Affordable Knee Joints Could Help Amputees in Developing Countries

Jan Andrysek, PhD, PEng, MASc started working with knee
joints several years ago while earning his master’s degree at the
University of Toronto. He began researching ways to create durable knee joints
for children with high levels of activity, because, at the time, the technology
was limited.

Andrysek soon realized that the same needs were present in developing
countries where amputees had limited access to functional knee joints.

“We thought the requirements were similar as for kids,”
Andrysek, who is now an assistant professor at the Institute of Biomedical
Engineering, University of Toronto and a scientist at the Holland Bloorview
Kids Rehabilitation Hospital in Toronto, told O&P Business
. “We wanted to have something that was functional for
high-activity individuals, but that was also simple and robust.”

Developing a low-cost knee

Recognizing the need for affordable joint technologies, Andrysek soon
began looking for ways to create not only a simple, functional knee joint, but
also one that was attainable for amputees without access to health care
coverage in developing countries.

  The LC Knee, made of injection molded plastic, enables a prosthesis to simulate able-bodied walking.
  The LC Knee, made of injection
molded plastic, enables a prosthesis to simulate able-bodied walking.
  Images: Institute of Biomedical
Engineering, University of Toronto.

This presented a number of challenges. Andrysek had to consider the
environment and type of terrain that amputees in developing counties typically
encounter, usually uneven and broken ground that can often be sandy and wet.
Andrysek also had to ensure that the joint would be stable and durable despite
using low-cost materials.

With this in mind, he began working with injection molded plastics,
which would be waterproof, resist corrosion and could be easily fabricated at a
low price.

“We started to take what we learned from previous work and tried to
implement it into a very simple design that revolved around the use of
injection molded plastics to develop a functional and low-cost knee,”
Andrysek said.

In 2006, Andrysek developed the Low-Cost (LC) Knee Joint, a simple joint
made out of injection molded plastic, with an estimated price between $50 to
$100. The three main plastic components of the knee can be molded for about

The LC Knee, which received a patent in 2011, is based on Simplified
Automatic Stance-Phase Lock technology. The knee joint enables a prosthetic to
resemble able-bodied walking more closely and the price makes it affordable to
most amputees.

“Our main concern was trying to come up with something that was
stable but didn’t disturb the natural bending motion at the knee,” he
said. “We wanted to have a stance phase control mechanism so the knee will
be stable and not bend under the person, regardless of the type of terrain they
may be walking on or the way they may be walking. But at the same time, it must
be easy for them to initiate flexion.”

Clinical testing

Andrysek and his colleagues have conducted clinical studies to ensure
that the LC Knee meets ISO standardization, maintains the functionality of
higher-end knee joints and can endure the environmental challenges presented by
the terrain.

In the pilot study, Andrysek and his colleagues saw a 10% increase in
walking speed when compared with the knees that the subjects had previously
been using. He said that participants also reported feeling more stable and
being able to walk further distances and that one of the participants, who
previously needed canes to walk, could walk independently with the LC Knee.

  Jan Andrysek partnered with the International Red Cross and rehabilitation centers to continue clinical evaluation of the LC Knee.
  Jan Andrysek partnered with the
International Red Cross and rehabilitation centers to continue clinical
evaluation of the LC Knee.

“These are people from developing countries who have had to use
knees that are designed for lower-activity people, like the elderly, because
they can’t afford other knees,” he said. “They are good quality
knees, but they don’t have functionality.”

Andrysek recently received a $100,000 from Grand Challenges Canada to
continue testing the LC Knee. The International Red Cross is currently
conducting studies of the knee in Ethiopia, Myanmar, Colombia and Nicaragua.
The trials will last about 18 months, including a year-long follow-up period.
Along with the Red Cross, Andrysek also has partnerships with rehabilitation
centers in Jaipur, India and Santiago, Chile. In total, approximately 40 people
are participating in the studies.

Andrysek hopes that these clinical evaluations will help him finalize
the mechanisms in the LC Knee and secure a manufacturing partnership to begin
distribution of the LC Knee. — by Megan Gilbride

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