Any New Data on Longevity of BHR/Resurfacing ?

[Canadian-Ice]

Hi All,

I noticed that surgeon data, including McMinn's data published on the McMinn Centre website, tends to project about 97% survival rate at 15 years.

This remarkable statistic, though, pertains to a span of years during which a certain number of devices were implanted, and accounts only for revisions ocurring at the date of publishing.

In otherwords, the 97% figure assumes that all remaining devicies will survive to the 15 year mark.

So, my question is: do we have data that tells exactly how long a certain cohort of devices has in fact lasted over say, a 10 or 15 year period, without any assumptons?

Hope this is clear. Just a little confused.

Thanks,

CI

[Dannywayoflife]

I think that the 2 men from Birmingham have the best longest data out there maybe email Mr McMinn?

[Tim Bratten]

Hi Canadian Ice

I guess I'm not sure what you mean. What an empirical study should do is look at the available data and count. For example, if we look at 400 hips that where resurfaced 15 years ago and 388 of them still have the same device in place then that means we see a 97% survival rate at 15 years. A good empirical study does nothing more than this. I don't know what is being "extrapolated" on the McMinn website, but if they are doing something more than reporting what they see then of course that should be taken into consideration. 
Cheers
Tim Bratten

[John C]

I could be wrong, but my understanding of the "97% at 15 years" statement does cover exactly what you are looking for. It looks at cases that are at least 15 years old, and shows that 97% of the prostheses are still in place. The study does not cover devices implanted during the past 15 years, but it covers devices that were implanted at least 15 years ago. The study itself makes no assumptions, but it would lead to assumptions about devices that have been put in place more recently than 15 years ago, leading us to believe that they will have at least the same survival rate.

[hernanu]

When you look at the surgeon information, you obviously look at that particular surgeon's practice and experience with the devices they selected, used on the patients that they selected, with both the surgeon's skill and recovery practices.

They are heavily influenced by the choices made, and would be much better for more skilled surgeons in all instances.

The best source of information for the opposite, a compendium of all surgeons of all skills with all possible patients, all sources of the disease (OA, dysplasia, etc...) and all devices comes from the national registries.

These are necessarily more diffuse in their analysis, since you are dealing with hard statistics without taking surgeon skill, etc. into account. They also blend in the results from devices that have been found wanting for different reasons - devices that may be fine in the hands of more skilled surgeons, but have a penchant for being put in improperly by less experienced, so they were recalled.

With those caveats, the Australian registries are probably the best aggregate of data that we have to date. Unfortunately the US does not keep a registry.

so,

I've attached

• the total cumulative revisions for HRs over an (about) ten year's span.
• total HR revisions by reason. This the percentage of all failures. So if the total failures is 6% over the 10 year span, the percentage of that 6%
• What I think you asked for, the cumulative percentage failure over time per device.

This is the cumulative amount at a particular year. If you want to know the total number that failed, just read the year's value. You don't add it across the years.

Hope that helps.  If you're interested in this, check out the national registries information that Pat has set up on the site. This is from the 2012 registry information.

[Tin Soldier]

Hern - you make some excellent points.  However, for a simple perspective in support of someone looking at HR as an option, I think Tim and John's summaries are answering Ice's orginal question.  I guess, if we assume that the patient will go to a very experienced surgeon, then they would most likely fall in a similar range of stats/success that we see in the McMinn dataset, which we know shows better success than the national registries due to dilution from less experienced surgeons and a host of other factors.   I tend to rely on the McMinn study/dataset as a top end of what a surgeon and HR can do.  I think we also assume that most experienced surgeons will have a similar success rate.

Not quite sure where I was headed with that, but this is often what comes to my mind when we discuss successs of HR, or BHR in the case of McMinn and many other surgeons.   

[hernanu]

Oh, I agree completely. It also points out the measurable increase in success when you compare a top surgeon's results to those leavened by the less skilled, etc.

[Canadian-Ice]

Hey Guys,

I guess what I'm getting at is:

Individual variable factors aside, what is the chance of MY (or any one's) resurfacing lasting 15 years?

