What is unicondylar knee arthroplasty? It is a minimally invasive surgical procedure in which the diseased articular cartilage and meniscus are replaced with an artificial unicondylar knee joint while preserving the normal articular ligaments and other tissues. The most common manifestation of osteoarthritis of the knee in China in the early and middle stages is the medial compartment lesion, the main pathological changes are damage and exfoliation of the articular cartilage, secondary synovitis, bone superfluity formation, causing joint pain, swelling, and dysfunction, while the lateral compartment and patellofemoral compartment have no obvious lesions and symptoms, only the medial compartment joint lesion is replaced, i.e., unicondylar replacement, which can cure the lesion, and also Compared with total knee surface replacement surgery, unicondylar knee replacement surgery is a minimally invasive procedure with less trauma, faster functional recovery, and better postoperative joint self-perception. It is particularly suitable for patients with more limited osteoarthritis, less than 65 years old, who need to regain their athletic ability. It is also ideal for elderly patients with osteoarthritis because unicondylar replacement surgery is less invasive, has fewer complications, and is safer than total knee surface replacement. Since the 1990s, unicondylar knee replacement technology has been introduced from abroad. With the gradual advancement in surgical techniques and artificial unicondylar joint materials and design, the unicondylar replacement surgery results have been comparable to those of total knee replacement surgery, with foreign clinical summaries reporting unicondylar joint survival times between 15 and 25 years. Patients with unicondylar knee replacements that require revision surgery due to prolonged use have comparable results to initial total knee surface replacement surgery, so unicondylar replacement surgery can extend the life of the artificial joint in patients for the benefit of middle-aged and elderly knee patients.