Symptoms of medial collateral ligament injury mainly include severe pain, limitation of activities, swelling of the knee joint and positive lateral stress test. In some cases of medial collateral ligament injuries, the sound of ligament rupture can be heard, and severe pain occurs at the site of injury, which often prevents the patient from continuing to exercise or work. The knee joint is obviously swollen and painful, pressure pain, blood accumulation, etc., and the patient’s knee joint is often in a forced position of flexion or extension. On physical examination, there are obvious pressure points at the rupture of the medial collateral ligament of the knee, and some of the broken ends of the ligaments may be palpable. Lateral stress test may be positive. Lateral stress test, i.e., during passive knee inversion and knee valgus maneuvers with the knee in full extension and 30° of flexion, pain or a bouncing sensation at an angle of motion outside the normal range may be present, which may indicate the presence of a sprain or rupture of the collateral ligament. If there is any discomfort, it is recommended to consult a doctor in time for diagnosis and treatment. Specific operations should be carried out under the guidance of a doctor.