OK, I think I should elaborate more on my situation and contribute with my story as this forum has been a great resource of information and inspiration for me. I ruptured my left ACL in April 2011 by an innocuous movement of my knee while coming to a stop. This was in a backcountry terrain. No pain, just felt a pop in my knee, not much swelling, skied off the mountain, only certain movements were painful. After getting diagnosis, I decided to go for surgery which was done in April 2011. I did not have any instability episodes before surgery. Recovery from surgery was long and painful and I started skiing after about 12 months (we ski here year-round).
In March 2013, I fell over back of my ski in a deep powder (Phantom Foot fall) and felt a weak pop but I knew right away what happened. Again skied off the mountain but this time I had a lot of swelling, a large bruise and little more pain, but again no instability. After getting a diagnosis, I decided to wait before committing to surgery (with which the doctor enthusiastically agreed) and did fairly aggressive PT (Olympic Physical Therapy in Seattle, great people). I also decided that if the knee showed any instability during everyday activity, I would go for surgery but it did not so far. I started skiing in June (with a Donjoy brace) and have been slowly ramping up as of now in January 2014; I also need some work on my skiing form as the backcountry skiing is not very good for that so I now ride lifts more often with my daughter.
As velox313 above says every person's situation is different but it is encouraging to read that many people go on skiing without ACL, and that this deficiency actually encourages one to keep in shape. And I have to say - the knee that was operated on feels worse than the other one and I think in ten years I will have arthritis in it. So it is useful to realize the surgery is not an automatic answer to ACL injury, even if one wants to remain active, unless it clearly is indicated by functional deficiency.
Edited by ps44 - 1/31/14 at 11:45am