Not sure my reply will be helpful as yours is based on previous injury and mine is simply fear due to old age.
I avoided even attempting to do squats for at least a year when I began working out (age 62). I would watch much younger guys doing it with a LOT of weight and I'd think to myself, 'noway!' However, I also knew that squats were important moves for overall body building so...
First, I worked with a personal trainer to show me exactly how to do it and watch me and make corrections while squatting with very (embarrassingly) light weight.
Second, after I felt comfortable with my form, I began increasing the weight each time but *never* going beyond what I knew I could safely handle.
Third, on occasion I'd set up the squat rack with the rails high up. I get under the bar and hoist it a couple inches. This way I could load the bar up (I've gotten up to 400lbs) and *safely* condition my body to be able to hold that much weight. Granted, I can't do a full range of motion with that much weight and may never be able to do that but by adjusting the height of the rails, I've 'conditioned' my body to handle more weight in less than full range.
I still don't squat full range with super heavy weight like some guys do but I feel comfortable doing multiple reps and sets full range with 160. I realize that's not a lot by most guys standards but considering where I started, that's a lot for me. I'll keep upping the weight little by little as I feel stronger and more confident.
If I were in your situation I'd make damn sure to discuss my previous injuries with a qualified professional before doing anything too heavy. Since you are young you're probably fine but, still, why take the risk? I know the *last* thing I need is an injury that will keep me out of commission for weeks or months!