Randomized Controlled Trial of Timing of Intravenous Tranexamic Acid in Total Knee Arthroplasty

IRB Number: 2015-056

Institutional Review Board, Hospital for Special Surgery

May 20, 2015

The safety of study participants is our top priority. The trial is approved and periodically reviewed by an Institutional Review Board (IRB), which includes doctors, administrators, ethicists, and members of the general public. The safety of clinical trials is reviewed by the U.S. Food and Drug Administration.

Before enrolling in a clinical trial, the investigator will explain the purpose of the trial, its expected benefits, any possible risks or side effects, and what your role will be. This is the time to ask questions! If you want to join the trial, you must sign the informed consent documents. You can leave a clinical trial at any time without penalty.

For further information, see Understanding Clinical Trials.

Principal Investigator

Michael B. Cross, MD


Steven B. Haas, MD
Friedrich Boettner, MD
David J. Mayman, MD
Sean Garvin, MD
Kaitlin Carroll, BS


The major cause of postoperative blood loss following TKA can be attributed to surgical trauma that leads to activation of both the coagulation cascade and local fibrinolysis.  The fibrinolysis is further compounded by tourniquet release at the end of the surgical procedure.  Multiple studies and meta-analyses have shown that intravenous (IV) administration of the antifibrinolytic agent tranexamic acid (TA) reduces postoperative bleeding and the need for transfusion.  As such, the goal of this randomized controlled, single-blinded, trial is to assess the timing of IV tranexamic acid.  Our specific objectives included analysis of (1) blood loss (primary outcome), (2) drain output (secondary outcome), and (3) transfusion of blood products between the 2 groups (secondary outcome).

The study will begin when IRB approval is granted and will continue until 100 patients are recruited .  Follow-up will be for 1 year after the index surgical intervention.

Inclusion/Exclusion Criteria

Patients will be recruited from the Hospital for Special Surgery. Patients will be prospectively enrolled when Institutional Review Board (IRB) approval is obtained.  All patients will be undergoing a primary unilateral total knee arthroplasty for a diagnosis of osteoarthritis. 

Patients will be excluded from the study if any of the following exist:

  • allergy to tranexamic acid
  • preoperative hepatic or renal dysfunction
  • serious cardiac or respiratory disease including coronary artery stent placement
  • congenital or acquired coagulopathy as evidence by INR > 1.4  or PTT > 1.4 times normal
  •  thrombocytopenia as identified by a preoperative platelet count of < 150,000/mm3
  • history of thromboembolic disease
  • pregnant or breast feeding
  • donated preoperative autologous blood
  •  diagnosis of inflammatory arthritis
  • younger than 18 or greater than 100 years of age and/or
  •  a preoperative hemoglobin < 10 g/dL.

Contact Information

Michael B. Cross, MD