Dr.Gross approves Biomet Cementless for marathoners.

[Dayton96]

Lee Webb told me today that Dr. Gross has decided that, after three years of implanting the Biomet cementless devices, he has decided to lift all restrictions on their use.  His patients will now be told that they can even run marathons with their Biomet implant.

[John C]

When Dr. Gross did my cementless hip 2 years ago, he said that there were no restrictions after one year. We did not specifically talk about marathons though. He did say that higher levels of activity could have potential unknown risks, since resurfacing had not been around long enough to have any long term studies on high activity levels. He also said that his personal opinion was that even with a high activity level, he did not see any reason that my resurfacing would not last a lifetime.

[Dayton96]

Hi John:

I know from your posts that you did a lot of research on the Biomet before pulling the trigger on your implant.  What did you think of the European studies that seemed to show such poor results for the Biomet?  More recently, there were the 2009 Australian Registry Results (thanks Vicky) that showed a revision rate of 7.60% for the Recap after 3 years. 

Dr. Gross reports a revision rate of 1% for 1000 cementless patients.  So I'm wondering if the Biomet devices (acetabular cup and fumur cap), used in the overseas studies, are in some ways different from the Biomet devices used by Dr. Gross.  I've heard it said that he "designed" the devices that he uses. So is his design different than the design used in the overseas studies? 

I appreciate Dr. Gross' statement that he believes the Biomet cementless can withstand the pounding of running a marathon.  I'm willing, for the sake of the discussion, to concede that "cementless" might be as reliable as "cemented" over the long term.  But what about the Biomet device itself.  Will it last 10 years, 20 years, 30 years? 

It's morning here in Ohio and I'm on my first cup of coffee and thinking out loud.

Mac   

[John C]

Hi Mac,
In answer to your last question, Dr. Gross feels that if the implant is positioned properly so that there is no edge wear, it would be virtually impossible to wear it out in a lifetime. Other things might happen, like infection or loosening, but wearing out the implant was not a concern.
I thought that I had read every study out there, but I am not sure about the European study that you mentioned. Send me a link if you have one.
As far as the Australian Registry; that is something that I did consider, and here are a few thoughts.
I think that most people agree that resurfacing surgery has a very steep learning curve, and that failure rates during the early phases of this learning curve can be unusually high.
Here is a quote from a study entitled 'The Learning Curve for Adopting Hip Resurfacing Among Hip Specialists': "The Australian hip registry indicates there is an increased risk of early revision after total hip resurfacing during the first 6 to 12 months postoperatively....These high early revision rates during the first 12 months are believed related to the more challenging surgical technique and the accuracy of component positioning". "Most major complications (54%) in this study occurred during the first 25 cases.."
Dr Shimmin, a leading resurfacing surgeon from Australia, found in one his studies that "the risk of revision was 66% greater in hospitals performing the least amount of cases."
In the Australian Registry for 2009, there were only 137 total cases with Biomet implants for all reported years. Of these, there were only 9 in 2006, 42 in 2007, and 45 in 2008. It is clear from these numbers that whoever is doing these is very early in their learning curve. It does not specify how many surgeons were using the Biomet, but we know from the statistics that it was more than one. Let us make the conservative assumption that there were only four surgeons using Biomet. That means that on average they are in only their first thirty-five cases, and are now averaging about 10 per year. If you look at the graph on page 94 of the registry, you will see that some of these surgeons were getting 8% failure rates in the first six months, and 15% at 18 months. Unfortunately the registry does not break down the reason for failures by implant type, but failures that happen that early on are often from femoral neck fracture, which is definitely surgeon error.
My choice in how to interpret the registry data was certainly based on my own unscientific viewpoint, but it seemed to me that, when taking into account Dr. Gross's success rate with Biomet, the findings in Australia could most likely be attributed to surgeons who were very early in their learning curve, rather than to the implant itself. These findings from the Australian Registry do not give us any insights into how long an implant might last since none had been in place for more than a few years, but it did give us a lot of insight into early complications by less experienced surgeons.
Since I am not a medical professional, please take all of the above with a grain of salt (or a whole salt shaker for that matter), but hopefully it does answer your questions about my own process.

John

[Dayton96]

Hi John:

Instead of emailing you, I thought I would continue our discussion online in case anyone else wants to contribute.  I took Aug 19 off from work and did nothing but research online.  I came across references to Biomet products connected with European studies.  I wanted to find out what kind of reputation/history the company's products have as a whole. 

For instance, there was a Finnish study looking at Biomet Cementless hip replacements implanted between 1985 and 1997 that reported poor survival rates related to the cementless cups: http://www.informaworld.com/smpp/content~db=all~content=a785805957

Also, if you google Biomet+FDA, you come up with some interesting stories (some of which include other implant manufacturers).

I still haven't been able to answer my own question though, which is,
when all the research is done, can it be said that Biomet products are of the same quality, reliability, and durability, as products made by other manufacturers, such as Smith & Nephew, Wright Medical, and Corin?

Mac