Intravenous Tranexamic Acid Reduces Postoperative Blood Loss After High Tibial Osteotomy.

backgroundMedial opening wedge high tibial osteotomy (HTO) entails extensive soft tissue release that may lead to substantial perioperative bleeding. Although tranexamic acid (TXA) is a well-established blood-conserving agent in total joint arthroplasty, its potential to reduce blood loss in patients undergoing HTO has not been studied extensively. QUESTIONS/PURPOSES: (1) Does TXA reduce total estimated blood loss in HTO? (2) Does TXA use in HTO affect in-hospital endpoints as measured by visual analog scale (VAS) pain scores at rest the day after surgery, wound complications in the immediate postoperative period, blood transfusions, or symptomatic deep vein thrombosis?

methodsBetween January 2015 and May 2017, a single surgeon performed 156 HTOs, all of which were done using the medial opening wedge technique. We began using intravenous TXA for all HTOs in June 2016. This left us with 89 patients who were treated during a time when no TXA was used and 67 patients who were treated when all patients received TXA. Two patients in the control group had simultaneous TKA in the contralateral leg and one patient in each group had missing data so these patients were excluded, leaving 86 (97%) patients in the control group and 66 (98.5%) in the TXA group available for analysis in this retrospective study. There were no demographic differences between the groups in terms of age, sex, body mass index, and baseline hemoglobin values. Total estimated blood loss was the primary outcome variable, which was calculated using total blood volume and decrease in hemoglobin values. Secondary outcome variables included pain VAS at rest the day after surgery, wound complications in the immediate postoperative period, allogeneic blood transfusions, and occurrence of symptomatic thromboembolic manifestations. The decision on when to transfuse was based on predetermined criteria. An orthopaedic surgeon not involved in patient care collected the patient data from electronic medical records and did chart review.

resultsThe TXA group had less total blood loss (372 ± 36 mL versus 635 ± 53 mL, mean difference 263 mL [95% confidence interval, 248-278]; p < 0.001). Between groups, differences in VAS pain scores at rest the day after surgery favored the TXA group but were small and unlikely to be clinically important. There were two wound complications in the control group (one hematoma and one superficial wound infection) and none in the TXA group. No patients in either group received a blood transfusion, and no symptomatic thromboembolic events were detected in either group.

conclusionsThis study demonstrates that the systemic administration of TXA reduces postoperative blood loss in medial opening wedge HTO; however, insofar as no transfusions were administered to patients even before the routine use of TXA in this series, and no clinically important differences in pain scores were identified, the clinical benefit of routine use of TXA in patients undergoing HTO is uncertain. Our study was too small to make safety-related claims on rare endpoints such as wound complications or thromboembolic events. Larger, and preferably randomized, trials are needed to help define whether it is important to use TXA in this setting. Our data can help inform sample size calculations for such studies. LEVEL OF EVIDENCE: Level III, therapeutic study.