A Phase 4 interventional study of Tranexamic Acid (TXA) and Placebo (NaCl 0,9%) in ACL Reconstruction and Hemarthrosis, sponsored by Chirec. Not yet recruiting at 1 site in Belgium. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-01-12.
Sponsored by Chirec · Phase 4, Interventional, and Prevention
Tranexamic acid (TXA) is widely used in orthopedic surgery to reduce perioperative blood loss, particularly in total hip and knee arthroplasty, due to its antifibrinolytic mechanism, low cost, broad availability, and established safety profile. Its use has recently expanded to minimally invasive procedures such as knee arthroscopy and ACL reconstruction, where postoperative hemarthrosis-rather than intraoperative bleeding-is a major cause of pain, swelling, reduced range of motion, delayed rehabilitation, and impaired early recovery.
Randomized trials and meta-analyses in arthroscopic ACL reconstruction show that TXA, administered intravenously, intra-articularly, or both, reduces postoperative hemarthrosis, joint swelling, drainage volume, and early pain, while improving early functional outcomes. These benefits are mainly short term, with no consistent long-term differences, and no increased risk of thromboembolic events. Evidence in arthroscopic meniscectomy is more limited but suggests modest improvements in early recovery, which may still be clinically meaningful given TXA's favorable risk-benefit profile.
Beyond its antifibrinolytic effects, TXA may influence inflammatory pathways by inhibiting plasmin, which is involved in complement activation and inflammatory modulation. However, existing data are conflicting, with reports of both anti- and pro-inflammatory effects depending on surgical context and dosing. Importantly, most arthroscopy studies focus on clinical outcomes rather than systemic inflammation. To date, no study has comprehensively evaluated perioperative inflammatory responses to TXA in arthroscopic knee surgery, making this low-trauma setting an ideal model to investigate its potential inflammatory effects.
Over the past decade, tranexamic acid (TXA) has been widely adopted in orthopedic surgery to reduce perioperative blood loss and transfusion requirements, particularly in total hip and knee arthroplasty. TXA is a synthetic lysine analogue that inhibits the activation of plasminogen to plasmin, thereby preventing fibrin degradation and limiting fibrinolysis. Due to its low cost, wide availability, and well-established safety profile when administered intravenously, TXA is now routinely used in many countries for procedures associated with a high risk of bleeding.
In recent years, interest has expanded beyond major joint replacement toward minimally invasive orthopedic procedures, such as knee arthroscopy and anterior cruciate ligament (ACL) reconstruction. Although these procedures are generally associated with limited intraoperative blood loss, postoperative hemarthrosis remains the most frequent complication of knee arthroscopy and accounts for a substantial proportion of postoperative morbidity. Hemarthrosis has been shown to induce transient histological changes in articular cartilage and synovial tissue and is associated with increased postoperative pain, joint swelling, reduced range of motion (ROM), delayed rehabilitation, and impaired early functional recovery.
Several randomized controlled trials have investigated the role of TXA in arthroscopic knee surgery. In arthroscopic ACL reconstruction, multiple studies and subsequent systematic reviews and meta-analyses have demonstrated that TXA administration-whether intravenous, intra-articular, or combined-reduces postoperative hemarthrosis, joint swelling, drainage volume, and early postoperative pain, while improving early functional outcomes such as ROM and knee scores. These benefits appear most pronounced during the first postoperative weeks, with no consistent differences observed at longer-term follow-up. Importantly, these studies have not demonstrated an increased incidence of thromboembolic events or major complications associated with TXA use.
In the setting of arthroscopic meniscectomy, data are more limited. A double-blind randomized controlled trial evaluating intravenous TXA in routine arthroscopic meniscectomy suggested modest improvements in early functional recovery, particularly during the immediate postoperative period, despite minimal expected blood loss. Editorial commentaries and systematic reviews have emphasized that, although the absolute benefit of TXA in low-risk arthroscopic procedures may be small, even modest reductions in hemarthrosis and early inflammation may be clinically relevant given the low cost and favorable safety profile of the drug.
