Parallel to the increasing technological development in the last decade, even though many instruments were presented to the surgeons for the purpose of fracture fixation, some of them have lost their popularity. However, circular external fixators are not only used for fracture fixation but also for fragmented fractures, unstable dislocations and deformity surgery; they are still widely used and popular. In this section, we mentioned the basic principles of circular external fixators in the knee fractures, and shared our knowledge and experiences with our young colleagues.