Quote by Barbara removed by Patricia Walter - The information below is excellent.
Hi Barbara, welcome to the site - I'm glad you found us to get more information about this. We have several people here who have had problems with this and been revised to a total hip replacement. Their stories, like Dan says are heart wrenching, and affect us all since it is a possibility for us all.
As Dan mentions, it's not shards of metal, but metal ions that are liberated due to friction from edge loading as far as is known. There may be other sources, but the overwhelming cases that have been seen is from edge loading.
As I've heard it described, edge loading happens when the implanted device is positioned incorrectly, at an angle that makes it impossible for the two parts to slide without impacting the edge. Over time, this generates the metal ions that then may cause muscle and bone problems.
This is why many people have their blood levels measured now, to make sure that is not happening within their bodies and if it is, to deal with the issue at an early point, when hopefully not too much damage has been done. The usual remedy is to replace the component, predominantly with a total hip replacement or when possible to replace the offending cup at the proper angle and keep the HR.
After the remedy, blood metal ion levels drop to normal fairly quickly, eliminating the problem. The result is hopefully a fully functional replacement hip.
The failure rate of hip resurfacing, for all hips done by all surgeons, for all devices is 3.6%. That is a 96.4 % success rate.
Surgeons who do a lot of resurfacings, who have gotten a lot of experience, or just are more skilled have higher success rates than that, and obviously those who are less skilled or experienced have a lower success rate. The best prevention for problems is to select your surgeon as well as you can, and to select a device that has a good record.
There have been some devices that have been failures, and have been 'recalled'. They had design flaws and were implanted in many patients. Even within the community of people who have those implants, the majority are still without problems, but a larger percentage than was seen in other devices had problems, so they were withdrawn. The articles written featured these devices and de-emphasized the more successful devices.
Even when a failure happened, it was seen in the Australian registries, which did a study of hip resurfacing over a period of ten years, the large majority of failures were caused by other reasons than metal ion problems. This does not denigrate the suffering that those of us who have these issues experience, but it speaks to the frequency of the problem.
The study found that 8% of all problems were caused by metallosis. That means that 0.08 X 3.6% = 0.288 % of hip resurfacing failures are caused by metallosis in Australia. Again - does not downplay the problem when it rears its ugly head, but it is not the predominant cause of failure.
To attempt to avoid it, the best approach is to have a skilled surgeon who preferably does many and is committed to its practice, a good recuperation regimen, and established and good devices, in my opinion.
I'm glad you're trying to find out good information. This site is invaluable for both discussion and research, roam around it and you'll find a lot of information both about the successes and unfortunately, some failures. We are open to both.