Changes in habitual physical activity after total ankle arthroplasty : A nationwide cohort study

Abstract Purpose Total ankle arthroplasty (TAA) is a motion-preserving alternative to ankle arthrodesis for end-stage ankle arthritis. However, population-level evidence regarding postoperative habitual physical activity is limited. This study aimed to assess pre- to postoperative changes in habitual physical activity after TAA in a nationwide cohort. Methods This retrospective cohort study used data from the South Korean National Health Insurance Service database. Adults who underwent primary TAA between 2008 and 2020 and underwent health check-ups before and after surgery were included. Physical activity was assessed using the metabolic equivalent of task (MET) minutes per week. Sufficient physical activity was defined as ≥ 600 MET·min·wk⁻¹. Results Among the 1,916 patients, the prevalence of sufficient physical activity increased from 19.6% preoperatively to 27.1% postoperatively (P < 0.001). Mean MET expenditure increased from 289.0 ± 475.2 to 686.7 ± 2072.8 MET·min·wk⁻¹. Overall, 74.6% of patients had increased MET expenditure after surgery. Women were more likely to show increased MET expenditure than men (78.4% vs. 71.1%). The prevalence of sufficient physical activity did not increase significantly in patients with stroke, cancer, or depression. Conclusion Following TAA, MET expenditure increased in 74.6% of the patients, and the prevalence of sufficient physical activity increased from 19.6% to 27.1%. However, these improvements were not consistent across all patient subgroups. These findings suggest that patient-specific factors and the expected postoperative activity levels should be considered.