Nonoperative management of rib fractures results in a high incidence of nonunion and malunion.

BACKGROUND

The true incidence of nonunion (NU) and malunion (MU) after traumatic rib fractures is unknown. Furthermore, contributory injury and patient factors to help guide treatment remain unclear.

METHODS

We conducted a retrospective cohort study of hospitalized patients with multiple traumatic rib fractures treated nonoperatively between 2014 and 2025 at a Level I trauma center. We included those with documented computed tomography imaging of the chest obtained at the time of injury and at least six months after injury. Study investigators assessed computed tomography imaging for NU (defined as persistent fracture gap) and MU (defined as abnormal angulation and cortical irregularity). Multivariable logistic regression was used to evaluate fracture charactereistics on the likelihood of developing NU/MU.

RESULTS

NU/MU was present in 40 of 219 patients (18.3%) and in 96 of 1229 individual fractures (7.8%). Regression modeling with anatomic rib-level covariates demonstrated bicortical displacement to be associated with NU/MU with an odds ratio of 20.9 (95% CI: 8.2-53.2, p < 0.001). Posterior location, flail segment, and offset fractures were also independently associated with NU/MU. In secondary regression analysis including patient-level covariates, smoking status was an independent predictor of NU/MU development (odds ratio: 2.8; 95% CI: 1.3-6.0, p = 0.006).

CONCLUSIONS

NU and MU were common after nonoperative management of chest wall trauma and strongly associated with bicortical displacement. Flail segment, posterior fracture location, and smoking status were also significant risk factors. Further work is needed to explore how surgical stabilization may influence the development or prevention of NU and MU. III. (J Trauma Acute Care Surg 2026;00:000-000 Copyright © 2026 Wolters Kluwer Health, Inc. All rights reserved.).

LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level III.