By identifying cyclic loading of weight-bearing bones as a mechanism of fracture due to the damage of microcracks over time, the research points to the importance of developing therapies that will also target cells in the bone responsible for bone quality—or those cells that help bones withstand loading or stress.
“It is now recognized that osteocyte cells are playing a bigger role than we thought,” says Dr. Acevedo.
Dr. Vail
For Dr. Vail, this broader understanding of the mechanisms of skeletal pathology is getting at what he says is the core of the problem—how to identify patients at risk of fracture and prevent an additional fracture in people after a fracture. “It is my sense that there are other opportunities to enhance a healthy skeleton more than we currently know about how the skeleton repairs itself and communicates with itself,” he says.
The current research points to a plausible new way to look at fracture risk and subsequently expanding thinking on potential new targets for treatment.
Arvind Nana, MD, an orthopedic surgeon in Fort Worth, Texas, however, questions the plausibility of fractures caused by microcracks in aging bones that over time weaken the bone and make it susceptible to fracture. Saying that such fragility fractures do seem plausible in compression fractures of the spine, he does not think these types of microcracks are commonly seen in hip fracture.
“If cyclic loading is the cause of a fracture, it most likely would be in the spine,” he says, adding that most hip fractures he sees are due to falls and rarely occur in people who say their hip just gave out.
Although Dr. Nana is primarily a trauma orthopedic surgeon and, therefore, sees patients who have fracture due to trauma, but as medical director of a geriatric hip fracture program in Fort Worth, he also sees a large number of hip fractures in older patients.
