Quote Originally Posted by BoomBoom View Post
not a doc, but by my understanding if the ACL fully tears then it separates, the ends pull apart from each other, and thus can't heal without surgery to rejoin the ligament. if the tear is partial, then it can heal on its own. that's what happened with mine.
Any trauma to the acl can make the acl to be considered "torn". The acl is made of 2 bundles which are comprised of fibers. When trauma occurs fibers are tearing hence "torn acl". It's just the degree which determines surgical route or no surgery at all. The fibers of the acl typical avulse from the attachment on the femur which may be the separation you are thinking of. Also the fibers pull away from each other when trauma occurs as the ligament pulls away from the femur or "ruptures".