Since femurs are slanted, does amount lengthened = amount gained? less/more?

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Quote from: Medium Drink Of Water on March 12, 2014, 06:09:33 PMThis is why the standing x-ray is important no matter how you're lengthening.  Looking at the gap or counting clicks/turns doesn't tell the whole story regarding standing height.  Measuring the legs in the before/after standing x-rays straight up and down will tell you how much height you gained.

Would this be a problem lengthening with a non-weight bearing nail? Standing xray while lengthening with PRECICE doesn't sound like a good idea to me.

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Yes with exfixes we lengthen along the mechanical axis which should correspond pretty much to patient height. With femoral nails, we tend to lengthen along the anatomic axis, which might not correspond perfectly to height gain (it is oblique). It is well described too that patients end up with 5-10 mm less than expected. I would suggest going 1cm beyond target length and then backing the nail up by 5mm. This would ensure quick consolidation. The downside of long lengthenings along the anatomic axis (like with precice, guichet, betzbone, iskd), is that we change the mechanical alignment of the femur, as we lengthen along a different axis. This means that intramedullary lengthenings in the femur beyond 5-6cm will inevitably lead to slight malalignment. This may in time lead to arthritis.
In short, keep to reasonable distances and go to a doc that understands this.
Standing xrays can be taken with Precice nails with certain precautions.

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Quote from: BilateralDamage on March 12, 2014, 02:47:29 PMWho did you get your femurs done with if you don't mind me asking?  And thru what method?

That's pretty significant but not surprising to me.  The femurs are very curved and slanted, which means the bone can lengthen all it wants but the actual height realized is always going to be less.

Femurs-Albizzia

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Mathematically, it wont be the same because of angle, I can measure the loss if you give me the original length of femur before the lengthening, and your x-ray..


 I did femur lengthening along with tibia lengthening, despite I lengthened the same amount for both part, but my tibia looks longer .. so maybe that due this reason,.

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Quote from: Disobedient on March 13, 2014, 08:40:38 AMMathematically, it wont be the same because of angle, I can measure the loss if you give me the original length of femur before the lengthening, and your x-ray..


 I did femur lengthening along with tibia lengthening, despite I lengthened the same amount for both part, but my tibia looks longer .. so maybe that due this reason,.

How much did you lengthen in your femurs? And how much actual height did you gain?

I want to get anywhere between 6.7cm to 8cm of actual height gain from my femur lengthening which will get me to 5'9.5 to 5'10, want to be at least average. However, I'm thinking those numbers might have to be revised to 7.7cm to 9cm to compensate for possible lossage of up to 1 cm, which worries me a little because I don't want to do 9cms of lengthening, past the normal safe zone, really confused on what to do, might just have to lengthen and take it day by day, see what my doctor says, and see what my body can handle.


Also I'll give you exact lengths/xray of my femurs when I have them, thanks!

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Quote from: Franz on March 12, 2014, 07:09:54 PMYes with exfixes we lengthen along the mechanical axis which should correspond pretty much to patient height. With femoral nails, we tend to lengthen along the anatomic axis, which might not correspond perfectly to height gain (it is oblique). It is well described too that patients end up with 5-10 mm less than expected. I would suggest going 1cm beyond target length and then backing the nail up by 5mm. This would ensure quick consolidation. The downside of long lengthenings along the anatomic axis (like with precice, guichet, betzbone, iskd), is that we change the mechanical alignment of the femur, as we lengthen along a different axis. This means that intramedullary lengthenings in the femur beyond 5-6cm will inevitably lead to slight malalignment. This may in time lead to arthritis.
In short, keep to reasonable distances and go to a doc that understands this.
Standing xrays can be taken with Precice nails with certain precautions.

That is very, very interesting. So with monorails for example, since it's running along your leg, when you have made the turns for 1mm, for example, your actual height gain should be about 1mm since it lengthens along the leg vs the anatomic axis of an internal nail!?

I'm strongly considering doing monorails lately, Dr. Mahboubian does them and he lives like 3 hrs away (driving), they are much cheaper than precise, I can get a nail put in after lengthening so I can weightbear while recovering. Monorails are more painful though right, because of those large pins? The thing is I've had pain in my life, nearly exploding appendix felt like I was dying, so the pain of ll doesn't scare me as much.

 I'm getting mixed comments on how far you can go for weightbearing on monorails though before you have to start relying heavilly on crutches/wheelchair, think it's somewhere around 5 or 6cm. And is that because it's hard to walk or because the monorail might actually not be stable at that point, possible breakage? Advice, knowledge on this guys?!?!

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The monorail patient I met in Beijing had to rely heavily on his wheelchair from the very beginning due to muscle weakness and pain.  I never even saw him use a walker or crutches.

I don't think that monorails become unstable after lengthening a certain amount, as long as you're using a nice and sturdy device.