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Mathematicians design
revolutionary artificial
bone implant


A team of mathematicians from The University of Queensland (UQ), Australia, has helped design a prototype for a new generation of bone implants that could potentially reduce surgery and rehabilitation times, as well as provide a solution for patients for whom current orthopaedic implants are not suitable.

Using a mathematical approach called “topology optimisation” – a method that optimises the layout of a material within a particular design space – the team has come up with a prototype of a threedimensional scaffold that closely matches the stiffness of human bone, while at the same time has an open pore structure for transporting essential nutrients through the implant.

Such scaffolds can form the building blocks of bone implants that will be fully customisable to patients’ needs.

Conventional implants are manufactured out of fully dense (and non-porous) titanium, which can be too stiff for the surrounding bone. This mismatch in stiffness has been identified as a major causal factor in implant loosening. Further, conventional implants can be unsuitable for patients who have suffered from severe trauma, tumours, infection or deformities.

“Customised, porous implants may be able to alleviate these issues by matching both the geometry and the properties of the surrounding bone,” said Dr Vivien Challis, of UQ’s School of Mathematics and Physics, and co-author of the study that was recently published in Advanced Engineering Materials.

“Our project is a great example of the way in which mathematics can drive interdisciplinary, cutting-edge research,” she said.

“A feature of our research is the constant interaction between theory, experiment and numerical simulation.”

The team has succeeded in manufacturing these complex bone implant designs using an advanced manufacturing technique called “selective laser melting” – a process in which a high-powered laser is used to melt metal powder into the required shape, layer by layer.

Speaking to Middle East Health about the way forward, Dr Challis explained that their next step is to continue developing both their computational tools and manufacturing technologies to improve on what they can currently do.

“We are not at the point of aiming for commercial production, there is still quite a lot of theoretical research to do both with our computational algorithms and the materials science aspects.“

He said they were at this stage not in a position to give a timeline for commercial production.

Other researchers in the study are Associate Professors Anthony Roberts and Joseph Grotowski (both from The University of Queensland), as well as Professor Timothy Sercombe and Dr Lai- Chang Zhang (both from The University of Western Australia).

Reference: Challis V.J. et al "Prototypes for Bone Implant Scaffolds Designed via Topology Optimization and Manufactured by Solid Freeform Fabrication," Advanced Engineering Materials. DOI: 10.1002/ adem.201000154 

ate of upload: 25th Apr 2011


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