# The Use of Tranexamic Acid in Anterior Cruciate Ligament Reconstruction: A Systematic Review
## 4 Discussion  
The common use of TXA in arthroscopies is beginning to gain traction, after it has already become widespread in arthroplasties and trauma. We believe that this subject is yet to be fully investigated. This is also proven by the small amount of good quality studies that can be found, and the small lot sizes they have. Having a reduced amount of data regarding a specific subject makes it very hard to define a certain degree of heterogeneity. This is caused by a high diversity of TXA administration protocols, a high diversity of analgesia options, a wide variety of rehab protocols and a multitude of outcome measures that can be defined. High heterogeneity is one of the reasons that can justify the low quality of meta-analyses that are currently published. When talking about the different TXA administration protocol, we can see two main ideas: IV and IA. Out of six studies, we saw three of them having an exclusively IV protocol, and a 4 th one having two intervention groups--one IV and one IA. Current literature facts indicate that most authors would prefer IV administration protocols over IA. This may be caused by the speculations that IA TXA can affect chondrocytes, as it was proven in an in-vitro study [33,34]. On the other hand, the authors showed that the cytotoxicity is related to the dosage of TXA, so further studies may be needed to determine a certain threshold that provides a sufficient benefit while not proving toxicity. Furthermore, recent studies [35] have also shown that topical use of TXA also reduces surgical blood loss and the need for blood transfusions during knee and hip arthroplasty while not increasing the risk for notable adverse events such as stroke or thromboembolism [36]. Our study failed to show a clear benefit for any one of the administration methods (IV vs. IA). Improving the postoperative life quality through lower pain levels and better function has been the main motivation behind using TXA in ACLR. We know that pain levels may be controlled either through analgesia or decreased intraarticular pressure that may be caused by postoperative hemorrhosis. Increased hemorrhosis can cause high levels of postoperative pain, infection rates, or cartilage damage [37]. Our systematic review shows a consistent association between TXA patients and decreased pain levels (VAS). Other reviews and meta-analyses have also found that the intraoperative and perioperative use of TXA in arthroscopic surgery decreases hemorrhosis volumes [13,38,39]. An important point of discussion here can be developed regarding the clinical significance of the drain outputs, as negative pressure drains tend to maintain bleeding. Some may consider the hemorrhosis level to be more significant, considering that drainage would not be used. Once low or moderate hemorrhosis occurs, the necessity for joint aspiration is paramount to reducing knee pain, joint effusion, intraarticular adhesion, and infection rates [40]. Another negative aspect of hemorrhosis is that it can cause decreased joint function and muscle strength due to a secondary deficit of rehabilitation caused by local pain. Analyzing the results of pain levels proved much more consistent (Table 4). All studies used the same measurable outcome, and all of them seem to have a common follow-up trend in the 1- and 2-week check-ups. This allowed for decreased variability in outcomes and the results regarding this matter can be considered \"high quality\" scientific data. Studies showed a consistent decrease in pain levels of the TXA groups compared to the control groups after 1 and 2 weeks respectively, while not indicating improvement in the first 3-5 days of the postoperative period. Comparing between the two methods of TXA administration, we found no significant differences in VAS scores. When looking at longer timeframes (2-3 months follow-up), we can see that VAS levels tend to equalize between TXA and control groups, indicating that the intervention has short-term benefits.