30-year-old patients with O-shaped leg, can be corrected by the following methods: 1, muscle exercise: if for mild O-shaped leg, you can enhance the joint stability of the lower limbs through muscle exercise, at the same time to strictly control the weight, reduce the pressure on the knee joint, even if the O-shaped leg can not be completely corrected, but also be able to significantly alleviate the pressure on the knee joint, reduce knee joint pain. 2, surgical treatment: if the O-shaped leg If O-shaped leg is serious, surgical treatment should be considered. By osteotomy of distal femur and proximal tibia and internal fixation of steel plate screws, the line of force of the lower limb can be corrected, the appearance of O-shaped leg can be completely relieved, and severe degenerative osteoarthritis of the knee joint can be prevented. Therefore, 30-year-old patients with O-shaped legs need to choose the appropriate treatment according to the different degrees in order to get satisfactory control of the clinical symptoms and prevent serious osteoarthritis of the knee joint.