"World’s first" multi-sensor system for knee implants

Called FollowKnee, the patented system integrates a deformation sensor, a pH sensor, a temperature sensor and an accelerometer in a titanium tibial baseplate.

A more accurate implant fitting is achieved via the deformation sensor and accelerometer that guide the surgeon during the operation. In a world’s-first application connecting a pH sensor with living tissue, the system’s pH and temperature sensors detect infection early, while the deformation sensor and accelerometer also trigger an alert if they detect mechanical problems, such as loosening of the implant. Those two devices also enhance rehabilitation by helping physiotherapists adapt therapy for knee-implant recipients.

At Eureka Park booth 60655, Jan. 5-8, CEA-Leti will demonstrate the sensors, electronics, and a reader integrated in a clear acrylic column representing a leg fitted with a complete knee prosthesis. A tablet displays data collected by the sensors.

Developed with CEA-Leti’s deep expertise in sensor and integration technologies, the system also includes the first low-power deformation sensor in a biocompatible system with highly compact electronics powered via inductive coupling.

“Accuracy is vital in knee-implant surgery,” said Dr. Eric Stindel, an orthopedic surgeon at Brest Hospital, France, and a member of the project team. “By integrating the deformation sensor and the accelerometer, this innovative architecture gives both the surgeon and the patient peace of mind for a successful operation and follow-up.”

The technology can be adapted for hip and shoulder replacements.

The Centre for Orthopedic & Neurosurgical Care & Research in the U.S. estimates knee-implants will increase by 673% by 2030, or 3.5m operations.