Cobalt toxicity; Realted to Clunking hip

[Dannywayoflife]

I can't understand docs saying we never knew the angle was important. I'm fairly sure the bhr and all other hr devices were designed in a similar fashion and were designed to be implanted in certain orientations. Surely when docs train they learn this?!

[Luanna]

Hi Danny,
I posted this on another thread but think it might help answer your question about surgeons knowing about importance of cup placement.

Here is a self report by sixstring about how his physician, Dr. Gross and others did not have access to the machines they use now to ensure cup angles. They do now and are able to measure angle before closing up.

Sixstring:

"I got a right hip resurfacing using the Biomet Magnum Recap by Dr. Gross in SC in June 2006.  The hip functions well other than frequent clunking/shifting when the hip is extended (standing/walking); the clunking causes no pain. I am a very active 59 year old male, 5'-8", 163 lbs....

In February 2011, I had blood levels of chromium and cobalt measured on my own - Dr. Gross did not suggest it.  Cr was 38 mcg/l ("normal" <1.4mcg/l) and Co was 81 mcg/l ("normal" <0.5 mcg/l), both extremely high.  I reported this to Dr. Gross who asked me to have them rechecked with a lab he uses - results there were virtually identical.  (Note: mcg/l means micrograms/liter; one lab measured serum metal levels and one measured plasma levels with very little difference between the two.) 

I talked to Dr. Gross after the elevated blood metal levels were confirmed.  He said my cup inclination angle is ~ 60 degrees (optimum is closer to 40 degrees) which is associated with excessive wear, probably due to edge loading of the cup.  He said steep inclination angles weren't known to be a problem in 2006 when I had the resurfacing, and that he didn't have a way then to set the angle during the operation.  He now uses an intra-operative x-ray to measure the angle at which the cup is placed and now never has cup angles > 50 degrees.  I recommend reading Dr. Gross's article on Acetabular Component Inclination Angle on his website ( newbielink:http://www.grossortho.com/ [nonactive]). Given that my hip is functioning well, he didn't feel my blood metal levels were a serious health issue, and said the options were to continue to track metal levels, get an MRI to check surrounding tissues for signs of metallosis, or to revise the cup."

Luanna

[curt]

      As I understand it, and giving even the most experienced docs the benefit of the doubt, lots of these data points are still a work in progress.  Edge loading, cup angle, metal, plastic, dysplasia, necrosis, blood supply, cemented vs uncemented...all of these are variables that I think are still being analyzed and debated.  There is simply not enough 10-30 year data to make firm conclusions, and like the weather, each variable probably effects another.
     I think that cup angle is NOW believed to be a major culprit in metal wear and if not, the cases requiring revisions with angles less than 50 degrees are almost non-existent without the femur failing.  I think those that follow us will get even better results due to increased knowledge and of course, the doctors are simply getting better after doing so many.  Just my thoughts (pre-dunce, not pre-med!).

Curt 

[ScubaDuck]

I am guessing that when the surgeons first started working with the devices they tried to match the original angle.  Some people simply have very steep angles naturally.  In fact, I think my surgeon commented on that in my consultation with him.  Still my cup was set at around 39 degrees.

As curt noted, they are learning as they go.  I benefited from those who went before me and appreciate that constantly.  Those that come after me will benefit from my data point.

Dan

[Kiwi]

Not great reading when your 2.5 weeks post op & clunking.
So are we still saying, as long clunking is not painful there's nothing to worry about?
The clunking Pete C explains he had in an earlier thread is exactly the same as mine; "Usually not painful, although there have been a couple of times when it did hurt, but mostly just uncomfortable.
My hip now does this all the time. Lying in bed when i wake up, if i stretch out my legs, in an outward extension motion, my left hip joint will "pop". Same during exercises, walking, etc."
I read quite extensively this is common early on, but some people get it much further down the road too.
Don't worry - unless it hurts etc. Well Pete C's didn't appear to hurt much either in the beginning. I think I'll confirm my cup angle with my surgeon & let him know about my clunking.
Not in panic mode, but an unsettling read this one.

[hernanu]

I think, Simon that early clunking is caused by weakened muscles that when they restrengthen hold the device well in hand and lower or eventually completely eliminate the clunking. The clunking from edge loading is a different animal, caused by a positional problem that doesn't go away. Even people with high angles, though may not run into issu

[Kiwi]

Thanks Hernan.
My surgeon has responded to me also. He said "Clicking is normal and relates to the capsule release. Avoid exercises that make it click to allow the capsule to heal properly."   (He also said I read too much). This pretty much what your saying?
Anyway, my mind is at rest. I'll move forward positively 
Thanks

[Pete C]

Pete here,
Well, i am now over 14 months post-op to convert a BHR to a THR. The THR components are Johnson & Johnson cobalt femoral and a J&J cross-linked poly acetabular cup. Due to the amount of pelvic bone that had to be removed to get the actabular implant out, the new THR cup ended up being very large for a THR. A size 44 or 46 i recall.
I just had my 1 year follow-up a couple weeks ago.

