It is definitely time to talk to a lawyer.
I know that you said that you were trying to be a company man, and didn't make any claim under worker's comp for the injury. I am not familiar with worker's comp laws so I have no idea as to whether this is even a possibility, but, given what is going on now, it may be a good idea to go back and check to see if you can still file a worker's comp claim for the injury. At this point, it is possible that you may have missed a required deadline for providing notice. However, given the apparently serious nature of the surgery, it seems possible that the injury may have been immediately apparent once it occurred and would have been reported to the higher ups. If this is the case, it may at least satisfy initial notice requirements and have kept the possibility of filing a claim alive. If you can still file a claim, it would be another possible avenue to get your bills covered. At a minimum, it would be worth checking into.