The effect of screw insertion configuration of Sinus Tarsi plate on biomechanical performance using finite element analysis

Sinus Tarsi plates are used as implants for minimally invasive surgery of calcaneus bone fractures. This study evaluated the screw fixation patterns of Sinus Tarsi plates for optimal biomechanical performance. Six three-dimensional (3D) finite element models with different positional screws were evaluated for calcaneus fracture stabilization using Sinus Tarsi plates with 5, 6, and 7 holes. Walking stance conditions as heel strike, midstance, and push-off phases were used to compare loading. Results indicated that the equivalent (EQV) stress exhibited in the implant was higher than in the surrounding bone, with the highest value during the push-off phase. The maximum EQV stress or risk of failure decreased when an insertion screw was placed in the anterior bone using a 7-hole plate, and the most stable strain result at the fracture bone site was recorded for a Sinus Tarsi plate with 7 holes (TT 7-1). The screw insertion pattern and configuration of the Sinus Tarsi plate impacted the biomechanical performance of the calcaneal fracture.