The 2nd operation was very smooth, although a bit long (4 hours) due to some precautions the surgeon (Robert Yancey, Gig Harbor/St. Anthony Hospital) had to take. That refers to another whole long story of an unfortunate side-effect of my BHR op, which i won't go into here. Doctor Yancey and his staff did an excellent job.
The hospital stay and discharge were uneventful, and much easier than the first op.
Recovery at home was easier as well, and i was up and driving my (clutch) auto inside of three weeks.
Going into the same incision point of the BHR caused some problems of it's own. The muscles and other stuff in there don't tolerate this length of incision very well the second time around, and between that and the tissue loss to get rid of the effects of the metalosis, there is a permanent degradation of the function of that leg. It mostly manifests itself in a pain  in the groin, and at the side where the incision is, after i work the leg in excersise. I can assume that i will have some discomfort with this for the rest of my life.

Because this one is a THR, my doctor strongly recommends no running. Continuing that part of excersising was the main reason for going with the BHR in the first place, so not being able to run has been a tough adjustment. I walk a lot, 4 -5 miles 2-4 times a week, but it is not the same as running. I am hoping to get back to mt. climbing again next Spring and Summer.
My doctor does not recommend a follow-up blood test for cobalt and chrome. He is convinced that these metals will have flushed out of my system by now.

All in all, i believe my choice of a BHR should have been rewarded with 15- 25 years of service out of that hip, and it seems like a huge waste of time and money to have had to go through a second surgery to rip it all out and do the THR. Unfortunately, i was in that 7-10 % of BHR recipients who became the test cases for the importance of placing the implants at the correct angle. Live and learn, i guess.

[Luanna]

Hi Pete,
Glad you are doing well but very sorry to hear that you had such a horrible experience. My friend is going through a similar experience right now. Her surgeon is in Colorado and she lives in Seattle now. She has a THR metal on metal and is facing a revision.

It's very traumatic and discouraging for her. She was adamant that I not do MoM. I was oblivious and just went with what my doc recommended. So far so good.

Best wishes to you.
Luanna

[cwg]

Pete C- Yeah, totally sucks being a statistic (7-10%).. All hindsight.
Did you feel you had other options?
Were there other types of surgery, or no surgery? At the time, what were the options?

Choose it or not, you are a thread to be read  here-
For informed questions and decisions people must have, and make

Be well. Don't mean to be cheeky, but it could be worse. You fixed things in good time.
Stay strong

[Pete C]

The original choice was down to THR or resurfacing. Doing nothing was not in the cards.....bone on bone. I actually stumbled across resurfacing, at a presentation by ortho surgeons, of the benefits of THR. From there i found this web site, and my first surgeon.  Resurfacing allowed me to continue running and other impact activities. So i went for it. That part's all on me.

If i were in medical research, and engaged in the development of artificial joints, i would be considering the wear factors and the ultimate failure mode of the original, natural human joint. Why are we needing to replace this part? Among many other considerations, an artificial replacement would want to be designed and installed to improve on those failure characteristics. I believe that the angle of the natural hip joint probably has a significant role in the life of that bearing surface. And a steep angle, such as that which is clearly visible in many x-rays i have seen, would indicate uneven loading of the spherical surface. Which would probably lead to premature failure.
With all this in mind, the correct design and placement of the components, to avoid uneven surface loading of this bearing, would seem to be of utmost importance.  We, the public, will probably never know, but someone should know why we got 5 years into the U.S. BHR surgical implant business before somebody figured out that "edge-loading" was a bad thing.

Hence, my test case comment.

But then, I'm venting.

[Two4One]

Pete C, I'm so sorry you had so little time from your hip resurfacing components and now have to endure a revision to THR.  Please keep posting, especially about your ultimate recovery that will be yours in the long run, and please know that everyone here is pulling for you.

Two4One

[hernanu]

Pete, sorry you had to endure the revision; you have every right to vent.

I hope your hip and tissues recover fully, the body is a very resilient organism, nothing to do but to help it. Please keep in touch, you should have had a long, good experience from the HR.

