First...worry about your knee and recovery. Its the most important thing. I have had 9 surgeries (including 2 major back surgeries) in the past 7 or 8 years, and absolutely no problem with medical. Usually, the hospital will get to the insurance first, so most, if not all of the maximum out of pocket will be absorbed by them (hopefully, you do have max). I have found hospitals very easy to work with, setting up payment plans with them. Dr's usually are pretty good - realize (at least in my case) they have already received the major portion of their $$$ from insurance. Only problems I ever had were with the medical supply people, walkers, etc...they seem to want their money yesterday. But never, ever had any collection or anything near it. Of course, neglected most of my other stuff to pay, which is a lot of the reason I got in the mess I was in...but also a good excuse.
Number one way I messed up, and recommend to anyone home and not used to it (4 months first back surgery, 51/2 months second) STAY OFF EBAY !