The tibial plateau is particularly important in the lower extremity, where the knee is the most mobile joint and the main weight-bearing joint. In the case of tibial plateau fractures, anatomical repositioning of the articular surface and restoration of the lower extremity force line are required in the middle of the surgery. Due to the complexity of the fracture, failure of internal fixation and loss of displacement of the fracture may occur. There are also some patients who, for various reasons, miss the time of surgical treatment and become old fractures. For this group of patients, in addition to restoring the joint surface as much as possible, attention should be paid to the repair of the force lines of the lower extremity. Case: old tibial plateau fracture with knee deformity Patient, male, 24 years old, 2 years after failed tibial plateau fracture. The patient had a collapsed internal plateau that was displaced inward and posterior, an inversion deformity of the knee, and an increased plateau width. Difficulty: 2-year old deformity, surgically treated, poor bone and skin condition. Difficulty level: Grade IV Surgical result: restoration of joint surface, restoration of lower limb force line, restoration of joint movement, avoiding the catastrophic consequence of knee replacement in young people. Video of the patient’s postoperative functional exercise: http://v.youku.com/v_show/id_XMTQ3NDU2MDQyNA==.html