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Researchers say a post-surgery treatment may help people with total knee replacements return to regular life more quickly. Roman Donar/EyeEm/Getty Images
  • As many as 3 in 10 people who have total knee placement surgery still have pain months after the procedure.
  • Researchers say a post-surgery treatment known as C-RFA may help relieve some discomfort.
  • The treatment involves inserting a needle around the knee that targets specific nerve locations.
  • The treatment is usually done after other recovery therapies haven’t worked.

People who experience chronic pain after total knee replacement surgery may benefit from a new treatment.

During a presentation at the annual meeting of the Radiological Society of North America, researchers said a rarely used procedure called cooled radiofrequency ablation (C-RFA) offers hope for these knee replacement recipients.

Researchers said C-RFA pain relief lasts longer than cortisone shots and is a less invasive, less expensive alternative to other treatments.

The research has not yet been peer-reviewed or published in a scientific journal.

C-RFA is done under local anesthesia. It involves the insertion of an introducer needle around the knee that targets specific nerve locations.

A probe is then guided through the introducers. The probe tip imparts a low voltage current (radio frequency) to the deep sensory nerves around the knee. Water circulating through the system allows for greater dissipation of heat from the tip of the probe.

The procedure could solve the long-term pain of at least 30 percent of total knee replacement recipients, Dr. Felix Gonzalez, a lead study author, told Healthline.

Since most recipients undergo surgery because of extreme pain, alleviating that discomfort and returning someone to the activities they love is the ultimate goal, said Gonzalez, also an assistant professor in the Division of Musculoskeletal Imaging of the Department of Radiology and Imaging Sciences at Emory University School of Medicine in Atlanta.

Yet, he said, as many as 20 percent of people still experience debilitating pain long after surgery. “It’s frustrating to the patient and the surgeon as well,” he said.

Radio-frequency treatments have been around since the mid-1940s, Gonzalez said, but using it in this way is newer – and seems to work.

The new study follows past studies by the same group showing that C-RFA provides lasting pain relief for people with knee, shoulder, and hip arthritis who weren’t helped by other recovery therapies.

This study focused on 21 people who were experiencing persistent chronic pain after total knee replacement. Study participants had no infections or hardware issues yet still experienced pain.

Within a year after C-RFA treatment, participants reported significant improvements in pain and stiffness reductions with no complications.

When you consider that about half a million people have total knee replacement annually, that means as many as 100,000 could be impacted by severe pain and could benefit from this procedure, Gonzalez said.

Dr. Michael P. Ast, an orthopedic surgeon and chief medical innovation officer at the Hospital for Special Surgery in the greater New York area, told Healthline that the hospital has used C-RFA on many occasions and found success.

When a patient is experiencing long-term post-surgery pain, it’s a matter of ruling out other possible reasons for the discomfort before taking this step, he said.

First, Ast said, is “making sure nothing is wrong with the implant.”

If there is no infection or issues with the hardware, he said, there’s another step: Patience.

Total knee replacement can take time to heal, and often impatience can get in the way, Ast said.

Surgeons at his hospital wait at least a full year and sometimes longer before assessing any possible long-term or permanent pain or stiffness from a total knee replacement.

“That tightness and feeling like it’s bending through concrete can take time (to resolve),” he said.

Once enough time has passed, surgeons then consider the level of pain and discomfort.

A fraction of those receiving total knee replacement “just don’t like (the feeling) of their (new) knee,” Ast said. “This treatment is not for them.”

But for those who have fought through physical therapy and still have pain and stiffness that stop them from living well, he said this is a solution to consider.

This procedure could have a profound effect in more ways than just cutting that pain, Gonzalez added.

“This could cut down on pain medication addiction,” he said. “Right now, besides narcotics, there’s not much else to choose.

“And remember,” Gonzalez added, “before this pandemic, we saw the opioid pandemic. We still need to conquer that.”

Past total knee replacement recipients still experiencing severe pain should talk with an orthopedic surgeon – or get a second opinion – about this process, experts say.

For now, the procedure is done in a hospital setting, and it can sometimes be difficult to get covered by insurance. Ast said some health plans require patients to try other therapies first to see whether they experience any improvement before the procedure is approved for coverage.

“It can be logistically challenging,” he said. “Patients have to come in multiple times (just to get the approval).”

But Ast said centers like his are advocating for more seamless coverage.

Gonzalez noted that C-RFA is covered by Medicare.

He hopes that another research team can study a larger group with a double-blind study with many more participants.

Ast said his hospital also has begun using C-RFA as a preventive before total knee replacement, hoping to reduce the number of recipients who experience long-term pain.