The human body has two cruciate ligaments at each knee: an anterior cruciate ligament (ligamentum cruciatum anterius) and a posterior cruciate ligament (ligamentum cruciatum posterius). The anterior cruciate ligament originates at the lower part of the knee joint, the tibia, and extends to the upper part of the joint, the femur. It runs from the front center of the so-called tibial plateau (Area intercondylaris anterior tibiae) to the outer part of the thigh bone.
This forms two pillars in the area of the knee joint, as it were, with the anterior cruciate ligament pulling towards the outer pillar (condyle lateralis femoris) and attaching to the inner side there. The posterior cruciate ligament is stronger than the anterior cruciate ligament and originates from the inner pillar of the femoral condyle (Condylus medialis femoris), from the inside of which it extends to the posterior center of the tibial plateau (Area intercondylaris posterior tibiae). The cruciate ligaments in their entirety serve to stabilize the knee joint in order to keep the bones involved – the tibia and femur – in position.
They also have the task of guiding rotary movements (rotation) when the knee joint is bent. In particular, the cruciate ligaments are used to inhibit excessive inward rotation (internal rotation). Cruciate ligament tears are among the most common ligament injuries to the knee, whereby the anterior cruciate ligament is usually affected.
In Germany, there are about 30 cruciate ligament tears per 100,000 per year. Cruciate ligament ruptures are caused by forces that are stronger than the strength or extensibility of the ligaments. Typical are acute injuries during sports (e.g. running or running), as the cruciate ligaments can easily tear due to the resulting rotational movements in the knee joint in combination with flexion inwards (valgus stress) or outwards (varus stress).
Other movements that can cause a torn cruciate ligament are excessive flexion or extension of the knee joint. Not only sports injuries, but also traffic accidents may cause a torn cruciate ligament. Typical are knee impact traumas (dashboard injury) in which the bent knee of the driver or passenger hits the dashboard with such force that this usually results in a torn cruciate ligament.
A torn cruciate ligament manifests itself in the form of pain, swelling, bloody joint effusion (hematoma) and impaired knee stability. Typically, the so-called drawer phenomena can be detected in the affected person, whereby the lower leg is displaceable towards the thigh.
