This is a randomized, double blinded, controlled trial in patients undergoing elective Total Knee Arthroplasty (TKA) and Total Hip Arthroplasty (THA). The study group will receive intra-articular Tranexamic Acid (TXA) while the control group will receive normal saline placebo.

The primary purpose of this study is to determine if intra-articular administration of low dose TXA following THA and TKA results in a clinically relevant reduction in blood loss. The secondary purpose is to determine if there is an increased risk of thromboembolic phenomena with the use of TXA following elective THA and TKA. The primary outcome metric will be - drop in hemoglobin following surgery; secondary metrics include blood loss, transfusion rate, d-dimers, troponin levels, symptomatic deep venous thrombosis (DVT) and pulmonary embolism (PE), vascular events (myocardial infarction, stroke), major and minor bleeding, and death.

Inclusion Criteria:

• with osteoarthritis
• scheduled for elective primary unilateral THR or TKR
• provided informed consent
• can read, write and speak English

Exclusion Criteria:

• history of arterial or venous thromboembolic disease (myocardial infarction, symptomatic ischemic heart disease, atrial fibrillation, cerebrovascular accident, deep-vein thrombosis, pulmonary embolus, or thrombogenic cardiac valvular disease or rhythm disease)
• pre-operative Hg of <120 g/L
• Known allergy to Tranexamic Acid
• Coagulation disorder
• Acquired disturbances of color vision
• Hepatic insufficiency, any history of liver disease
• Renal insufficiency (on dialysis)
• Preoperative prophylactic use of antiplatelet or anticoagulant therapy such as Clopidogrel, Warfarin, dabigatran or Rivaroxaban. This does not include low dose Aspirin (81mg)
• Patients with a history of subarachnoid hemorrhage [20]
• Simultaneous bilateral THA or TKA
• Any contra-indication for spinal anesthesia
• Allergy to Celecoxib, which will be the only nonsteroidal anti-inflammatory drugs (NSAID) used in the multi-modal analgesia regime.
• Retinal vein or retinal artery occlusion
• Female on oral contraceptive pills and/or premenopausal
• Concurrently taking hydrochlorothiazide, desmopressin, sulbactam-ampicillin, carbazochrome, ranitidine and/or nitroglycerin for the duration of the surgery.