The difference between ACL tear and rupture is that the degree of ligament damage is different, and ligament rupture is generally more serious than tear. 1. Ligament tear: when the patient in the activity to make beyond the range of knee activities, can pull the ligament, causing a tear, can lead to anterior cruciate ligament part of the fibrous tissue damage, is to subcutaneous petechiae, local swelling, pressure and pain, or joint instability, pain, activity is limited as the main manifestation. The ligament is connected by fibrous tissue and is not completely ruptured. 2. Ligament rupture: When the anterior cruciate ligament is subjected to violence, the fibrous tissue of the ligament is completely ruptured and there is no intact fibrous structure. The integrity of the fibrous tissue of the ligament is compromised, and the continuity of the ligament after rupture is not present. The ACL also loses its restraining effect on the tibia. An ACL rupture is more serious than an ACL tear, and it is recommended to seek prompt medical attention for an ACL tear or rupture to avoid delaying the condition.