**7. Conclusions**

Posterolateral rotatory instability of the knee (PLRI), which is a consequence of injury to the structures of PLC, is a serious condition causing clinical symptoms and biomechanical changes which may lead to early osteoarthritis development and cruciate ligament reconstructions failures. Many clinical tests and imaging modalities are available for making a proper diagnosis and differentiate injured structures. It is widely accepted that only injured structures should be addressed, whereas reconstructions of structures which are not damaged should be avoided. Surgical treatment remains a gold-standard for high-grade PLC injuries. Arthroscopic popliteus tenodesis and minimally invasive arthroscopic-assisted PLC reconstruction are another surgical procedures which may be useful in hands of arthroscopic surgeons involved in the treatment of instabilities around the knee.
