Summary
While mobile-bearing total ankle replacement systems have a promising track record in Europe, to date all the the FDA-approved total ankle systems in the United States have been fixed-bearing. This system is the first mobile-bearing device to receive FDA approval.
Analysis
Currently there are four or five total ankle replacement systems being used in the United States. All of these are fixed-bearing by design. There are certainly some theoretical advantages to a mobile-bearing system. It remains to be seen, though, if these advantages play out clinically. There is still some level of skepticism in the orthopaedic surgery community as to the benefit of total ankle replacement surgery given the poor track record of early designs in the 1970's.
As with all total ankle replacement systems, long-term prospective studies which compare these devices to the current gold standard of treatment (ankle fusion) will be necessary.
