Are the rib fracture score and different computed tomography measures of obesity predictors for mortality in patients with rib fractures? A retrospective cohort study

Traumatic rib fracture patterns associated with bone mineral density statuses derived from CT images

Background

The impact of decreased bone mineral density (BMD) on traumatic rib fractures remains unknown. We combined computed tomography (CT) and artificial intelligence (AI) to measure BMD and explore its impact on traumatic rib fractures and their patterns.

Methods

The retrospective cohort comprised patients who visited our hospital from 2017-2018; the prospective cohort (control group) was consecutively recruited from the same hospital from February-June 2023. All patients had blunt chest trauma and underwent CT. Volumetric BMD of L1 vertebra was measured by using an AI software. Analyses were done by using BMD categorized as osteoporosis (<80 mg/cm3), osteopenia (80-120 mg/cm3), or normal (>120 mg/cm3). Pearson's χ2, Fisher's exact, or Kruskal-Wallis tests and Bonferroni correction were used for comparisons. Negative binomial, and logistic regression analyses were used to assess the associations and impacts of BMD status. Sensitivity analyses were also performed.

Findings

The retrospective cohort included 2,076 eligible patients, of whom 954 (46%) had normal BMD, 806 (38.8%) had osteopenia, and 316 (15.2%) had osteoporosis. After sex- and age-adjustment, osteoporosis was significantly associated with higher rib fracture rates, and a higher likelihood of fractures in ribs 4-7. Furthermore, both the osteopenia and osteoporosis groups demonstrated a significantly higher number of fractured ribs and fracture sites on ribs, with a higher likelihood of fractures in ribs 1-3, as well as flail chest. The prospective cohort included 205 eligible patients, of whom 92 (44.9%) had normal BMD, 74 (36.1%) had osteopenia, and 39 (19.0%) had osteoporosis. The findings observed within this cohort were in concurrence with those in the retrospective cohort.

Interpretation

Traumatic rib fractures are associated with decreased BMD. CT-AI can help to identify individuals who have decreased BMD and a greater rib fracture rate, along with their fracture patterns.

Risk factors that predict mortality in patients with blunt chest wall trauma: an updated systematic review and meta-analysis

BACKGROUND

Over the last 10 years, research has highlighted emerging potential risk factors for poor outcomes following blunt chest wall trauma. The aim was to update a previous systematic review and meta-analysis of the risk factors for mortality in blunt chest wall trauma patients.

METHODS

A systematic review of English and non-English articles using MEDLINE, Embase and Cochrane Library from January 2010 to March 2022 was completed. Broad search terms and inclusion criteria were used. All observational studies were included if they investigated estimates of association between a risk factor and mortality for blunt chest wall trauma patients. Where sufficient data were available, ORs with 95% CIs were calculated using a Mantel-Haenszel method. Heterogeneity was assessed using the I² statistic.

RESULTS

73 studies were identified which were of variable quality (including 29 from original review). Identified risk factors for mortality following blunt chest wall trauma were: age 65 years or more (OR: 2.11; 95% CI 1.85 to 2.41), three or more rib fractures (OR: 1.96; 95% CI 1.69 to 2.26) and presence of pre-existing disease (OR: 2.86; 95% CI 1.34 to 6.09). Other new risk factors identified were: increasing Injury Severity Score, need for mechanical ventilation, extremes of body mass index and smoking status. Meta-analysis was not possible for these variables due to insufficient studies and high levels of heterogeneity.

CONCLUSIONS

The results of this updated review suggest that despite a change in demographics of trauma patients and subsequent emerging evidence over the last 10 years, the main risk factors for mortality in patients sustaining blunt chest wall trauma remained largely unchanged. A number of new risk factors however have been reported that need consideration when updating current risk prediction models used in the ED.

PROSPERO REGISTRATION NUMBER

CRD42021242063. Date registered: 29 March 2021. https://www.crd.york.ac.uk/PROSPERO/%23recordDetails.