"Pop" means?

by Derek
(Canada)

Hi, I recently injured my ACL. After seeing 3 different doctors, 2 told me it is torn and 1 told me it's not. Although I've never been through this type of injury, it is hard to convince myself (whether denial or not)that i've torn my ACL because I still don't have the knee-giving-out problem that everyone talks about. At first when the docs told me it's torn, i was pretty confident with them because i heard a "pop" sound, which made me think of something tearing immediately. However, when I saw a third doctor telling me that "pop" doesn't mean a tear, it made me wonder as well (especially when i could start putting more weight on my knees now, and it's only been less than a week). Could you give me more details on what the "pop" sound could mean?