Not a Dr, or an expert, so I would say talk to your surgeon(s) before doing anything. Might also want to discuss PT with the doc as well.
If that is all good, do extensions, hamstring curls, and maybe low weight leg press or hack squat? A lot of this is based on what I did for myself after 17scopes on my knee and an ankle reconstruction. I am now getting into squats, but i relied on leg press and hack squats for 20yrs.
Sent from the Planet Fitness holding cell because I asked to use the squat rack.