Skull fractures may be associated with hyperfibrinolysis in patients with isolated traumatic brain injury.

Objectives: To identify the association between skull fracture (SF) and hyperfibrinolysis (HF) among patients with isolated traumatic brain injury.

Methods: This study was the retrospective cohort study based on the nationwide neurotrauma database in Japan. Adult patients with isolated traumatic brain injury (head abbreviated injury scale (AIS) >2, any other AIS <3) registered in the JNTDB from 2015 to 2017 were included. To examine the association between SF and HF, we conducted multivariable logistic regression analyses to calculate the adjusted odds ratios (ORs) of SF with their 95% confidence intervals (CIs) for HF. HF was defined as a D-dimer level ≥ 38 mg/L on arrival based on the previous study.

Results: A total of 335 patients were enrolled and the median age of the cohort was 64 years (interquartile range, 44-76 years). HF was observed in 161 patients (48.1%). The association of SF with HF yielded an adjusted odds ratio (OR) of 4.78 (95% CI: 2.71-8.42) compared to non-SF in multivariable logistic regression analysis. In addition, the association of skull base fracture, skull vault fracture, and combination of skull base and vault fracture with HF yielded the corresponding adjusted ORs of 3.60 (95% CI: 1.20-10.81), 4.99 (95% CI: 2.63-9.44), and 4.84 (95% CI: 2.41-9.72), respectively, relative to non-SF.

Conclusion: This multicenter observational study demonstrated the association of SF with HF in patients with isolated TBI.