Is Subtalar Joint Preservation With Total Ankle Arthroplasty (TAA) Overhyped?

by Vince Vacketta, DPM

One of the long-proposed advantages of TAA over ankle arthrodesis (AA) has been the preservation of adjacent-joint motion and protection of the subtalar joint. But does that theoretical benefit hold up in practice?

Examining the evidence

In a recent Level III retrospective matched cohort analysis, researchers examined data from 4,210 patients to compare rates of progression to subtalar arthrodesis after TAA versus AA. The two groups were matched for age, sex, surgical indication, and obesity. Patients with a prior ipsilateral subtalar fusion were excluded from the analysis. 

At the five-year mark, the results were striking:

• 4.2% of patients who underwent AA progressed to subtalar arthrodesis.

• 1.4% of patients who underwent TAA required the same procedure.

That’s roughly three-fold difference in cumulative incidence. 

Even after multivariate analysis, AA remained independently associated with 1.9 times greater odds of subsequent subtalar fusion. 

Takeaway

Maybe subtalar joint preservation with TAA isn’t overhyped after all. While the absolute risk of subtalar fusion remains relatively low in both groups, these findings provide clinical support for one of TAA’s most cited benefits: preserving ankle motion may may meaningfully protect the subtalar joint and reduce the need for future fusions.