# Severely displaced rib fractures are independently associated with reduced pulmonary function at 3 months

## TL;DR

Severely displaced rib fractures are linked to worse lung function three months after injury, even in non-flail chest cases.

## Contribution

Identifies displaced rib fractures as an independent risk factor for reduced pulmonary function in trauma patients.

## Key findings

- Each additional displaced rib increases odds of FVC < 80% by 31% at 3 months post-trauma.
- Effect is strongest in patients with non-flail chest injuries.
- Three or more displaced fractures is the optimal cutoff for predicting impaired pulmonary function.

## Abstract

Multiple rib fractures are common injuries resulting from blunt chest trauma. However, the effect of rib fracture displacement on pulmonary ventilation remains unclear. This study aimed to investigate the effect of severely displaced ribs on pulmonary ventilation function (PVF) 3 months post-trauma.

This retrospective case–control study was conducted at Chang Gung Memorial Hospital. Patients with multiple rib fractures (≥ 3) who underwent chest computed tomography (CT) from January 2019 to September 2023 were included. Patient demographics, injury severity, and rib fracture morphology were assessed. Displaced rib fractures were defined as bicortical displacements observed on CT. PVF was measured using forced vital capacity (FVC) and forced expiratory volume in 1 s. Univariate and multivariate logistic and linear regression analyses were performed to determine whether displaced rib fractures significantly affected PVF 3 months post-trauma.

Overall, 111 patients with multiple rib fractures were included. Displaced rib fractures were identified as an independent risk factor for having FVC < 80% at 3 months post-trauma, with each additional severely displaced rib increasing the odds by 31% (odds ratio: 1.31, 95% CI 1.09–1.57, p = 0.004). Subgroup analysis revealed that this effect was particularly significant in patients with non-flail chests. The receiver operating characteristic curve and Youden index identified that the optimal cutoff value for significantly displaced rib fractures affecting PVF was three or more fractures.

Severely displaced rib fractures significantly impact PVF 3 months post-trauma.

The online version contains supplementary material available at 10.1186/s13017-025-00667-7.