Posterior cruciate ligament
Ligamentum cruciatum posterius
Also known as: PCL
The stronger of the two cruciate ligaments, running from the posterior intercondylar area of the tibia upward, forward and medially to the lateral side of the medial femoral condyle. It prevents posterior displacement of the tibia on the femur.
Overview
The PCL arises from the posterior intercondylar area of the tibia (extending onto its posterior surface) and passes anterosuperiorly and medially, crossing medial to the ACL, to the anterolateral aspect of the medial femoral condyle. It is thicker and roughly twice as strong as the ACL. It tightens during flexion and is the main stabiliser of the knee in the flexed, weight-bearing position (e.g. walking downhill or descending stairs) and the principal restraint to posterior translation of the tibia. It is accompanied by the meniscofemoral ligaments (anterior — Humphrey; posterior — Wrisberg) from the lateral meniscus.
- Location
Intercondylar notch, posterior to and crossing the ACL.
Anatomy
- Origin
Posterior intercondylar area of the tibia.
- Insertion
Anterolateral aspect of the medial femoral condyle.
- Arterial supply
Middle genicular artery.
Function
- Prevents posterior translation of the tibia on the femur (anterior sliding of the femur on the tibia)
- Main stabiliser of the flexed, weight-bearing knee
Clinical significance
PCL injury
Classically a dashboard injury — the flexed knee strikes the dashboard, driving the tibia backward — or a fall onto the flexed knee with the foot plantarflexed. Positive posterior drawer test and posterior sag sign. Often managed non-operatively unless combined with other ligament injuries (posterolateral corner).
Compiled from standard anatomy and physiology references — see the Skeletal System sources. For education only; not medical advice.