The data suggests a less than 97% chance, because it is quite possible that some of the resurfacings doing between 1997 and 2010 in the McMinn study, will fail before they reach the 15 year mark. For instance, some of those done in 2010, will require revision by 2025. Some of those done in 2009, by 2024, and so on.

The only years for which the actual 15 year survival data is known, are 1997-98. But that's not on the chart.

Am I reading this correctly?

Just went to post it, but the graph is gone. Oops.

Still think results are good. Just trying to get a sense of how long any given device, individual factors aside, is likely to last. 

[TheMcMinnCentre]

Hello

This is our first time posting on the forum, but we hope to contribute often and share our vast resources at The McMinn Centre.

The McMinn Centre have a lot of data on the BHR and we recently added a new lecture to our website and it's also available on this website, it's called 'BHR & Other Options.

In this lecture Mr McMinn talks about his results with the BHR at 15 years. The results are based on a cohort of the first 1000 BHRs (886 patients (598 Men, 288 Women)). These patients have had their BHRs 12-15 years and were operated on between July 1997 and August 2000. All of the procedures were done by Mr McMinn.

This cohort of patients are producing a survivorship of 95.8% at 15 years (both genders, all ages, all diagnoses). When broken down male survivorship is 98% and female survivorship is 91.5% at 15 years. These results are then broken down by gender and age and into diagnoses and head sizes also.

Hopefully this first post will help Canadian-Ice and the rest of you understand our latest data on the BHR.

Any questions don't be shy to ask!

Patricia Walter added url to page discussed above:
http://www.surfacehippy.info/mcminn-lecture-bhr-2013.php

[Dannywayoflife]

What a fantastic reply! Great to see the McMinn centre on here!
Welcome and thank you for your work to help us hippies regain our lives!

Danny

[Canadian-Ice]

Excellent news! Guess this post really paid off. Thanks to all and thanks to the McMinn Centre for posting!

Those results are highly encouraging. 91.5% and 98% survivorship of 1000 BHRs over 15 years clearly suggests the vast majority of recipients will not need revisions in their lifetimes! That's just an amazing result.

Since more questions are welcomed, may I ask for the results breakdown for various demographics? ie. average sized (175lbs) males who have a resurfacing in their mid 40s?

Also woundering what data might be available on any controllable factors that might influence longevity, such as continuing to do hip strengthening exercises and engaging in impact sports?

I've noticed many people on this site are very active. A lot of competitive athletes who sprint, marathon, bike, swim, and do martial arts very seriously, from the recreational to the elite. I run, myself, sprinting and long distance.

Any info. recognizing any impact differences between recreational and elite athletes, such as runners?

And lastly, woundering about those 5% who do require revision for whatever reason at 15 years. Do we have survivorship data for post-BRH Revision THRs? Considering if one is relatively young, say 60 years old, and a revision THR is necessary, can they expect that to last 10-15 years?

Thanks so much for any and all information! And again, to second Danny, thanks for ALL that you do. Even for those of us without a resurfacing yet, it gives us such hope and peace to know this solution is available.

CI

[bluedevilsadvocate]

Here are some comments elsewhere on this site by various surgeons on running after resurfacing.  Dr. Amstutz's comments include reference to a study in which he involved.

http://www.surfacehippy.info/running-after-hip-resurfacing.php

[bluedevilsadvocate]

The "BHR & Other Options" lecture by Mr. McMinn on the McMinn Centre website runs just over 1 hour, but it provides a LOT of information and is VERY interesting.  When you have a chance, take the time to view it.

[TheMcMinnCentre]

Hi

Unfortunately I can't get the breakdown demographics of the results you quite wanted Canadian-Ice. However, I can tell you from our 12-15 Year results of the first 1000 BHRs... Over 20% are aged between 40-50 years and that males under 60 have 98% survivorship at 15 years (over 60s have 99%!) There has only been 13 male revisions in this cohort.

