hintere Kreuzbandruptur

Posterior cruciate ligament (PCL) tears are less common than anterior cruciate ligament tears.

Epidemiology

Posterior cruciate ligament tears account for ~10% (range 2-23%) of all knee injuries .

Clinical presentation

Sports injuries and car accidents (dashboard injury) are equally responsible for these injuries . Many patients will be asymptomatic and their clinical examination is unremarkable. However, some patients may have knee instability or posterior sag sign.

Pathology

Three mechanisms of injury have been proposed :

  • posterior tibial displacement in a flexed knee
  • hyperextension
  • rotation with an abduction or adduction force
Associations

PCL injuries are isolated in only 30% of cases and are thus commonly associated with other injuries :

Radiographic features

MRI

Features of posterior ligament tears include :

  • PCL usually remains contiguous (~70%) although there may be complete or partial ligamentous disruption
    • absent PCL replaced by high T1 and T2 signal
  • enlarged and swollen PCL: >7 mm AP diameter of the vertical portion on sagittal imaging is indicative of a tear

Treatment and prognosis

PCL tears may result in chronic instability and early degenerative change .

Differential diagnosis