Researchers have achieved a breakthrough in curing broken bones from adult stem cell transplants that could eventually serve as a new treatment for fractures that fail to heal.

A study conducted at the University of North Carolina at Chapel Hill has shown that transplantation of adult stem cells can improve healing by 10 to 20 percent of fractures that might otherwise be hard to repair because of a deficiency in adult stem cells, which normally become reparative cells in response to damage.

The study's senior investigator, Dr. Anna Spagnoli, said in a press release that stem cells in human bone marrow, called mesenchymal stem cells, can become bone, cartilage, fat, muscle, and blood vessel cells.

Mesenchymal stem cells can be obtained from a patient's bone marrow.

The results of the study were presented Monday at the Endocrine Society's 90th annual meeting in San Francisco by Froilan Granero-Molto, research associate of the University of North Carolina.

Researchers cautioned that animal studies are needed before clinical trials can begin.

Current therapies include multiple surgeries with bone autografts and artificial prosthetic materials. But these often fail to help patients. If successful, the treatment could help nearly 600,000 people in the United States every year who suffer fractures that do not heal properly.