Patella tracking maybe? **Help**

[BeefHat]

So 5 years ago I had trained for up to 4 years no problems, then one month started getting weird knee soreness and I was an idiot and ignored it, sore knee turned into knives behind my knee cap one day and that's when I shut down and saw my doctor and he told me the cartilage was most likely work down and to take 2 months off from the gym, so I did. Went back and it was still there and I just fell apart from then on because he said try 4 months and I didn't have the money to really push farther with it, so 5 years later and I'm about 2 months back in the gym and my left knee is starting to maybe feel sore and it has me nervous as **** again....I did find out I have flat foot so I got some orthotics which have helped, I got a knee compressor with a patella opening as well for any leg/cardio day. I've only had these for about 2 leg days so far though and the soreness still feels minimal but I'm looking for anything that maybe you guys were doing to cause this or ways to fix it for good? I've read a lot about toe positions when squating and warming up before going into your workout as well as stretching which I've been doing all of those. Hope some of you guys can help me out, my last resort is Physical Therapy to hopefully learn to track my knee properly so I don't end up having surgery to fix it.

[ToPHeR35]

strengthen the vmo

[BeefHat]

It wouldn't be due to vmo though wouldn't it, since it wasn't the first time around I would have seen symptoms the first 4 years a lot earlier wouldn't I?