Posterior cruciate ligament

Last revised by Wilson Tang on 09 Mar 2022

The posterior cruciate ligament (PCL) is one of the two cruciate ligaments that stabilize the knee joint

The posterior cruciate ligament is intracapsular but extrasynovial and is, on average, 38 mm in length and 13 mm in width. It contains two fiber bundles - anterolateral and posteromedial 1,4. ​Despite its shorter length compared to anterior cruciate ligament, it's considered to be the stronger of the two 5. Its origin is from the lateral surface of the medial femoral condyle to insert onto the posterior lateral intercondylar surface of the tibial plateau 4. When the knee is in extension, it makes an almost 90º turn as it passes anterosuperiorly. 

The anterior cruciate ligament passes lateral to it and curves around it.

During flexion, the anterolateral band becomes tight, whereas the posteromedial bundle tightens during extension 1 and the posterior cruciate ligament as whole acts to resist anterior translation of the femur on the tibia 2. While in flexion and weight-bearing (such as walking downhill), PCL is the stabilizer for the femur 5.

The two bundles cannot be separately identified on MRI and the PCL appears as intensely hypointense. The apex of the posterior cruciate ligament is susceptible to magic angle effect (an MR artefact) and a high signal can be seen in this area but it is of no pathological significance 2

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Cases and figures

  • Case 1: normal cruciate ligaments (MRI)
    Drag here to reorder.