Evaluation of 3D Printed Materials for Surgical Education in Orthopaedic and Trauma Surgery: A Focus on Osteotomy and Osteosynthesis

Introduction: Three-dimensional (3D) printing enables the creation of anatomically accurate and customizable bone models for surgical training. However, limited evidence exists regarding which stereolithography (SLA) materials most realistically replicate bone behavior during osteotomy and osteosynthesis. This study systematically compared eight SLA resins to identify optimal materials for orthopaedic and trauma surgery simulation. Methods Distal fibula models were fabricated from eight Formlabs resins (Grey Pro, High Temp, Tough 1500, Tough 2000, Durable, Rigid 4K normal cure, Rigid 4K cure without heat [cwh], and Rigid 10K) using SLA printing. All models were filled with rigid polyurethane foam (150 g/cm³) to simulate trabecular bone. Six trauma surgeons evaluated each model on a six-point Likert scale for visual appearance, drilling, sawing, screwing, and splitting behavior. Statistical comparisons were performed using one-way ANOVAs followed by Tukey's post-hoc test for multiple comparisons. Results Significant differences between-material were observed for appearance ( p  = 0.013), screwing ( p  = 0.025), splitting ( p  < 0.001), and training adequacy ( p  < 0.001). Rigid 4K (cwh) achieved the highest overall realism rating (4.3 ± 0.8) and unanimous suitability for surgical training (100%). It outperformed high-stiffness resins such as Rigid 10K ( p  = 0.009) and heat-cured Rigid 4K ( p  < 0.001), which tended to fracture abruptly and lacked realistic splintering. Tough 1500, Tough 2000, and Durable also demonstrated favorable handling and fracture characteristics, providing cost-effective alternatives for specific training tasks. Conclusion Among eight SLA resins tested, Rigid 4K (cure without heat) most closely replicated the tactile and mechanical properties of human bone. The combination of a rigid outer shell and polyurethane foam core provided lifelike feedback during drilling, sawing, and fixation, supporting its use in structured orthopaedic and trauma curricula. The findings establish empirical material benchmarks for developing standardized, reproducible 3D-printed training models in surgical education.