Washington, Apr 15 : A drug commonly used to treat severe osteoporosis can mend hard-to-heal broken bones of elderly patients at a rate typically seen when they were young kids, say researchers.

The study led by Dr J. Edward Puzas, who heads orthopaedic bone research at the University of Rochester Medical Centre showed that the drug teriparatide, or Forteo can significantly boost our bodies'' bone stem cell production.

The researchers may have discovered a new, in-the-body stem cell therapy that can jumpstart the body''s natural healing process in bones.

In the study involving 145 patients who had an unhealed bone fracture, the researchers found that 93 percent showed significant healing and pain control after being on teriparatide for only eight to 12 weeks.

"In many people, as they get older, their skeleton loses the ability to heal fractures and repair itself," said Puzas.

"With careful application of teriparatide, we believe we''ve found a way to turn back the clock on fracture healing through a simple, in-body stem cell therapy," Puzas added.

Dr Susan V. Bukata, medical director of the Center for Bone Health at the University of Rochester Medical Center Bukata revealed that elderly confined to nursing homes or require additional medical attention because of non-healing fractures might be able to live an independent life.

The impetus for the research began in Bukata''s clinic, where she saw painful bone fractures in osteoporotic patients quickly heal within a few months of taking teriparatide.

"I had patients with severe osteoporosis, in tremendous pain from multiple fractures throughout their spine and pelvis, who I would put on teriparatide," said Bukata.

"When they would come back for their follow-up visits three months later, it was amazing to see not just the significant healing in their fractures, but to realize they were pain-free - a new and welcome experience for many of these patients," she added.

When a fracture occurs, a bone becomes unstable and can move back and forth creating a painful phenomenon known as micromotion. As the bone begins healing it must progress through specific, well-defined stages.

First, osteoclasts - cells that can break down bone - clean up any fragments or debris produced during the break. Next, a layer of cartilage - called a callus - forms around the fracture that ultimately calcifies, preventing the bony ends from moving, providing relief from the significant pain brought on by micromotion.

Only after the callus is calcified do the bone forming cells - osteoblasts - begin their work. They replace the cartilage with true bone, and eventually reform the fracture to match the shape and structure of the bone into what it was before the break.

According to Puzas, teriparatide significantly speeds up fracture healing by changing the behaviours and number of the cartilage and the bone stem cells involved in the process.

"Teriparatide dramatically stimulates the bone''s stem cells into action. As a result, the callus forms quicker and stronger," said Puzas. (ANI)