Partners Zimmer Holdings ($ZMH) and orthobiologics company ISTO Technologies are working together on a Phase III clinical study to evaluate the DeNovo ET engineered tissue graft to help repair cartilage defects in the knee. The study will include 225 patients at up to 25 U.S. centers. The program is designed to demonstrate superiority of the graft over the current standard of care for articular cartilage defects. Release