What do the BHR dimensions actually refer to?

[OtterDriver]

Hello Everyone!

My first "New Topic"...I'm so nervous! ~8^)  I didn't use the right search words or it hasn't been previously discussed here, but was curious what the BHR dimensions are actually referring to?  For instance...is a "52mm femoral head" 52mm across from Outside edge to Outside edge?  That seems fairly obvious!?  Then is a "58mm acetabular cup" 58 mm across from Inside edge to Inside edge!?  Does that mean there's 6mm of "slop" in such a pairing?  I pictured the tolerances to be more precise than that.

Thanks in advance!

Bruce

[Tin Soldier]

Nervous about us?  Come on we're an easy bunch, usually.

52 mm is the diameter of the femoral component.  58 is the diamter to the outside of the acetabular cup, the BHR has about a 3 mm thick wall.  The tolerance is very close, like in the 10 mciron range?  I think.  Chuck, and Lop know this stuff pretty well.

[OtterDriver]

Was being facetious about being nervous!  Thanks for the response.  Guess that's what didn't make sense to me on the other side of the equation...figured these things had a stouter wall thickness than 3mm!

[Dannywayoflife]

Hi mate! Welcome. Tin nailed the dimensions question but I "think" is off with the tolerances. Off the top of my head the asr had the tightest @ around 65 microns I think and the bhr I "think" is around 100 microns. But obviously the asr didn't work and the bhr and biomet and c+ do. If well placed.

[Tin Soldier]

Yeah that's sounds more like it.  Thanks Danny.  I think I made that exact reply once ahwile back and I think Lop corrected me on the tolerances.

Otter - keep in mind the back side of the cup is porous in order for the bone to grow into the material.  If you picture a fully supported cup, inserted into the pelvis, with bone growing into the backside of it, then the cup doesn't seem as feable as it may look by itself.  It really does suggest the idea of re"surfacing". 

[Dannywayoflife]

Lop really knows his stuff on those things I think he did a lot of research on it prior to his hr.

[OtterDriver]

Thank you Gentlemen!

Was curious because of what seems to be a bit of detectable movement now and then.  No pain involved!  Had a BHR done about three weeks ago on the right side.  I'll inquire during my one month follow up next week.

Mr. Wayoflife - By process of elimination...you go under the knife tomorrow!?  Best wishes for you...I'll have a Pimms Cup and some Weatabix in your honor!

Bruce

[Dannywayoflife]

Bruce I've been done mate was done at 1200hrs gmt seems to of gone well I just carnt sleep now even dosed up on tamazapam!:-/
How did your proceedure go?
Danny

[OtterDriver]

Good Morning Danny!? 
Just past midnight there?  I was just trying to reply that I read the fine print of your reply and realized that TODAY was your day...congratulations!!  I can concur...the first night in the hospital was not terribly restful.  Catheter didn't seem to want to work as intended and couldn't get comfortable enough to fall away to LaLa land.

Outcome of the procedure seems to be great so far...unfortunately the weather here in Southeast Alaska today is not conducive to getting my outside walking completed!

Try and get some rest.  I hope you're blessed with an attractive nurse or two!

Bruce

[Tin Soldier]

The "detectable movement" might simply be the well-known clunk that folks speak of.  It's not really an audible clunk, but more of a deeper, light bump when doing certain movements.  I think I was pretty swollen and didn't notice it until a week or so after surgery.  Even with lots of leg strengthening, I still get it here and there, gotten sort of used to it. 

[obxpelican]

Devices have unique measurements, perhaps Pat can contact one of the doctors to explain sizing.

As to the chances that your loose feeling is relate to "slop" between the devices I sincerely doubt it, although Smith and Nephew did issue a recall for acetabular mismatched cups explained here:  http://www.surfacehippy.info/recallbhr.php

Again, I seriously doubt the feeling you are having as having anything to do with tolerances, hip devices have VERY tight tolerances, it's been explained to me that your device has enough room to allow for fluid from your body to lubricate it and that is about it.

Your condition is probably clunking and you will find lot's of information just by searching this site.


Chuck

Hello Everyone!

My first "New Topic"...I'm so nervous! ~8^)  I didn't use the right search words or it hasn't been previously discussed here, but was curious what the BHR dimensions are actually referring to?  For instance...is a "52mm femoral head" 52mm across from Outside edge to Outside edge?  That seems fairly obvious!?  Then is a "58mm acetabular cup" 58 mm across from Inside edge to Inside edge!?  Does that mean there's 6mm of "slop" in such a pairing?  I pictured the tolerances to be more precise than that.

Thanks in advance!

Bruce