Abstract:

Objective To identify independent risk factors for acute cerebral infarction （ACI） in elderly patients with hip fracture and to develop a clinically applicable nomogram for individualized risk prediction. Methods This retrospective study included 603 elderly patients with hip fracture admitted to the Third Department of Traumatic Hip Surgery， Tianjin Hospital， China， between January 2023 and June 2025. Patients were randomly allocated to a training cohort （n = 400） and a validation cohort （n = 203） and categorized based on the occurrence of ACI. Clinical and laboratory variables were collected. Univariate and multivariable logistic regression analyses were performed to identify independent predictors of ACI. A nomogram was constructed using R software based on these predictors， and its performance was evaluated in terms of discrimination， calibration， and clinical utility. Results In the training cohort， 27 of 400 patients （6.75%） developed ACI. Multivariable logistic regression identified seven independent predictors： prior cerebral infarction， lower lymphocyte count， lower albumin level， elevated serum homocysteine， higher cystatin C， elevated glycated hemoglobin （HbA_1c）， and prolonged prothrombin time （all P < 0.05）. The nomogram based on these factors demonstrated excellent discrimination， with an area under the ROC curve （AUC） of 0.896 （95%CI： 0.843 ? 0.949） in the training cohort and 0.830 （95%CI： 0.737 ? 0.923） in the validation cohort. Calibration plots showed good agreement between predicted and observed probabilities of ACI. Decision curve analysis confirmed the model's favorable clinical net benefit across a range of threshold probabilities. Conclusions Prior cerebral infarction， lymphopenia， hypoalbuminemia， hyperhomocysteinemia， elevated cystatin C， higher HbA1c， and prolonged prothrombin time are independent predictors of ACI in elderly hip fracture patients. The developed nomogram exhibits robust discrimination， calibration， and clinical utility， offering a practical tool to facilitate early identification and targeted prevention of ACI in this high-risk population.

Key words: hip fracture, acute cerebral infarction, elderly patients, risk factor, nomogram