Why i can't have back surgery when i need it?

Need to talk: to surgeon, if you need surgery and no contraindications you will receive it

Hard to say: Some people may think they need back surgery but are really not good candidates for surgery and may be worse off if they get it; others may have something on MRI that is very fixable, but may have contraindications to surgery based on other reasons. Such as a person that has multiple, severe medical problems. I would discuss this directly with your surgeon.