This is an important discovery, because the ACL, the stabilizing ligament that connects the thighbone to the legbone, usually does not heal after it is torn during sports or other injuries. The ACL unravels like an unbraided rope when torn, making healing difficult. More than 200,000 people in the United States suffer this rupture each year.
"This is the first tissue-engineered matrix for ACL to demonstrate such substantial neo-ligament formation, in terms of both vascularity and collagen formation," said Dr. Laurencin, Chairman of the UVa Department of Orthopaedic Surgery and leader of the team. "We tested one synthetic matrix with actual ACL cells from our animal model and one without these cells. While both systems encouraged the ingrowth of neo-ligament tissue, matrices with seeded cells performed particularly well in this study."
Dr. Laurencin concluded that the ACL replacement with ACL cells had a robust functional tissue outcome in the rabbits that received this matrix. While the researchers found that the tissue and mechanical evaluations showed promising healing and regeneration, follow-up studies will be conducted over a longer period of time, to allow for maximal healing. "It is my hope that these studies will lead to a revolutionary new treatment strategy for patients suffering from ACL tears," Laurencin said.
This report appears in the Proceedings of the National Academy of Sciences online at http://www.pnas.org/ and will be published in print on Feb. 27.