O-legs can still be recovered at age 30, but the specifics will depend on the severity and the presence of symptoms. Treatment methods include conservative treatment, surgical treatment and so on. 1. Conservative treatment: Some patients with mild O-legs can be treated with corrective insoles, leg binding, ortho-O instrument, splints and other methods, plus rehabilitation exercises. Mainly through the relaxation of the knee joint medial collateral ligament, so that the stable structure of the knee joint inside and outside can be restored, so that the tibia is turned out, to achieve the purpose of correction. It requires long-term persistence and cannot achieve the purpose of correction in a short period of time. 2. Surgery: It is suitable for patients with very serious O-legs, or patients with osteoarthritis and joint pain. Surgery mostly adopts inverted U-shaped osteotomy of the tibial tuberosity, with cast external fixation after surgery. Surgical correction is usually immediate, but the surgery requires osteotomy, which is painful and risky. If the above patients want to return to normal, it is recommended to go to the hospital for examination, and under the advice and guidance of the doctor to carry out regular exercise and treatment.