As Tom Brady and other athletes can attest, you really, really want to avoid tearing your knee's anterior cruciate ligament (ACL). It can't heal up, and the tendon graft used to reconstruct it will likely leave you with permanent pain. Victims may have a much easier time of things if Northwestern University's nanotechnology-infused ligament becomes a practical reality, though. Their remedy combines calcium nanocrystals (like those in your bones), a porous biomaterial and strong polyester fibers to replace your ACL without having to perform grafts and leave you in continued agony. Both the artificial implant and the bone integrate with each other, stabilizing the knee in a way that both lets you move more naturally and spares you from losing some muscle.
Scientists have only tested the procedure with lab animals so far, and it'll require more studies before it's safe to use with humans. Should everything work well, however, it could do a lot for ACL injury victims. Sports stars would be less likely to miss whole seasons or end their careers, and you could get back to work without frequent, wince-inducing reminders of your accident. The nanotech probably won't make you feel as good as new, but it should let you focus on resuming your life.
[Image credit: AP Photo/Will DiTullio]