What is a posterolateral corner (PLC) injury of the knee? Why is it often missed in diagnosis?

Doctor’s answer

The posterolateral corner (PLC) is a critical structure for maintaining external rotation and varus stability of the knee, including the lateral collateral ligament, popliteus tendon, and popliteofibular ligament. It often occurs in conjunction with anterior/posterior cruciate ligament tears; focusing only on ACL/PCL injuries while ignoring PLC damage can lead to excessive rotational stress on the graft, causing early loosening and failure. Suspected PLC injuries require a Dial Test and varus stress examination, and significant instability often necessitates early repair or anatomical reconstruction.

This content is for education. Diagnosis, treatment, and rehabilitation require an individual assessment by a sports medicine specialist.