Bones that are involved with the ACL are the Femur, Patella and the Tibia.
When you tear your ACL it is a pretty serious injury.Some symptoms that you tore your ACL may be serious swelling, your knee gives out or feels unstable. You will have serious pain when trying to extend your leg.
An ACL tears when the ligament gets stretched or tears when the foot is firmly planted and the knee locks and twists or pivots at the same time.
Recovery from surgery can take six to nine months.