A durable, cheap prosthetic knee is tested for developing countries

The M1 knee is tested in developing countries and is manufactured locally. Photo courtesy of legsforall.com

Prosthetic limbs in the developing world are often expensive, imported, and not always designed for humid climates and dusty fields. This trifecta of cost, maintenance and durability has stymied treatment before, and now thousands of new Haitian earthquake survivors may confront these problems too.

Yet there is a solution. The LEGS M1 knee is a rugged prosthesis that's been tested in developing countries for the past five years. It's designed for local manufacture and maintenance. And it's amazingly cheap, just $15 to $20 each.

Dr. Roger Gonzalez developed the knee with his students at LeTourneau University in Longview, Tex. It's made of plastic – he found that DuPont’s Delrin polyacetyl works well – and standard stainless steel bolts. It's polycentric, as opposed to a simpler single-axis (hinged) joint, to better mimic the multiple directions that a flesh and bone knee moves. Tested against a commercial knee that costs 30 times more, the M1 kept pace on 80 to 90 percent of the performance, Gonzalez said. And it conforms to ISO 10328 prosthesis strength standards, maybe the only locally-produced knee in the developing world that can make that claim.

Photo courtesy of legsforall.com

Tested in Kenya
The knee is manufactured internationally at a dozen clinics in four countries. For the last five years, clinicians have distributed the knee to children at the CURE International Children's Hospital in Kijabe, Kenya. About 8,000 children are admitted every year, and a few undergo amputations for infections and injuries from car accidents, animal attacks, falls, and war and violence. Local manufacturers produce the M1 knee and other prostheses.

“The M1 knee is easy to produce, it is affordable to our clients and has been well researched and tested. It is a low cost, high quality knee,” the hospital's director, Jack Muthui, wrote E4C in an email.

That first point, “easy to produce,” is the clincher, Gonzalez is quick to point out. “You don't just need a design – the secret lies in the manufacturability of it,” he said. To improve that, Gonzalez and his team have developed a graphic, wordless instruction manual for distribution in any country.

Also, he only works alongside established enterprises that can train local technicians in the production and use of the prostheses.

Photo courtesy of legsforall.com

A sustainable solution for Haiti
Hewing to that model, he is now talking with organizations about distributing the M1 in Haiti. “The issue with Haiti is we want to ensure that we have an appropriate and sustainable response,” he said. “Our intention is not to just go in there and hand out knees. We're about empowering the local entities to be self-sufficient, so the people of Haiti don't depend on us.”

To reach Haitians in need, Gonzalez and his team will partner with the Institute for Latin American Concern at Creighton University in Omaha, Nebraska. ILAC has a facility near Santiago in the Dominican Republic and connections with a web of clinics throughout the island.

“The plan is actually to teach Dominicans and Haitians how to fabricate this prosthesis,” said Dr. John Tessier, an orthopedic surgeon who works with ILAC. “They would be taught how to repair and fit these, so that ultimately the gift can keep on giving.”

Gonzalez founded the organization LEGS to develop the LEGS knee and other projects. For more information or to donate, please visit the LEGS site.