Is it possible that you see a tiny detail that nobody else would notice? I'm not seeing anything unusual about your knees.
If you are still growing, as it sounds like from your post, I wouldn't worry about anything like this. My advice is to eat healthy, be active, and enjoy being young
Started - 12/25/11 at 265 lbs.
ONEderland - 2/16/13 at 199 lbs.
Goal - Normal BMI! - 7/17/13 at 155 lbs.
Refocus - 1/29/15 - 185 lbs.