Comparative Accuracy of Preoperative Planning Technologies in Spinal Deformity Surgery: A Systematic Review.

Preoperative surgical planning is central to achieving optimal spinal alignment in spinal deformity (SD) surgery; however, the extent to which different planning modalities accurately translate preoperative goals into surgical outcomes remains incompletely characterized. This systematic review evaluates the accuracy and clinical usefulness of existing preoperative planning tools in SD surgery. A systematic search of MEDLINE, Embase, and the Cochrane Library was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies reporting quantitative accuracy data for any preoperative planning modality in SD surgery were included. Study quality was assessed using the Newcastle-Ottawa Scale, the National Institutes of Health (NIH) Quality Assessment Tool, and the Cochrane Risk of Bias 2 (RoB 2) tool for randomized controlled trials. A total of 32 studies involving more than 3,500 patients published between 2006 and 2025 were included, encompassing the following six planning modalities: robotic-assisted navigation, three-dimensional (3D)-printed patient-specific guides, virtual surgical planning (VSP) software, advanced imaging techniques, mathematical regression formulas, and artificial intelligence (AI)-assisted platforms. Pedicle screw placement demonstrated high rates of accuracy overall with planning-assisted techniques than with 72-90% with free-hand techniques. A limited proportion of cases achieved simultaneous attainment of all three primary sagittal alignment targets, despite per-parameter achievement rates exceeding 68%. The integration of patient-specific rods within virtual surgical planning (VSP) contributed to improved alignment outcomes. Three-dimensional printing-guided osteotomy demonstrated a substantial reduction in neurological complications compared with traditional freehand techniques. Planning-assisted technologies improve surgical accuracy across multiple modalities in SD surgery; however, simultaneous achievement of all sagittal correction goals remains challenging. Key limitations include the lack of standardized outcome measures and the need for prospective comparative studies evaluating the relationship between planning accuracy and patient-reported outcomes. This systematic review aimed to map available planning tools, evaluate their accuracy in achieving preoperative goals, and identify factors associated with planning success or failure.