Influencing Factors and Nomogram for Reoperation After Internal Fixation of Displaced Femoral Neck Fractures

Yu Hongwei; Zhou Xuelian; Lu Junqin; Yu Junfei; Gu Guangxue

Abstract：Objective To analyze the influencing factors of reoperation after internal fixation in patients with displaced femoral neck fractures and to construct a nomogram.Methods From January 2020 to January 2024,342 patients with displaced femoral neck fractures who underwent internal fixation at the First Affiliated Hospital of Kangda College of Nanjing Medical University were enrolled.Patients were allocated 1∶1 into a modeling group(n=171)and a validation group(n=171).Follow-up lasted 1 year.In the modeling group,76 patients who required reoperation formed the reoperation group and 95 who did not formed the non-reoperation group.The incidence of reoperation after surgery was 44.44％.Multivariate logistic regression was used to identify independent risk factors for modeling group reoperation,and a nomogram was constructed using R software.Model discrimination and calibration were assessed by receiver operating characteristic(ROC)curve and Hosmer-Lemeshow(H-L)test.Results Multivariate logistic regression analysis revealed that age＞50 years,smoking,Garden classification,intraoperative reduction quality,and time from injury to surgery were significant influencing factors for reoperation after internal fixation in patients with displaced femoral neck fractures(P＜0.05).The area under the ROC curve(AUC)for predicting reoperation in the modeling group was 0.854[95％CI(0.792,0.903),P＜0.05],with a sensitivity of 88.16％and specificity of 71.58％.The H-L test yielded x2=9.389(P=0.310),and the calibration curve closely approximated the ideal curve,with a mean absolute error of 0.058.For the validation group,the AUC was 0.878[95％CI(0.820,0.923),P＜0.05],with a sensitivity of 85.92％and specificity of 79.00％.The H-L test result was x2=6.185(P=0.627),and the calibration sely matched the ideal curve,curve clowith a mean absolute error of 0.047.Decision curve analysis demonstrated that the constructed nomogram model exhibited favorable clinical validity.Conclusion Early assessment of reoperation risk in patients with displaced femoral neck fractures using the constructed nomogram can guide timely interventions to reduce reoperation rates.