Stem cells help regrow long bones

People who suffer catastrophic breaks to their long leg bones usually face multiple surgeries, and all too often, amputation.

Scientists at the University of Arizona have been working for more than 20 years to improve the treatment protocol.

Yudith Burreal broke her leg when an ATV rolled on her a year ago.

“It was completely missing. They didn’t know, it was a big chunk of my bone. It was my tibia bone,” said Burreal.

Her doctors used her bone and marrow to fix the break. But Burreal ended her plans to go into the military, believing her leg wouldn’t support her in training.

University of Arizona researchers are developing a way to fix broken long bones with stem cells, a 3D printed scaffold, and a sensor to monitor exercise that helps bones heal.

“If we can fill our scaffold with these cells, the bone will start to form throughout the length of the scaffold,” said John A. Szivek, PhD, Professor, Orthopaedic Surgery, William and Sylvia Rubin Chair of Orthopedic Research, Director, Robert G. Volz Orthopedic Research Laboratory, and Senior Scientist at Arizona Arthritis Center.

Stem cells are multiplied in a lab, and run, with calcium particles, through the scaffold between the bone ends. A rod holds it in place for six to nine months. The bone grows in and around the scaffold.

“Lately, we have been successful with removing all of the supporting hardware and showing that supporting the bone that we’re regrowing is actually functional tissue, to show that it does not need any additional orthopedic hardware in order to function,” David Margolis, MD, PhD, Assistant Professor, Orthopedic Surgery at the University of Arizona.

This work is funded by a two million dollar grant from the Defense Department.

Szivek said, “We believe that using this type of approach could regrow the bones for the soldiers and they would be able to return to active military service.”

Researchers will report the recent success they’ve had with procedures on sheep to the FDA. If the agency accepts it, a phase one trial of fewer than ten people could start soon at Banner-University Medical Center in Phoenix.