Early Wear Issues?

[Buddy]

I have bilaterial Birmingham hips done by Dr. Pritchett. So far, they have worked great. From being nearly crippled, I returned to cycling, hiking, hunting, and even playing tennis and tennis tournaments. In the last month or so, though, I've been experiencing some pain and what feels like loosening or "laxity," and after consulting with Dr. Pritchett, have just had x-rays taken and whole blood cobalt test (awaiting results next week). Wondering if anyone out there has experienced early wear or pain. I was under the impression that these Birminghams lasted an average of 14 years-- maybe i've been over doing it? Also, what have been the implications (if any) of high cobalt levels in blood?


Thanks.

[karlos.bell]

  Hi how long ago?. Positioning is it bang on? Cobalt level? has to be above 7 PPB to have tissue damage I think from memory of my tests. Cheers K

[karlos.bell]

  From memory when looking around at different devices BHR by McMinn was designed to last only 10 years. It was a bone conserving operation to give the younger patient more time before a THR. As it is we have seen them last marathons, time past 15 years and so on.
The metal compounds are different from device to device BHR - Conserve Plus is different, and so are the standards in the USA to Europe in mm increment of fitting.
There are so many factors to consider on how and why these can last so long.
Cheers K

[chuckm]

All hip replacement and resurfacing devices were created to last as long as they can - forever if possible.


Provided they are implanted correctly, these hip devices don't "wear out" as you would think like the treads going bald on the tires of your car or the ball bearings wearing out on the axle.


Instead, "wearing out" is a term that has been given to poly on metal devices where the device has come loose from the bone. This is called aseptic loosening. It happens when the micro wear debris from the polyethylene becomes too much and causes an immune response. The result is the bones resorb around the device and it comes loose from the bone.


New high density poly is so much improved that it takes a long time for the poly debris to accumulate so they are now expected to last 30 years plus now.


But metal on metal is different, especially because the metals in the hip resurfacing devices, such as the BHR, are made of cobalt, chromium and nickel. These are substances the body already has trace amounts of. The wear rates on these resurfacing devices is extremely low. Too low for you to actually wear out the metal. But the major advantage of having no poly is that not only are the particles shed extremely small, the body is able to capture and dispose of them as waste. They do not accumulate around the device over time and cause the "wearing out" or loosening.


But, a poorly implanted device can cause too much wear for the body to keep up with, or wear particles that are too large for the body to dispose of and that is when you get problems with metal on metal.


The point is that running is doing no harm to the BHR and recent studies are showing that impact exercise is helping patients retain their hip implants better due to better bone density and muscle strength.


The latest version of the BHR is now 20 years old and going strong. So Mr. McMinn's is correct that at the very least, the BHR is an excellent option to keep you pain free and active until you are old enough to get a total hip replacement in the event the BHR needed revising.


Chuckm

[karlos.bell]

  Thanks Chuck.
One has to remember nutrition a factor as well. If we loose bone density it will fail as well but I would be surprised if I die of a loose implant in years to come it will be something else that will get me.
Cheers K