OBJECTIVE: To investigate the biomechanical characteristics of Salto Talaris tibial components of different heights at the bone-prosthesis interface during different gait support phases after total ankle replacement. METHODS: An ankle joint model was reconstructed using a weight-bearing CT of a 61-year-old female patient with ankle arthritis, and Salto Talaris tibial components of different heights (5-11 mm) were modelled to simulate the loading of the tibial-prosthesis during four gait support phases, and to analyse the micromotion and stresses at the bone-prosthesis interface. RESULTS: The peak micromotion values of the 11 mm and 9 mm models exceeded 50 μm, and the peak internal the tibial stresses were 30.75 MPa and 29.86 MPa, respectively. The average peak micromotion values of the 7 mm and 5 mm models were only 42.66 μm and 40.32 μm, and at the same time, the tibial stresses were within 15 MPa, and the 5 mm model had the smallest stress shielding effect. Conclusions: The 11 mm and 9 mm models demonstrated poorer prosthesis stability and more significant internal tibial stress shielding, with peak stresses exceeding the cancellous bone yield stress and higher risk of bone damage; the 7 mm and 5 mm models had tibial stresses within a reasonable range, with better load transfer, while the 5 mm model had the lowest micromotion and the best initial prosthesis stability in comparison. The Salto Talaris prosthesis should be used for total ankle replacement with the appropriate tibial component height, with 5 mm being the optimal height, and excessive flexion and extension of the ankle joint should be avoided to maintain the stability of the prosthesis after surgery.