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ABSTRACT
Objective: In the surgery of calcaneal fracture, whether the sustentaculum tali screw should always be placed is widely controversial. The aim of this study was to explore the necessity and function of the sustentaculum tali screw placement for the treatment of Sanders type II calcaneal fracture.
Methods: The finite element analysis was used in this study. After the establishment of the finite element model of Sanders type II calcaneal fracture, the two internal fixation simulations were designed. In one model, the AO calcaneal plate was simulated on the lateral side of the calcanues with 7 screws being fixated at different position of the plate. In the other model, the calcaneus was fixated with the same AO calcaneal plate together with an additional screw being infiltrated into the sustentaculum tali. The two models were simulated under the same loading and the displacement of the fracture line and the stress distribution in the two models were calculated respectively.
Results: The maximum principal stress focused on the cortical bone of sustentaculum tali in both the models under the same loading. The displacement of the fracture line, the maximum principal stress of calcaneus and internal fixation system in the model with sustentaculum screw fixation were smaller than that in the model without sustentaculum screw fixation. The stress in the model with sustentaculum screw fixation was more dispersed.
Conclusions: The placement of sustentaculum tali screw is essential for fixation of type II calcaneal fracture to achieve the biomechanical stability.
KEYWORDS: Calcaneal fracture; Sustentaculum tali; Screws; Finite element analysis; Biomechanics.
doi: http://dx.doi.org/10.12669/pjms.305.5301
INTRODUCTION
Calcaneal fracture is common seen fracture in foot and ankle surgery, which accounts for 60%~65% of the entire tarsal bone fractures.1 The improper treatment of calcaneal fracture might lead to the severe calcaneal malunion, which can result in abnormal gait with symptoms and dysfunction of the joints and muscles, eventually leading to the pain and permanent disability.2
When the calcaneal fracture occurs, the vertical pressure from the talus often causes the calcaneus to be compressed while the posterior articular surface is usually comminuted. However, as the powerful tendons and ligaments in the surrounding of the sustentaculum tali, the displacement of the sustentaculum tali rarely occurs in the calcaneal fracture, which might provide powerful fixation site...