Re: Post magnetic rod surgery, how many lenghtenings?
I don't know much about the magnetic rods, as they haven't been in use for all that long (and I've had a bit of a hiatus from the site), but I did want to say that although Manchester may not have done any rod insertion surgeries yet, I wouldn't see this as any reason for concern regarding them doing the lengthenings.
As far as the frequency goes, I wouldn't expect it to be less than twice a year, but I would guess that they'll need to see how much correction they're able to obtain before they consider whether to change how regularly they're doing it. Perhaps you could discuss with them what the procedure would be for you to contact them to see about bringing it forward (or at least getting a review) if you feel there's been a big change before the next lengthening is due? The other thought that occurs to me - which is just guesswork, so I don't know how likely it is - is that children tend to have their major growth spurts at relatively reliable ages, and between those times, growth is slower, so it may be that frequency of lengthening is partly based on that - this might be something else that you could ask the docs about.
Diagnosed at 15 with 50° curve, but probably juvenile IS. Fused in kyphosis (by non-specialised ortho) with a/p surgery T10-L2 @ 21, posterior only revision surgery to correct kyphosis @ 29. Now 38 with further revision surgery and extension of fusion to sacrum required to correct residual kyphosis, restore lordosis and address spinal stenosis.