Allogeneic blood products transfusions are often necessary to treat perioperative bleeding in patients undergoing complex scoliosis surgeries. A prospective, randomized trial is designed to evaluate if the infusion of fibrinogen concentrate may reduce allogeneic blood transfusion in patients undergoing scoliosis surgery. Eligible patients will be randomly assigned to treatment group (fibrinogen concentrate infusion) and control group (normal saline infusion), and functional fibrinogen will be measured to guide the infusion of fibrinogen concentrate. Perioperative blood loss, intraoperative blood loss, and the amount of perioperative allogeneic blood transfusion will be compared between the two groups to determine the effect of fibrinogen concentrate infusion.