I'm 77 and had my right knee replacement done April 2019 at Mayo Clinic Rochester. I'm really happy that I finally got it done and did the pre-surgery and post-surgery exercises faithfully which I think made the surgery go much better. I am extremely lucky that I have a good Medicare Advantage plan through Minnesota UCare and my out of pocket was less than $300. Of course I guess I could factor in the cost of the UCare plan at 217/month but I bumped it up to a more costly plan in 2019 specifically because of the knee replacement and the better hospitalization coverage. I was fortunate enough to still be working full time from home in 2019 but retired at the end of the year so my fun money has disappeared so I'm old and now on a fixed income 😊

Here's some information that may be helpful for making a decision. If you have a supplemental or advantage Medicare plan, it would be worth calling and asking them about your options and the cost.

Does Medicare Cover Knee Replacement Surgery Costs?: https://www.ehealthinsurance.com/medicare/coverage-all/does-medicare-cover-knee-replacement-surgery-costs

Have you called United Healthcare? Saves me alot