First, what is limb lengthening? Limb lengthening is based on the principle of cell regeneration under stress stimulation, and the application of osteotomy to form a “second growth line” in the femur or tibia. Next, who is limb lengthening suitable for? Limb lengthening indications: congenital deformity, trauma, tumor, infection and other causes of bone loss or limb unequal length, as well as limb deformity caused by disease. Next we look at the collected cases. The patient, a female with shortened limb deformity, was admitted to the second department of orthopedics at the National Rehabilitation Hospital. The director formulated a surgical plan based on relevant examinations and performed limb lengthening using an external fixator. Post-operative care: 1. Prevent pin tract sensation, keep the skin around the pin hole clean and dry. 2.Check the tightness of the steel needle regularly. 3.Postoperatively, the affected limb will be slightly too high and padded with a thin pillow. 4.Closely observe the blood flow of the distal end of the affected limb and the sensation and movement of the toes. 5.Start 7 days after surgery, twist the scale on the lengthening rod every day, each lengthening should not exceed 1, 0mm, the speed of lengthening depends on the patient’s tolerance. 6, massage, functional exercise, gradual, 3-4 times daily activities, not fast and violent.