Just doing a bit of research on these things I know now that I should probably have my wife knees worked on (if they need it) over here before/if I move.
I'm dealing with knee problems in the UK, and I knew it would be a problem before I came (though it's worse dealing with it here than I imagined), but we had a specific set of circumstances and decided to come -- though the sad fact is that no matter how much hubby loves his job here, we'll probably need to get back to the States in 2 or 3 years just so I can get good insurance again without dealing with all the hassles I have right now by being overseas and using my U.S. insurance. These knee problems are why I pay $400 a month to continue my private insurance through COBRA, except that because I now live overseas the insurance company can't seem to get things straight in their system -- refund checks never carry the zip code or country name, and so they don't make it to me (they enter my zip code, the system doesn't recognize it and the zip is replaced automatically with zeros, and the post office in the U.S. doesn't know what to do with it). Because I'm overseas, everything is "out of network" and I have to pay upfront and file for refunds. I'm trying to work out the problems, but it's really a nightmare and highly stressful. And I did look into seeing a specialist through the NHS, and was told there was no point even getting on a list, the wait was just ridiculous.
I say all that to say that I can relate to having pre-existing health issues, and can tell you unless the knee problem is something due to an accident (meaning you fix the problem and the knee doesn't continue to deteriorate and get bad again due to various medical conditions), keep in mind that your wife may need more knee work in the future even if you do surgery now. And getting it on the NHS won't be a feasible option, most likely. Any private insurance you buy here in the UK will not cover pre-existing conditions, so if you want coverage for any future knee problems she might have you will have to continue (at a high rate) your old insurance through COBRA (which only lasts about 18 months, though at the end of that time you can swap it to another plan with the same company). The other option is just to save up and pay out of pocket for any procedures you need, which is something many Brits resort to because they simply can't get the care they need through the NHS -- and a simple procedure like knee debridement and lavage (for instance) costs $8,000. And that's before you pay for physical therapy afterwards, which in my experience costs $168 per one hour session. So much for a "free" system that takes care of everyone in the UK. It really is true that there's no way any system could give everyone good care, the funds just don't exist. Here everyone gets care, it's just not that good, access-wise; however, the medical professionals are as good as you get in the States -- if you can get in to see the ones you need.
What I'm trying to say (and probably not doing so well at), is really consider hard your wife's current medical needs and her future needs, and what stresses it will put on both of you to deal with those needs in a socialist country.As to your friend who has to keep working for the health insurance, consider this: How much would the average Brit with a median income pay into health insurance (basically) by way of taxes to the NHS in his or her lifetime? How much is the average American paying in, by way of payroll deductions and co-pays? I bet you'd find that many Brits pay more, but get less for their money. In America, if one took some of that extra money he wasn't paying into taxes like the Brits are and actually planned for the future, he'd have the funds to buy adequate health insurance when he retired (and that's if he didn't retire from a job that lets him continue healthcare through the company). Just a thought.