Establishment and evaluation of a prognostic model for surgical outcomes of patients with atlanto-axial dislocations.

Objective Atlanto-axial dislocations (AADs) are potentially fatal disturbances with high spinal cord compression syndrome. As surgeons are still uncertain who is likely to benefit the most from surgery, a prediction tool is needed to provide decision-making support. Methods The model was established based on 108 patients with AADs using multiple binary logistic regression analysis and evaluated by calibration plot and the area under the receiver operating curve (AUC). Bootstrapping was used for internal validation. Results The prognostic model can be expressed as: logit(P) = -2.2428 + 0.3168SCOPE - 2.0375SIGNAL, in which two covariates were accepted (SCORE represents the preoperative modified Japanese Orthopedic Association (mJOA) score and SIGNAL represents the intramedullary hyperintense T-weighted imaging (TWI) with AUC = 0.8081). Conclusions The model was internally valid, and the preoperative mJOA score and hyperintense TWI were important predictors of outcomes. The threshold was defined as logit(P) = -0.7282 according to the receiver operating curve (ROC).