Engineers study bone breakages

Mechanical engineering, computers and medicine have all come together in a Trinity College Dublin (TCD) research effort to better understand how bones break and why.

Prof David Taylor of TCD's mechanical engineering department and colleagues in the Royal College of Surgeons in Ireland (RSCI) hope a new phase of their ongoing research into hip fractures in elderly patients will improve knowledge of osteoporosis.

Nearly half of all women and a quarter of men over 50 will suffer a bone fracture due to the condition, in which bones gradually lose density and strength. But Prof Taylor said doctors had been baffled at the high number of elderly patients with bone fractures that did not seem to be directly related to osteoporosis.

About 200 elderly patients present with bone fractures annually at Meath Hospital, Tallaght, he said. "About 70 per cent can be explained - an X-ray will show clear signs of osteoporosis. But for another third, we don't know why their bones break. It's almost forensic work," he said.

Prof Taylor's speciality as an engineer is in "how things break". About half his work involves looking at problems such as metal fatigue in cars and aeroplanes, and the rest involves the same general problem in bones. "Like an aeroplane, bones have to operate at quite high levels of stress. But they also can repair themselves."

For Prof Taylor and RSCI colleagues Jan Hazenberg and Clive Lee - who have just published a review article on global research on how cracks form, grow and are repaired in human bone in the journal Nature Materials - the next phase of their research will hopefully provide some helpful answers to several questions.

"We have a scientific goal of a better understanding of osteoporosis, but we also hope there will be practical spin-offs," said Prof Taylor. "One immediate spin-off is to better understand the mechanisms by which the drugs work that help this condition. We know many drugs work, but we don't understand how they do it."

They also hope to uncover better screening processes to assess individuals who may be at higher risk for breaks. Right now, Prof Taylor said, the only way of assessing risk was to take out some bone and examine it. They hope to find ways of assessing individuals less invasively, though X-rays, CT scans or MRIs.

The team has received €2 million in funding through the Programme for Research in Third-Level Institutions Bone for Life project, the Health Research Board and Science Foundation Ireland.