Hindfoot Arthritis Progression and Arthrodesis Risk After Total Ankle Replacement.

Abstract

The purpose of this study was to assess the radiographic progression of subtalar and talonavicular degenerative joint disease in a series of patients who had undergone TAA (total ankle arthroplasty) with minimum follow-up of 5 years. TAA patient radiographs from a single institution were analyzed for peritalar arthritic changes by extrapolating the modified Kellgren Lawrence (KL) grades of the knee to the subtalar and talonavicular joints. Patients were included if they had a minimum of 5 years of follow-up. Patients who had undergone prior arthrodesis of the talonavicular or subtalar joints were excluded. A total of 140 patients with average follow-up of 6.5 years (range, 5.0-8.9 years) were included. Overall, 27% of patients advanced 1 KL grade at the subtalar joint and 31% of patients increased 1 KL grade at the talonavicular joint. Furthermore, 60% and 66% of patients showed no progression in the subtalar and talonavicular joints, respectively. Two patients progressed greater than 2 KL subtalar arthritis grades and only 2 patients with talonavicular arthritis progressed to the same extent. Sixteen patients went on to require a subtalar arthrodesis compared to 2 requiring a talonavicular fusion ( P < .05). This study suggests a moderate but nominal radiographic increase in adjacent subtalar and talonavicular arthritis over a minimum of 5 years after TAA. Future studies require a comparative control group of ankle fusion, but these data may suggest the motion preserved with an arthroplasty diminishes the stresses and compensatory motion incurred during tibiotalar arthrodesis. Level IV, retrospective case series.