Again, name me one instance in which an athlete performed again within one year of an ACL tear. Outside Tiger (and that is golf, does not count) it never happens. All googling the subject aside, proof is in the pudding; it takes a year to get back.
Maybe for typical person who just needs to walk or climb some stairs, 6-9 months. Athlete in NFL, 1-2 years.
It is not clear to me, why that long standing fact, is not clear to you.