Biomechanical comparison of modified Calcanail system with plating fixation in intra-articular calcaneal fracture: A finite element analysis

The calcanail system is a novel intramedullary approach for calcaneal fractures but is believed to be insufficient to treat complex fractures. We propose a modified Calcanail technique by adding a transfixation screw to improve stability. The aim of this study was to evaluate the biomechanical stability of the modified Calcanail system and compare it with the traditional Calcanail system and plate fixation. A Sanders type-IIIAB calcaneal fracture model was built and simulated fixation with the three implants. A vertical loading of 700 N was applied to the subtalar joint surfaces, and the posteroinferior calcaneal tuberosity was fixed. Construct stiffness, fracture migration, and von Mises stress were assessed. The results showed the modified Calcanail system demonstrated the highest construct stiffness, smallest migration, and lowest von Mises stress among three fixations. The study suggested that the modified Calcanail system can provide comparatively sufficient stability, that makes it preferable to treat complex calcaneal fractures.