Similar Clinical Outcomes of INBONE II Total Ankle Arthroplasty in Patients Under 50 and Over 65 Years: A Four-Year Retrospective Study

Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: There is still no consensus on the age restriction for total ankle arthroplasty (TAA) patients. The aim of our study was to analyze the clinical function, radiographic outcomes, patient satisfaction, and complications between patients under 50 years old and those over 65 years old who underwent TAA with the INBONE II prosthesis for end-stage ankle arthritis. Methods: Patients who received TAA with the INBONE II prosthesis between September 2016 and August 2021 were included in the study. A total of 68 patients were enrolled and divided into two groups based on age: the younger group (28 patients under 50 years) and the elderly group (40 patients over 65 years). Demographic data and patient-reported outcomes, including 36-Item Short-Form Health Survey (SF-36), American Orthopaedic Foot & Ankle Society (AOFAS), Foot Function Index (FFI), and Visual Analogue Scale (VAS) scores, were collected preoperatively and at the latest follow-up. Radiographic measurements, including tibial articular surface angle (TAS), talar tilt angle (TT), and tibial lateral surface angle (TLS), were evaluated on weight-bearing images preoperatively and at the latest follow-up. Range of motion (ROM) and complications were documented. Patient satisfaction was assessed using a 5-point Likert scale. Results: With a median follow-up of 4 years, there were no significant differences in AOFAS and SF-36 scores between the two groups at the latest follow-up. However, the elderly group showed slightly lower VAS and FFI scores compared to the younger group, while the younger group demonstrated slightly greater dorsiflexion angles. There were no significant differences in radiographic evaluations, patient satisfaction, and complication between the two groups. Conclusion: The 4-year postoperative outcomes of TAA using the INBONE II prosthesis were similar between patients under 50 years and those over 65 years, suggesting that age alone should not be a strict criterion for patient selection.