Abstract
<title>Abstract</title> <p> <bold>Background</bold> Elderly patients with severe multiple rib fractures undergoing surgical fixation treatment exhibit a high incidence of postoperative complications. Existing prediction tools largely fail to integrate the combined risk effects of underlying diseases and trauma-related indicators, and lack simple scoring systems suitable for rapid bedside assessment in clinical settings.This study utilized single-center real-world retrospective cohort data to identify independent predictive factors for short-term adverse outcomes postoperatively in this population, analyze the risk interactions between each risk factor pairwise, and develop a rapidly applicable preoperative risk stratification scoring system. <bold>Methods</bold> A retrospective study was conducted involving 286 severe multiple rib fractures patients aged ≥ 60 years who underwent internal fixation surgery for rib fractures at our hospital between January 2013 and December 2023. These patients were categorized into an adverse outcome group and a no-adverse-outcome group based on the occurrence of various adverse clinical events within 30 days postoperatively. Univariate and multivariate binary Logistic regression were adopted to screen independent risk factors; 15 sets of pairwise interaction terms constructed from the 6 independent risk indicators were incorporated into the regression model to assess risk superposition and synergistic amplification effects; ROC curves were used to compare the predictive performance of single indicators and the six-factor combined model; a weighted scoring scale was established based on adjusted odds ratios, and risk stratification verification was completed. <bold>Results</bold> A total of six independent risk factors for adverse postoperative outcomes were identified: age ≥ 75 years, preoperative presence of chronic obstructive pulmonary disease (COPD), hypoalbuminemia (serum albumin < 30 g/L), a delay between injury and surgery > 48 hours, Injury Severity Score (ISS) ≥ 25, and severe pulmonary contusion. Among the 15 pairs of indicators, only 3 groups of trauma-related indicators exhibited significant synergistic interactions (all P < 0.001); no statistically significant interaction effects were observed in the remaining 12 groups. This suggests that only acute trauma indicators can induce a cascading amplification effect of inflammation, while chronic underlying conditions solely increase risk without mutual exacerbation effects. The AUC interval for a single risk factor was 0.665–0.734, while the combined six-factor model achieved an AUC of 0.874 (95% CI: 0.829–0.919). The optimal Jordon index cutoff exhibited a sensitivity of 85.30% and specificity of 79.70%. This study developed a simplified weighted scoring scale ranging from 0 to 20, with an AUC of 0.868, which showed no statistically significant difference in predictive performance compared to the multivariate regression model. Patients were classified into low-, medium-, and high-risk groups based on total scores, with postoperative adverse event incidence rates of 9.82%,32.38%, and 76.81%, respectively; complication risks increased progressively with higher scores. <bold>Conclusions</bold> Advanced age, preoperative chronic respiratory diseases, preoperative malnutrition, surgical delay, and severe chest trauma each independently increase the risk of short-term complications in elderly patients undergoing rib fixation surgery; when multiple acute trauma risk factors coexist, the incidence of complications is significantly amplified synergistically. The six-factor combined model demonstrates stable and reliable predictive efficacy, and its accompanying simple scoring scale enables rapid preoperative risk stratification, guiding clinicians in developing personalized perioperative intervention plans and reducing the incidence of postoperative adverse events. </p>