I've had the displeasure of tearing my cartilege twice and rupturing my anterior cruciate ligament all at different times all in the same knee. Initially, the cartilege was worse as I couldn't straighten my leg or put any weight on it at all and an op occured within a couple of days on both occasions. The recovery was done within a few months. The ACL is a much longer process - after a week on crutches I had an op about a year after the rupture. Swiss is right in that it is not essential to have it repaired - you can live a normal life with a ruptured ACL but getting back to sport is different and unless you have massive muscle bulk you have to get your knee restructered else it will just keep on buckling. I did not play football for about 2 years after my operation but then I didn't have physio day in day out and now I play regular 5 a side but I have to keep the muscles strong around my knee with gym work. On paper, when a restructure occurs it should make the knee stronger than the original but there are possible complications. Some players lose their confidence in the knee and are not the same player and some come back hungrier and more appreciative of their 'gift' than before. I hope Diego is the latter.
Oh, I forgot as well - I strained my knee ligaments (same knee) and whilst that was uncomfortable and painful I was ok within weeks. This occured a week before I got married, our lass weren't happy when I was on crutches days before we tied the knot.
With me there is no way I could do 11 a side regularly as my knee swells after each time I play 5 a side weekly but it's not painful. I think this was Morg's problem and possibly Dane Whitehouse.
I'm only 33 and still awaiting a call from Roy Hodgson.