travel insurance operates under different regulations than other health insurance. however a pre-existing health condition is a condition that you previously had and were treated for. the fact that it's now healed is irrelevant in the insurer's eyes. from your description it sounds like you did fracture your l1 vertebrae prior to applying for coverage. if that's accurate then you do in fact have a pre-existing condition and assuming travel insurers are allowed to consider that when you apply for coverage (insurers of major medical health plans cannot) the insurer could use that to deny you coverage or charge you more for a policy.
what is considered preexisting condition by travel insurance companies. in april fractured l1 vertebra. in july booked trip as felt fine. in august fractured l2 l3 and l4 vertebrae. doctors insisted i cancel trip. insurance company claiming preexisting condition due to l1 fracture. i don't think so as l1 had healed and i had no way of knowing i'd do something stupid and cause fractures to addi\titional vetebrae.