The ligament tear can be judged by the following aspects: first, symptoms, when the ligament tear can appear obvious pain, swelling and bruising ecchymosis at the injury site, joint movement is limited, part of the patient can hear the sound of ligament tear when the ligament tear, to be highly suspected of ligament tear. Second, physical examination, physical examination in the ligament tear site can be palpable pressure pain, as well as obvious bruising, swelling, tearing serious can lead to poor joint stability, can appear joint instability, weakness, also should be highly suspected of ligament tears. Third, nuclear magnetic examination, nuclear magnetic is the best means of ligament tear examination, can determine the site and degree of ligament tear. The tear of the ligament can be determined by the above aspects.