I had a arthroscopic lateral meniscus removal about a year a go. It was a nasty bucket handle tear, that had my knee physically locked at a 90 degree angle for a couple of days before i got the surgery.
I Trained the day i got out of hospital, so a day after the surgery. Was a bit awkward limping around with crutches, and some movements were impossible, but you can always find a way.
I was off crutches in one week, but had problems walking for maybe a month. Stairs were hard to do without crutches or a rail. mostly due to pain and low range of motion. first couple of weeks i couldn't even bend my knee enough to get in a car. I did ROM and physical therapy two times a day, on my own, for i don't know how long. maybe 3 months.
Doc told me no leg training or running for 6 months. The physical therapy program had me doing BW squats as soon as i was able to, so I just added weight as soon as i was able to. this was maybe 3 months out from surgery.
Running and squatting is fine. Just minor pain/discomfort.
I already have Osteoarthritis, but there is little to be done about that, so i just ignore it. Using a knee sleeve when squatting and when i know im gonna be on my feet the entire day, seems to help. Not knee wraps but sleeves, just to keep it warm and keep the blood flowing.