Knee deformity mainly refers to the change of anatomical relationship of the knee joint due to injury or disease, the alignment is not normal, and at the same time, the force line of the knee joint will also be changed, which will lead to the abnormal function of the knee joint. Common deformities of the knee joint, such as rotund leg or X-shaped leg, are common in daily life. This condition is mainly seen in the inversion and eversion deformities of the knee joint. The knee joint can also have anterior and posterior deformity, such as hyperextension deformity of the knee joint, etc. Due to the injury can be directly caused by the change of the structure and position of the knee joint, but also due to inflammation or meniscus disease, soft tissue diseases, resulting in imbalance of power in the knee joint, which will cause the knee joint bone quality to change and structural changes, and the corresponding deformation and deformity of the knee joint will occur. Patients with knee pain, injury, must go to the hospital for timely diagnosis and treatment, to prevent the occurrence of injury or disease leading to end-stage knee deformation.