Abstract
BACKGROUND: Thoracolumbar fractures are common and complex spinal injuries, critical to the training of assistant general practitioners (AGP). Traditional lecture-based teaching struggles to effectively convey the intricate three-dimensional anatomy of these fractures. While both Problem-Based Learning (PBL) and 3D printing (3DP) have demonstrated individual benefits in medical education, their combined effect has not been rigorously evaluated for AGP training on thoracolumbar fractures. This randomized controlled trial (RCT) aimed to compare the effectiveness of a 3D printing-integrated PBL approach with conventional lecture-based teaching in improving AGP trainees' knowledge and competencies regarding thoracolumbar fractures. METHODS: A randomized controlled trial was conducted at Zhuzhou 331 Hospital from June 2022 to September 2023. Eighty AGP trainees were randomly assigned to the 3DP group (n = 40) using 3D-printed fracture models within a PBL curriculum, or the control group (n = 40) receiving traditional lecture-based instruction. Randomization was performed with computer-generated sequences, and allocation concealment was maintained. The primary outcome was the score on a post-course knowledge test, with secondary outcomes including a delayed test at 4 weeks and self-reported evaluations. Outcomes were analysed with Mann-Whitney U tests and reported as medians (IQR) with effect size r and 95% CI. RESULTS: Eighty learners were randomised (3DP n = 40; control n = 40) and completed follow-up. The 3DP group achieved significantly higher scores than the control group on both the immediate post-course test (80.0 vs. 70.0, U = 523.50, r = 0.301 (95% CI 0.087-0.488), p = 0.007) and the delayed post-course test (4 weeks) (82.5 vs. 70.0, U = 255.00, r = 0.593 (95% CI 0.429-0.719), p < 0.001). Learner-reported outcomes favoured 3DP in 9/10 domains, including clinical thinking, initiative, self-study, anatomy recognition, teamwork and satisfaction (all p < 0.001), with no difference in mastery of basic knowledge (p = 0.640). CONCLUSION: Integrating 3D printing with PBL significantly improved AGP trainees' knowledge of thoracolumbar fractures and enhanced their clinical reasoning, engagement, and satisfaction. This combined approach offers a promising educational strategy for AGP training. TRIAL REGISTRATION: Not applicable.