Lateral collateral ligament injuries of the knee are often caused by trauma, which is the stress of internal rotation causing injury to the lateral ligament. The lateral ligament injury can be divided into grade I, II, and III from MRI, and the symptoms are mainly as follows: 1. pain in the lateral side, often with pressure pain in the area of the fibular tuberosity; 2. swelling in the lateral side, with petechiae in severe cases; 3. dysfunction, with pain when walking, and possibly also pain when flexing and extending the joint; 4. lateral collateral ligament injury, when examined by a doctor, with pressure pain in the fibular tuberosity, and also with internal rotation test. Often when doing internal rotation, the lateral gap will open, will open more than the healthy side, while the patient will appear more painful symptoms, is the sign of lateral collateral ligament injury, lateral collateral ligament injury at the same time to check whether the cruciate ligament, cartilage, meniscus injury. Through the doctor’s examination, it is basically possible to determine the lateral collateral ligament injury. Nowadays, the extent of the lateral collateral ligament injury can be clearly seen through MRI, so that a correct diagnosis can be made.