Is general or local anesthesia used for knee replacements? Anesthesia for knee replacement needs to depend on the situation. Some patients may choose general anesthesia because they are afraid of hearing the sounds of the operation; if they don’t care about that, they can choose local anesthesia. General anesthesia is a little slower to recover and more expensive, while local anesthesia is less expensive because the patient will be awake when the anesthetic wears off. Most hospitals in the United States used general anesthesia in the early years, but that has changed. I prefer local anesthesia for a knee replacement on one side only, because the entire surgery takes just over an hour and local anesthesia is sufficient and the patient recovers quickly afterwards. Is the incision caused by the surgery large? The incision is usually 15-20 centimeters, and may be smaller in thin patients. However, for patients with keloid, although the incision is also 15-20 cm, the wound will heal into a large, hard scar within 1~3 months after surgery, and the scar will soften slowly after a period of time. Does the surgery bleed a lot? Do I need blood transfusion? There are now two methods of blood management during surgery. One is to put a tourniquet at the root of the thigh during the surgery and there is no bleeding from the incision throughout the surgery. After the surgery is done, the tourniquet is released and the surgeon injects a tourniquet into the joint cavity to stop the bleeding. Another way is to operate without a tourniquet. This is because studies have concluded that the use of a tourniquet during surgery may aggravate the formation of a blood clot. If a tourniquet is not used, a blood recovery device can be used to collect the blood coming out of the surgery, filter it through the device, and reinject it into the body. 200 to 300 ml of blood is usually re-recovered during the surgery. If only one side of the knee is replaced, the intraoperative bleeding can be recovered after washing and filtering, and the final post-operative bleeding is only 100-200 ml, so no blood transfusion is needed at this time. However, if both knees are replaced at the same time, a blood transfusion may be necessary after surgery. There was a patient who had a double knee replacement, and after the operation, his hematocrit dropped to 6-7 grams, he was white and weak and could not exercise. How long does a patient need to stay in the hospital after surgery? Generally, joint replacement takes about 14 days from the time the surgery is done to the time the stitches are removed. In the past, we used to wait until the stitches were removed before we were discharged, but this is not the case now.