The Low-Cost Prosthetic Knee: Mobility for Everyone

Andrysek, Jan

Jan Andrysek, an IBBME assistant professor and a scientist at Holland Bloorview Kids Rehabilitation Hospital, is developing the Low Cost (LC) prosthetic knee joint for market readiness. This robust joint suitable for wet and sandy environments is meant for use in developing nations. The price tag? A very affordable $50.

Research for the prosthetic knee began in 2006 with a CIHR/SSHRC collaborative grant. He had been working on the MiniMac, another pediatric knee joint that incorporated two of his patented innovations—a locking mechanism that responds to the walking patterns of an individual, and a mechanism that controls how the artificial knee bends. Both innovations provide a stable, robust joint that allow its users to run, jump and climb in challenging terrains. His work on the MiniMac won him the University of Toronto Patent Award in 2008. It was licensed to Fillauer, a US prosthetics manufacturer, in 2006 and commercially launched globally in 2009. A second model, GeriMac, using the same technology and targeted at adults, launched concurrently.

While developing the MiniMac, Andrysek was noting reports in the literature speaking to the gaps in appropriate prosthetic knee joint technologies for developing countries. The Red Cross is one of the largest suppliers of artificial limbs to developing countries. The knees they supply have a manual lock. The user can either lock the knee as they typically would when walking (so that it doesn’t bend and cause them to fall) and then unlock it for tasks such as sitting. When users walk, they walk with a straight leg, which is not only unnatural in appearance, but also likely to contribute to secondary health complications such as back pain and joint degeneration. Andrysek’s innovative joint overcomes these challenges. It’s no surprise that his work on the MiniMac had caught the eye and interest of various organizations in the industry, including the International Committee of the Red Cross. The first pilot test with the ITIC is complete, and further tests are forthcoming. Field testing has also begun in El Salvador and will begin soon in Chile.

The results in the field have been very encouraging, says Andrysek. The knees stood up to real-world wear and tear of a children in their natural surroundings. Initial data has shown that patients are able to get around more easily than with other knees used in developing countries. They can walk faster, more on par with able-bodied individuals. They are also able to negotiate a variety of terrains with greater confidence that they will not fall. The price point of $50 overcomes a gap, too. Andrysek noted that knees priced under $50 tend to be crude devices, but even purchased joints in the $100-500 range do not allow for the high-level activity Andrysek’s design enables.

Andrysek is one of four researchers associated with U of T whose work was recognized February 9 with $100 000 Rising Stars in Global Health grants by Grand Challenges Canada. The funding means that further evaluation of the technology can proceed. Before long, this rehabilitation innovation developed at IBBME will be transforming the lives of people around the world.

Hear Dr. Andrysek talk about the LC Knee at the Globe and Mail or catch Dr. Andrysek on CBC News.

Learn more about Rehabilitation Engineering at IBBME .