Study on BT-114143 Reducing Perioperative Bleeding in Total Knee Arthroplasty（TKA）

• Aged 18-70 years, regardless of gender (including boundary values);
• Patients with osteoarthritis who meet the diagnostic criteria of the American College of Rheumatology (ACR), meet the indications for knee replacement, and plan to undergo total knee arthroplasty;
• American Society of Anesthesiologists (ASA) physical status classification ≤ Grade 3;
• Patients with mild knee deformity: flexion deformity \< 20°, varus deformity \< 15°-5.No abnormalities in preoperative platelet level and coagulation function;
• Body Mass Index [BMI = weight (kg)/height² (m²)] within the range of 20.0-35.0 kg/m² (including critical values);
• Patients voluntarily sign the informed consent form.

Exclusion Criteria:

• Uncontrolled systemic or local infections, including but not limited to pulmonary infection, skin infection, urinary tract infection, etc.;
• Serum albumin concentration \< 35g/L;
• Patients with preoperative hemoglobin \< 110g/L;
• Patients with a known history of severe venous thromboembolism or those with severe thromboembolic risk indicated by lower extremity venous ultrasound (such as popliteal vein and proximal venous thrombosis);
• Patients with severe cardiovascular and cerebrovascular diseases (history of myocardial infarction, angina pectoris, stroke, epileptic seizure, subarachnoid hemorrhage, heart failure, etc. within 6 months before screening);
• Patients with severe varicose veins or severe peripheral arterial diseases affecting distal blood supply (lower extremity arterial stenosis, occlusion);
• Patients with cancer within 5 years before screening, except for cured skin basal cell carcinoma;
• Hypertensive patients with poorly controlled blood pressure (SBP ≥ 140mmHg and/or DBP ≥ 90mmHg), or those requiring combined use of thiazide diuretics, loop diuretics, potassium-sparing diuretics, etc;
• Patients with poorly controlled diabetes (fasting blood glucose > 8 mmol/L);
• Patients with known severe history of allergic reactions that may affect the evaluation of the study, or those allergic to tranexamic acid and its similar drugs;
• Patients who have undergone open knee surgery on the ipsilateral knee (arthroscopic surgery is allowed);
• Patients planning to undergo other surgeries within 1 month (including simultaneous bilateral total knee arthroplasty);
• Patients with combined severe liver or kidney dysfunction (eGFR \< 60 mL/min/1.73 m², ALT and/or AST > 2 times the upper limit of normal range);
• Positive for hepatitis B surface antigen, hepatitis C antibody, HIV antigen/antibody, or syphilis antibody during screening;
• Patients who have used drugs affecting coagulation function within 1 week before surgery (such as aspirin, clopidogrel, ticlopidine, dipyridamole, ginkgo biloba preparations, heparin, warfarin, citrate, hemocoagulase, vitamin K, antifibrinolytic agents, etamsylate, etc.);
• Patients who have used drugs with risks of bleeding and thrombosis within 1 week before surgery, such as oral contraceptives, estrogens, or prothrombin complex concentrates;
• Patients who have used drugs that can increase hemoglobin levels (such as erythropoietin, EPO) within 4 weeks before screening;
• 1-Patients who have taken iron supplements within 1 week before surgery or used intravenous iron supplements within 4 weeks before surgery.
• Patients with mental or neurological diseases, a history of drug abuse, or a history of alcoholism that, in the investigator's opinion, could affect their -participation in the study,specifically, those who consumed more than 14 standard units of alcohol per week within 3 months before screening (1 standard unit equals 14g of alcohol, such as 360ml of beer, 45ml of spirits with 40% alcohol content, or 150ml of wine);
• Patients who have participated in or are currently participating in other clinical trials within 3 months before screening (participation in a clinical trial is defined as the patient receiving an intervention);
• Pregnant or lactating women, or patients of childbearing potential who cannot ensure the use of at least one acceptable form of contraception during the study and for 3 months after the end of the study;
• Patients whom the investigator deems unsuitable for participation in this clinical trial.