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Friday, January 16, 2015, 10:32

Close to the bone

By KARL WILSON in Sydney
Close to the bone
Len Chandler, 71, has recovered after receiving a 3D-printed replica heel, which saved his leg from amputation after he contracted cancer in his heel bone. Inset: A titanium heel which was created using 3D printing technology. (PHOTOS PROVIDED TO CHINA DAILY ASIA WEEKLY)

When Len Chandler was told he had cancer in the heel bone of his right foot, he was facing the grim prospect of losing his leg from the knee down.

But Peter Choong, who is director of orthopedics at St Vincent’s Hospital in Melbourne among many other titles, was not so sure that 71-year-old Chandler needed to lose his leg.

One of the leaders in his field, Choong recalled an article he had read about work being done at the Commonwealth Scientific and Industrial Research Organization (CSIRO), Australia’s national science agency. What had caught his eye was the CSIRO’s work on the production of an orthotic horseshoe using 3D print technology.

He contacted John Barnes, a project director for high-performance metals at the CSIRO, to see if he could help produce a titanium implant, or, more specifically, a titanium heel using 3D printing technology.

“We were working with a biotech company, Anatomics, on metallic implant technology when Peter rang me,” Barnes says. “It was a challenge for us as we had never done anything like this before. Basically, we scanned the heel of his good foot and made a mirror image of it, then made a 3D copy of the heel in titanium. The surgeons did the rest.”

Barnes says there were a number of risks: Would the implant take the weight and would it wear down over time?

But the operation took place in October and today Chandler is doing better than expected and is well on the road to a full recovery.

A spokeswoman for St Vincent’s tells China Daily Asia Weekly: “Mr Chandler is walking around at home without the use of his crutches but is still undergoing physiotherapy. He is doing well and feels great.”

At the time, Choong said: “It was a risk, but it was a risk we both (Chandler) were prepared to take.”

In an interview with the broadcaster ABC, Choong explained that medical procedures using 3D technology could be tailored to patients’ individual requirements.

“Take orthopedics for example... You can get bones from the bone bank, which is other people’s bones, but sometimes this causes reactions or infections,” he said. “What this technique does is make it very patient-specific so you can build something to exactly match the defected part, and it does not carry the risk of transmissible disease.”

Last year, doctors at Peking University Third Hospital successfully implanted the first ever 3D-printed section of vertebra into the spine of a 12-year-old boy.

The boy had developed a malignant tumor on his spinal cord and some of his bones needed to be removed. So, during spinal cord surgery that lasted many hours, surgeons at the hospital replaced part of the cancerous vertebra in his neck with the implant.

The surgeons did not need to use cement or screws to hold it in place, as they do with traditionally manufactured implants. Instead, they made tiny holes in the implant so that surrounding bones can grow into the print and secure it in its spot.

At the University of Sydney, scientists have developed a new material that will revolutionize the way broken bones are fixed, using 3D print technology to make a perfect copy of the broken bone.

Hala Zreiqat, a professor who leads a small team at the university, has developed a unique ceramic material that acts as a scaffold on which the body can regenerate new bone, which then gradually degrades as it is replaced by natural bone.

“Metal, which is now used, is with you for life. It doesn’t break down. By using 3D printing we can make an exact fit,” says Zreiqat, who heads the tissue engineering and biomaterials research unit at the faculty of engineering.

The breakthrough came last year in controlled experiments with rabbits.

“We found that the ceramic material we developed is 100 times stronger than what is now used,” she says. “Using 3D printing, you can make a perfect replacement part — custom-made. As the bone grows the material dissolves, leaving a strong bone. Metal, which is usually used, stays with you forever.”

Clinical trials on humans are expected to begin in October and, depending on how the trials work out, the product could be commercially available within 10 years. Zreiqat says that if the trials are successful, it will make metals redundant in treating bone breaks.

“The bone substitute we have developed resembles natural bone in terms of architecture, strength and porosity. So it is strong enough to withstand the loads that will be applied to it, and also contains pores that allow blood and nutrients to penetrate it,” she says. “In this way it is designed to encourage normal bone growth, and to eventually be replaced by natural bone in the body.”

She explains that because the ceramic material actually kick-starts the process of bone regeneration, it is far superior to other available materials.

“There are some synthetic bone substitutes currently available but they have weak mechanical strength, so are very brittle and crushable,” Zreiqat says. “Hence there is a need for materials that mimic bone in its strength and structure and ability to support new bone growth but also are strong so they can share the load of the skeleton once implanted.”

Tests have shown that the ceramic implant will not be rejected by the body, and another bonus is that as many implants as necessary can be made from the material, so availability will not be a problem.

A final selling point is cost. “The material we have developed is way, way cheaper than metal implants,” Zreiqat says.

The Queensland University of Technology (QUT) and the University of Wollongong have partnered with the University Medical Centre Utrecht in the Netherlands and the University of Wurzburg in Germany to offer the world’s first international master’s degree in 3D body-part printing.

The two-year master’s course in biofabrication will look at how to use 3D printing to create living artificial tissues and biological tissue substitutes.

Mia Woodruff, QUT’s biomaterials and tissue morphology group leader, told the ABC in an interview recently that 3D technology offered an alternative to traditionally used artificial biomaterials, such as silicone breast implants and metal pins.

“Because 3D printing is becoming such accessible technology ... people are starting to use 3D printing technology to process these biomaterials into three-dimensional structures,” she said. “We’re able to add cells from the actual patients we’re trying to treat, and that makes a three-dimensional living tissue.”

She said another advantage of biofabrication was that the polymers implanted into the body would degrade over time.

“During the period they’re dissolving, new tissue is forming in a way that exactly mimics the original tissue,” she said. “It just gets smaller and smaller and the tissue forms more and more in the scaffold, which is highly porous, and eventually the polymer disappears and you’re left with regenerated tissue.”

In the same interview, Stephen Beirne, a research fellow at the University of Wollongong, said biofabrication technology could even allow the 3D printing of whole implantable organs — eventually.

“There are numerous hurdles between here and there, but an early estimate would be 50 years,” he said.


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