Development and experimental validation of a finite element model of total ankle replacement

Abstract

a b s t r a c tTotal ankle replacement remains a less satisfactory solution compared to other joint replacements. The goal of this study was to develop and validate a finite element model of total ankle replacement, for future testing of hypotheses related to clinical issues. To validate the finite element model, an experimental setup was specifically developed and applied on 8 cadaveric tibias. A non-cemented press fit tibial component of a mobile bearing prosthesis was inserted into the tibias. Two extreme anterior and posterior positions of the mobile bearing insert were considered, as well as a centered one. An axial force of 2 kN was applied for each insert position. Strains were measured on the bone surface using digital image correlation. Tibias were CT scanned before implantation, after implantation, and after mechanical tests and removal of the prosthesis. The finite element model replicated the experimental setup. The first CT was used to build the geometry and evaluate the mechanical properties of the tibias. The second CT was used to set the implant position. The third CT was used to assess the bone-implant interface conditions. The coefficient of determination (R-squared) between the measured and predicted strains was 0.91. Predicted bone strains were maximal around the implant keel, especially at the anterior and posterior ends. The finite element model presented here is validated for future tests using more physiological loading conditions.

Incidence of Revision After Primary Implantation of the Salto® Mobile Version and Salto Talaris™ Total Ankle Prostheses: A Systematic Review

“…Finally, unequal dispersion of the load about the subarticular bone adjacent to the metallic prosthesis components could be responsible for aseptic osteolysis and loosening. Specifically, the location of osteolysis concentrated around the tibial keel and conical fixation plug for the Salto Ò mobile version prosthesis correlates exactly with the increased load transmission and strain during thermoelastic stress analysis (71) and finite element modeling (72). Therefore, additional refinement of the tibial component to redistribute stress for more even dispersion of load should be an area of future study.…”

Total ankle replacement design and positioning affect implant-bone micromotion and bone strains

“…hip, [14], [15]; shoulder, [16], [17], [18]). Several studies have employed FEM to explore the performance of current TAR devices: Terrier et al [19], [20], [21] modelled the Salto ® implanted in the tibia to explore bone strains and stresses occurring at the implant vicinity. Espinosa et al [22] developed a model to study contact pressures occurring in the PE component of the Agility ® and Mobility ® .…”

Fixed and mobile-bearing total ankle prostheses: Effect on tibial bone strain

“…Using a validated finite element model (Terrier et al 2014), we compared both Salto mobile bearing and Salto Talaris fixed bearing prosthesis types. Based on seven tibias, our results showed that there are no significant differences in critical bone strain and bone-implant interface stress between the two prostheses.…”

“…A comparative analysis was performed on seven finite element models, built and validated from seven cadaveric tibias (Terrier et al 2014). All tibias were segmented from CT images, using the imaging software Amira (FEI Visualization Sciences Group, Bordeaux, France).…”