Three-dimensional printing technique aids screw insertion into the sustentaculum tali of the internal fixation of intra-articular calcaneal fractures

Introduction: Treating complex calcaneus fractures remains challenging. This study evaluated the influence of 3D printing and simulation on precision screw insertion into the calcaneus sustentaculum tali (ST). Hypothesis: 3D printing and simulation improve the treatment for calcaneal fracture. Patients and Methods: This retrospective cohort study included 85 patients admitted with 93 Sanders type II-IV intra-articular fractures from January 2015 to June 2020. Multi-slice computed tomography (MSCT) images were used in the conventional group, and MSCT data were used to construct a 3D model of the calcaneus to simulate screw insertion and verify parameter accuracy in the 3D group. Results: The designed parameters (upward and backward oblique angles and screw-path length) were similar to the actual values in the 3D group (P=0.428,0.287,0.585) but not in the conventional group (P=0.01,0.002,0.023). The Maryland foot functional score, accuracy rate, and average screw number were higher and operative time was shorter in the 3D group (P=0.005,0.007,0.000,0.000). Discussion: Preoperative simulation using the 3D printing model helped guide the screws into the ST more accurately, lending better-quality treatment for Sanders type II-IV calcaneal fractures. Level of proof: III; Retrospective case-control study.