Minimally invasive treatment of calcaneal fractures via the sinus tarsi approach based on a 3D printing technique.

The sinus tarsi approach can be used for a limited exposure of the calcaneal fracture site. The reduction of the posterior articular surface, the shape of the calcaneus, the precise placement of the sustentacular screw (SS), the posterior articular surface screw of the calcaneal (PASS), and the long axis screw of the calcaneal (LAS) are still challenging. To that end, we proposed a minimally invasive technique for the treatment of calcaneal fractures via the sinus tarsi approach in combination with a three-dimensional (3D) printing technique. First, a 3D reconstructed model of the bilateral calcanei was obtained according to the computed tomography (CT) scan data and was used to simulate the placement of screws and acquire the screw trajectory parameters. Next, using 3D printing, a model of the calcaneus was printed, and the minimally invasive steel plate was pre-shaped to fit the lateral wall of the model. Finally, a total of 25 patients underwent this procedure. The results showed significant accuracy improvement in terms of the SS, PASS and LAS placement and in terms of the parameters including Bohler's angle, Gissane's angle, and the calcaneal width. In this work, the technique of the personalized minimally invasive treatment of calcaneal fractures improved the accuracy of screw placement (SP) and the reduction rate of posterior articular surface, improved the shape of the calcaneus, and increased the precision of the minimally invasive treatment of calcaneal fractures via the sinus tarsi approach.