Medial collateral ligament injuries of the knee are more common in physical work and sports. Medial collateral knee ligament injuries can be caused by violence that forces the lower leg to abduct, whether the knee is in extension or flexion, causing the knee to abduct suddenly. Injury to the medial collateral ligament can also occur when the knee is slightly flexed and violence is applied directly to the lateral aspect of the knee. When the middle of the capsular ligament is ruptured, it is often combined with a tear of the medial meniscal rim or a rupture of the anterior cruciate ligament. In mild sprains or contusions, pain is seen in the medial knee joint with slight local swelling and significant pressure pain. When the ligament is ruptured, in addition to increased local swelling and pain, there may be widespread ecchymosis of the knee and lower knee in the fissure of the ligament rupture, followed by significant knee dysfunction and a feeling of loosening and instability of the joint during activity, with the knee in a semi-flexed position of about 45. The pressure point is at the medial epicondyle of the femur. Clinical presentation and diagnosis had a significant history of injury with abduction of the lower leg and external rotation. The medial knee was painful, swollen, and subcutaneous bruised. In partial rupture, walking is painful and daily activities can be accomplished; if the injury is severe the medial collateral ligament of the knee is completely ruptured, the pain is severe and the affected limb cannot bear weight and loses function. Positive floating patella test. Positive ligament tension test. Positive knee valgus stress test. Treatment Currently, surgery is used for moderate and severe patients, depending on the degree of injury, and most patients also use transposition of the semitendinosus tendon to repair the medial collateral ligament.