Swelling in the small of the foot and the ball of the foot one month after knee arthroscopy is usually a normal reaction. However, some patients have swelling due to inflammation. 1. Knee arthroscopy surgery is less invasive, with smaller incisions and fewer complications, and recovery is usually quick. Most of the postoperative swelling can be basically reduced in about 1 month. However, patients with more serious conditions, slower recovery and poorer physical condition may take longer for the swelling to go down, such as 2 to 3 months. 2. Localized swelling after knee arthroscopy due to wound infection and inflammation is an inflammatory pathological reaction and should be treated properly under the guidance of a doctor. If the above symptoms occur, it is recommended to go to the hospital for review in time, to clarify the cause of the disease, and to carry out formal treatment as early as possible if any abnormality occurs.