I would definitely suggest that you consult with a neurosurgeon. I'm still not sure how things work in the UK, but if possible, insist on seeing a neurosurgeon. Spines are their specialty; I'm not sure if your orthopaedic consultant has the most current and accurate information.
Don't tell him that! Do be direct and ask the questions that Wendsong suggested. I have dealt with the obesity prejudices personally, and have gone from morbidly obese to normal to obese, the last because of pain issues, not caused by the weight, as my back was in decent shape when I was at my lowest weight for several years.
Weight can cause problems, or add to them, but it is not the answer to everything that goes wrong with a person. If he just sees your weight, he won't look for any other underlying conditions that might be causing a "weak" spine.
I think the fact that you were told to look stuff up on the internet and that nothing was done to address your concerns about such a surgery is a big red flag. Here in the U.S., I would just make an appointment with a good neurosurgeon, and politely cancel the follow-up with the orthopaedist. I know your medical system works differently, so I'm just telling you what I would do.
I wish you the best of luck. They have made great strides with diskectomies, microdiscectomies, nucleoplasty, and other options for back issues such as yours. A good surgeon should have no problems, and he would make sure to calm your worries. Many, many people have had similar surgeries with excellent results.
Wishing you all the best,
Kathy
I can feel your angst. My daughter was morbidly obese and ran into the same problems with doctors, because most of them believe, essentially that the obese cause their own problems (who "chooses" obesity as a life style?). Also, they don't see the surgery as a "cure" and it makes them insensitive. Next time you see him, instead of allowing him to be tactful, be direct and discuss your weight with him. Find out how much you should weigh to keep this from recurring after and what weight he feels you need to be prior to surgery. Find out how long you have before you must have surgery, in order to avoid more damage, to give yourself time to loose the necessary weight (the more weight you loose, the more time you have). Many insurance companies will now cover obesity medical expenses, so call yours, too, to see what treatments are available.
Additionally, I think you should contact a neurosurgeon to get an opinion about your spinal cord and how surgery could/would impact it.