A baby with one leg long and one leg short may be caused by hip dislocation, scoliosis, or a fracture that causes the legs to be unequal in length. 1. Hip subluxation: Hip subluxation can lead to the symptoms of a baby with one leg long and one leg short, and the child may also have the symptoms of asymmetry of the hip line and thigh line, as well as limp gait and duck step when the child walks. 2. Scoliosis: scoliosis is a disease of spinal deformity, which can also lead to symptoms of one leg long and one leg short, and children can also have symptoms such as high and low hips, unequal shoulders on both sides, and back deformity and pain. 3. Fracture: If the baby has had a fracture, if it is a comminuted fracture, or fracture damage to the epiphysis, then it can also lead to the symptoms of one leg long and one short. Baby a leg long a leg short, there may also be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.