It is more or less related to some "fixed mindset", I think. They just believe that those sports medicine specialists in Germany are better. To be honest, Plushenko's spine surgery is not that advanced as some thought, which can also be done successfully in Russia, so I don't know why he chose to go to Israel for that operation. Perhaps the service there makes some difference? I think each country has its own sophisticated medical disciplines, and Russia is no exception.
Well, working as doctor do not make you lots of money in russia, so there are actually few professionals who are up with the most recent treatments and methods and everything. Also, they not always have access to top technology, modern equipment and so on. Which makes sometimes easier to get treatment abroad as you have more options and the cost will be around same.