Abstract
BACKGROUND: This study validates the intra-hospital design and 3D printing process of personalized surgical guides to enhance the accuracy of pedicle screw insertion in patients with thoracic scoliotic deformities. It introduces a novel collaborative paradigm between surgeons and engineers, aiming to improve efficiency and reduce errors in the manufacturing of patient-specific instruments (PSIs). METHODS: The process began with the generation of 3D biomodels of vertebrae from computed tomography scans. Surgical guides were then created using two 3D printing techniques: Fused Filament Fabrication (FFF) with polylactic acid (PLA) and Stereolithography (SLA) with photopolymer resin. Three different prototypes were compared based on multifactorial indicators, including economic cost, macroscopic surface finish, and mechanical stability. The mechanical performance of the guides was evaluated under loads generated during pedicle screw penetration and threading. RESULTS AND DISCUSSIONS: PLA models printed using FFF were found to be cheaper and simpler to manufacture than SLA resin models. Despite differences observed under a microscope, PLA models exhibited a macroscopic surface finish comparable to that of SLA resin models. Both materials demonstrated similar mechanical properties, although their values were lower than those reported in the manufacturer's datasheet. Importantly, both types of guides successfully withstood the mechanical loads generated during surgical procedures. The intra-hospital collaboration between engineers and surgeons was identified as a key factor in improving outcomes and reducing error risks, showcasing the benefits of interdisciplinary teamwork. CONCLUSIONS: 3D-printed PSIs made from PLA using FFF are more cost-effective and quicker to produce compared to SLA resin models, while achieving similar results in surface finish and mechanical stability. The implementation of a collaborative approach between engineers and surgeons within hospital settings enhances the efficiency and accuracy of patient-specific surgical guide manufacturing, offering a promising solution for improving surgical outcomes in thoracic scoliotic deformities.