You are likely dealing with an abnormal scar; hypertrophic or keloid scarring. Your plastic surgeon will likely address it with agent such as injectable steroids. Best wishes.
It looks like a hypertrophic scar. You should go see your plastic surgeon so they can see it in person and treat it appropriately.
I think that is a small area of hypertrophic scarring. I would go in and get him to asses it. I would likely inject it with a small amount of steroids.