CORR Insights®: Intravenous Tranexamic Acid Reduces Postoperative Blood Loss After High Tibial Osteotomy

Where Are We Now?

In the current study, Palanisamy and colleagues [7] evaluated the efficacy of intravenous tranexamic acid (TXA) in reducing postoperative blood loss after medial opening wedge high tibial osteotomy (HTO) by comparing those with to those without intravenous TXA in a single-surgeon practice. The data demonstrated reduced blood loss (without a difference in transfusion usage), and no clinically important differences in pain scores between the groups. Although previous studies [1, 5, 9] examined perioperative blood loss and use of TXA following TKA, THA, and posterior lumbar interbody fusion, few studies have evaluated this in the potentially more-hazardous opening wedge osteotomy, since many fewer osteotomies are performed each year than arthroplasties. A recent study by Suh and colleagues [8] compared patients who underwent medial opening wedge HTO with and without topical intraoperative TXA administration and, similar to the current study’s results, found small improvements in hemoglobin values and drainage volume in patients receiving TXA treatment.

Both the current study [7] and Suh and colleagues [8] have shown reductions in blood loss after osteotomy surgery as a result of using TXA, but it is not clear whether the differences are substantial enough to justify the cost of the drug, or the potential risks of adding a medication to the surgical routine. Nevertheless, they represent an important first step in answering those questions.

Where Do We Need To Go?

The current study raises important questions: (1) Is the perioperative blood loss that occurs in medial opening wedge HTO large enough to justify treatment with TXA? (2) Are all osteotomies about the knee created equal in terms of blood loss?

The absence of transfusions in the current study suggests that a large blood loss volume is unlikely to occur, which contrasts with the frequent administration for transfusions following TKA when TXA is not used [7]. In fact, it appears that blood loss after medial opening wedge HTO is less than that of arthroplasty and periacetabular osteotomy [2], suggesting that TXA may be less important in the setting of knee osteotomy surgery.

Fortunately, intravenous TXA’s safety regarding thromboembolic phenomena, deep venous thrombosis (DVT), and pulmonary embolism (PE) is well documented [4]. Although Palanisamy and colleagues [7] did not routinely evaluate patients with ultrasound or chest CT for thromboembolic events, no patients in that study developed symptomatic DVT or PE; it is important to note, though, that this study really was too small to draw firm inferences about these less-common complications. Given how rare transfusions seem to be after osteotomies, it would seem that any increase in thromboembolic risk associated with TXA could render its use clinically unacceptable; future studies need to look at this. This area of study is particularly important given that postoperative DVT and PE do occur after osteotomy about the knee [3]. If, on the other hand, larger studies demonstrate a small but nonzero risk of transfusion following HTO, and that risk can be reduced with the use of TXA, then TXA may indeed prove to be worth using.

Both the current study [7] and Suh and colleagues [8] have focused on medial opening wedge HTO, blood loss, and TXA. Distal femoral osteotomy has a different osseous vascular supply that may alter the risk of perioperative blood loss. Moreover, a closing-wedge technique, in which the metaphyseal osseous surface is reapproximated and secured, may also alter this risk compared to an opening wedge technique. Future studies should determine how these differences influence the risk of transfusion (and also the benefit, if any, of TXA) after different approaches to osteotomy.

How Do We Get There?

The development of a large, multicenter study remains a potentially viable option for research on this topic. However, is this methodology a feasible or important path to pursue? While knee osteotomies in patients younger than 50 years of age have recently increased in frequency [6], they are still rare, with the Swedish national registry data documenting only six to seven osteotomies per clinic per year [10].

The first aim for a multicenter study would be to establish the baseline frequency of blood transfusions and thromboembolic phenomena for each osteotomy subtype. By obtaining these data, researchers can determine the importance of further evaluation and treatment in this area following osteotomies around the knee, or perhaps, the lack thereof. However, the current study [7] as well as Suh and colleagues [8] have evaluated osteotomies about the knee and demonstrated a zero-transfusion rate and no thromboembolic events, bringing into question whether there is a need for further study regarding TXA and these events. Rather, I would suggest that perhaps an adequate conclusion can be drawn at this time that, while TXA has been effectively utilized for hemostasis in the TKA and THA perioperative period, it may not represent a clinically important intervention for osteotomies about the knee. In a similar vein, allocation of resources into research in this field such as those required to conduct multicenter studies may also not be necessary. Nevertheless, if future cohort studies suggest a higher risk of transfusion or thromboembolic phenomena, then this conclusion may require reevaluation.