I fell about 6 days ago. My right knee just buckled inward. When I got up, my knee popped a few times. It was hard to place weight on that leg. I went to the doctor the next day and he did an xray. He said there are no fractures and gave me a brace. I am pretty sure I tore something but he told me to wait two weeks and come back. I am having pain, tenderness, and swelling in my knee. My right foot also goes numb at times. I am unable to bend my knee all the way nor straighten it all the way without severe pain? Could this be a tendon, ligament, or ACL injury?