Application of Artificial Intelligence and 3D Printing for Surgical Planning in Single-level Transforaminal Lumbar Interbody Fusion

Study Design: Prospective cohort study. Objective: To evaluate and compare the performance of artificial intelligence (AI) and 3D printing technologies in preoperative planning for single-level transforaminal lumbar interbody fusion (TLIF). Summary of Background Data: Accurate surgical planning is essential to restore spinal alignment and optimize outcomes in TLIF. While AI and 3D printing have been individually applied in spine surgery, limited studies have compared their predictive accuracy for key parameters such as cage height and postoperative alignment. Methods: Twenty patients undergoing single-level TLIF were included. An AI model trained on 311 lumbar x-rays was used to predict cage height and postoperative pelvic incidence minus lumbar lordosis (PI–LL). Separately, 3D-printed surgical planning models were created from CT-based 2D planning. The performance of the AI model during external validation and the performance of the 3D printing model were evaluated by calculating accuracy, root mean square error (RMSE), and mean absolute error (MAE). Due to the small sample size (n=20) and non-normal data distribution, the Wilcoxon signed-rank test was applied to compare the two methods. Results: The AI model achieved an RMSE of 3.28 mm and an MAE of 2.91 mm in cage height prediction. In contrast, the 3D printing approach showed superior accuracy with an RMSE of 0.59 mm and an MAE of 0.25 mm. For postoperative PI-LL prediction, 3D printing also outperformed AI, demonstrating lower RMSE and MAE values (2.62° and 2.02°, respectively). Statistical analysis indicated significant differences in PI-LL prediction between the models ( P =0.037), although no significant difference was found in cage height prediction ( P =0.249). Conclusions: The application of AI and 3D printing significantly enhances the precision of surgical planning in single-level TLIF, improving the selection of appropriate surgical interventions.