Medical case that could potentially affect thousands of Americans who have gone in for surgery the case involves replacement hips that had gone bat. Now come questions about whether the maker of those -- knew there was a good chance there would be trouble. Here tonight ABC's medical editor doctor Richard -- Three years after Dennis Brooks had his arthritic hip replaced he began to feel the pain it became so bad that he just had his hip replacement replaced. -- the press. They had to go through this again because. Now because I was concerned and didn't do their -- Brooks original hip replacement was made entirely of metal and -- appears to been a problem. Something is new surgeon doctor Steve Harwin says he's he's all too often. I've never been an advocate of metal on metal hips I would -- -- skeptical. About. Some of the results when we had these really reports of failure. Hip replacements are a great medical success story. Versions made of ceramic and plastic but some new artificial hips are entirely metal. -- for the estimated half a million Americans who now have metal -- metal -- the news hasn't been good. Johnson & Johnson recalled they're all metal -- in 2000 intent. A deposition revealed a 2011 internal company document predicted that almost 40% of those -- would go bad within five years. Johnson & Johnson says that estimate was based on a small limited -- and should be generalized but the New York Times reports that lawyers for the patient now suing the company. Introduced internal documents in court showing that Johnson & Johnson knew of the problems with the -- all the way back in 2007. The failure rate for all brands of metal -- varies it happens more often in women and the overweight. It's believed that constant friction can cause -- to break off into your body. Even end up in your bloodstream. That can -- joint pain and swelling in symptoms you'd never associate with your hip. Including rash heart problems fatigue depression problems was seeing or hearing. Those -- some serious symptoms but -- there are thousands of Americans walking around with this medal in their hip right now what if they're not. Feeling any symptoms at all what do you do well even if you're not having any problem every one to two years see your doctor get checked out. But you know as TC decision to have very strange so any change -- your health and you have one of these tips and BC right away and -- those were watching tonight at hip surgery weeks -- months away what do they do well good news they're not using these metal on metal -- anymore you can go in with confidence. All right rich -- -- -- -- and the case richer thanks to you.