What are the main post-operative complications? The incidence of post-operative complications after artificial knee replacement is very low, the most common being infection. Once an infection has occurred and there is bacteria around the prosthesis, the most common method is to surgically remove the prosthesis, kill the bacteria around it, and reinstall a new joint, which can be slightly painful for the patient. There is now worldwide research on how to prevent infection. In fact, the infection rate after joint replacement used to be very high, with foreign data showing 1% to 2%, but now the statistics for major hospitals in China are about 0.5%, which is quite low. However, for many people, this is only a probability, but for each patient, it is “yes” or “no”, i.e., either infection or no infection. There are many factors that can cause infections, such as diabetes. In addition, postoperative pneumonia can also cause infection if not taken care of. To prevent infection, my experience is to keep some antibiotics at home. After a joint replacement, patients need to take antibiotics promptly if they have a cold, fever, pneumonia, urinary tract infection, etc. It is important to know that if left untreated, the inflammation travels through the bloodstream to the artificial joint and can cause infection. In addition to infection, a common complication after artificial knee replacement is a blood clot. Usually blood clots occur 2 to 3 weeks after surgery, or 4 to 5 weeks after surgery. After having an artificial knee replacement, the clotting factors in the blood vessels of the patient’s lower extremities increase in viscosity, clotting in the blood vessels, slowing the flow of blood and creating a blood clot. More seriously, the clot can travel down the bloodstream to the heart if it falls, causing a pulmonary embolism, and once a pulmonary embolism occurs, the patient’s life is in danger, and the incidence of this condition is 1 per 1,000 to 2 per 1,000. In order to prevent thrombosis, after the surgery, we will let the patient move as early as possible, or use plantar vein pump, elastic stockings and anti-thrombotic drugs. Through various measures, the incidence of blood clots is now very low. However, after the surgery, if the patient’s leg is very swollen, he or she must be seen promptly for ultrasound to check for thrombosis, and if there is any thrombosis, it must be treated promptly. In addition, other complications, such as neurovascular injury, are mostly caused by improper operation during surgery, but this is very rare. Some patients cannot lift their feet after surgery, mostly because the nerves were temporarily paralyzed during the surgery, and after the surgery, some patients’ nerves are still paralyzed, which is only temporary and will improve after a period of time. Swelling and incisional ooze are complications that occur in many surgeries.