Construction and validation of a risk model for preventing intraoperative stress injury in elderly hip fractures

Objective To investigate the influencing factors of intraoperative stress injury in elderly patients with hip fractures, and establish a preventive risk prediction nomogram model.

Methods A total of 252 elderly patients who underwent hip fracture surgery were selected, and divided into the occurrence group (n = 42) and non-occurrence group (n = 210) according to whether stress injury occurred during the operation. The influencing factors of intraoperative stress injury in elderly patients with hip fractures were analyzed by multivariate logistic regression and differential analysis. The nomogram model for predicting the risk of intraoperative pressure injury was established, the ROC curve was used to analyze the efficiency of nomogram model, and its prediction stability and decision-making efficiency were verified.

Results The differences of the diabetes mellitus, fracture to operation time, operation time, intraoperative hypothermia, local moisture and body position movement were statistically significant between two groups (P ＜ 0.05 to P ＜ 0.01). The results of multivariate logistic regression analysis showed that the diabetes mellitus, longer operation time, intraoperative hypothermia, local moisture and body position movement were the independent risk factors of intraoperative stress injury in elderly patients with hip fractures (P ＜ 0.05 to P ＜ 0.01). The risk prediction nomogram model and ROC analysis revealed that the AUC of diabetes mellitus, operation time, intraoperative hypothermia, local moisture, body position movement and nomogram model were 0.629, 0.754, 0.638, 0.629, 0.698 and 0.905, respectively. The results of DeLong test showed that the AUC of the nomogram model was higher than that of each single factor (P ＜ 0.05). When the cut-off value was taken, the sensitivity and specificity of nomogram model were 0.905 and 0.810, respectively. Bootstrap (B = 1000) internal verification showed that the nomogram model had good stability, and the decision analysis found that the nomogram model had a positive net return rate.

Conclusions Diabetes mellitus, longer operation time, intraoperative hypothermia, local moisture and body position movement are the independent risk factors of intraoperative stress injury in elderly patients with hip fracture. The constructed nomogram model has high prediction accuracy and clinical decision value.