Implant Longevity

[rbt2011]

**Please comment and share your thoughts, ideas, research you have done**

I have seen a few posts recently referring to how long Hippys expect their implant to last.  A few have mentioned that they only expect 15 years out of their resurfacing.

Recently, I have been reading a few articles as well as watching some videos lately that deal specifically with the issue of implant survivability.  I have to say, I disagree with those that believe their implant will only last 15 years or so.   

1. Dr. Su recently released some results showing a 98.4% survivorship at 68 months. 
2. Dr. McMinn reported in his interview with Vicky a 95.4% survivorship at 10+ years.
3. Dr. Gross reported 11 year survivability of the Corin Hybrid HSR of 93%
4. 2011 Australian Joint Registry total cumulative revision rate of BHR at 10 years 6.3% (93.7% survivability)

Obviously, in some respects we are all guinea pigs in that we are the first generation of modern metal on metal resurfacing patients and there is very limited data past 10 years.  Certainly, the failure rate of an implant would increase as time passes so anything past 14 years is unknown.  That being said, when you look at the numbers, I think the vast majority of us can reasonably expect 20-30 years on these.  Who knows, maybe more. 

Thoughts?   Anyone have a lot of spare time and a stats background that can plug in some of the existing data and try to project out a survivability graph?   

[Pat Walter]

I expect my hip resurfacing to last my lifetime.  That said, I also understand that our hip resurfacings depend on how well our bone growth into the components remains strong.  In my opinon, which is based on almost 7 years of reading thousands of stories, reading hundreds of articles, attending many hip resurfacing courses and interviewing many of the top resurfacing surgoens; there is no reason to think a hip resurfacing won't last as long as the best THR.  If anything, keeping the original femur bone helps the bone to act more normally.

I am with you and many thousands of hip resurfacing patients - there is no reason why our hip resurfacings can't last a lifetime. I am sure there will be a normal bell curve for the retention rate of hip resurfacing - some people will require a revision early, while most will keep them a long time and others will have them their whole life. 

I do have the story of one person that has had their BHR for 17 years from McMinn. 

Let's all keep active, walk a lot and keep our bone density strong.  That will help keep our hip resurfacings last a long, long time!

Pat

[Dannywayoflife]

Hay rob,
             I asked this continually before my op. I've read as much as i can find. I think pat has a point I think a lot of the longevity will have to do with how the bone recovers.
I asked Mr Treacy this and although he couldn't give me a full answer he indicated that he felt that the bhr survivorship In his hands would be over 90% at 20 years. I figured that from say 90% at 20 years to zero won't happen over night so I'd think 25-30 years is possible.
I think that so long as the bone is allowed to fully heal initially then impact will be good in the long run so long as it's introduction is gradual as impact is essential for healthy bone density.
I sincerely hope that all our hr's last till the end of time!
Danny

[obxpelican]

I personally believe that most of us will die (hopefully after a long life) with our HR implants firmly implanted in our hips.

I think what is going to happen is that the %s will flatten out after 10-15 years and stay somewhere around 90%.

Right now we're experiencing the percentage results of many inexperienced surgeons.

I know Dr. Gross feels that we will take our implants to our graves.

Chuck

[PistolPete]

My surgeon said that with my lifestyle that my HR should last me into my 60's.  I'm 35 now and if I can make it that long with this thing it will be fantastic.  If I can live a long active and healthy life and go to the grave with this thing then even better.  That being said I train VERY HARD and once healed I can promise I will be training just as hard if not harder than I was prior to surgery.  My life is Martial Arts and that is what brings me joy besides my family etc.  Brazilian Jiu Jitsu is my passion right now and I'm thinking might be better for the hip than Muay Thai and stand up for the fact that you're not throwing kicks.  That said in BJJ you put your body thru some very contorted positions and put a lot of strain on your joints etc.  I'm praying I won't need to go thru this again but like I've said before if I can live the next 15+ years of my life training hard and improving then I'll be happy. 

I know a lot of people will disagree with me and tell me my thought process is all messed up but to me this is what my life revolves around.  I'm confident that the reason I had to have my hip replaced at 35 years old is because of all the abuse I've put my body thru.  Knowing what I just went thru if I could do it all again I wouldn't change anything.

[stevel]

The only long term study I have found is "Metal-on-metal resurfacing of the hip in patients under the age of 55 years with osteoarthritis" by McMinn et al.  Of this group of 420 BHR resurfacings (360 patients), 55 % participated in impact sports or were involved in heavy occupational work.  The survival rate is excellent at 99.75 % for 5 to 11 year follow-up.
I imagine for the 55 % that participate in impact sports or heavy occupational work, activities can vary in the degree of impact.
For instance, one patient may ski 3 times a week whereas another patient may run outdoors 100 miles a week and another patient may be a smoke jumper/fire fighter.

This issue nags at me when I decide to run on the treadmill for 30 minutes or use the stairmaster or recombinant bicycle instead.
My left hip definitely aches after the treadmill run (including pain in the right knee) whereas I have no symptoms after exercising the other devices.
I can ski 3 days in a row, all day long with no symptoms.

Basically I think back to Dr. Mont's response to question no. 6 during an interview that heavy impact sports are more likely to shorten the life of any implant.  But how much will the implant life be shortened and will it be worth it? 

[Luanna]

Hi Steve,
Do you have any idea why the treadmill causes pain when the others don't? That's interesting. I'm doing easy walking on the treadmill with no problem but I haven't tried running and probably won't as I'm only 12 weeks post op.

Implant longevity is something that I think about from time to time but then put out of my mind. Kind of one of those people who'd worry it to death if I started thinking about it.

