Intense aching in Luz Graciela Gamero’s arthritic knees would force her to sit down during her managing shifts at Medici on 57th, a popular restaurant in Hyde Park.

The cartilage in her right knee had worn out, so her bones would grind against each other and her leg would bow outward.

“It was just painful,” said Gamero, 73. “I had to rely on painkillers all of the time.”

Gamero’s primary care doctor referred her to University of Chicago Medicine orthopaedic surgeon Sara Wallace, MD, MPH, a knee and hip replacement specialist who recommended Gamero have a total knee replacement surgery with a high-tech implant.

What is a 'smart' knee?

Although UChicago Medicine offers a wide array of implants for knee replacement surgery patients, Gamero opted for the  Persona IQ smart knee implant that offers enhanced monitoring capabilities.

The FDA-approved device is embedded with sensors that collect motion data — including the knee’s range of movement while walking and the patient's stride length — that is securely delivered to a HIPAA-compliant, cloud-based platform.

Physicians may use this information to remotely track how well the knee is recovering. Patients can access their data through an app, and even compare their recovery to other patients.

“For older patients, patients who live far from the hospital or those who benefit from an enhanced level of postoperative monitoring — such as patients with very limited range of motion in their knee before surgery — this is a really great option,” Wallace said. “At any moment in time, I can log into our platform and check to see if their step count and range of motion are improving."

The implant tracks the effectiveness of a patient’s physiotherapy program, and it continues to monitor a wearer’s knee function for years to come.

In order to be approved for smart knee replacement surgery, Gamero worked with her primary care doctor to improve her diet, better control her diabetes and reduce her hypertension. By September 2024, she had lost 30 pounds and was ready for the surgery that would end years of pain in her right knee.

How does the 'smart' knee work?

During the operation, Wallace reshaped the ends of Gamero’s shin bone and thigh bone and replaced the worn-out bone and cartilage with the implant.

The next day, Gamero returned to her Hyde Park apartment and immediately began physiotherapy, first via home visits and then at a physiotherapy clinic. Patients typically go to physical therapy for 12 weeks after their operation.

Meanwhile, a small boxlike device connected to Gamero’s home internet began uploading her motion data from her implant and sending it to a secure platform that Wallace could access. (The device does not share the wearer’s location.)

Four weeks after the operation, Gamero was above the 90th percentile for moving average and functional knee range-of-motion.

The first three months of recovery from smart knee replacement surgery are critical. If patients do not regain their strength and motion during this time, it can be difficult to make up those losses later.
“If a patient was increasing their step count for three weeks straight and then all of a sudden their step count plummeted because they were having knee pain and not walking very much, that would be a red flag to us,” Wallace said.

“With this implant, I can see that right away and intervene. This might mean additional physical therapy or even something as simple as a phone call.”

Pain-free after smart knee replacement surgery

For Gamero, the most challenging aspects of her recovery were using a tub rather than a walk-in shower, and taking a break from driving. Today, her right knee is pain-free.

Now retired, she only brings her cane when she plans to walk for a long distance.

“It's amazing how I feel,” Gamero said. “I wish I had the surgery a long time ago.”

Although her implant will gradually reduce its data collection over time, it will remain active for its battery’s approximate 10-year lifespan, or as long as Gamero wishes it to share information with her care team.

The only question that remains is now that Gamero’s right knee has successfully been replaced, is it time for implant surgery on her left knee?

“I'm already on the schedule for the second one,” Gamero said.