Orthopedic surgeons at MedStar Union Memorial Hospital in Baltimore and MedStar Montgomery Medical Center in Olney have become among the first in Maryland to implant the Persona IQ smart knee, a total knee replacement that includes an integrated sensor to monitor recovery progress in real time.
The device, manufactured by Zimmer Biomet, features a small sensor built into the stem extension of the tibial component. Made of biocompatible materials and the same length as a standard stem, the sensor records daily step count, walking speed, stride length, cadence, and range of motion. Each night, when the patient sleeps within six feet of a bedside transponder, the data uploads securely to a cloud-based portal accessible by the surgeon. The system does not track location.
The sensor’s battery lasts at least 10 years before depleting, after which the implant continues to function as a conventional knee replacement without data transmission.
Dr. Mark Hasenauer at MedStar Union Memorial performed the state’s first Persona IQ procedure ten weeks ago on Mary, a 66-year-old Frederick resident who suffered a severe knee injury last year.
“I consider myself an early adopter,” Mary said. “Around week four or five, Dr. Hasenauer saw my step count had dropped and reached out. I explained I had tendonitis flare-up. He reassured me I was still on track and later watched the numbers climb again as I healed. It made me feel seen.”
Hasenauer has since performed nearly a dozen smart knee replacements.
“The goal is not to replace office visits,” Hasenauer said, “but to add objective data between appointments. Every patient recovers differently, and this lets us spot trends early while keeping patients engaged.”
Last week at MedStar Montgomery Medical Center, Dr. Katharine Harper implanted the device in a 72-year-old male patient who was discharged the same day.
Patients may also consent to contribute anonymized data to a national registry that already contains billions of motion points from Persona IQ users across the country.
“We’re starting to generate gait curves that once required a full motion-analysis lab,” Harper said. “Now we can see those patterns from normal daily walking and potentially catch issues before they become symptomatic.”
The Persona IQ received FDA clearance in 2021 and is now available at select centers nationwide. Surgeons at both MedStar facilities report the surgical technique mirrors standard total knee replacement, adding no extra operative time.
“Our mission is care that is innovative and personal,” Hasenauer said. “This technology bridges the gap between clinic visits and shows us how patients actually move in their real lives.”