60 patients who were scheduled to receive posterior approach lumbar surgery for degenerative lumbar instability with stenosis were randomly assigned into one of two groups: a tranexamic acid or placebo group. The purpose of the study was to test the effect of intravenous tranexamic acid on postoperative blood loss. Results demonstrated that there were no intra-operative differences in blood loss. However, patients who received tranexamic acid experienced less blood loss over a 48 hour period following surgery. Additionally, those who received treatment with tranexamic acid did not experience any serious complications.