Foot & Ankle

Weightbearing After TAA May Be OK — Key Word is “May”

The nugget in this study is about weightbearing after TAA

What’s the Claim

In this retrospective, comparative study drawn from a high-volume referral center, the authors suggested that same-day bilateral total ankle arthroplasty (TAA) is as “safe and effective” as staged bilateral TAA. They based this on a comparison of 25 patients who were treated using each approach, and they found no differences in these small groups in terms of outcomes scores or reoperations.

How’s It Stack Up?

There are few comparable studies to this one, but some prior work has suggested that the revision risk after same-day bilateral TAA may be as high as 22% at 8 years. In general, it’s prudent to trust studies painting darker pictures than brighter ones in this context. And, certainly, there is no reasonable way to claim that any intervention is “safe and effective” by studying 25 patients in a group; differences between treatments in terms of even moderately common complications would be missed in such small studies. The question of whether same-day bilateral arthroplasty is as safe as staged bilateral arthroplasty has resisted analysis in the hip and knee literature despite availability of vast numbers; the patients at baseline are just too different. But we’re not covering this because we expect many surgeons to do same-day bilateral TAA, we’re covering this one because . . .

What’s Our Take?

. . . it tells us something about weightbearing after TAA. Most studies of TAA involve keeping the patient off of the leg for a period of time. If one has bilateral ankle replacement, one has to bear weight immediately. A thoughtful commentary by CORRelations’ Foot & Ankle advisor on this article made that point, and it is true that weightbearing here was not associated with any apparent increase in premature revisions. Giving us further hope on this point is the fact that the authors here had complete follow-up out to two years. In the back of our minds, though, is whether those revisions are yet to appear. The first patients in this study had surgery in 2007; a patient who had surgery in ’07 and only two years of follow-up afterward has not been seen in nearly 15 years, so it's fair to say we don’t know how that person’s ankle is holding up (and the vast confidence intervals in the survivorship curve — Figure 4 in the original study — drive this point home). Still, the absence of premature revisions leaves open the very real possibility that early weightbearing may be tolerated by contemporary ankle arthroplasty implants.