No specific knee advice, but anytime there is any kind of injury or any kind of "dis-ease" in the body, it's important to keep the body as healthy as possible, so that it can heal as fast and efficiently as possible.
Diet is so critical in that, next to exercise and attitude too of course. More specifically, look up Alkaline-Acid theory for diet. Many people, especially in the western world eat an over acid reacting diet. Since virtually all of our metabolic and waste producing processes are already acid forming to begin with, eating a acid reacting diet along same can really stress the body.
I've been researching and practicing this for quite awhile now. As long as i eat a more alkaline, or at least more balanced diet, i don't even get a hint of the common cold let alone any other kind of sickness. I also tend to have much higher energy levels, better stamina and endurance, cuts heal faster, and it helps my mood as well among other benefits.
Generally speaking, it's primarily fruits and vegetables which are more alkaline reacting in nature (even if they are acidic in their natural state, like citruses--lemons are one of the most alkaline reacting foods there are, despite the high innate acidity). Generally speaking, most natural starches, grains, etc are mildly to moderately acid reacting. Generally speaking, most light proteins (like most legumes, regular yogurt, milk, etc) are mildly to moderately acid producing (there are exceptions like soy--very acid reacting).
Generally speaking, heavier i.e. more concentrated proteins (like meat, certain cheeses, etc) are in between moderately to very acid reacting.
Junk foods etc are always extremely acid forming in nature.
Then there is combinations. The least acid reacting and easiest to digest combos generally are non starchy vegetables with carbs/starches or proteins. Then easier to digest starches/carbs like brown rice with lighter proteins like lentils or yogurt are moderately acid reacting.
The most acid forming combos are things like heavy/concentrated proteins with amounts of starches/carbs, so the meat and bread is an extremely acid producing. Starches/carbs with amounts of sweets/sugars is very acid reacting, so a typical pastry is quite acid forming. Another bad, but common combo is coffee with amounts of sugar and/or milk, very hard to digest and very acid forming. Decaff black coffee is ok.
While fruits and vegetables are generally the most alkaline reacting and easier to digest foods, generally speaking combining them within the same meal is detrimental since they generally digest differently. There are exceptions of course, like in much of the above general outlines, like tomatoes with salads, or avocados with salads. However, most sweet and/or citrus type fruits don't combine well with most vegetables.
Anyways for myself, i just make sure i eat more fruits and vegetables, avoid certain combinations most of the time, avoid junk foods and caffeine most of the time, and avoid stress (stress is also acid forming for the body) most of the time and as long as i do same, i feel great, stay super healthy and vital, and allows my body to heal faster.
Btw, there are more studies starting to come out that point to positive visualization as having real merit and affect beyond chance in healing (something many top athletes in their fields have known and practiced for awhile for increasing performance). So taking a little time each day to calm your mind, and picture your knee healthy, strong, and working well might be a good idea--certainly couldn't hurt.