I had back surgery performed 6 months ago due to an injury sustained in a car accident and yes the health insurance did cover the back surgery since it was medically needed and I was in severe pain without the back surgery.
So if you do actually need the back surgery because the back pain is causing you severe pain and problems then yes the health insurance plan should cover the cost of the back surgery.
I did have to pay out of pocket though a deductible of $500.00 but they covered the rest so $500.00 was nothing compared to the $160,000.00 that they billed my health insurance for to have the back surgery performed.