The anterior cruciate ligament (ACL) has a very important role in stabilizing the knee joint. It prevents the lower bone of the knee joint (tibia) from sliding forward on the top bone (femur). The ACL also has a role in providing rotational stability to the knee. ACL injuries have increased a lot over the past 20 years, especially in teenaged females. It is thought that the increased incidence of ACL injuries is due to the increase in higher intensity competitive sports and early specialization.
ACL injuries can be sustained through both contact and non-contact injuries. Contact injuries occur when the knee receives a direct blow, usually when the foot is planted, such as in football. They account for approximately 30% of ACL injuries. Non-contact injuries are more common, accounting for approximately 70% of ACL injuries. These injuries usually occur when there is sudden deceleration, especially with a change of direction, landing from a jump, pivoting or twisting. ACL injuries often occur in combination with medial collateral ligament (MCL) injuries and meniscus injuries. ACL Part 2 will focus on the risk factors for ACL injury.
Anterior cruciate ligament injury. Physiopedia website available at: https://www.physio-pedia.com/Anterior_Cruciate_Ligament_(ACL)_Injury