What is ACL Knee Injury?
An anterior cruciate ligament injury is the over-stretching or tearing of the anterior cruciate ligament (ACL) in the knee. An acl tear may be partial or complete. The knee is similar to a hinge joint, located where the end of the thigh bone (femur) meets the top of the shin bone (tibia). Four main ligaments connect these two bones: • Medial collateral ligament (MCL) – runs along the inner part (side) of the knee and prevents the knee from bending inward. • Lateral collateral ligament (LCL) – runs along the outer part (side) of the knee and prevents the knee from bending outward. • Anterior cruciate ligament (ACL) – lies in the middle of the knee. It prevents the tibia from sliding out in front of the femur, and provides rotational stability to the knee. • Posterior cruciate ligament (PCL) – works with the ACL. It prevents the tibia from sliding backwards under the femur. The ACL and PCL cross each other inside the knee, forming an “X.” This is why they are called the “cruciate” (cross
