Smart Orthopedic Implants Support Healing and Repair of Injured Bones

When treating fractured bones, doctors generally use standard implants. A plate is screwed into the bone to stabilize the fracture - regardless of whether the bone was twisted, bent or crushed. In 10% of cases, however, complications arise. To improve treatment, researchers are developing intelligent implants that not only stabilize the fractured bone but also detect and counteract incorrect weight bearing in individual patients.

A team of physicians at the Saarland University Medical Center (Homburg, Germany) together with partners from the fields of applied mechanics, mechatronics and computer science is developing smart implants that can monitor the healing of fractures and help to remedy incorrect weight bearing - autonomously, with no action required from either doctor or patient. The aim is to create intelligent implants that can detect and respond to incorrect weight bearing on a fractured bone. For instance, if too much pressure or weight is placed on a fracture, the implant stiffens, relieving strain on the bone. By contrast, if a patient is too sedentary, the implant changes its shape and becomes more flexible, increasing the pressure on the bone.

The implant can be monitored by an external device, such as a computer or smartphone, and is removed when healing is complete. The team plan to manufacture the components in a variety of shapes and sizes that can be combined to best treat the individual fracture. An additional benefit is that post-operative care is simplified. But before they can design intelligent implants that aid healing processes, the researchers must identify which conditions are conducive to healing and which factors cause complications. The researchers plan to test persons with a lower-leg fracture wearing an intelligent insole in their shoe. The insole has 16 pressure sensors that record 82 parameters per step taken, enabling the researchers to identify the forces acting on an affected bone.

Using the data, experts will conduct simulations and experiments to determine exactly what happens to bones when they are exposed to everyday pressure and strain. The researchers plan to use artificial intelligence (machine learning) to distinguish between behaviors that promote healing and behaviors that tend to result in complications. Based on the test data, specialists are developing algorithms that precisely predict which conditions are most likely to promote healing. To this end, the computer scientists define limit values for diverse parameters such as physical stress or strain; they also employ imaging techniques to enable healing prognoses on the basis of pictures. The project team is aiming to build a prototype of an intelligent implant and to complete initial testing on animals by 2025. Nevertheless, it will probably take another two decades before the new technology can be used to treat fractures in humans, as approval procedures are very complex.

“Innovative technologies could make bone fracture treatment safer, more individual and more cost-effective,” said Dr. Marcel Orth, who is leading the project at the Saarland University Medical Center. “Smart applications are already standard in a variety of areas, such as automobile technology. There’s no reason why innovations from materials science can’t be of great benefit in medicine, too.”

Related Links:
Saarland University Medical Center