Magnets Allow Fused Leg to Bend

A locking orthopedics innovation uses magnets to help patients with knee problems. Lindsey Alexander, a writer for MedCity News, quotes Eric Lucas, founder of the Engage Knee System, as explaining that many patients with knee dysfunction for whom a knee replacement is not appropriate, choose to have their two leg bones fused together—a knee arthrodesis. This means that the leg cannot bend and is always rigid. The procedure allows a patient to walk around on his own, but it makes some daily activities such as driving, bathing, or sitting in the front seat of a car, difficult.

Lucas explained that the Engage Knee System is a knee replacement that can be locked in place. This is done by waving a handheld device with a magnet in it over the knee. This pass locks the knee enabling the patient to be stable enough to stand and to be able to walk. When the device is waved over the knee again, the knee unlocks, can bend and the patient can sit comfortably. The mechanical locking system is actuated by a powerful magnet which allows communication of sorts from the implant to the outside of the body.

Lucas developed the Engage Knee System when he was a biomedical engineering graduate student at Clemson University. The medical device company spun out from Clemson a year ago. Lucas and his team are applying for grants and have built several prototypes. Because other devices use magnets in similar ways, Lucas anticipates a relatively fast path to FDA 510(k) clearance.