NEWS
10/03/2011 12:56 EDT | Updated 12/03/2011 05:12 EST

Scientists developing cement that could be used for hip replacements, fractures

HALIFAX - Shelley McMullen used to love speed-walking.

The 47-year-old powered through the streets of Halifax, mixing the sport with other forms of physical activity as part of a busy and active lifestyle.

But at age 39 and suffering from lingering pain in her feet, McMullen found out she had severe osteoporosis, a condition that left her bones brittle and susceptible to breaking.

She changed her life markedly by eliminating vigorous exercise, not lifting heavy objects, wearing flat shoes and resting often because of fatigue and discomfort.

But McMullen is hoping a new product being developed at a Halifax university will bring relief to the pain caused by vertebral fractures that can be caused by a simple sneeze or picking up a small dog.

"It feels like it's made me an old person before I am," she said. "Then I saw this cement thing ... and I thought, 'Wow this is really cool.' It may be an option for me."

McMullen saw information online about an innovative research project at Dalhousie University involving new compositions of cement that could dramatically change the treatment of everything from hip replacements and spreading cancers to spinal fractures and other broken bones.

The materials are being developed by a team of biomaterial scientists, an orthopedic surgeon and an interventional radiologist which hopes to bring the product to market within four years.

Daniel Boyd, a scientist at Dal who is leading the project, said the cements are better than materials now being used in hip and knee replacements because they don't contain toxins, they adhere better to bone and don't overheat.

They will also turn into bone after the've been injected into the site, Boyd said, making them a more natural strengthener for vulnerable areas in people like McMullen who have osteoporosis.

"It's very, very exciting, that's for sure," Boyd said from his office at the university.

"The problem that we have right now with the current clinical approach is that the material that's being injected is really nowhere near optimized for the job and it's causing a lot of concern in the industry."

For people with osteoporosis, the cements are injected into the spine to stabilize fractures in the vertebrae, which can cause excruciating pain. The cement is also a key ingredient in knee and hip replacements because it holds the implants in place.

But Boyd says the current cements get very hot very quickly, which can damage healthy tissue. They also contain toxic elements, which can harm tissue.

Physicians have also found that they become stiff and cause fractures above and below the implant. Boyd says they don't bond well to the bone, causing loosening of the knee or hip implant in thousands of people every year.

"We're working up a solution where doctors could inject cement around loosened implants to stabilize them permanently," Boyd said. "It would mean patients wouldn't need a full surgical procedure a second time around and that, for young patients, is a huge thing."

Bob Abraham, an interventional radiologist at the Queen Elizabeth II Health Sciences Centre, said the other exciting possibility with the cement is that it can be used in people who have had cancer spread to the bone in an area that needs to be strengthened or is fractured.

The material could secrete therapeutic agents to remove any residual cancer cells.

"I'm excited as heck. I can't wait to get it off the ground," Abraham said, cautioning that the actual product could be years away. "We're very early in the game. We're in the product development phase and we've not used it in a patient."

The group received funding from the federal government and private industry to continue research so that the scientists can get regulatory approval before doing clinical trials.

Boyd expects the first product could have regulatory approval within two years, which could put the some of the cement on the market in four or five years.

The team is also developing a new set of surgical tools that would provide physicians with a loaded, ready-to-use needle containing the cement.

Abraham said the biggest use will likely be in hip and knee replacements, but that it could one day be used for acute bone fractures.

"This is pie in the sky," he said. "But it would mean that instead of putting a cast on, could we inject cement into the fracture and stabilize it from the inside."