Objective: This study aimed to create an ideal machine learning model to predict mechanical complications in adult spinal deformity (ASD) surgery based on GAPB (modified global alignment and proportion scoring with body mass index and bone mineral density) factors.
Methods: Between January 2009 and December 2018, 238 consecutive patients with ASD, who received at least 4-level fusions and were followed-up for ≥ 2 years, were included in the study. The data were stratified into training (n = 167, 70%) and test (n = 71, 30%) sets and input to machine learning algorithms, including logistic regression, random forest gradient boosting system, and deep neural network.
Results: Body mass index, bone mineral density, the relative pelvic version score, the relative lumbar lordosis score, and the relative sagittal alignment score of the global alignment and proportion score were significantly different in the training and test sets (p < 0.05) between the complication and no complication groups. In the training set, the area under receiver operating characteristics (AUROCs) for logistic regression, gradient boosting, random forest, and deep neural network were 0.871 (0.817-0.925), 0.942 (0.911-0.974), 1.000 (1.000-1.000), and 0.947 (0.915-0.980), respectively, and the accuracies were 0.784 (0.722-0.847), 0.868 (0.817-0.920), 1.000 (1.000-1.000), and 0.856 (0.803-0.909), respectively. In the test set, the AUROCs were 0.785 (0.678-0.893), 0.808 (0.702-0.914), 0.810 (0.710-0.910), and 0.730 (0.610-0.850), respectively, and the accuracies were 0.732 (0.629-0.835), 0.718 (0.614-0.823), 0.732 (0.629-0.835), and 0.620 (0.507-0.733), respectively. The random forest achieved the best predictive performance on the training and test dataset.
Conclusion: This study created a comprehensive model to predict mechanical complications after ASD surgery. The best prediction accuracy was 73.2% for predicting mechanical complications after ASD surgery.
Keywords: Adult spinal deformity; Body mass index; Bone mineral density; Machine learning; Mechanical complication; Random forest.