Most general knee surgeries are sterilized with povidone-iodine, while tincture of iodine is needed for knee replacement surgeries. 1. Povidone-iodine disinfection: Povidone-iodine is the most commonly used surgical disinfectant. For most of the knee surgeries, such as knee fracture disinfection, minimally invasive knee surgery and other general surgeries, povidone-iodine disinfection is sufficient to meet the needs of the surgery. 2. Tincture of iodine sterilization: Knee replacement surgery is a high-level and demanding knee surgery, due to the concentration of povidone-iodine is lower than tincture of iodine, which is not up to the standard of disinfection for knee replacement surgery, so tincture of iodine is needed for sterilization. Tincture of iodine is very irritating to the skin, so after tincture of iodine disinfection of knee joints, 75% alcohol is needed for deiodination to complete the disinfection process. Therefore, the decision to use tincture of iodine for knee surgery depends on the specific circumstances of the surgery.