But a makeover is in the works.
"More engineering analysis goes into the washing machine in your home than into the artificial knee joints implanted in people," said B.J. Fregly, an assistant professor of mechanical and aerospace engineering at the University of Florida.
Fregly is applying the latest techniques from the world of mechanical engineering to the human body. By linking video, CT scans, computer models, specially developed computer software and other technologies, he and his colleagues expect to enhance understanding of the causes for failure of artificial and natural knee joints -- as well as improve surgical procedures and create longer-lasting artificial knees. They also are working to develop tools that will shed light on the causes of arthritis in the knee and improve the success of a surgical approach to correct damage from the disease. Seventy million adults, or about one in three Americans, suffer from some form of arthritis, according to the Centers for Disease Control and Prevention in Atlanta.
Fregly, who has published several papers on his work in the Journal of Biomechanics and the Journal of Biomechanical Engineering, said knee implants may last 20 years or longer in sedentary patients, but those who are active tend to wear out the implants more quickly many after just 13 years. As younger and younger patients are requiring knee replacements and people are living longer, the durability and functionality of the artificial knees currently in use is becoming a cause for concern.
"We want knee implant recipients to be able to resume their favorite activities - playing tennis or going on walks - without limitations or fear of wearing out their new knees prematurely," Fregly said.