What sort of problem is joint replacement with an artificial joint?

Let me explain: Joint replacements done when your joint wear out and start to be painful it is very t hard ambulate with it. The joint replacements to cap the joint with metal and polyethylene. There are two main complication.1-from the surgery itself.2-from wear and tear. Artificial joints like any thing artificial , follow the law of wear and tear? In general they have good result.