Posterior cruciate ligament (PCL) injuries have a reported incidence of between 
3 and 37%, depending on the clinical setting. The most common mechanism of 
injury in motor vehicle accidents is a dashboard injury or direct force to the 
proximal anterior tibia. Sports related injuries result from hyperflexion of the 
knee with the foot typically plantarflexed. The latter mechanism is the most 
common cause of isolated PCL injuries, while in the trauma population as many as 
95% of patients with knee injuries have combined ligamentous damage. Improved 
knowledge at an anatomical, biomechanical and clinical level has provided the 
orthopaedist with a more defined treatment algorithm. Isolated, partial PCL 
injuries (grades I and II) can best be treated nonoperatively while complete 
injuries (grade III) may require operative treatment based on clinical symptoms. 
All combined ligamentous injuries usually respond best with surgical management.