Our Anterior Cruciate Ligament (ACL) is a major ligament in our knee joint. It stops excessive internal tibial rotation, stabilizes the knee in full knee extension, and prevents anterior tibial translation. In other words, very important.
Mechanisms for ACL sprains involve an externally rotated tibia with a valgus force at the knee, occasionally the result of hyperextension or from a direct blow. It may be linked to landing strategies, an inability to decelerate, valgus and rotational stresses. ACL injuries are common in athletes who participate in sports that involve sudden changes in direction, jumping, or landing.
Females are 6-8 times more likely to sprain their ACL compared to males. The research is quite extensive in regard to the impact of the femoral notch, ACL size and laxity, malalignment (Q-angle), and faulty biomechanics. Extrinsic factors may include, conditioning, skill acquisition, playing style, equipment, preparation time, and more. ACL sprains may also involve damage to other structures including the meniscus, capsules, and MCL.
Signs and symptoms of an ACL sprain include experiencing a 'pop' with severe pain and disability. Positive ACL tests, such as the Anterior Drawer, Lachman's, and Pivot Shift tests. Other symptoms include rapid swelling at the knee joint line and above anteriorly and experiencing instability.
ACL sprains are classified based on the injury's severity, ranging from Grade 1 to 3.
Grade 1 ACL sprains are mild and involve overstretching or slight ligament tearing. There may be slight joint instability and some pain, swelling, and stiffness. However, overall the joint should be relatively stable. Treatment includes rest, ice, compression, and physical therapy to strengthen the muscles around the knee joint and improve range of motion.
There is partial tearing of ligament fibers with Grade 2 ACL sprains. Which results in more dysfunction, involving a decreased range of motion, increased instability, pain, swelling, and stiffness, including decreased strength. Leading to walking difficulties, presenting as a limp. Treatment includes immobilizing the knee joint with a brace or cast and physical therapy to improve strength and flexibility. In some cases, surgery may be recommended to repair the torn ligament.
Grade 3 ACL sprain is a severe injury that involves a complete tear of the ligament. The knee joint becomes very unstable, and the affected leg is unable to bear the person's weight. There is usually significant pain, swelling, and stiffness. Treatment for a grade 3 ACL sprain involves surgery to reconstruct the damaged ACL using a graft from another part of the body or a donor. After surgical intervention, physiotherapy and rehabilitation are necessary to restore strength, flexibility, and stability to the knee joint by gradually increasing activity intensities over several months.
Stay tuned for part 2 on post-ACL surgery rehab!