Human Achievement of the Day: Knees on Sale

Today’s Human Achievement of 2009 highlights an oft overlooked benefit of defending individuals’ right to freely innovate and compete: technologies become more available and cheaper for everyone. After many centuries and countless individuals’ contributions to chemistry, medicine, and materials science an engineer at Stanford University created an artificial knee joint that will cost just $20.

The new kind of prosthetic, dubbed the JaipurKnee, was created by Joel Sadler and his classmates at Stanford’s Institute of Design as a class project.

“We’re doing magical things in these classes,” Sadler said. The project’s presence at [Stanford’s annual Cool Product Expo]was a callout to our students to be thinking in the mode of, ‘What am I doing in my education? How can I apply this to what I want to do in my life?'”

High-end prosthetic knees can range in cost from $10,000 to over $100,00 but the lower-end models provided little stability for the person because the design (a basic hinge) did not move in the same way a human knee would.

Old models of low-cost knee joints used a single-axis joint, which rotated like a door hinge. They were unstable and unsafe for India’s varied terrain; the joint tended to buckle under weight, which could be physically as well as psychologically painful for a freshly fitted amputee.

Sadler’s team developed a new model out of a less costly oil-filled nylon polymer and is self lubricating. The design was based on the models of high-end titanium joints and has proven to be flexible and high-performing. While the estimated cost of production is only $20 Sadler noted that he expects the costs to drop even further–and he is correct. As technologies advance, as market saturation increases, as competition heats up, the costs and prices of technologies almost always decreases.