An injury to the anterior cruciate ligament can be a debilitating musculoskeletal injury to the knee, seen most often in athletes. Non-contact tears and ruptures are the most common causes of ACL injury.
The pivot-shift test, anterior drawer test and the Lachman test are used during the clinical examination of suspected ACL injury. The ACL can also be visualized using a magnetic resonance imaging scan (MRI scan).
An ACL tear can be determined by the individual if a popping sound is heard after impact, swelling after a couple of hours, severe pain when bending the knee, and when the knee buckles or locks during movement.
Though clinical examination in experienced hands is highly accurate, the diagnosis is usually confirmed by MRI, which has greatly lessened the need for diagnostic arthroscopy. MRI has a higher accuracy than clinical examination in detecting ACL tears when multiple ligaments are torn. This is of particular benefit if there is a coexisting posterolateral corner injury. Addressing the posterolateral corner injury at the time of ACL reconstruction will prevent premature graft failure.