title: Development and experimental validation of a finite element model of total ankle replacement.
abstract: Total 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 2kN 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.
authors.affiliation: Laboratory of Biomechanical Orthopedics, Ecole Polytechnique Fédérale de Lausanne, Station 19, 1015 Lausanne, Switzerland. Electronic address: alexandre.terrier@epfl.ch.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Terrier
authors.affiliation: Laboratory of Biomechanical Orthopedics, Ecole Polytechnique Fédérale de Lausanne, Station 19, 1015 Lausanne, Switzerland.
authors.forename: Xabier
authors.initials: X
authors.lastname: Larrea
authors.affiliation: Laboratory of Biomechanical Orthopedics, Ecole Polytechnique Fédérale de Lausanne, Station 19, 1015 Lausanne, Switzerland.
authors.forename: Jonas
authors.initials: J
authors.lastname: Guerdat
authors.affiliation: Service of Orthopaedics and Traumatology, University Hospital Center and University of Lausanne, Rue du Bugnon 46, 1011 Lausanne, Switzerland.
authors.forename: Xavier
authors.initials: X
authors.lastname: Crevoisier
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000843:Ankle Joint / Q000502:physiology / Q000601:surgery*; D058737:Arthroplasty, Replacement, Ankle; D001696:Biomechanical Phenomena; D015519:Bone Density; D002102:Cadaver; D004548:Elasticity; D004867:Equipment Design; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D008297:Male; D008954:Models, Biological; D019736:Prostheses and Implants; D013977:Tibia / Q000502:physiology / Q000601:surgery*; D016474:Weight-Bearing
keywords: Ankle; Arthroplasty; Finite element method; Mobile-bearing; Stereo digital image correlation