ACL (anterior cruciate ligament)

ACL (anterior cruciate ligament): One of the ligaments in the knee, the ACL crosses from the underside of the femur (the thigh bone) to the top of the tibia (the bigger bone in the lower leg). ACL injuries can occur in a number of situations including sports such as football, can be quite serious, and require surgery. The anterior cruciate ligaments, one on either side of the knee, are so called because they cross each other in front of the knee. "Cruciate" taken from the Latin "crux" for "cross" means "in the form of a cross."