Zimmer Biomet this summer announced a so-called “smart” knee implant—a first of its kind to be cleared by the Food and Drug Administration.
A little over a month later in October, orthopedic surgeons in New York City completed the first total knee replacement with the device—a knee implant with an embedded sensor that counts the steps a patient takes, their walking speed and range of motion, so that the surgeon can monitor their progress from afar.
It hints at a future where a sensor implanted in the human body can detect—and maybe even predict—a patient not recovering as expected.
“Data is key,” said Dr. Peter Sculco, an orthopedic surgeon specializing in hip and knee replacements at the Hospital for Special Surgery, and one of the surgeons who performed the surgery. “Now we have the ability to analyze big data in a much more rapid fashion.”
It’s the first smart implant to be cleared by the FDA for a joint replacement surgery—but other medical devicemakers also have their eyes on the market.
“We’re just in the early innings of where this technology can go,” said Ryan Zimmerman, an analyst at BTIG who covers medical technology.
Devicemakers manufacturing implants for joint replacements want to continue to innovate and build on their products, as hospitals are exploring new ways to move more care to the home. An investment in smart implants also takes a page from developers of other medical technologies—like cardiac pacemakers and diabetes management tools—that have put data into the hands of patients, analysts say.
But medical device companies will have to prove the value of the innovative devices—and make sure they’re not adding unnecessary cost—to make a convincing pitch to customers.
“The potential is significant,” Zimmerman said, but it’ll take large research studies to prove the value to providers and payers.
A surgical first
As of mid-October, orthopedic surgeons at the Hospital for Special Surgery in New York City had performed one procedure with the smart implant, with plans to recruit others.
Today, post-operative monitoring for knee replacements tends to rely on patients reporting how they’re feeling, how much they’re walking and whether they can do daily activities.
“It’s very hard to get granular data,” Sculco said.
He’s interested in whether a smart knee can help with that, collecting daily data between a patient’s follow-up visits after the surgery.
Zimmer Biomet’s smart knee was a collaboration with Canary Medical, a company founded nearly a decade ago with a vision of putting sensors on medical implants.
The companies added a sensor from Canary Medical into an existing knee implant from Zimmer Biomet, called Persona, to create a new product named Persona IQ. Zimmer Biomet licensed the sensor from Canary Medical as part of an exclusive agreement to develop orthopedic implants together.
A sensor ideally will not only be able to collect more data points, but also more objective data, compared with the existing system that relies on patients reporting their outcomes.
The sensor collects and wirelessly transmits data to a small base station that a patient keeps in their home; from there, it’s shared with a platform that the surgeon reviews and then to a patient app. Data is collected multiple times a day for the first year after surgery and continues on a less frequent basis after that.
The battery that powers the device is supposed to last for at least 10 years, so it doesn’t have to be charged.
In theory, this data could one day help to identify patients who aren’t recovering as expected, so that surgeons can intervene early to make changes to physical therapy plans or medications.
“There’s a saying that hips are ‘wow’ and knees are ‘ow,’” said Dr. Fred Cushner, an orthopedic surgeon specializing in knee replacements at the Hospital for Special Surgery and a founder and chief medical officer at Canary Medical, citing a figure that up to 20% of knee replacement patients aren’t satisfied after their surgery.
Surgeons are still figuring out why that is—studying whether different strategies could be helpful when setting a knee replacement on patients with different body types, for example, he said.