Patellar ligament injury is more commonly caused by strenuous exercise, external factors. 1. Strenuous exercise: more common in sports, acrobatics, etc., excessive activities in the knee joint, pulling the patellar ligament, easily triggered patellar ligament injury. 2. External factors: such as car accidents, falling from a height, etc., violence from the outside world to the knee joint, resulting in damage to the medial capsular ligament, patellar ligament and other joint parts, leading to dislocation or fracture in severe cases. After the patellar ligament is damaged, it is necessary to limit the activities of the knee joint so as not to aggravate the patient’s injury. At the same time, we should consult a doctor in time, follow the doctor’s instructions for further examination, in the doctor’s help for targeted treatment or treatment, you can local physical therapy and hot compresses as well as oral some of the medicines that activate blood circulation and remove blood stasis.