DXA scan of the lower back showing
individual spinal bones.
Image courtesy of Fresh Science

A WA physiotherapist has developed a new technique that can measure bone density variations in spinal vertebrae as a way of identifying people at risk of breaking their backs.
 
Curtin University of Technology research fellow Andrew Briggs said the next step was to test it in a clinical study of up to 500 people over a period of two or three years, depending on government funding.

Nearly two million Australians suffered from osteoporosis in 2001 - costing the country about $1.9 billion. By 2021, the number of sufferers will rise to three million.

Osteoporosis affects about 30 per cent of women and eight per cent of men over the age of 50. It causes a decrease in bone strength, leaving mostly older people vulnerable to fractures and serious breaks.

Spinal fractures account for nearly half of all osteoporosis-related breaks and cause extreme pain, postural changes, mobility and breathing problems, diminished strength, reduced balance and emotional stress.

The new method developed by Dr Briggs and colleagues in Victoria and South Australia, involved modifying the analyses of existing bone density x-ray scans for bone thinning or osteoporosis to assess bone density distribution in the back.

Bone mineral density is routinely measured using a DXA scanner subsidised by Medicare. Presently, DXA scans only provide a gross or 'average' measure of bone mineral density in spinal bones. The measurement does not describe how bone mineral density is distributed within spinal bones, which may be the key to identifying high-risk patients.

Researchers are investigating ways to improve the routine DXA scans so that the pattern of bone mineral density can be measured easily and more accurately.

"There is some variation in all bones, particularly spinal bones," Dr Briggs explained. "But we needed a lot more detail to determine variations in spinal bones not picked up by conventional scanners."

Dr Briggs said the team, which included researchers from the University of Melbourne, Royal Melbourne Hospital, and the Institute for Medical and Veterinary Science in South Australia, was now testing the technique on donor spines as a lead-up to the larger clinical study planned next year.

If successful, the technique may have major implications for clinical practice.

Dr Briggs said the team would investigate chronic back pain as part of the study, including long-term users of steroids for chronic inflammatory conditions.

"About 80 per cent of the population have back pain," he said, adding osteoporosis was increasing generally because people were living longer.