I. Patient inclusion criteria 1. adult, osteoarthritis of the knee 2. clinical manifestations are mainly medial compartment lesions ① narrowing of the medial compartment of the knee (X-ray shows) ② pain in the medial compartment of the knee as the main symptom (can be active pain, resting pain, or acupressure pain) ③ destruction of cartilage in the medial compartment of the knee (MRI shows) 3. weight-bearing radiographs of the lower limb force line measurement of the presence of knee valgus deformity 4. Conservative treatment is ineffective 2. Patient exclusion criteria 1. knee valgus deformity with narrowing of the lateral space, pain 2. rheumatoid arthritis, septic arthritis and other joint diseases 3. history of trauma, injury or rupture of the major ligaments of the knee