That is a devastating injury. At his age I really hope he retires. Greatest of all time for sure, had a storied career. Chris Weidman has his number though, at least at this stage in his career. Silva I think can still beat just about anyone at 185/205, but he will never be champion again. Weidman is the better MMA fighter right now at this point in their careers.
I hope Silva is able to get the treatment he needs and heal up quickly with no lasting damage. Best of luck to him, and i'm glad I had the opportunity to watch him fight and advance the sport the way he did.