Athletes with torn anterior cruciate ligaments (ACLs) will be happy to hear about a man-made ligament being created at Northwestern University in Illinois with the goal of replacing ruptured ACLs.
These ligaments connect the femur to the tibia, and they cannot heal once they have been ruptured, according to Gizmag. Grafts from the patellar tendon, which connects the kneecap, or patella, to the tibia, are often used to fix torn ACLs, but this method comes with its own issues. Project leader Guillermo Ameer pointed out problems like knee discomfort or, worse, the chance of what's left of the patellar tendon breaking as well.
To make sure these problems don't occur, Ameer, a professor of biomedical engineering at Northwestern Illinois, and his team designed an ACL made from braided polyester fibers. Its tensile strength is equal to that of your average ligament, and the team blended the fibers in its ends into a mixture of a porous antioxidant biomaterial and hydroxyapatite nanocrystals that occur naturally in bones and teeth.
The scientists conducted studies with the artificial ACL on rabbits, drilling holes in the femur and tibia so they could reach each end of the ligament, Gizmag reported. The ACL proved to be effective, as the rabbit's surrounding bone and tissue cells moved into the pores of the ligament's biomaterial/nanocrystal mix.
Ameer says the ligament is capable of stabilizing the knee. The goal of the study is that the ACL would completely blend into the femur and tibia over time.
"Most importantly, we may have found a way to integrate an artificial ligament with native bone," Ameer said.
The team plans on conducting more studies with their man-made ligament before testing them on humans. The study was published in the Journal of Tissue Engineering and Regenerative Medicine.