Several surgeons use smart implants designed to improve patient monitoring after total knee replacements, but the emerging technology has room to grow, they say.
Zimmer Biomet's Persona IQ received FDA approval in August 2021 and debuted a couple of months later. The technology uses a sensor to count steps and measure walking speed, range of motion and other indicators of knee function after surgery.
The Persona IQ has since debuted in New York, Illinois and Colorado, among other states. Four of the surgeons who introduced them in these states talked to Becker's about the technology's limitations and possibilities for improvement.
Question: What are the limitations of smart implants in orthopedics? How can the technology grow?
Note: Responses and conversations were edited for clarity and length.
Fred Cushner, MD. Hospital for Special Surgery (New York City): The battery lasts more than 20 years, so we're not really worried about that. Even if the battery dies, the implant still functions as a stem. I think the biggest issue is the cost. You are adding more technology, and there's a cost, and we have to make a case for why that extra cost is worth it. That's something I think we'll see as we develop more algorithms based on big data.
Peter Sculco, MD. Hospital for Special Surgery: The limitations in smart implants in orthopedics is identifying the right data at the right time and having it delivered in real time back to the right person so a timely clinical decision can be made that can impact patient outcomes. That is not an easy feat, but smart implants do have the benefit of removing patient compliance issues as well as optimized data integrity from being implanted in a fixed position rather than placed on skin surfaces.
The technology can grow by developing improved interoperability between the smart implant, the patient and the surgical team. The technology will also grow as utilization grows and the benefits of large data sets allow for improved prediction algorithms and when patients are 'falling off the curve' of expected recovery or implant maintenance.
Jacob Sams, MD. Decatur (Ill.) Memorial Hospital: The current limitations of smart implants is that their utility is really isolated to the early rehabilitation phase after surgery, and the information technology requirements for the patient limits wide adoption. Currently, patients are required to have a home Wi-Fi network and a computer. Hopefully in the future, the only technology requirement for the patient will be a smartphone or tablet device.
Opportunities for future development include monitoring on demand by the patients and surgeons. In the early weeks of recovery after surgery, it would be informative to see the activity related to physical therapy protocols vs. activities of daily living. Current technology codes when the sensors are active. If we could monitor on demand, future developments could also let the surgeon calibrate the smart devices with the physical exam.
Hopefully, future smart implants will also give us data on aseptic loosening, polyethylene wear and possible early detection of infection.
Brian Larkin, MD. Orthopedic Centers of Colorado (Denver): Currently, the data being collected allows a critical assessment of gait metrics and overall functionality. This objective data is very helpful in assessing compliance with postoperative protocols and gives patients access to objective data as to how they compare to peers that have gone through the same procedure. As more of these implants are inserted and the depth and quality of the research grows, we will see opportunities for improvement with the implant, the patient and the surgeon. Some future growth opportunities may include the ability to alert the surgeon and patient to impending issues about the replacement, such as wear, loosening or infection, hopefully allowing early intervention for patients at risk.
Critical to the current and future states of these implants are dedicated researchers and resources to make sure that the data being collected answers key questions that improve patient outcomes. I believe that this data and subsequent analysis will lead us to improved patient outcomes in total knee arthroplasty.