The fourth column in thoracic vertebral fractures: concomitant thoracic cage injuries and mortality in 27,814 inpatient cases from the german national DRG database.

PURPOSE: Population-level data on fourth column fractures and prognostic implications remain lacking. This study aimed to characterise the epidemiology of thoracic vertebral fractures in Germany, including the prevalence of fourth column injuries and geriatric patients, comorbidity burden and the in-hospital mortality across distinct fracture populations. METHODS: A Nationwide cross-sectional administrative inpatient data analysis of all adult thoracic vertebral fracture cases (ICD-10-GM S22.0x/S22.1) from the 2024 German Diagnosis Related Groups database was conducted across three groups: thoracic spine group (n = 27,315), geriatric subgroup (≥ 75 years; n = 16,276), and fourth column group with concomitant sternal fracture (n = 499). Data were provided by the German Institute for the Hospital Remuneration System. RESULTS: Among 27,814 cases 63.0% were female and 58.5% aged ≥ 75 years. Fourth column fractures (1.8%) defined a mechanistically distinct entity: male predominance (57.7%), younger age distribution (≥ 75 years: 30.3% vs. 59.0%), prolonged hospitalisation (14.7 vs. 10.1 days) and comorbidity burden (PCCL ≥ 3: 59.3% vs. 11.7%). Mortality in the thoracic spine group was 2.00%, rising to 2.89% in patients aged ≥ 75 years, accounting for 86.1% of all deaths. In geriatric subgroup, mortality was dominated by acute organ-failure: cardiac arrest (OR = 51.74), sepsis (OR = 42.96) and respiratory insufficiency (OR = 14.67). In thoracic spine group, concomitant thoracic cage injuries were associated with elevated mortality: haemothorax (OR = 5.73) and serial rib fractures (≥ 4 ribs, OR = 3.31). CONCLUSIONS: Fourth column fractures constitute a mechanistically distinct high-energy injury entity, while in the geriatric thoracic spine fracture population, mortality is governed by vulnerability rather than fracture severity, suggesting that frailty assessment may be of value and risk-stratified clinical pathways.