Association of four or more rib fractures with complications in isolated blunt chest trauma.

INTRODUCTION: Rib fractures are common in blunt chest trauma and are associated with significant morbidity. Although increasing rib fracture count has been linked to worse outcomes, a clear and clinically applicable threshold for complication risk remains uncertain. This study aimed to evaluate the predictive value of rib fracture burden in patients with isolated blunt chest trauma and to identify a clinically meaningful cut-off.

METHODS: This retrospective observational study included adult patients with isolated blunt chest trauma presenting between January 2021 and December 2025 at a tertiary care center. Patients with radiologically confirmed rib fractures were analyzed. The primary outcome was the development of thoracic complications. Multivariable logistic regression was performed to identify factors independently associated with complications. Receiver operating characteristic (ROC) analysis was used to determine the optimal cut-off value of rib fracture count.

RESULTS: A total of 184 patients were included. The median number of rib fractures was 3.0 (IQR: 2.0-4.0). Complications were significantly associated with a higher number of rib fractures (median 4 vs 2, p < 0.001). In multivariable analysis, age (OR = 1.07, 95% CI: 1.03-1.12), rib fracture count (OR = 33.23, 95% CI: 11.13-99.18), and displaced fractures (OR = 161.48, 95% CI: 21.24-1227.78) were independently associated with complications. ROC analysis demonstrated strong predictive performance (AUC = 0.872, 95% CI: 0.814-0.920). The optimal threshold was ≥4 rib fractures, with 65% sensitivity and 98% specificity.

CONCLUSION: Rib fracture count is strongly associated with complications in isolated blunt chest trauma. A threshold of ≥4 rib fractures may provide a simple and clinically useful tool for early risk stratification.