Cruciate ligament

Anatomy and function

Humans have two cruciate ligaments on each knee: an anterior cruciate ligament (ligamentum cruciatum anterius) and a posterior cruciate ligament (ligamentum cruciatum posterius). The anterior cruciate ligament arises from the lower part of the knee joint, the tibia (Tibia) and pulls towards the upper part of the joint, the thigh bone (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. In the area of ​​the knee joint, this forms, so to speak, two pillars, with the anterior cruciate ligament to the outer pillar (Lateral femoral condyle) pulls and starts there on the inside.

The posterior cruciate ligament is stronger than the anterior and originates from the inner pillar of the femur (Condylus medialis femoris), from the inside of which it goes to the rear center of the tibial plateau (Area intercondylaris posterior tibiae) pulls.

The cruciate ligaments in their entirety serve to stabilize the knee joint in order to keep the bones involved - the tibia and thighbones (femur) - in their position. They also have the task of guiding turning movements (rotation) with the knee joint flexed. In particular, excessive inward rotation (internal rotation) is inhibited with the help of the cruciate ligaments.

Figure cruciate ligament

Illustration of the right knee joint with cruciate ligaments (red) from the front (A) and from the rear (B)
  1. Anterior cruciate ligament -
    Ligamentum cruciatum anterius
  2. Posterior cruciate ligament -
    Lig. cruciatum posterius
  3. Outer meniscus -
    Lateral meniscus
  4. Outer band -
    Ligament collaterale fibulare
  5. Inner meniscus -
    Medial meniscus
  6. Transverse ligament of the knee joint -
    Ligament transversum genus
  7. Inner band -
    Ligament collateral tibial
  8. Inner articular knot -
    Medial condyle
  9. Femur - Femur
  10. Kneecap area -
    Facies patellaris
  11. External articular knot -
    Lateral condyle
  12. Calf community -
    Corpus fibulae
  13. Shin community -
    Corpus tibiae

You can find an overview of all Dr-Gumpert images at: medical illustrations


Cruciate ligament tears are among the most common knee ligament injuries, mostly affecting the anterior cruciate ligament. In Germany there are about 30 cruciate ligament ruptures per 100,000 per year.
The cause of a cruciate ligament rupture are the forces acting on them, which are stronger than the strength or elasticity of the ligaments.
Acute injuries are typical Sports (for example when running or running), as the resulting rotational movements in the knee joint in connection with inward flexion (Valgus stress) or outside (Varus stress) the cruciate ligaments can tear easily.
Other movements that trigger a cruciate ligament tear are too strong diffraction (Flexion) or Elongation (Extension) of the knee joint.
Not only sports injuries, but also traffic accidents can cause a cruciate ligament rupture. Are typical Knee injuries (dashboard injury), in which the bent knee of the driver or front passenger hits the dashboard with such force that it usually tears a posterior cruciate ligament.
A cruciate ligament tear manifests itself in the form of Pain, swelling, bloody Joint effusion (Hematoma) and impaired stability of the knee. Typically, the so-called Drawer phenomena demonstrate, the lower leg being able to move towards the thigh.