The knee is the largest joint in the human body , is the most vulnerable for injury ,and so it is protected by a huge amount of collagen condensations forming very strong ligaments ,tendons ,retinaculae , and capsule. In the sagittal plane we have the ACL , PCL , Patellar tendon , and the quadriceps tendon. In the coronal plane we have the MCL , LCL , Biceps tendon , Popliteofibular ligament and the ILiotibial band . Ligamentous bony avulsions occur after injury in children and adolescents as the ligaments are strongly attached to the perichondrium and also occur in adults when there is relative osteopenia at the ligament attachment sites. A large variety of ligamentous bony avulsions inside and around the knee will be discussed , as well as their different mechanisms of injury , operative fixation modalities and postoperative rehabilitations. Special attention is given to ACL avulsion from tibial side , PCL avulsion from tibial side ,and PLC avulsion at the arcuate fibular head fracture. Also patellar tendon avulsion from tibial tuberosity , quadriceps tendon avulsion in transverse fracture patella , popliteus tendon bony avulsion , capsular Segond bony avulsion , and iliotibial band avulsion at Gerdy`s tubercle will be demonstrated.