So I had a thought and want to run it by you experts...
So lets say I want to do ironman's after my surgery. Is there a way that the Dr. could periodically xray my implant and measure the wear or lack of wear during training to see if infact running is detremental to the BHR? Is there a way to measure this?
As far as I'm aware there's no way of measuring that mate. The wear low I doubt that even with RSA beads attached there would be enough wear to show up.
Now to put that into perspective, Mcminn spoke about a THR that was revised after I think 26 years invitro( revision was due to cup loosening not wear) and the measurable wear after 26 years was 20 microns! Now that's just incredible.
As we have discussed before I don't believe it to be humanly possible to wear out these devices. I think the longevity factor will be down to how long they will stay fused to the bone.
Hope this helps
What they CAN measure if you choose to start stressing the device is the position of the implants and the condition of the bone. Also, as a precaution, Dr. Gross makes it standard to get a metal ion test at the two year point.
Curt
I believe that the accepted best way to measure wear is by measuring the metal ion level in the blood. In THRs with poly liners, the wear of the poly can be great enough that it can be measured by x-rays, but as Danny said, the wear in metal is so small in microns that it would be difficult to measure unless the parts are removed.
I think that your idea of wanting to monitor the amount of wear generated by your intense training is a good one, and metal ion tests may be the best way to do it. If the parts are put in correctly so that there is good lubrication and no edge loading, hopefully the wear will stay low.
Many equine athletes will have joint fluid aspirates examined for viscosity and signs of inflammation after heavy competition or during training. Do human athletes go through this as well? You could see if metal ion concentration in the synovial fluid increases with training/competition. safe to do on a horse, not sure about a metal hip, though.
In the horse, its pretty easy to pick up joint stress as you can usually see or palpate increased synovial effusion (puffy joint). I'm not sure if you can identify that in a human hip but it might show up in pre and post ultrasound exams.
BTW, horse hips are almost bulletproof ;D
Don't think that would work in humans
"So lets say I want to do ironman's after my surgery. Is there a way that the Dr. could periodically xray my implant and measure the wear or lack of wear during training to see if infact running is detremental to the BHR? Is there a way to measure this?"
Man, I so understand this. I was set for IM AZ in 2009 before this hip deteriorated. There probably has to be a balance in here somewhere, but consider also what you would lose by not doing an IM. You can make your new hip last forever by never getting out of bed, but to what end? I would plan on it and let the chips fall where they may. If you end up with a revision to a THR several years down the road, you at least got some mileage out of your BHR, more than you can get out of your existing hip.
Strictly my opinion, of course. While I plan to live forever I'm at the age - 58 - where the occasional friend or acquaintance is dying. While I am past the need to do an IM, I NEED to jump off the cliff at Palisades in Squaw Valley, at least once.
The Ironman will not wear it out. The training for the Ironman will. Just adjust your training. Split running 1/3 pool, 1/3 elliptical 1/3 road, race on flat courses, master the two beat swim kick, get a good bike fit to accommodate your hip, get some well cushioned shoes (i run with Aisic Nimbus). You may not get a 11 hour time but believe me you will be a top ten HR person to cross the line, you'll just be behind me (lol)
One of the fantastic things about a MOM bearing couple is the fact that the vitalium ally is self polishing. And as we all know a smooth surface is a surface with little friction. This trait is one of the huge plusses to MOM I think. Even ceramic can't self polish.
To be honest if/when I get back to feeling totally normal then I'm going to use the S##T out of mine! You have to be in it to win it!
Yeah I am kinda thinking I just go full in for one more IM. I don't know I read stories about Mr. Faulk and all the stuff he does and wonder why no me? But i don't want a revision in a few years. I don't really have a kick in the swim, just purchased a new bike so hoping that i can get aggressive with it, and well running maybe i will do a lot of water running.
I suppose that I'm pretty lucky in that my planed activities are I'm my mind fairly hip friendly. Ie boxing judo and submission grappling. Yes they are extreme but they don't load the hip with the constant pounding as say running.
Ive just rechecked the measurement of a micron and I thought that it was a hundredth of a MM. it's actually a thousandth!! So 20 thousandths of a MM in 26 years! Come on wear is not an issue with the modern MOM alloy. The way that the media bangs on about metal ions people think that people's blood is metallic! Nothing could be further than the truth!
