Objective:To explore the evaluation and influence factors of computed tomography(CT)and magnetic resonance imaging(MRI)on thoracolumbar burst fracture combined with injury of posterior ligament complex(PLC).Methods:A total of 68 patients with thoracolumbar burst fractures who were diagnosed and treated in Handan First Hospital from January 2020 to June 2023 were selected as the research object,and the surgical result was used as gold standard.The 32 cases,who were diagnosed as thoracolumbar burst fractures combined with PLC injury according to the gold standard,were divided into PLC group.The 32 cases without PLC injury were divided into non-PLC group.Before operation,all patients underwent CT and MRI examinations,and the positively and negatively predictive values of CT and MRI in diagnosing thoracolumbar burst fracture combined with PLC injury were calculated by four-grid method.The area under curve(AUC)value,sensitivity and specificity of CT and MRI in diagnosing thoracolumbar burst fracture combined with PLC injury were analyzed by receiver operating characteristic(ROC)curve.Logistic regression model was used to analyze the risk factors of patients with thoracolumbar burst fracture who occurred PLC injury.The differences of the scores of ligamentous complex stability(LCS)score,intraspinal space occupancy rate and thoracolumbar injury classification and severity(TLICS)score,and the scoliosis angle(Cobb),superior iliac crest angle(SIEA),local kyphosis(LK)angle and intervertebral disc space depth(IISD)between two groups were compared.Results:For 68 with thoracolumbar burst fractures,the 34 cases were confirmed as PLC injury and 34 cases were confirmed as non-PLC injury by using CT examination.The positively and negatively predictive values of CT examination were respectively 70.59%(24/34)and 76.47%(26/34)for PLC injury,and the consistency between CT and gold standard was general(Kappa=0.471,P<0.001).The 33 cases were confirmed as PLC injury and 35 cases were confirmed as non-PLC injury by using MRI examination.The positively and negatively predictive values of MRI examination were respectively 90.91%(30/33)and 94.29%(33/35)for PLC injury,and the consistency between MRI examination and gold standard was general(Kappa=0.853,P<0.001).The diagnostic accuracy of MRI was 92.65%(63/68),which was significantly higher than that(73.53%,50/68)of CT(x2=8.843,P<0.05).ROC curve analysis showed that the AUC values of CT and MRI were respectively 0.730 and 0.919 in diagnosing thoracolumbar burst fracture combined with PLC injury.The sensitivities of them were respectively 70.60%and 75.40,and the specificities of them were respectively 88.20%and 95.70%.There were no significant differences between PLC group and non-PLC group in gender,age,body mass index(BMI),cause of injury,LCS score and intraspinal space occupancy rate(P>0.05).There were significant differences in TLICS score,Cobb angle,SIEA,LK and IISD between the two groups(x2=19.443,4.181,4.973,5.198,5.056,P<0.05),respectively.Logistic regression analysis showed that TLICS score>5 points,Cobb angle,SIEA,LK and IISD were risk factors that affected the occurrence of PLC injury in patients with thoracolumbar burst fracture(OR=13.973,1.155,1.365,1.385,5.262,P<0.001),respectively.Conclusion:The efficiency of MRI is higher than that of CT in diagnosing PLC injury in patients with thoracolumbar burst fracture,and TLICS score,Cobb angle,SIEA,LK and IISD have influences on the occurrence of PLC injury in patients with thoracolumbar burst fracture.