Artificial Ligament May Revolutionize ACL Repair

The worst of material failures are those that involve your body. Broken bones, strained muscles and torn ligaments are all game-changing injuries, especially for athletes; the most likely to incur the injuries. One of the most common, and devastating, is a torn ACL. There is an impetus for faster recovery and better long-term results. A new combination of materials is aimed at delivering just that.

Medicine has come a long way in repairing damaged structures in the body. It seems, however, that the better treatment gets, the more we want the next advancement. Guillermo Ameer, professor of biomedical engineering at the McCormick School of Engineering and professor of surgery at the Feinberg School of Medicine, is hoping to keep pushing the limits of engineering and medicine.

The anterior cruciate ligament (ACL) helps stabilize the bones at the knee, and is often damaged during harsh pivoting or offset landings. The ACL does not heal after being torn, so reconstructive surgery is commonly performed using donor tissue from the patient (autograft) or someone else (allograft), typically a cadaver.

The surgery often involves removing part of the patellar tendon which is then grafted to bone. This involves drilling into the femur and tibia to make connecting points for the graft. This type of surgery often results in lasting discomfort, and a less invasive, off-the-shelf product could improve recovery.

As described in a Northwestern University News article, “Ameer and his research team are working to engineer such a product by combining three components: polyester fibers that are braided to increase strength and toughness, an inherently antioxidant and porous biomaterial previously created in Ameer’s lab, and calcium nanocrystals, a mineral naturally found in human teeth and bones.”

The artificial replacement has some distinct advantages over other methods. The bone-like ends, with the porous material and calcium nanocrystals, accelerate bone healing and integration. The artificial tendon does not require tissue donation either. Since the tissue most often comes the patient, this results in a less invasive surgery.

The artificial ligament has shown promising results in animal studies, but don’t expect this product to be rolled out very soon. There is still a significant body of research to be completed. As Ameer noted, “Most importantly, we may have found a way to integrate an artificial ligament with native bone.” Just try to keep off the operating table until further notice.