Just another note on the wear issue. I'm keeping an eye on guys like Corey fulkes,floyd landis and John Lee Augustyn. John Lee is still a pro cyclist and I read some where my surgeon who installed floyd landis 's bhr say that on average a "normal" person/BHR patient does around 3million cycles a year. While your average pro cyclist does around 30 million. So if wear really is an issue then these guys devices should be failing anytime now as for each year in them is like 10 years in a "Normal" person. And I very much doubt we will see them failing anytime soon(just a hunch).
To provide some idea as to how small 20 microns is, here is a quote from wisegeek.com:
"The limits of visual acuity for the human eye is often cited as objects 50 micrometers in diameter, about the size of a dust speck. The average width of a human hair is 80 micrometers."
So, 20 microns would be about 1/4 the width of a human hair, and invisible to the human eye.
That's a good way to put it in perspective.
Danny,
One thing to keep in mind. Just because guys like Augustyn, Faulks do extreme stuff doesn't necessarily mean they will wear out their devices quicker. I'd bet money theirs will last longer then someone who is sedentary. When one exercises there is a drastic increase in synovial joint fluid. Therefore putting more fluid between the new Ball of the femoral head and the acetabular cup. Therefore, there's actually no metal articulating surfaces because there is a thin molecular fluid between the metal surfaces. I've spoken to Corey several times about this, as I continue to race at a Pro 1-2 level in cycling, the highest domestic level. I was very interested in this. Corey has told me that they monitor his metallic ions quite closely and they're finding out that the amount of metallic ions in his blood are much less then the average person; especially a sedentary person who doesn't exercise much, if at all. It makes a lot of sense to me. If the cup angles are correct, there should be minimal wear issues. As I get back ready to race again after this surgery I'll be putting 300-400 miles a week on my new hip on the bike and it will be interesting to see how many years I get out of it.
That's exactly the point I'm trying to get across. But good to know Corey's ion levels are so low.
Quote from: Dannywayoflife on February 17, 2012, 01:31:52 PM
I suppose that I'm pretty lucky in that my planed activities are I'm my mind fairly hip friendly. Ie boxing judo and submission grappling. Yes they are extreme but they don't load the hip with the constant pounding as say running.
I don't want to be a party popper but I wouldn't count Judo as being hip friendly.
I think there's worse things mate. I you get thrown onto big crash mats and although there can be big impacts involved there not constant like say running. I think i should be able to train around it without too much of a problem.
I miss Judo best sport I've ever done. Had neck fusion so can't do that anymore. I would think Judo would be extremely stressful on the joint, but not in the same way running is. I would think some throws...ouchi gari and other leg attacs could be straining but not impacting on the joint. Once the restrictions are lifted, I think Judo would be fine, given you regain full range of motion and strength.
I agree with you mate. It will put stress on the area but unless thrown arkwardly I think that other activities put far more impact on the joint. My ROM is not far off fully recovered already and in the hydro pool today was far better on my bhr side than on my natural side with nothing wrong with it! My strength is really comming on so come the 12 month point will be back to normal. My surgeon told me he didn't see a problem with me doing judo. So touch wood I'll be able to train in it again.
Yeah once you are full range you'll be good. Uchi mata might be a little difficult at first but after a while good as new.
http://www.youtube.com/watch?v=R43op-tg-_E
enjoy best throw in judo.
Never been an uchi mata man anyway. My silly I phone won't let me load the video I'll have to watch it in the morning when I get home.
Once again, I vaguely recall (my hips are better, but my memory is failing ???), a study that looked at metal ions in blood after heavy activity. That might work in the early period of working the components in, but I'm not sure if that would work after the component has been worked in.
I can't remember where I read that, but it would be kind fun? maybe to be in a study where you would measure your blood before an event and then measure after to see if there is much of a difference. Although, I think with the low concentrations, you'd have to be very careful with your environmental factors contributing to elevated levels in the blood. Nice thing about Co is that it is not very common in soil, foods, chemicals,...
The next thing you could possibly do is a mass balance of the the blood metals concentration and try to sum up the amount of metal that has come off the device. Although, you might have those metals locked up in fat cells, muscle, syn fluid, bone,...? On second thought, that might be hard to compare at such low levels.
Realisticly I can't see blood metal levels being used to measure any wear rates as there's way too many variables that could effect the numbers. But from what we've seen from recovered THR's that lasted out to 40+ years wear is hardly an issue and don't forget that the bhr was designed using the same proven metallurgy as these THR's for this very reason. The alloy has been proven to be a long term viable material.