I could write a thesis on this topic. Have had 3 meniscus surgeries in my right knee.
1st surgery was a true repair. 2nd and 3rd surgeries were trimming and shaving. I went 10 years between the 1st and 2nd, and 3 years between the 2nd and 3rd. Knock on wood, been good for 7 years now. In terms of managing the pain and health of the knee, I do pay a lot of continued attention to it. Knee sleeve when I'm doing a certain level of physical activity. When I am hiking, lifting lower body weights, etc., I have more of a sleeve brace that helps.
Which knee are you getting fixed up? I do agree with Jawn that being diligent with rehab exercises is the best start to it all. After that, long term, the better the strength of you and your leg, the better it will be protected.