Luanna

[ScubaDuck]

I have been trying to look at this subject objectively.  It is difficult since I want to believe my implant will last my lifetime.

Rather than focussing on the survivorship rates, I have been looking at the failures that could happen.  In this way I can apply them to my situation.

Failures include.
1.  Implant placed a poor angle resulting in edge wear and possible metallosis.
2.  Bone doesn't grow into implants to allow loosening.
3.  Trauma to the bone before it has a chance to heal.
4.  Bone necrosis as a result of the surgical trauma or reaction to foreign matter.
5.  Device wears out.

It seems to me that we have a good handle on the first four.  The question really surrounds the last one.

It is hard for me to imagine that I could do enough of anything to wear out a metal on metal surface.

So count my vote for a lifetime device.

Dan

[Dannywayoflife]

Nicely put Dan. Once again it just high lights the inportance of surgeon selection!!

[obxpelican]

IMHO, it would take a lot for a device to wear out.

For a lot of you long timers, how many of you have read that a revision was caused because the implant "wore out"??   In other words both or one of the sides of the implant combo just got too worn.

Now, loose implants, bad angles, necrosis etc yeah, I've read hundreds of them.  But again how many have you read about are the result of the wearing surfaces just worn down to the point where you need a revision.

Pat?  How about it?   Maybe I am wrong.

At least in the device Gross uses the tolerances are so close that your body fluid rides between the surfaces.  In fact you can take the femoral component and spin it in the cup and it spins like crazy and does not stop very quickly.

I don't know, maybe I am being way too optimistic.

Chuck

[Dannywayoflife]

Chuck I think your right. I think that once again surgeon selection and then a proven device are the most important factors!
Danny

[obxpelican]

Thanks Danny, but, I am holding out the possiblity that I could be way off, I could have forgotten some posts where a device did indeed wear out.

YO!  Pat, have you heard of any?


Chuck

Chuck I think your right. I think that once again surgeon selection and then a proven device are the most important factors!
Danny

[Pat Walter]

I haven't heard of any device components wearing out. I did hear about a pin breaking off a femur cap one time.  Very unusual.  The hip device is a very highly machined metal bearing.  Holding one in my hand reminds me of any heavy bearing from mechanical equipment.  I really can't see how a human could wear out such a metallic bearing - but that is only my opinion. Many types of bench testing has been done with the devices where they cycle and cycle them in different positions and they haven't worn one out yet that I know of. 

I really don't think wearing out a component is anything to worry about.  The most important thing to worry about is your bone density and ability to remain connected to the device with good bone growth.

If I run across any medical studies about components wearing out - I will post them, but up to now, don't remember seeing any.

Pat

[obxpelican]

That's always been my understanding, now of course we're not discussing anything but metal on metal devices.


Chuck

[Dannywayoflife]

So would it be fair and objective to say a good device ie a bhr,biomet or a c+ placed perfectly by an experienced surgeon and if well "accepted"(ie bone grows well in to the device) then it should last a long long time?
I was pleasantly supprised at the build quality and the lack of friction with the bhr I got to play with. I'm going to ask to look at another and try the water trick with one at my next appointment!
Danny

[stevel]

Hi Luanna,

I believe running on the treadmill generates more impact force to the hip and knee.
I don't notice the pain until I slow down to a walk speed (3 mph) after running for 30 minutes at 6 mph.
Then the ache continues for the evening.
I wear high quality running shoes (Asics Gel Kayano) but I'm about 25 pounds heavier than a lean physique so the impact load is greater.
It certainly is a lot better than when I ran at 6 months or a 1 year post-op.
I run occasionally, so maybe it will improve if I am more consistent.
I have been mostly playing racquetball the past year and tomorrow the ski area opens with lots of fresh snow, so I'll be skiing the next three days.

[Dannywayoflife]

Steve, I always thought that treadmills generated less impact because of the generous give of the deck that the belt sits on. Is this not the case?

[Dannywayoflife]

Surely they generate less impact as Derrick Mcminn likes people who are goin to return to running to start on the treadmill at about 11 months in good quality running shoes. I carnt see him advising you to start something that's higher impact than the act of running it's self?

[rbt2011]

Great comments so far and very encouraging as well.  It is nice to hear different viewpoints on how long they believe the device will last and why.  I don't think I will get 60 years out of mine but I honestly think that 30 is totally achievable.  Even with a high level of activity done in an intelligent manner (i.e. slight modification to avoid high impact like box jumps, jumping/landing from high places, running on the road vs running on a track, etc) 

Glad to hear that no studies/tests are out there showing that the device will wear out at X number of revolutions.  I searched for this and did not find anything.  The closest thing I found is a discussion that Danny posted about the wear rates (I wasn't smart enough to figure out exactly what it meant...No pictures

I like DGossack's approach to looking at the failures and focusing on those which you have some control over:

Several have mentioned the bone ingrowth as a key factor.  I understand this is the case for the acetabular component on all resurfacings and in the Biomet Recap this is an issue on the femoral side (uncemented), but does this matter on the BHR femoral side?  If the BHR is cemented does the bone really need to grow into it on the femoral side?

I will try to work out a graph today based on the values that are out there.  Not sure if I can project this out but I will try.

[Dannywayoflife]

''If the BHR is cemented does the bone really need to grow into it on the femoral side?''
This is something Vicky Marlow mentioned to me that in retreval bhr devices she has seen she thought that the bone had appeared to grow into the cement somewhat. I asked her further and she said that ther were always large pieces of bene that they wernt able to seperate from the cement so therefore she thought that it may have grown into the cement.
I intend on asking Mr Treacy about this as well as a shed load of other things i have on my ever growing list!! If i get an answer i will o course post it on here.
Danny