If a person were to have a ring, of diameter approximately two inches, implanted under the skin (with the intent of remaining there permanently), what medical problems might arise? The ring could be made of any material that keeps its basic shape, but is soft enough to bend slightly. The intent is to have a raised inner ring remain above the skin level, with an outer ring underneath the skin to keep it firmly in place.
Will the body reject it like a transplant organ? Will it carry high risks for infection? Will it be itchy and uncomfortable all the time? Will the skin grow over the raised part that is supposed to be exposed? Will anything else happen that I haven’t thought of? What material might be used to minimize irritation?

Yeah I know this sounds really odd without the context. I can give more details if asked.