Development of a finite element model of ankle injury and stability

Hao Chen, Aashish Gulati, Jitendra Mangwani, Claire Brockett, Elise Pegg

Research output: Contribution to conferenceAbstractpeer-review

Abstract

Objectives:
The aim of this study was to develop an open-source finite element model of the ankle for identification of the best clinical treatment to restore stability to the ankle after injury.

Methods:
The ankle geometry was defined from the Visible Human Project Female CT dataset available from the National Library of Medicine, and segmented using Dragonfly software (Object Research Systems, 2020). The finite element model was created with FEBio software (University of Utah, 2021) using the dynamic nonlinear implicit solver. Linear isotropic material properties were assigned to the bones (E=7300MPa, ν=0.3, ρ=1730kg/m3) and cartilage (E=10MPa, ν=0.4, ρ=1100kg/m3). Spring elements were used to represent the ligaments and material properties were taken from Mondal et al. [1]. Lagrangian contact was defined between the cartilaginous surfaces with μ=0.003. A standing load case was modelled, assuming even distribution of load between the feet. A reaction force of 344.3N was applied to the base of the foot, a muscle force of 252.2N, and the proximal ends of the tibia and fibula were fully constrained.

Results:
The von Mises stresses closely matched those reported by Mondal et al. for the fibula (Present study: 1.00MPa, Mondal: 1.30MPa) and the talus (Present study: 2.20MPa, Mondal: 2.39MPa). However stresses within the tibia were underpredicted (Present study: 1.08MPa, Mondal: 5.86MPa). This was because the present study modelled a shorter tibial length because of a limitation in the CT slices available, which reduced the bending force.

Conclusions:
This first step in producing an open source ankle model for the biomechanics community has shown the potential of the model to generate results comparable with those found in the literature. Future work is underway to examine the robustness of the model under different loading and explore alternative open-source CT datasets.

[1] Mondal, S., & Ghosh, R. (2017). J Orthopaedics, 14(3), 329–335. https://doi.org/10.1016/j.jor.2017.05.003
Original languageEnglish
Publication statusPublished - 14 Sep 2021
EventBritish Orthopaedic Research Society - Online, Online, UK United Kingdom
Duration: 13 Sep 202114 Sep 2021
https://borsoc.org.uk/bors-2021/

Conference

ConferenceBritish Orthopaedic Research Society
Abbreviated titleBORS
Country/TerritoryUK United Kingdom
CityOnline
Period13/09/2114/09/21
Internet address

Keywords

  • Finite element analysis
  • Ankle
  • Open-source

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