Limb Lengthening Forum

Limb Lengthening Surgery => Limb Lengthening Discussions => Topic started by: oklama on December 24, 2024, 05:23:18 PM

Title: How much is lost to curvature on 8cm femurs typically
Post by: oklama on December 24, 2024, 05:23:18 PM
Activatedxx told me he lost about 1cm to it but the numbers I saw previously were much lower. Anyone got a good number on this or a paper with stats on it?
Title: Re: How much is lost to curvature on 8cm femurs typically
Post by: KiloKAHN on December 24, 2024, 10:48:22 PM
Activatedxx told me he lost about 1cm to it but the numbers I saw previously were much lower. Anyone got a good number on this or a paper with stats on it?

Here's what Dr Birkholtz had to say about actual height gained compared to distraction with femur lengthening:

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.

http://www.limblengtheningforum.com/index.php?topic=413.msg6957#msg6957
Title: Re: How much is lost to curvature on 8cm femurs typically
Post by: oklama on December 25, 2024, 12:20:12 AM
Here's what Dr Birkholtz had to say about actual height gained compared to distraction with femur lengthening:

http://www.limblengtheningforum.com/index.php?topic=413.msg6957#msg6957

This is talking about exfixes, here hes insinuating that precise will give a full height gain in femurs. has that proven true for patients?
Title: Re: How much is lost to curvature on 8cm femurs typically
Post by: oklama on December 25, 2024, 12:24:17 AM
Here's what Dr Birkholtz had to say about actual height gained compared to distraction with femur lengthening:

http://www.limblengtheningforum.com/index.php?topic=413.msg6957#msg6957

Ignore previous post I misread, hes actually saying the opposite. thats really unfortunate. idk what to do now.
Title: Re: How much is lost to curvature on 8cm femurs typically
Post by: GrowGrow123 on December 27, 2024, 10:53:57 PM
I did 8.3 cm femurs on Precice. As far as I can tell, I got pretty close to the full amount. Like at least 8cm. My understanding is that the femurs are not perfectly vertical from the ground, but the amount lost by that angle is quite minor. Someone did the math and it was like 0.15 cm if you do 8cm (although, of course, this angle is not necessarily exactly the same on a person to person basis and women, in particular, have a more oblique angle than men for obvious reasons).

I have heard of LON patients losing height as they consolidated, but never heard of this for Precice.