For many people, bones are smooth, white rocks — dead deposits of calcium that keep humans standing taller than our hairier relatives. But skeletons are alive, and when bones are broken, the body works to bridge the gap.

In a 2008 study published in the Journal of Bone and Mineral Research, Yale researchers found that a treatment of bone marrow and anabolic parathyroid hormone (PTH) increased bone formation in rats by 30 percent after three months. Researchers said the experiment could change how doctors treat fractures and bone deformities.

“It opens a way to add bone where a fracture is likely to take place: the vertebrae, wrists and hips,” said lead author Agnès Vignery, a researcher at the Yale School of Medicine.

The team, led by Yale School of Medicine researcher Agnès Vignery, removed bone marrow from the femurs of rats and administered PTH to the subjects for three months. Bone formation in the rats increased by 30 percent over conventional treatments, Vignery said.

Vignery said this treatment could allow doctors to prevent specific bone fractures. Doctors may soon be able to administer a drug to patients for the localized growth of broken bones, she added.

“This approach is simple and fast, and can lead to the formation of an amount of bone sufficient to prevent fractures in specific skeletal sites,” Vignery said.

Vignery and her team, in collaboration with Unigene Laboratories, also found that when they added a cement made of calcium phosphate to the treatment, bone thickness also increased.