There are a plenty of options to support your Knee with diet or supplements.
Glucosamin, CHondroitin, MSM, Collagen hydrolysate, Omega-3 fatty acids, Vitamin E etc.
Avoid to eat to much normal fat and to much porteins.
Your plan with your protein shakes and creatin wount work.
To increase your strength of your muscles, it is more important to train their coordination and frequence of nerval activation. Therefore not only the size is important.
Good luck so far!