There is no AS that will speed up your recovery, take it slow. Had my acl reconstructed 5 years ago. You will be back in the gym in a couple of weeks, and sooner for PT. Had meniscus tear operated on 2 years ago.. Knee is now close to 100%. In most cases, the knee will never be 100% again.
Bulldog - The acl is the main ligament in the knee which prevents hyperextension. Ta63 is exactly right about the other stuff holding the knee together. People who have this surgery either tear it completely or damn close..
I have my acl surgery on video, pretty cool stuff seeing the scopes in your knee. Although when they take the scope out and reveals your whole knee skin peeled back. it makes for some interesting viewing.