View Full Version : Playing doctor

13th March 2005, 10:39 PM
Thinking of growth rods in the thread on little Emmeline, and how one of the main drawbacks to the procedure is the repetitive surgeries to adjust them, I thought of something. I've recently seen a documentary about persons with various forms of dwarfism, and one girl was offered a series of (painful-looking) cosmetic procedures to lengthen her limbs for added height and proportional arms. The initial surgery involves opening the limb and inserting pins to hold an external brace-type appliance in place around it. Then the bone is broken in between, and the limb is closed. The brace has something similar to the key-and-crank method that is used to tighten oral braces, and once a day (week?) over a period of months, the key is turned to very slightly widen the space. As the bone attempts to heal, it slowly builds additional bone tissue in the gap, making the limb longer. The patient is able to get around, for the most part, on crutches throughout the procedure (after the initial surgery recovery, of course). I don't know if I've explained this well, but hopefully you understand what I'm saying.

Anyway, I realize that the titanium rib and the growth rods don't involve breaking bones and letting them heal longer, or anything like that. But they DO involve successively lengthening the device through repeated surgeries. For the longest time I assumed the reason they were internal devices was to prevent infection, but then I remembered the limb-lengthening surgeries in which the appliance is external, so I don't think infection is the reason.

So my question is, why can't they create an external "titanium rib" that can be lenghthened gradually, without the need for multiple surgeries? Any ideas?

13th March 2005, 10:59 PM
Nice idea. Maybe there's a risk of an air leak (pneumothorax)?

Or maybe you've stumbled upon a great idea that no-one's thought of yet.

Amazed Jean
14th March 2005, 06:19 AM
Don't they use the halo surgery to try to do this a bit. So logically they should be able to figure out a way to stop bones moving if they can successfully predict where our silly spines are going to go. Maybe its the tortioning that can't be predicted so there isn't a good way to do several stresses at once. It really is confusing. I have seen the lenghteing surgeries and implants for dwarfs etc. It really is great that they can do it but boy I still get all creeped out watching them turn the screws.

14th March 2005, 09:02 AM
But that's the thing... the growth rods and the titanium rib do the a very similar thing, only the devices are implanted, rather than external. Also, they push the ribs/vertebrae, rather than causing bones to be built longer. I don't see why they can't be attached externally with pins, and the screws turned without having to re-operate every few months. If it could be done, it'd be less trauma on the child.

14th March 2005, 12:27 PM
I knew many kiddies having limb-lengthening procedures in Stanmore when I was a child. They all had those external apparatus and I never saw any of them who were traumatised by their treatment, which is good to know.

However, the external apparatus did restrict their lives a great deal, as they had to avoid certain activities so they didn't bump the hardware. I'm thinking that maybe a child with an external form of the titanium rib might face an extremely restricted life, even more so than a child with hardware fixed to a limb, and that it might be seen as kinder to do a little operation once every few months and let the child have as normal a life as possible?

14th March 2005, 01:15 PM
Bionic Bone at Stanmore (http://www.rnoh.nhs.uk/news.php#n49)

In the past, children would go to the operating theatre for a small incision to be made in the leg. The surgeon would turn a screw to extend the prosthesis and the child would then have to spend at least five days in hospital recovering. A child would need drugs for pain relief, physiotherapy and there would always be the risk of infection. On average a young person would need this procedure about five times until they are 16.

The secret to the new device, designed on-site by Bio-Medical Engineering, University College London (UCL), is a tiny gear box. This is activated when a specially designed electromagnetic box is placed over the leg. The magnetic force activates the gearbox inside the prosthesis extending it by a specified amount. The magnet inside the gear box spins at 3,000 revolutions per minute and 13,000 revolutions are needed to extend the prosthesis by just one millimetre.

The best of both worlds - internal and infection-free, but dynamically adjustable. Could that be transferred from limb to spine? I'm sure it would need a lot more force...

14th March 2005, 02:14 PM
I'm sure there are physicians exploring this already, or they know of some reason why it can't be done. Right?