Machine learning-based prediction of perioperative complications in spine surgery: a large-scale model development...

Spinal surgery carries substantial perioperative risks. Early identification of high-risk patients is critical for improving outcomes. Machine learning (ML) can enhance predictive accuracy over traditional risk scores by modeling complex clinical data, but many existing models lack large, heterogeneous cohorts.

To develop and validate ML models for predicting perioperative complications in spine surgery, and assess fairness across patient subgroups.

We conducted a retrospective cohort study of 5,060 adult patients from the SpineReg registry (2015-2023), each with 160 preoperative demographic, clinical, imaging, and patient-reported outcome features. Six ML algorithms-logistic regression (LR), decision tree, k-nearest neighbors, naïve Bayes, random forest (RF), and eXtreme gradient boosting-were trained with 80/20 train-test split, cross-validation, and hyperparameter optimization. Class imbalance was addressed via repeated undersampling. Performance was assessed using area under the ROC curve (AUC), balanced accuracy, positive predictive value (PPV), standardized net benefit (sNB), calibration, and fairness metrics.

RF achieved the best performance, obtaining an AUC of 0.87, balanced accuracy of 0.80, PPV of 0.71, and sNB of 0.44. RF maintained robust performance across demographic and surgical subgroups. Key predictors of increased complication risk included sagittal imbalance, and multilevel surgery, whereas degenerative pathology and monosegmental fusion were protective. Sensitivity declined for rare complications but exceeded 75% for most categories.

RF-based models can accurately and equitably predict perioperative complications in diverse spine surgery contexts, supporting personalized counseling, targeted monitoring, and optimized resource allocation. Integration into clinical decision support systems may enhance surgical safety and efficiency.