Component Sizes

[FlbrkMike]

I had my four week post-op appointment this afternoon.  It's actually been only 19 days, but my second surgery is scheduled for exactly four weeks after my first, so we moved it up a little.  I then had my pre-op meetings with anesthesiology for next Friday.  The doctor seemed very pleased with the results, including placement, and my progress.  I can put my left foot on my right knee while sitting to put sock and shoe on, also walk a mile on hilly roads with no problem.  I take my cane but don't use it all the time.  ROM on my operated leg is already much better than on the other one.

I asked the doc what size components I have, and he said 52 mm for the ball (I'm sure of that) and either 56 or 58 for the socket.  I don't think that the inside diameter of the socket would be 4 mm or more larger than the ball, so that must be the outside measurement.  Does anybody know about this?  Also, I'm under the impression that 52 mm is pretty large.  He said that I have large bones, which is good because generally a larger ball and socket reduces chance of dislocation.

Does anybody know what the "normal" range of component sizes is?

[Tin Soldier]

I can't believe you're sticking with the next surgery, I can't think about my next one.  Maybe my right hip isn't as bad as others who have bi-lat OA.  I need to get the right done, and I was planning to jump on it 6 weeks post-op of the left, but I don't know.  Although, I will probably get it done on the same deductible, so I guess I'm committed before the end of the year.

Great question.  I think the sizing is based on the outside diameter on both of the components.  The acetabular component appears to be about 3 mm wall thickness, so if you double that and add it to the 52mm femoral component diameter, throw a few microns in for good measure and you have 58 mm.  I have a 52 with a 58. 

I found this document while doing a search.  This is pretty informative on the procedure for BHR, if nothing else.  Somewhere in there it might discuss the measuring.  I bet some of the senior members here would be able to tell you about the measurements also.   

http://global.smith-nephew.com/cps/rde/xbcr/smithnephewls/BHR_FDA_Surgical_Technique_NEW_06-07.pdf

[FlbrkMike]

I did want to make sure that I got both procedures in under one deductible, especially because I'm on a high deductible plan.  But another major consideration was that the closer I could make them, the shorter the total recovery time would be because the individual recoveries will somewhat overlap.  I'm trying to be very aggressive in my PT exercises and walking, while being careful not to push too hard, so that my strength will be as good a possible before the second surgery.  Also pretty much repeating all of the PT exercises on my non-operated leg to prepare ot beforehand.

Luckily my doctor has me on limited restrictions - 120 degree flexion, 100% weight bearing as soon as I could bear it.  I still have some night time pain, but otherwise things are going extremely well.

Thanks for the link, I'll definitely browse through that site.

Mike

[Lopsided]

Mike, you should have got from your surgeon at least one set of the identity stamps that come with the device. There should be identity stamps for each of the two components. They are small sticky labels that the doctors use to append to their records. The identity stamps have all the details of the components of your device including serial number and the size.

My sizes were 50mm and 56mm. So the thickness is 3mm.

I do not think 52mm is particularly large, I think it is about average.

D.