really not supposed to until 6 months. no matter how much muscle you build, the graft needs to get mature.
so while you will probably be able to ski again at 4 or 5 months, you shouldnt, because you are still highly at risk for tearing it again, even if your muscles are STRONGER than before.
right now, i'm at 4 months post surgery for mine..but i completely tore mine, and tore my meniscus.
I'm going to be back on snow at the beginning of february.