I know when I had to have my spinal surgery my helthcare provider had an independent company contact me to see if the disk herniation was caused by an accident or something so they could off set their costs with another insurance. But it was not the case so they paid for the whole bill.
I am pretty lucky to have two back surgeries all covered by military insurance (Tricare). When my Husband retires, I will continue to be covered but I wonder if my daughter (who has the same disk degeneration disease with two surgeries before she was 18) will have problems later with her insurance when she has more back issues.