Activity wise I would like to direct you to our facebook page, where there is an excellent infographic explaining what percentages of patients do what types of sports. It should help show that a lot of our patients are very active and continue to do well 12-15 years down the line. The infographic is at...

https://www.facebook.com/photo.php?fbid=551608094896123&set=pb.114693228587614.-2207520000.1375348616.&type=3&theater

You don't have to be on facebook to see the image, but if you are then why not 'Like' the page anyway and keep updated!

Hope this helps answer some of your questions, I will try and find some answers to the others.

Thanks
The McMinn Centre

[Dannywayoflife]

The amstutz paper only discusses the use of the conserve plus device and high impact. The bhr is pretty different and is line to line unlike the C+. Mr McMinn has published a paper on the subject of high impact post bhr although I can't find it at present.

Danny

[evant]

It's hugely reassuring to have The McMinn Centre onboard and posting - many thanks for taking the time to do so.

[chuckm]

Hi TheMcMinnCentre, do you know how those 10-15 year statistics would compare to a similar cohort who still have their native hips? I always wondered which is more likely, a BHR patient needing a revision, or a native hip owner needing their first hip arthroplasty. If 95.6% of BHR patients are surviving without revisions to THR can the native hip population be that durable as well? I guess you could call it a native hip revision rate?

Chuckm

[Tim Bratten]

Hi TheMcMinnCentre, do you know how those 10-15 year statistics would compare to a similar cohort who still have their native hips? I always wondered which is more likely, a BHR patient needing a revision, or a native hip owner needing their first hip arthroplasty. If 95.6% of BHR patients are surviving without revisions to THR can the native hip population be that durable as well? I guess you could call it a native hip revision rate?

Chuckm

I can give a sort of reasonable answer to this question by using some easy to find data on the internet, but to get a number I will need to make various assumptions. First off I focus on the US population (obviously there is a much higher rate of hip replacement in the US than in India or China, for example). More importantly, I will not consider the entire US population. For example, if we consider people younger than 18 y.o. (years old), almost no one in this group will need a hip replacement over a 15 year period, yet we are talking about 24% of the total population. Including this group, would make the chance of needing a hip repalcement very small. As a sort of arbitary cut-off (and because the data is available) I will take the value to be 45 years of age (or more). Since I imagine that almost everyone in the BHR study group was > 44 y.o.  for their first surgery I suppose this is not unreasonable.

According to the Center for Disease Control there were 332,000 hip replacments in the US in 2010. Extrapolating over a 15 year period this gives 15x332,000= 4,980,000 hip replacements (roughly 5,000,000).  On the other hand, according to the US Census Bureau, in 2010 there were 121,758,429 people (roughly 120,000,000) in the US whose age was > 44 y.o. This gives (approximately) 240,000,000 hips. Now we make more simplifying assumptions: no-one in the > 44 y.o. group has a hip replacement at the start of the 15 years (observe I've already taken away more than 3 million hips by rounding down) and the 5,000,000 procedures over the next 15 years all get handed out to these 240,000,000 hips.  Obviously these assumptions are false, but the error involved will be be very small compared to these large numbers.   

That means 5/240 =1/28 which is almost 4% of these hips will need to be replaced over 15 years. In other words: if you have your natural hips, live in the US and are more than 44 y.o. than you have roughly a 4% chance of having a hip repalcement in the next 15 years. 

[Canadian-Ice]

Chuck, Tim, that's just awesome.

[TheMcMinnCentre]

That's great Tim, otherwise I don't think I would have had an answer for Chuck! In our first 100 BHRs series I think it's something like 87% were between 40-70 at time of surgery (A slide in the lecture shows the correct amounts) so your >44 y.o. assumption was a fairly good one.

From your calculations it appears the survivorship of natural hip is similar to the BHR in that wide age range. I assume once you narrow it down to 40-50, 50-60, 60-70 etc the odds would probably favour the BHR. Remember in men 60+ y.o. at time of operation the survivorship in Derek McMinn's first 1000 BHRs series is 99%!!