Posterolateral or Posteriormedial Corner Injury
Posterolateral corner injury is damage or injury to the structures of the posterolateral corner. The structures of the posterolateral corner include the lateral collateral ligament, the popliteus tendon, and the popliteo-fibular ligament. Injuries to the posterolateral corner most often occur with athletic trauma, motor-vehicle accidents and falls. An isolated injury to the posterolateral corner is rare, but often occurs with injuries to the cruciate ligaments, the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL).
The dial test where you doctor will determine the rotation of the knee by turning the foot outwards is the most important test to diagnose posterolateral corner injury. If there is increased rotation, it is indicative of an injury to the posterolateral corner.
Depending on the severity and extent of injury PLC injuries can be divided into grade 1, 2 or 3. Grade 1 to 2 injuries show 8mm opening and grade 3 injuries show more than a 10 mm opening. Treatment of a posterolateral corner injury depends on the severity of the injury. Grade 1 and grade 2 injuries may be treated conservatively with a knee brace for 8 to 12 weeks. Surgical PLC reconstruction is required for grade 3 injures.