When the knee joint is subjected to lateral compression or torsion force, lateral collateral ligament injury is easy to occur, and the specific clinical manifestations after the injury are as follows: 1, there will be a certain degree of swelling in the medial or lateral side of the knee joint, and the pain will be very obvious when pressing on the place where the swelling is obvious, and the pain will be further aggravated when the knee joint is straightened and flexed; 2, in the internal and external knee turnover stress test, the pain will be further aggravated in the part of the original pain. The pain will be further aggravated, and even the whole movement can not be completed; 3, when doing the internal and external turning stress test, you can obviously feel the loosening of the knee joint; 4, when doing the MRI of the knee joint, you can see the continuity damage of the medial or lateral collateral ligaments, and at the same time, you can also make clear the severity of the lateral collateral ligament damage, and judge the corresponding means of treatment, especially for the medial collateral ligaments, and if the damage is serious, surgical repair should be considered. Surgical repair should be considered for severe injuries, as it is very important for the stability of the knee joint.