From Knee Pain to Safari: Minimally-Invasive Procedure Delays Joint Replacement

Recently retired Phyllis Marino had no intention of letting knee pain keep her from seeing the world.

The avid traveler had managed pain in her left knee for years following ACL surgeries in 1992 and 2016. But osteoarthritis, a common occurrence with ACL injuries, eventually set in – which led to cortisone injections and gel injections to reduce inflammation and friction within the joint.

“It helped for a while,” says Phyllis. “I was walking four miles a day. But by 2023, the pain had intensified so much that a police officer offered me a ride home one day because I was limping so badly.”

Still, Phyllis, who just turned a very young 70, wanted to stay active. She was planning a family trip to Glacier National Park and looking ahead to an African safari. She had no time for a knee replacement in 2025, although she knew it was inevitable.

That’s when she was referred to Ben Boswell, DO, an orthopedic surgeon with the University Hospitals Drusinsky Sports Medicine Institute. Dr. Boswell offered Phyllis another option: cryoneurolysis, also known by the device name Iovera. The procedure uses extreme cold to temporarily stop nerves from sending immediate pain signals.

“It’s a nerve ablation that adds a whole other layer of pain management,” Dr. Boswell says. “Before, if injections were no longer helping, the next conversation was often knee replacement. This gives us another option.”

The procedure uses ultrasound guidance to locate small cutaneous nerves that carry pain signals from the knee. After numbing the area, Dr. Boswell places a small catheter near the nerve and freezes it, temporarily eliminating pain sensation.

Unlike steroid or gel injections, cryoneurolysis is not injected into the joint. That distinction matters for patients who may be preparing for joint replacement, because it can provide pain relief without delaying surgery.

“In Phyllis’ case, it was a good option because she intended to proceed with joint replacement, but she needed pain relief in the meantime,” Dr. Boswell says.

For Phyllis, the impact was immediate.

“I opted for the ablation because it was less painful than surgery and had no recovery time,” says Phyllis. “The ablations gave me immediate pain relief.”

The procedure is performed in an exam room and typically takes 30 minutes. Much of that time is spent identifying and marking the nerves with ultrasound and numbing the treatment areas. Relief generally lasts three to four months, as the nerves eventually regenerate.

Phyllis had the procedure twice on her left knee and once on her right. It helped her get through her travels before she ultimately had knee replacement surgery performed by UH orthopedic surgeon Breana Siljander, MD, in January. She also had an ablation two weeks before surgery, with the goal of supporting a smoother recovery.

“My surgery and recovery were very successful,” she says. “Every aspect of the experience was well-planned and organized, and I’m working my way back to normal, already walking three miles daily.”

Dr. Boswell notes that while cryoneurolysis has been available for some time, it’s becoming an option for more patients as Medicare and some commercial insurers have begun covering it for knee pain.

“It may sound new because we’re starting to do more of it as insurance coverage expands,” he says. “We just want to get the word to more people who now have access to it.”

For now, Dr. Boswell’s practice is using the procedure primarily for chronic knee pain, including arthritis-related pain and persistent pain after knee replacement, because the targeted nerves affect pain sensation without affecting function. Future uses may expand as research and coverage evolve.

For patients like Phyllis, that can mean more time moving, traveling and participating in life before surgery becomes necessary.

Her advice to others considering the procedure is simple: “Try it. It’s so minimally invasive – you have nothing to lose and a lot to gain.”