Technological progress in materials, manufacturing, and design allows O&P professionals to use more effective products or processes to restore the lost functions of the biological system. They are doing so with some exciting results, including prostheses that can autonomously deliver better biomechanical function. The improvement in function makes these "bionic" technologies appropriate for many individuals living in industrialized countries seeking to minimize the effects of their limb loss.
The need for appropriate prosthetic technologies also exists in developing countries. The definition of "appropriate technologies," established by experts in the prosthetics industry, extends beyond function to include cultural, environmental, and economic considerations. Concomitantly addressing all of these considerations to improve the current state of prostheses is not straightforward considering just how much these conditions can vary from one region to another. To tackle the problem and develop better solutions, we need to focus on what is truly essential and common across the world—people want better functioning prosthetic technologies to make it possible for them to do more. The challenge is to make such technologies is affordable and accessible without compromising quality, durability, and reliability of the component. In many industries, technological progress can be credited with solutions that are better and less expensive. This has generally not been the case with prostheses, as more advanced prostheses tend to be many times more expensive than their predecessors. Procuring more functional and affordable prostheses for amputees in developing countries requires a paradigm shift.
The approach that I have favored from the beginning is to use sound scientific principles to design simple systems and techniques that target the most important aspects of prosthetic function. In terms of the Low-Cost Prosthetic Knee Joint (LC Knee), that philosophy has led us to try to develop a stance-phase control device that provides greater stability without inhibiting natural movements at the knee. (Editor's note: For more information, read "Canadian Scientist Develops Low-Cost Prosthetic Leg," www.oandp.com/articles/news_2012-02-22_01.asp). This approach will not produce a more functional knee than the Ottobock C-Leg, for example, but as we are starting to see from our clinical evaluations, it is working considerably better than conventional knee mechanisms, including four-bar knees and braking safety knees that are used in the developing countries. This is exciting, since the LC Knee mechanism is very simple, which is an important part of the formula for delivering a more affordable and durable device.
While the hope is that the LC Knee will have an immediate impact to help people in developing countries, it is unlikely that its one embodiment will meet all of the needs, just as a microprocessor-controlled knee, for example, is not appropriate for all amputees in developed countries. Dozens of varieties of knees are able to co-exist on the market. Similarly, in developing countries, cultural, environmental, and economic adaptations are likely needed. Therefore, the LC Knee should not be seen as the sole product of this work. The science and techniques behind it should serve as a foundation for developing appropriate prosthetic technologies for the global community. The fact that these basic technologies will be accessible to help amputees around the world regain mobility and independence is an exciting reward in itself, and one that more researchers, engineers, and scientists in developed countries should consider pursuing, and more governments and funders should be supporting.
Jan Andrysek, PhD, PEng, is a research scientist at Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada, and an assistant professor at the Institute of Biomaterial and Biomedical Engineering, University of Toronto. He is the designer of the Low-Cost Prosthetic Knee Joint currently undergoing clinical testing.
