you've had a number of doctors, have any been QMEs or AMEs?
if the carrier paid TTD, then they have accepted the injury as covered by workers comp.
unless there is newly discovered evidence they would have no basis for denying the injury after a year of paying benefits. your facts are a bit contradictory or there is a more detailed explanation that you are not giving or don't understand.
basically if the upcoming QME says there never was a work injury then unless the doctor based their decision on false information your claim and all further benefits will be stopped-no settlement.
having a QME now after months of paying benefits on whether the injury was work related is strange and i think there is missing information. Generally the injury is disputed before any benefits are paid. why now?
maybe the QME is only on the issue of maximum medical improvement/pernanent disability and is not about "dismissing the injury at all or the QME is on the issue of just the back injury which would make more sense. disability determination is a separate decision then whether there was a work injury.
and a second body part is also a separate determination.
maybe you are confusing all the different issues?
on the issue of "settlement".
you may be confusing it with the payment of permanent disability benefits. Permanent Disability is based on an Impairment rating. certain medical factors and measurements are used by a doctor to determine your level of permanent Impairment. California uses the AMA guides to rating Impairment. If the QME gives you a 0% rating then there would be no permanent disability due. if you have a rating then there would be PD due.
if you search/read other posts on this site about permanent disability you would likely have seen links to the california Department of Workers Compensation that I have posted repeatedly and often. for more information on PD read factsheet D:
http://www.dir.ca.gov/dwc/iwguides.html
your post and questions are confusing. I've tried to understand where you got confused and provide a response that you were looking for. if not you need to be more clear with what information you want.