Posterior cruciate ligament (PCL) tears are less common than anterior cruciate ligament tears.
Posterior cruciate ligament tears account for ~10% (range 2-23%) of all knee injuries .
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.
Three mechanisms of injury have been proposed :
- posterior tibial displacement in a flexed knee
- rotation with an abduction or adduction force
PCL injuries are isolated in only 30% of cases and are thus commonly associated with other injuries :
- ligamentous injury (~40%)
- meniscal tears
- posterolateral corner injury
- bone contusion (80%) or avulsion fracture (<10%)
- knee joint effusion
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 .
- Ligamentum meniscofemorale posterius
- avulsion fractures of the knee
- Verletzungen hinteres Kreuzband
- hinterer Kreuzbandausriss
- Ruptur des vorderen Kreuzbandes