Phil,
My name's Tom.
Had a fight with BUPA international to get pre-approval for L4-5 Disc replacement and possible L5-S1 Fusion (or poss replacement).
The orginally denied cover, saying it was a pre-existing condition. Part from getting help from Specialist and GP, I also discovered the Financial Ombudsman - UK who oversee UK based insurance companies (like BUPA). Their site is
Financial Ombudsman Service
On that site I read a lot of great info as to what can and cannot be denied by insurance companies (at least UK ones). I'm glad to say I didnt have to go to the ombudsman, and BUPA agreed to cover when I challenged them and laid out all the pertinent facts. (I sent them a bit of a novel!)
Anyway- they recognise the surgery and I think only denied as a way of trying to limit payouts.
Hope that helps.