For long and short legs, that is, the existence of unequal length of both lower limbs, the following treatment measures can be taken: 1. Thorough treatment of the primary disease. For such symptoms, the more common primary disease is the presence of congenital hip dislocation on one side, scoliosis, or there is some serious injury involving the pelvis and lower limbs. Only after thorough treatment of the primary disease will the unequal length of the lower extremities be significantly improved, and then we can discuss the next corrective measures. 2. After the treatment of the original disease, there is still a significant difference in the length of the lower limbs, can be treated by means of bone lengthening surgery of one lower limb. The principle of this surgery is to amputate some suspected shortened bones in the lower extremity, and then gradually lengthen the external fixation brace by implanting it, so that the fracture site, that is, the interrupted site, gradually grows with the external fixation brace, and then lengthens the length of the bone to balance both lower extremities.