Metal Ions By Mark Bloomfield
|November 15, 2008 |
So now to metal ion problems. These fall into 2 broad groups, which are not at all the same.
The first is metallosis. This is when there is a manufacturing or alloy or placement problem that leads to high metal ion or particle production. This causes localised inflammation, swelling, pain and tissue necrosis, but not usually implant loosening. It is something everyone and anyone can have although the threshold level at which the 'overload' becomes a problem will vary. Some alloys are more 'toxic' than others. It is NOT an allergy! The second is a true 'allergic' reaction and this may occur at very low metal ion levels. It is called ALVAL and seems exceptionally rare. The 'allergic' reaction is different to skin reactions to metals eg nickel allergy on the skin. Although posters are saying McMinn is using a blood test for metal ion allergy [Melisa] I am not aware of any definitive proof that it is reliable and he may be reacting to the concerns being expressed rather than because he is persuaded it is valid! Look at http://www.melisa.org/
There is money in this folks, and I am always suspicious of secondary gain when money is involved. Plus these people are involved in helping to 'diagnose' chronic fatigue syndrome...
Allergies are the new designer disease. A gift for the introspective and manipulative attention seekers. Please do not get me wrong, allergy can be extremely serious and life-threatening. But some 'allergies' seem a bit too convenient or contrived.
In some patients, both metal ion overload and some unspecified allergy or reaction may co-exist.
So perhaps you are getting a flavour of how complex and difficult a field we are getting into!
Lastly, there is definitely an element of hysteria or introspection in some individuals which makes accurate assessment very tricky indeed. Only medical practitioners who have been in the game a while will have seen this effect whilst the general public will have understandable difficulty believing it is possible at all.
In my own practice, I am seeing very few metal ion problems. I have yet to see a definite case of ALVAL. One which might have been, but not sure and this happened before we understood ALVAL. I am aware of a definite case in the geographical area.
I think metallosis is much more common. If the prosthesis is not the McMinn BHR, I am immediately suspicious that this is the reason. If the prosthesis is the BHR, I consider whether it has been properly inserted, and is properly bonded to the bone. I also consider whether there could be avascular necrosis [AVN] of the femoral head. This is rare.
Finally, there are causes of hip pain that have nothing to do directly with MOM hip resurfacing and are seen in other techniques. These include psoas tendonitis, bursitis, low grade infection and referred pain from elsewhere.
In summary: MOM hip resurfacing works so well in the vast majority of YOUNG ACTIVE patients that I will continue to offer it without a second thought unless there is an anatomical reason it is impossible. MOM resurfacing is technically difficult to do well. And unless it is done well, it is more likely to suffer from metallosis. The implant seems important or even critical, so ask what you are getting and be sure you are happy with the choice!
If your MOM hip resurfacing disappoints you, see an expert about why and what to do next!
I am not God. I do not know everything. I could be wrong about one or more issues discussed above. Feel free to challenge me, but I have limited time to spend on the site, thus do not get individual posts. I only occasionally browse.
Good luck whatever your situation.