Abstract: Objective To explore the influencing factors of infection after internal fixation of traumatic pelvic fractures and establish a nomogram model.Methods A prospective study design wasused to conveniently select 246 patients with traumatic pelvic fractures who were treated at Hebei Medical University Third Hospital from October 2022 to February 2024 as the research subjects.Patients were divided into an infected group and a Non-infected group based on the infection status after open reduction and internal fixation.The difference between the two groups of covariates was balanced by 1∶1 propensity score matching.Logistic regression equations were used to analyze the factors that contribute to infection after internal fixation for traumatic pelvic fractures.R4.3.2 software was used to establish the nomogram model,and the receiver operating characteristic curve (ROC),calibration curve and decision curve were drawn to test the predictive efficacy of the nomogram model.Another 100 patients with traumatic pelvic fractures who were treated from March 2024 to December 2024 were selected for external validation of the nomogram model.Results After matching,the ISS score,IL-23,IL-17 and TLR7 in the infection group were (16.11±1.34) scores,(735.59±213.75) pg/ml,(542.42±160.66) pg/ml and (72.55±10.24) ng/ml,respectively,the incidence of acetabular fracture was 30.00%.The data in the non-infected group were (15.18±1.46) scores,(568.81±166.71) pg/ml,(400.03±118.86) pg/ml,(66.43±9.27) ng/ml and 10.00%,respectively(P<0.05).ISS score (OR:1.597),acetabular fracture (OR:2.296),IL-23 (OR:1.544),IL-17 (OR:1.512) and TLR7 (OR:1.384) were the influencing factors of infection after internal fixation in patients with traumatic pelvic fracture (P<0.05).The AUC of nomogram model for predicting infection after internal fixation of traumatic pelvic fractures was 0.885 and 0.886,respectively.The predicted probability was close to the actual observed probability.When the threshold probability was between 0.1 and 0.8,or between 0.0 and 0.8,the net patient benefit was high.Conclusion The nomogram model constructed based on ISS score,acetabular fracture,IL-23,IL-17,and TLR7 has good predictive performance and can provide a reliable tool for early screening of infection after internal fixation of traumatic pelvic fractures,assisting clinical treatment decisions.

Key words: traumatic pelvic fracture, internal fixation, infected, influencing factors, nomograph model