Beyond its antifibrinolytic properties, increasing experimental and clinical evidence suggests that TXA may exert biological effects on inflammation and coagulation pathways. Plasmin is known to play a role not only in fibrinolysis but also in the activation of the complement system and modulation of inflammatory mediators. By inhibiting plasmin generation, TXA may influence postoperative inflammatory responses. However, the available evidence remains conflicting. While some studies suggest anti-inflammatory effects, others-particularly in major orthopedic procedures such as total knee arthroplasty-have reported paradoxical increases in circulating pro-inflammatory cytokines following TXA administration.
These discordant findings highlight the complexity of the interaction between coagulation, fibrinolysis, and inflammation, and suggest that the effects of TXA on inflammatory pathways may depend on surgical context, tissue trauma, and dosing strategy. Importantly, most existing studies in arthroscopic surgery have focused primarily on clinical outcomes such as hemarthrosis, pain, and function, with very limited assessment of systemic inflammatory markers.
To date, no study has comprehensively evaluated the perioperative inflammatory response to TXA in arthroscopic knee surgery using serial cytokine measurements and integrated inflammatory burden assessment. Arthroscopic procedures, characterized by limited surgical trauma and low baseline inflammatory activation, represent an ideal clinical model to investigate the potential anti-inflammatory-or pro-inflammatory-effects of TXA in a controlled and sensitive manner.
21 studies on the registry are indexed under Hemarthrosis; 5 are open to participants now.
This study's planned enrollment of 60 is above the median of 22 across 12 interventional studies indexed under Hemarthrosis.
Browse Hemarthrosis studies →Chirec is the lead sponsor of 3 studies on the registry; 3 are open to participants now.
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Exclusion Criteria
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
This group will receive 1 dose of tranexamic acid during the induction phase, before the surgical tourniquet
Drug: Tranexamic Acid (TXA)
This arm will receive NaCl 0,9% at the same volume as calculated for 15mg/kg of tranexamic acid (before the surgical tourniquet)
Drug: Placebo (NaCl 0,9%)
1 dose of Tranexamic Acid 15 mg/kg
Also known as: TXA
This arm will receive NaCl 0,9% at the same volume as calculated for 15mg/kg of tranexamic acid
Also known as: Placebo
Anti-inflammatory response: Variation of IL-6 over 24 hours
To evaluate the effect of a single intravenous dose of tranexamic acid on the perioperative inflammatory response, assessed by serial plasma interleukin-6 (IL-6) concentrations measured preoperatively, at 6 hours, and at 24 hours postoperatively, with quantification of the inflammatory burden using the area under the curve (AUC) over the first 24 postoperative hours.
Time frame: 24 hours
Hidden blood loss
To quantify hidden blood loss (HBL) using perioperative hemoglobin and hematocrit measurements obtained preoperatively, at 24 hours, and on postoperative day 3. Total blood loss (TBL) will be estimated using validated hematocrit-based formulas incorporating postoperative day-3 hematocrit and estimated blood volume, and hidden blood loss will be calculated as HBL = TBL - intraoperative blood loss (IBL).
Time frame: 3 days
Anti-inflammatory response
To characterize the perioperative inflammatory profile associated with tranexamic acid administration by measuring plasma levels of TNF-α, IL-8, IFN-γ, IL-1α, IL-1β, IL-2, IL-4, IL-10, and C-reactive protein (CRP)at baseline, 6 hours, and 24 hours postoperatively.
Time frame: 24 hours
Fibrinolysis
To assess the effect of tranexamic acid on perioperative fibrinolysis, evaluated through serial measurements of D-dimer levels obtained preoperatively, at 6 hours, and at 24 hours postoperatively.
Time frame: 24 hours
Rehabilitation score
\- KOOS score: Knee Injury and Osteoarthritis Outcome Score - 0 (worse score) - 100 (best score).
Time frame: 1 week
Rehabilitation score
IKDC score (International Knee Documentation Committee) - evaluate impact of treatement in everyday activities: 0 (worse score) - 100 (best score).
Time frame: 1 week
Rehabilitation
Range of motion: 0-150 % (extension to flexion)
Time frame: 1 week
adverse effect
One of these described: Arterial or venous thrombosis, Seizures, Hypersensitivity reactions (including anaphylaxis), Gastrointestinal adverse effects, Acute renal failure 0 = Not described 1 = described
Time frame: 1 week
Plan to share: Undecided
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Studies of the drug tested here: Tranexamic Acid