trial picked patients who had already responded to one.

Later work compared standard monopolar radiofrequency with cooled radiofrequency, which makes a bigger burn. Both are in common use. We choose based on your anatomy and how your diagnostic block went, not on a fixed habit.

Radiofrequency does not remove a nerve. It makes a small heat burn that cuts off the signal along the nerve fiber. The tube of tissue around the fiber stays whole. The fiber grows back along that tube at about one to two millimeters per day. That is why relief lasts months and is not permanent. It is also why the procedure can be repeated when feeling and pain return.

This is also why the genicular nerves are a good target and motor nerves are not. The three usual targets are the superior medial, superior lateral and inferior medial genicular nerves. They carry only feeling at the point where they are treated. Sensory and motor testing before each burn confirms this. That is what keeps the method from affecting your ability to move the leg.

Radiofrequency ablation works the same way elsewhere in the body. For low back pain that comes from the vertebral endplate, not a joint, the target is the basivertebral nerve — see Intracept basivertebral nerve ablation. It is not repeated on the same schedule because that nerve is treated differently.