Background and study aims Osteoarthritis (OA) is the most common type of arthritis, which most often affects the knee. It occurs when the protective cartilage on the end of bones wears away. The bones then rub against one another, which can cause stiffness, pain and a reduction in a person's range of movement. A knee joint replacement is a common procedure where the weight bearing surfaces of the knee joint are replaced with metal and plastic components to relieve the pain and disability brought on by OA. Tranexamic Acid（TXA） is a traditional method to reduce blood loss, pain score and complications. It is not known however, what is the best method of TXA for the patients with TKA. The aim of this study is to find out whetherVisual Field Infiltration of Tranexamic Acid Reduced the Blood Loss in patients who have had knee replacement surgery.

Who can participate? Adults who have OA and need a total knee replacement. What does the study involve? Participants are randomly allocated to one of three groups. For the interventions field, could you please provide a brief methodology for each of your treatment arms, and the total duration of treatment and follow-up? Group A: Visual Field Infiltration of Tranexamic Acid during the operation of total knee replacement. Group B: No Visual Field Infiltration of Tranexamic Acid during the operation of total knee replacement.

The blood loss, VAS pain scores, length of their hospital stay, swelling and bleeding, and range of motion of the affected knee are assessed in the days following surgery.

What are the possible benefits and risks of participating? Participants who are allocated to receive treatment with Visual Field Infiltration of Tranexamic Acid may benefit from a reduction in blood loss, pain, swelling and blood loss after surgery, shortening their hospital stay.

There is a small risk of discomfort, frostbite or deep vein thrombosis (a blood clot in a major vein in the leg) when using Visual Field Infiltration of Tranexamic Acid.

Inclusion Criteria:

Adults who have OA and need a total knee replacement.

Exclusion Criteria:

1. Patients had abnormal blood coagulation.
2. Patients were diagnosed as rheumatoid arthritis, traumatic osteoarthritis, ankylosing, spondylitis, hemophilic arthritis, peripheral vascular disease.
3. Cold urticaria.
4. Preoperative anticoagulation, patients had preoperative deep vein thrombosis (DVT).
5. Preoperative history of anemia.