Recently had surgery on dodgy left knee and am concerned because of cartilage loss.
Looking for advice on what is the best leg, specifically squat, exercises I could do that would not further injure my knee.
I have attached my mediacl report as picture 42 years old not 47 as stated.
Thanks for adding that medical report it does clarify things a lot. Your Dr's advise is spot on, especially concerning your high protein intake.
Concentrate on R.O.M first on the affected knee, physio will help and try and stay away from weight training exercises for know. Your aim for the 'first year or so' would be to concentrate on getting the knee healthy. Nb...get the knees healthy and be super careful for septic arthritis in the affected knee.
You are quite welcome to train the rest of your body as per normal.