[Pat Walter]

I wanted to comment on why it took surgeons so long to learn how important acetabular cup angle was.  If anyone has worked in the engineering or design field, they will realize that usually the original design of a product or machine is never what the final design turns out to be.  We are not machines that can determine perfect designs for anything.  There are always unknowns.  If you think about many things in our lives, they are always under constant change and updates.  Car models are often changing, TVs are changing, cell phones, computers, etc are constantly in change.  Software for computers are always updating and changing.  Athletes are always changing to improve their skills.  Musicians are always practicing to improving their skills.  Medicine and joint replacement is not any different.  Engineers are trying to design a device to replace a human joint while doctors are trying to place that foreign object in our bodies to act as the original equipment.  This is not an easy task.  There have been thousands of designs of hip devices over the years. The metals or plastics continue to change, the metelurgy changes, the sizes of the components change.  There is nothing static about designs, they are constantly changing.

I have learned from the many hip resurfacing conferences, that it takes time for doctors to learn how the devices are actually working in patients.  Typically it takes about 4 years for them to start to see trends about how the device has acted and how the bone growth has occur ed.  It takes time for the results to become statistics.  So with any device, the wait period takes time and often by then, there has been a change in the device.  So there are few devices of the same design left after a few years to compare results. 

It simply is very difficult.  Many of the top experienced surgeons were placing the actabular cups at a good angle.  They knew instinctively that it should be in a certain position to work well.  I have always said and heard surgeons say the same thing - that surgical skill is more than a skill or learned process, it is also an art.  It is like the great athletes that instinctively know what to do.  They do learn and practice, but have a God given skill that places them way above many other athletes.  The same is true with the really top surgeons.  If you think about sports or activities you are personally really good at, you are not looking at the educational videos or books to learn how to throw a ball, play an instrument or type on a computer.  Those with really good skills are able to do it almost without thinking.  That's is the way it is with the top surgeons.  They had an instinct about how things should work and were very successful.  McMinn is doing that all the time as he develops devices.  Many of the other top surgeons have helped develop hip devices and many of the surgical instruments to help place hip devices.  A recent example of one is with Dr. Kusuma in Columbus.  He wanted a better way to insure his placement of BHRs was correct.  He developed a template system which no other surgeon had done before.  Smith & Nephew are suppose to have him teach it to new surgeons.

So there is a great deal of constant change with any hip device or any man made mechanical device. Designs keep changing and hopefully for the better. Skills keep changing and hopefully for the better.  It is very complex and just takes time to develop excellent devices.

Pat

[Dan L]

To add to Pat's very informative points above, the sheer number of variables involved, and the combinations/permutations of variables involved in this very complex set of equations-- that are hip problems and hip solutions-- represent essentially an infinite number of possible outcomes.  Consider the widely variable human element, as well as the physics, biomechanics, geometry, physiology, metalurgy, psychology, surgical approaches, devices, disease process, etc, etc, etc and the possible things that can go right or wrong is really, really large.  So many differences in all these elements are possible and in play in each one of these surgeries, and each one of the recoveries, and everyone is essentially unique to some degree.

I can't speak for any other surgeons, but as far as my surgeon, he exhibits a genius-level command of many, many things related to these complicated surgical procedures, but even then, me, the patient, accepted a substantial risk, knowingly, by seeking to undergo the HR procedure because it is relatively new and certainly still evolving.  I accepted that risk to get out form under the last couple of very difficult and limiting years, and with the knowledge that I was enagaged with a top-notch surgeon who continues to learn and evolve constantly based on sound, quantitative research, and with trust that he would do his absolute best.  It has gone very well for me so far at 12 weeks, but I do understand it is not a given that will continue beyond today (although I'm confident it will, a matter of hope not statistical certainty at the end of the day).

That kind of trust has to something you have to be very, very comfortable with as you approach something as complicated as this surgery.  Also critically important to acknowledge the risks involved and how this may not turn out as desired, days, months or years down the road.  I follow what I'm told to do very closely to minimize those risks, but nonetheless, nothing is guaranteed.  A 90-something positive outcome, for me, was completely acceptable.

[Dan L]

Pete,

Reread this thread from the beginning again, and very sorry to hear about how difficult this has been for you.  I hope you continue to do well with your THR.  The doc scared the bezeebers out of me about having to go to a THR at some point, and your comments seem to suggest it can be OK, if it must be done.

I didn't do a very good job of saying this above, (and apologies for botching it) but to some degree, we're all test subjects in this realm, something that is not good at all to think about and consider as one goes through all the gyrations around the decisions to proceed.  To that I can really identify with the frustrations and venting you have expressed, and by all means your story is a must read for everyone here.

Best regards,

Dan