Knee replacements just got ‘smarter’

Smartphones. Smart home appliances. Now a ‘smart’ implant is available for patients seeking a total knee replacement at Falmouth Hospital.

Orthopedic surgeon Paul Dimond, MD, has done about 30 knee replacement procedures using new technology called Persona IQ® smart knee implant. The joint implant is accompanied by an extension to the tibia bone that contains a feedback device called the Canary Health Implanted Reporting Processor or CHIRP. The device provides feedback to the physician and patient about their progress, and also allows them to communicate through a phone app.

In addition to Dr. Dimond, Falmouth orthopedic surgeon Jonathan Sunkin, MD is also trained on the Persona IQ® platform.

“It’s exciting; everything’s changing,” said Dr. Dimond.

The Persona IQ procedure differs from other implants because it:

• Securely transmits to the surgeon’s computer information on a patient’s gait, walking speed, number of steps, stride length and range of motion using the mymobility® platform.
• Allows patients and their doctors to message each other via the mymobility® phone app.
• Provides timeline instructions and reminders to patients starting 30 days prior to surgery, and physical therapy exercises before surgery and during recovery.

“I don’t think there’s any downside. I think it’s definitely a win-win” for patients and doctors, Dr. Dimond said.

The implant’s electronics are powered by a pacemaker battery that lasts 15 years, he said. It uses an external modem to connect to the internet, similar to some CPAP machines and personal safety alarm devices.

The contraindications for the implant are the same as those for standard knee replacement, Dr. Dimond said. They include inadequate bone on ends of the tibia and femur, osteoporosis or neuromuscular condition affecting the knee, lack of supporting ligaments, rheumatoid arthritis with skin breakdown, and history of infection of the knee or systemic infection.

The manufacturer also said use of ionizing radiation near the implant site can damage the device’s battery and should be avoided. Dr. Dimond said MRI (magnet resonance imaging) and other forms of imaging could be used instead of X-rays and CT (computerized tomography), if needed.

The cost of implant surgery is the same as standard knee replacement and is covered by insurance, according to Dr. Dimond. The Persona IQ® system can be used for telemedicine visits, which may also be covered by insurance, he added.

Other Benefits

The device and software can allow a doctor to compare a patient’s performance with a profile matching their age to see if post-operative goals are being met, he said. The manufacturer’s website says the system offers recovery curve data analysis and data comparison with other Persona IQ® patients. Dr. Dimond said while the implant only tracks motion, he could see other valuable data possibly being collected in future versions.

“As the technology grows, maybe it picks up temperature,” which could indicate an infection, he said.

The mymobility® platform has not yet been fully implemented on the patient app but will be for the “next generation” of patients, he said. The messaging portion isn’t yet working, but, in the meantime, he and patients can communicate via Cape Cod Healthcare’s MyChart patient portal.

Patient feedback to the Persona IQ® system has been positive, according to Dr. Dimond, although some were concerned their movements might be tracked. Data gathered by the implants does not include location, he said.

“In the future, some of this data will be shared with Brown University,” as part of a project on knee replacement, he added, but any personal identifying information will be stripped out.