As a resident who's scrubbed and seen many (Inbone/II and STAR), I believe in them. Maybe because I'm getting trained in them from the beginning of my training, but I think they're the real deal, especially the STAR. There are better, more biomechanically and anatomically correct, TAR's out there (in Europe --> BOX is the one that comes to mind off the top of my head), but IF they're allowed in the US, it won't be for another 10-15 years at the earliest. That being said, they're not the come all, end all. If a surgeon is offering them to you saying it's a miracle cure, etc, etc, I'd run. You want the guy that has done 100 of them, but only on people that need them. If they tell you all the complications involved, the rehab, that very little ACTUAL ankle motion is acheived after the surgery, etc, then they're probably legit. I have every intention of putting them in when I'm done and out practicing. The data is not lying, the results are looking pretty good for long term results. I think within the next 15 years, you'll see the gold standard change for the treatment of end stage ankle arthritis from fusion to TAR, IMHO. Unlike ankle fusions, not every Joe Blow, DPM or MD should be putting them in (and you can even make the same case for fusions). But that's a whole other can of worms...
And BTW, the ankle is just as prone to degenerative arthritic changes as any other major joint in the body. One could argue that a higher proportion of people actually have ankle arthritis than what's reported compared to knee or hip. Data has shown that even a single ankle sprain in your life can result in ankle arthritis years down the road (albeit much less likely than chronic/repeated ankle sprains/instability). And it's been shown in several studies that the impact of ankle arthritis has a much more detrimental effect on people and their daily lives than having knee or hip arthritis alone, respectively. But yes, post-traumatic arthritis remains the number 1 cause of end stage ankle arthritis. Like any surgery, any technology, anything in general, there's pro's and con's. As a foot and ankle surgeon, if you're not willing and able and have the training and have the understanding and capacity to deal with any and all of the complications of a TAR (and even though the newer 3 component's have fewer complications OVERALL, but when it goes bad, it can be disastrous), then you really have no business putting them in. You shouldn't "dabble" in TAR's, you need to do them or don't do them. 1 every 2 months is not sufficient. More like 1 every week to 2 weeks or more is sufficient (and yes, I have attendings that do that legitimately).