Anatomy and Biomechanics.- Classification and Algorithm treatment.- Management in the emergency room.- Instrumental Evaluation.- Neurovascular associated injuries.- Surgical Timing. Surgical Techniques: ACL+Anterolateral capsular injuries.- PCL/MCL injuries.- PCL/PLC injuries.- Bicruciate injuries.- ACL/MCL injuries.- ACL/PLC injuries.- Acute Knee Dislocations.- Chronic Knee Dislocations. Specific Scenario: Associated bone fracture.- Osteotomy in chronic complex ligaments injury.- Complex knee injuries in the young adult.- Knee dislocation in obese patients.- Knee dislocation in athletes.- Complications in complex knee ligament injuries.- Rehabilitation/bracing.- Future trends in ligaments surgery: the role of biology. sakriti opis