By Lars Engebretsen MD, PhD. Are you old enough to remember these orthopedic implants: GoreTex, Dacron, Polyester, Polypropylen, or carbon fibers? Let me remind you that these were not raincoats, mountaineering apparel or shoelaces— they were knee ligament substitutes! I am old enough to have tried these as substitutes for torn ACL or PCL, or augmentations […]