What is it?
A common injury of the knee is a tearing of the ACL (Anterior Cruciate Ligament). This ligament is very important for the stability of the knee and often needs to be repaired surgically. The primary function of the ACL is to keep the bottom surface of the knee joint from sliding forwards during movement. An unrepaired knee may feel unstable or give way suddenly.
Not all ACL injuries require surgery and some may heal well with proper rehabilitation however, for those who do need surgery, there is a significant rehabilitation period afterwards.