**Abstract**

Injuries to the posterolateral corner (PLC) of the knee may have a devastating impact on whole joint. Posterolateral rotatory instability, despite getting more and more popular among orthopedic surgeons, still remains challenging to diagnose and even more challenging to treat. Available surgical techniques are demanding and require advanced surgical skills. In this chapter we are going to review the diagnostic tools which help to recognize posterolateral rotatory instability of the knee, to outline its importance and consequences of misdiagnosis as well as present arthroscopic popliteus tenodesis and arthroscopic-assisted posterolateral corner reconstruction which are our minimally invasive techniques used to treat this condition depending on PLC injury pattern and grading. Presented techniques are reproducible, safe and do not require advanced surgical skills being a useful alternative for available open PLC reconstructions.

**Keywords:** posterolateral corner of the knee, popliteus tendon, lateral collateral ligament, multiligament knee injury, popliteus tenodesis, arthroscopic posterolateral corner reconstruction
