PCL avulsion fracture
Posterior cruciate ligament (PCL) avulsion fractures are a type of avulsion fracture of the knee that represent the most common isolated PCL lesion. This typically involves the separation of the posterior tibial insertion of the PCL to variable degrees.
These injuries are commonly seen in motorcycle or car accidents (dashboard injuries) in which posteriorization forces occur against the tibia in a flexed knee. They also are seen in individuals who jump and land on a plantarflexed foot whilst the knee is in flexion, often in the context of sport (essentially placing the tibia under posteriorization force) .
Avulsion at its tibial insertion is the most common PCL isolated lesion (~50%) .
- type I: non-displaced
- type II: upward displacement of the posterior aspect of the avulsed tibial bone fragment
- type III: totally displaced avulsed bone fragment
It can be identified as a bone discontinuity at the posterior tibial articular surface (lateral radiograph view). On MRI or CT imaging, a fractured bone fragment can be noted attached to a retracted/redundant PCL ligament.
Treatment and prognosis
Surgical reinsertion of the avulsed fragment is the standard treatment.