Dr Franz Birkholtz (Pretoria, South Africa)

Edit Post

In the case of salameh's device, the bottom part of device is out when you have some consolidation after lengthening. Then he take off the screws bit a bit. Then the device is smaller, and it still support the body.
I think you need to stay with the device the time necessary for consolidation  without urgency, perhaps minimun 1,5 months by centimetre and you should make somes milimetres plus, mínimum 0,5 plus to secure 4 cm because lose lengthening.
That it will be that i will make if i do the surgery only with external, with doctor salameh

Edit Post

Hi,

Subsidence is something we cannot fully explain. Logically if the bone is strong enough, the length should stay the same. There are however some patients where some length is lost gradually afterwards -> probably due to some 'plastic deformation' of the new bone. This is disconcerting. Especially since it tends to happen gradually and long after the procedure.
Most doctors would recommend slow destabilization of an external only frame, in order to strengthen up the bone gradually before frame removal.

Preventing subsidence? Using internal methods, or combinations of internal and external may be the answer...

Edit Post

Quote from: Franz on March 30, 2014, 08:21:23 PMHi,

Subsidence is something we cannot fully explain. Logically if the bone is strong enough, the length should stay the same. There are however some patients where some length is lost gradually afterwards -> probably due to some 'plastic deformation' of the new bone. This is disconcerting. Especially since it tends to happen gradually and long after the procedure.
Most doctors would recommend slow destabilization of an external only frame, in order to strengthen up the bone gradually before frame removal.

Preventing subsidence? Using internal methods, or combinations of internal and external may be the answer...

Thank you for the answer, this is definitely concerning, i guess i will have to lengthen around 4,5 cms to make sure..

But it seems like if plastic deformation is the explanation, then it could happen after the surgery to remove the internal nails as well.. or maybe after a year or so when the nail is removed, is long enough for subsidence to no longer be possible..

Ive looked at 2 studies about this:

one study claims that the median subsidence loss was insignificant at around 0.28 - 0.6 mm, such a small loss would be acceptable to me.

The other one however reports the large losses mentioned in this thread...and it doesnt even seem to be uncommon to experience large losses, some even above 3 cm..that must be a case of removing the frame way to early..

http://informahealthcare.com/doi/full/10.3109/17453674.2010.533934

http://www.ncbi.nlm.nih.gov/pubmed/18923832

However reading further, it is interesting that the positive study actually argues against the other study where large losses where reported, and the authors of the first study acknowledged the errors that where brought up. So it seems the positive study of less than 0.6 mm subsidence loss on average is the more reliable one based on this. I hope it holds true, still gonna lengthen some mm extra to make up for the potential loss.

Edit Post

Thank you very much Frank, for your answers.
You look like a very good option but the idea that you only have made two cosmetic lengthening it go me to back.

Edit Post

it would be good idea to wear somes braces or cast when you take off the device to protect  the new bone.If one person makes only external.What do you think?

Edit Post

Excellent update, Dr. Birkholtz. Looks like a great hospital.

Edit Post

Quote from: paco1 on March 30, 2014, 08:33:41 PMThank you very much Frank, for your answers.
You look like a very good option but the idea that you only have made two cosmetic lengthening it go me to back.

Why, paco? My doctor had only done 30-ish cosmetic lengthenings but everything went great. Keep in mind that these doctors have done hundreds to thousands of normal, non-cosmetic lengthenings both for achondroplasia patients (dwarfism) and leg length discrepancy lengthenings. It's actually better for the doctors as they face all sorts of complications in these patients and become more experienced in treating possible complications in simpler cosmetic cases. That being said, isn't it also technically the same thing? Leg length discrepancy or cosmetic, one leg or both legs, it's the same procedure.. (Yes there's increased risk of fat embolism when you add a leg, but it's not a problem in bilateral lengthenings when the doctor is experienced, the risk is surpassed with proper venting methods during surgery and post-op medications). In brief.. You make it seem like Dr.Birkholtz has only done two surgeries so far (I know you don't mean that, no offense) whereas his actual experience is so much more than that. I only wrote this to assure you that hopefully everything should go fine.

Edit Post

Hello, Dr. Birkholtz,
Can you please give a rough estimation, for a normal patient, after how many months can he walk in crunches ?
Thank you,

Edit Post

Dr B regarding safety in S.A. Are there any special security precautions that have to be taken
in day to day life.

Edit Post

Quote from: Keep Growing on April 09, 2014, 08:55:11 AMHello, Dr. Birkholtz,
Can you please give a rough estimation, for a normal patient, after how many months can he walk in crunches ?
Thank you,

It depends on the type of technique we use. For external fixator based lengthenings we encourage full weight bearing as soon as possible. In general, for bilateral cases, most patients are walking on crutches before discharge from hospital and progress to full weight bearing over the next 6 weeks or so.
For Precice 2, it depends on the patients weight. If you weigh below 150 pounds, we can get you onto crutches pretty soon, provided weight is shared between the two legs. Most patients should be on crutches by 6 weeks though.