Determine the Efficacy of TT-173. Reducing the the Total Blood Loss Associated With Total Knee Arthroplasty (HESTAT)

Inclusion Criteria: 1. Patients who signed the informed consent. 2. Patients affected of degenerative osteoarthritis of the knee that have to undergo a primary total knee replacement. 3. Patients of both sexes older than 18 years. 4. Female patients in childbearing age\* that are not permanently sterile, should present a negative pregnancy test and should agree to use a medically accepted anti contraceptive method during its participation in the study. This includes oral, intravaginal, transdermal, injectable or implantable hormonal contraceptives, sexual abstinence, bilateral tubal occlusion, intrauterine hormone-releasing system or dispositive and vasectomy of the partner. \* Includes the period between menarche and until becoming post-menopausal. A woman is considered post-menopausal when she has gone without a period for 12 consecutive months. 5. Patients must have a haemoglobin concentration ≥ to 12.5 g/dL at the selection visit. Exclusion Criteria: 1. Patients affected of any kind of congenital or acquired coagulopathies or with personal history of abnormal haemorrhagic episodes. 2. Patients subjected to knee replacement due to rheumatoid or seronegative arthritis, infection or other autoimmune inflammatory causes of join degeneration. 3. Patients subjected to revision procedures of the knee, hemiarthroplasty or that will receive non-cemented knee prosthesis. 4. Subjects affected of a serious medical condition that would compromise their clinical outcome such as hepatic, respiratory, cardiac or renal insufficiency, acute infectious disease and active cancer. 5. Subjects with known history of haematological alterations which are causative of thrombophilia. 6. Subjects with personal history of deep vein thrombosis, pulmonary thromboembolism, retinal vascular occlusion or multiple abortions. 7. Subjects with known hypersensitivity or allergy to any component of the drug. 8. Subjects that are currently under treatment with anticoagulant, antiplatelet or antifibrinolytic drugs. These subjects may be eligible if the treatment is stopped preoperatively according with the conditions indicated in section 9.2. 9. Subjects who have received treatment (erythropoietin, iron, folate) to improve preoperative anaemia. 10. Subjects who are not free to give informed consent or who are mentally incapacitated to the discretion of investigators. 11. Subjects who participate or have participated in the past three months in another clinical trial with drug treatment. 12. Subjects that are the investigators, collaborators, nurses, centre employees or any other person directly related to the development of the protocol. 13. Subjects who are pregnant or lactating.