Researchers at a US university are using a robot from a car factory to study the anterior cruciate ligament (ACL), which is often injured when playing sports.
The 8-foot-tall, pumpkin-orange machine at the UCLA Orthopaedic Biomechanics Laboratory helps the research team investigate the workings of the human knee. It applies hundreds of pounds of force to a cadaver knee specimen implanted with a custom-designed sensor that measures forces in a knee ligament.
According to the university, by pairing this setup with a computer program that analyses every move, bioengineering researcher Keith Markolf, bioengineer Daniel Boguszewski and orthopaedic surgeon Dr. David McAllister are shedding new light on how the knee works, how it gets injured and how best to repair it.
“The ACL is a very complex ligament in terms of its geometry,” Markolf said. “It has different bands within its structure, and some of the bands become tight in full extension, and some become tight when the knee flexes. Overall, the ACL is extremely important in terms of stabilising the knee. When the ligament is ruptured, the knee moves in ways that it didn´t before — in ways it shouldn´t move.”
The robotic testing system allows the UCLA researchers to simulate potential injury scenarios and directly measure forces in the ACL that can lead to rupture — providing insights into the mechanisms that lead to injuries.
The researchers also want to develop treatment strategies that will best stabilise the knee to prevent future osteoarthritis and cartilage damage, and understand the best way of rehabilitating the knee after ACL reconstruction surgery.
McAllister and his collaborators are applying their research to scientifically determine which approaches to reconstruction used by surgeons around the world are actually working and which ones aren´t.
“What we learn has clinical relevance,” McAllister said. “I can it use immediately with patients — and with confidence that it will work.”