Metal on metal artificial hips are causing problems, as reported here in the past.
Now, is getting more attention than ever in the media. According to the New York Times article, there have been more than 5000 reports to the FDA, this year alone. Some of the devices only last few years. This is major surgery and can cause tremendous problems to patients.
The A.S.R., the articular surface replacement of Johnson and Johnson is recalled last year and account for the majority of the complaints cited by the Times. It is exceedingly difficult to determine the number of problems because under FDA rules, many devices were sold out testing in patients or without tracking their performance. Pieces of chromium and cobalt can shed, due to movement causing severe injury.