Development and validation of a risk prediction model for pseudarthrosis after transforaminal lumbar interbody fusion: A retrospective analysis.

Background: Pseudarthrosis is a common complication of transforaminal lumbar interbody fusion (TLIF) that can affect the long-term prognosis and increase revision surgery risk. Therefore, it is crucial to investigate the risk factors associated with pseudarthrosis and develop a predictive model.

Methods: Patients who underwent TLIF at a single hospital between January 2019 and June 2021 were included. Each patient's fusion status was determined based on thin-section lumbar spine CT scans performed at least one year postoperatively. A nomogram was subsequently established to predict the probability of pseudarthrosis based on the results of least absolute shrinkage and selection operator (LASSO) and multivariable analysis. Receiver operating characteristic curve (ROC), calibration curve, and decision curve analysis (DCA) were applied to evaluate the prediction effect and clinical value of the model.

Results: In total, 284 patients (131 men [46.1 %]; mean [standard deviation, SD] age, 63.0[12.1] years) were included in the analysis (mean [SD] follow-up, 19.2[9.2] months). The incidence of pseudarthrosis was 13.4% (38/284). In LASSO and multivariable analysis, independent risk factors for pseudarthrosis included: history of smoking (odds ratio [OR]:2.966, 95% confidence interval [CI]: 1.135-7.750, P=0.027), osteoporosis (OR=6.362, 95% CI: 2.433-16.636, P<0.001), and the change of mean disc height (ΔMDH) (OR=2.401, 95% CI: 1.638-3.519, P<0.001). The areas under the curves (AUC) in the training and validation cohorts were 0.870 and 0.809, respectively.

Conclusions: History of smoking, osteoporosis, and ΔMDH are all independent risk factors of pseudarthrosis following TLIF surgery; a nomogram based on these may help predict the probability of pseudarthrosis.