ACL Tear Symptoms: When Do You Need Surgery? You Twist your knee while playing football, running, or even stepping off a curb. You hear a "pop." Your knee swells and feels weak. Some people assume the injury will improve without treatment. But these could be ACL tear symptoms, and https://www.tumblr.com/maheshnadgir/831971012245585920/acl-tear-symptoms-when-do-you-need-surgery?source=share