Total Ankle Replacements have been done for over 50 years. They have increased in popularity over the last decade due to improved outcomes. This has been facilitated by increased knowledge of the way an ankle moves (this is very complex) and improved design and materials used to make the implants. The X-ray guided jigs and even custom made CT guided jigs have improved the precision of surgical alignment of these.
I have been replacing ankles for 14 years. When judging a joint replacement we talk about how many of these are still working well after ten years, for my ankles the expectation based on the results is that over 95% are still working well. (There is reason to think they won't last much longer) The reoperation rate is 7%, normally to treat arthritis in one of the other foot joints. Joint infections are less than 1%.
Not every one can have an ankle replacement, some people are too young, too old or have a pattern of arthritis which makes the surgery impossible, usually a big deformity. These factors would be discussed in detail and the alternatives balanced against the risks, to allow informed choice.