Effects of Systemic Tranexamic Acid on New Bone Formation in a Critical-Size Calvarial Defect Model

Tranexamic acid (TXA), a widely used antifibrinolytic agent, effectively reduces perioperative bleeding in various surgical procedures, including craniofacial surgery. While hematoma formation is known to support early bone regeneration, the impact of systemic TXA on cranial bone healing remains unclear. This study aimed to investigate the effects of systemic TXA, administered pre- and postoperatively, on new bone formation and hematoma volume using a critical-sized calvarial bone defect model in rats. Thirty Sprague-Dawley rats were randomly assigned to 5 groups. Group 1 served as the control; group 2 received 10 mg/kg TXA preoperatively; group 3, 10 mg/kg on postoperative day 1; group 4, 10 mg/kg on postoperative days 1, 2, and 3; and group 5, 20 mg/kg on postoperative days 1, 2, and 3. Hematoma volume in the surgical area was measured on postoperative days 1 and 3 using ultrasonography. On day 28, the rats were sacrificed for new bone formation analysis via micro-CT and histopathologic evaluation. No statistically significant differences were observed among the groups regarding new bone volume or histopathologic scores, and hematoma volumes showed no significant variation between groups ( P > 0.05). Systemic administration of tranexamic acid did not significantly influence new bone formation or hematoma volume in a rat critical-sized calvarial defect model.