Clinical outcomes of surgical treatment for end-stage ankle osteoarthritis in patients aged ≥ 75 years: a multicenter, retrospective study

BACKGROUND: This study aimed to clarify the clinical outcomes of surgical treatment for end-stage ankle osteoarthritis in patients aged ≥ 75 years and compare these outcomes with those of patients aged < 75 years. METHODS: A total of 148 patients, including 65 who underwent total ankle arthroplasty and 83 who underwent ankle arthrodesis, were retrospectively surveyed. Clinical outcomes were assessed preoperatively and at the last follow-up using the Japanese Society for Surgery of the Foot Hindfoot Scale and a self-administered foot evaluation questionnaire (SAFE-Q). Patient characteristics, including age, sex, body mass index, radiographic severity, and follow-up period, were also assessed. The patients were divided into older (≥ 75 years) and younger (< 75 years) age groups. Improvements in outcomes were then compared between age groups using univariate analysis and analysis of covariance adjusted for patient characteristics. Total ankle arthroplasty and ankle arthrodesis were analyzed separately. RESULTS: All clinical outcome scores improved postoperatively in the older age groups for both procedures. Scores for the pain and pain-related subscale of the SAFE-Q improved by 37 points (p < 0.001) in post-total ankle arthroplasty patients and by 35 points in post-ankle arthrodesis patients (p < 0.001). Furthermore, multivariate analysis showed that the improvements observed in all scores were not different between the older and younger age groups for both post-total ankle arthroplasty and post-ankle arthrodesis patients, except for the SAFE-Q physical functioning subscale score for post-ankle arthrodesis patients. The clinical outcomes improved significantly in post-total ankle arthroplasty and post-ankle arthrodesis patients aged ≥ 75 years. Moreover, these improvements were similar to those observed in patients aged < 75 years. CONCLUSIONS: Surgical treatment of end-stage ankle osteoarthritis can be a viable treatment option, even in elderly patients, and can be expected to improve similarly to younger patients. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13018-023-03734-4.