The knee is divided into three compartments, the medial compartment, the lateral compartment, and the patellofemoral compartment. Degenerative arthritis of the knee can affect any of these compartments, and 1/3 of patients with knee osteoarthritis have early lesions limited to only one compartment. Current surgical options for the treatment of unicompartmental arthritis include unicondylar arthroplasty, tibial high osteotomy, and total knee arthroplasty. High tibial osteotomy is mainly used as a transitional treatment to total knee replacement, and has the disadvantage of incomplete symptomatic relief and short maintenance of efficacy, and is less commonly used in older age groups. In contrast, unicondylar arthroplasty has received increasing attention due to improvements in prosthesis design, case selection, and surgical technique. Unicondylar arthroplasty is a minimally invasive surgical procedure that replaces the diseased articular cartilage and meniscus with an artificial unicondylar knee, while preserving the normal articular ligaments and other tissues. The mechanism of treatment is to use joint surface replacement technology to compensate for the loss of original tissue. In China, osteoarthritis of the knee joint in middle-aged and elderly people is most common in medial compartment arthritis, and the main pathological changes are: damage and exfoliation of articular cartilage, secondary synovitis, and formation of bone redundancy, causing joint pain, swelling, and dysfunction, which in severe cases leads to disability of the limb and affects the quality of life. With the rapid changes in science and technology, minimally invasive joint surgery has become the development trend, and is increasingly favored by patients because of its small incision, small scope of surgery, reliable results, few complications and fast functional recovery.