Surgical graded treatment of osteoarthritis of the knee includes arthroscopic dilation and clearing, osteotomy and orthopedics, unicondylar replacement, and total knee surface replacement. Arthroscopic expansion clearing is only effective in patients with free bodies and significant meniscal damage in the knee, and tibial high osteotomy (HTO) is a very effective surgical approach for unicompartmental lesions (commonly medial compartment) with inversion deformity and age under 60 years. Our 15 years of clinical experience can fully illustrate the results of HTO. Typical case: Patient, 60-year-old female, had progressive pain in the left knee for 5 years. Pre-operative knee range of motion was 100°, FTA 184°, and FTA 168° after HTO, with improvement in pain and motion. The results are still satisfactory at 14 years of follow-up.