Seniors' Health: Electrical pulse may calm arthritic knees

A pricey gadget available south of the border may help relieve the pain of worn-out knees, allowing users to cut down on their pain medication and maybe even delay the need for joint replacement surgery.

The device produces an imperceptible electrical signal in the form of pulsed electrical stimulation (PES). Laboratory and animal studies suggest this specific signal can stimulate the production of cartilage, the low-friction coating on the bones in the knee. Called the BioniCare Knee Device, it consists of a battery pack that can be worn around the waist and a knee wrap containing the electrodes.

"I don't want to say at the moment that it's growing cartilage, but it certainly has some more beneficial effect on osteoarthritis of the knee than just pain relief," says Dr. Thomas Zizic, one of the device developers.

Zizic, co-founder and chairman of BioniCare Medical Technologies, Inc., and associate professor of medicine at Johns Hopkins University in Baltimore, stresses PES is different from transcutaneous electrical nerve stimulation (TENS), a pain-relieving treatment which produces a stronger signal that may actually damage cartilage cells.

One recent study of PES involved 288 patients who had persistent knee pain and disability despite physiotherapy, weight loss, pain medication and other non-surgical treatments for osteoarthritis, the common wear-and-tear form of arthritis.

Study participants were advised to use the BioniCare Knee Device for six to 10 hours a day, with most wearing it while sleeping. Just over 35 per cent of patients improved more than 50 per cent in measurements of arthritis severity. The more patients used the device, the more likely they were to benefit. Among the 86 participants who recorded daily use of anti-inflammatory drugs, 45 per cent cut their medication by at least half and nearly 19 per cent discontinued it entirely.

The most common side-effect of treatment was a rash beneath the electrode sites of the knee wrap, likely related to the gel applied to the skin under the electrodes.

In an earlier study, more patients who used the PES device were able to delay the need for knee replacement for one to four years than in an earlier group of patients who did not use the device.

Zizic says the BioniCare Knee Device has been approved in Canada, but the company is still looking for a marketing partner. In the U.S., where it was launched in 2003, the price tag is a hefty $4,425.