
The field of orthopedics is about to get a little bit greener. A Ryerson University researcher is breaking new ground with a green joint-replacement design that will have a longer lifespan, reduce the number of repeat surgeries, cut health-care costs and leave behind a smaller environmental footprint than other joint replacement options currently available. Funding recently received from the Province of Ontario will provide the momentum needed to get this new design into the hands of the thousands of Canadians dealing with the severe joint pain associated with osteoarthritis.
Habiba Bougherara is a professor of mechanical and industrial engineering and a 2011 recipient of an Early Research Award from the Province of Ontario. The award, which is worth $140,000, helps recently appointed researchers build their research teams of undergraduates, graduate students, postdoctoral fellows, research assistants, associates and technicians. Bougherara's team is among the first in Canada to explore green materials for medical applications.
"We are developing stronger, longer-lasting medical implants that are made with sustainable materials," says Bougherara. "As a result, we will also expand the knowledge base of orthopedic surgeons, who will need to learn how to work with these new materials."
About 10 per cent of Canadians have osteoarthritis, the common form of arthritis. Many of them will undergo joint-replacement surgery, receiving medical implants made from metal, including titanium. The next generation of medical implants that Bougherara is studying will be made from two types of natural sources: sheep's wool and bacteria. The former is being investigated with the help of research partners at Toulouse University in France, while the latter involves collaboration with Yaser Dahman of Ryerson's Department of Chemical Engineering. Each material - after undergoing sophisticated processing - will yield medical implants that function like real human bone. As a result, they are more likely to be seamlessly integrated into the body.
Furthermore, because the medical implants are made from natural materials, they can be recycled. But it's not just the planet that will benefit from Bougherara's work. A patient's health will improve, as well. Specifically, the green materials will minimize a phenomenon known as "stress shielding." That is, traditional implants are heavy and stiff, and bear most of the force that is exerted on a joint. While this is a good thing for a patient immediately after surgery, ultimately it can lead to bone deterioration.
It's akin to the idea of "use it or lose it," says researcher Rad Zdero. A member of the Martin Orthopaedic Biomechanics Laboratory at St. Michael's Hospital, Zdero frequently collaborates with Bougherara and has conducted experiments on her previous implant prototypes.
"Green materials are softer than other implants and allow the bone to carry more load. That way, the bone will avoid atrophy, which can cause an implant to loosen and require a patient to undergo surgery to repair or replace the implant," he says.
Taken together, the benefits of green medical implants will add up to significant savings for the health-care system. Longer-lasting and better-performing implants will mean fewer surgeries. Moreover, recyclable materials will mean more implants will eventually be reprocessed and reused.
According to Bougherara, the first eco-friendly medical implant will be ready for human use in about 10 years. In the meantime, she is working to involve undergraduate and graduate students from various Ryerson programs in her work - a testament, she says, to the multidisciplinary nature of the research, a mixture of biology, and biomedical and mechanical engineering. Finally, Bougherara also participates in outreach activities that are aimed at attracting female high-school students to the field of engineering.