Three-dimensional modelling and finite element analysis of an ankle external fixator

• Main Authors: Ramlee, Muhammad Hanif Anif, Abdul Kadir, Mohammed Rafiq, Harun, Habibollah
• Format: Conference or Workshop Item
• Published: 2013
• Subjects: QH Natural history
• Online Access: http://eprints.utm.my/id/eprint/63687/; https://dx.doi.org/10.4028/www.scientific.net/AMR.845.183
• Institution: Universiti Teknologi Malaysia

The use of ankle external fixator to treat pilon fracture Type III is popular amongst surgeons as it can reduce complications such as non-union and mal-union. Even though configurations of the connecting bars are important, the material also plays a major factor for a successful outcome. In this paper, the Delta external fixator with simulated ankle pilon fractures Type III were modelled and analysed under two different materials; titanium alloy and stainless steel. The finite element model includes tibia, fibula, talus, calcaneus, cuboid, navicular, three cuneiforms and five metatarsals bone. To simulate the pilon fractures Type III, a cutting segment was utilised. The ligaments were assigned with linear spring properties and cartilages were modelled using Mooney-Rivlin hyper-elastic behaviour. The Delta external fixator was designed using a three-dimensional software with two different material properties - titanium alloy and stainless steel. High von Mises stress concentrated at the pin-bone interface with the highest value observed for the titanium fixation. The results also showed less deformation for the stainless steel compared to titanium.