Laxity of soft tissues such as the lateral knee capsule, ligaments, and parapatellar tendon membrane is the main factor in the occurrence of osteoarthritis that leads to inversion deformity and narrowing of the medial space in the knee joint. The human tibia shows osteoporosis with age. The lateral fibular support leads to the uneven settlement of the medial and lateral tibial plateau of the osteoporotic degeneration is a decisive factor in the secondary inward displacement of the knee force line and inversion deformity of the knee. Among them, the fibular support is the main factor of uneven settlement of the medial and lateral tibial plateau. The uneven subsidence leads to increased medial loading, resulting in inversion of the knee, which accelerates the subsidence and makes the role of the fibular support more pronounced, thus further advancing the unevenness of the subsidence. According to this theory, the application of simple fibular segmental osteotomy for the treatment of knee degeneration with knee inversion deformity and pain can achieve good results. The method is simple and less invasive, and after surgery, it can effectively relieve the tension of the lateral soft tissues of the knee and reduce the pain, and the patient can walk with weight immediately, and the long-term knee function is well recovered by the longest staff long-year follow-up. Therefore, this surgical method is one of the effective methods to delay knee replacement or even avoid knee replacement. In recent years, domestic scholars have gradually promoted this method and achieved good therapeutic results. The patient is placed in a lateral position, under local anesthesia or unilateral lumbar anesthesia, and a 3 cm incision is made at the junction of the middle and upper third of the fibula, and the muscle is peeled away layer by layer to reveal the fibula. The 1.5-2.0 cm fibula block was amputated with a bone saw or grinding drill, and the stump was trimmed and closed with bone wax. After saline rinsing, the incision is closed and bandaged layer by layer. The operation takes about 15-30 minutes. After the surgery, the patient rests for 3-7 days, during which time he/she can take care of himself/herself and return to normal life in a week. The procedure is short, small incision, lightly traumatized, and it is a new treatment method especially for patients who want to relieve pain and improve the function of the knee joint.