Comparison of Clinical Outcomes of INBONE II Total Ankle Arthroplasty in Patients Under 50 and Over 65 Years: A 4-Year Retrospective Study.

OBJECTIVE

There is 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 age ≤ 50 years) and the elderly group (40 patients age ≥ 65 years). Demographic data and patient-reported outcomes, including 36-Item Short-Form Health Survey (SF-36), American Orthopedic 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 five-point Likert scale.

RESULTS

With a median follow-up of 4 years, there were no statistically 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 statistically significant differences in radiographic evaluations, patient satisfaction, and complications between the two groups.

CONCLUSION

The 4-year postoperative outcomes of TAA using the INBONE II prosthesis were comparable between patients younger than 50 years and those older than 65 years, indicating that age alone may not serve as a definitive criterion for patient selection in TAA with this implant.

TRIAL REGISTRATION: Retrospectively registered.