Hack Shaft is a budding martial artist and aspiring middle-agester (below 40, but nearly there) who blew out his ACL recently. His blog is an account of his "journey from defeat in injury to victory in reconstruction," and well worth following. As of this writing, he's 14 hours away (CORRECTION: 14 days) from his surgery.
Black Belt Mama, a widely read blogger whom I mentioned before, just underwent ACL surgery and is recovering now.
Best wishes to both of them, and speedy recoveries!