Similarly, UCH-L1 concentrations were higher in the orthopedic injury group (median (IQR): 2494.3 (670.1 to 5708.1) pg/mL) compared with those without trauma (262.8 (153.8-595.3) pg/mL; P < 0.001).<h4>Conclusions</h4>Orthopedic trauma is associated with higher serum concentrations of GFAP and UCH-L1 in CT-negative mTBI patients, which may reduce the specificity of these biomarkers for ruling out intracranial injury. Here, GFAP is linked to concussion.