subluxed kneecap

Hi,
Im very much into powerlfting but sometimes go for the odd game of soccer etc. A few years ago i dislocated my left kneecap and have had problems with it ever since. After it happened for the second time my doctor advised an op but i didnt want to have it then so i trained hard with the weights and was problem free for a long time, i was however avoiding all sports like soccer/racketball etc. I have subluxed it a couple of times in the last few years (5 in total). Last week i was playing soccer again and guess what happened… anyways needless to say im not doin much at the moment, hopin to get back to some upper body training tomorrow. Does anyone have suggestions on rehab for this type of injury??, and what about squatting, since its happened on a number of occasions would sqautting be dangerous??,(ie coul it go during a squat), has anyone had the op done??
Thanks