Osteoarthritis (OA) or degenerative arthritis, also known as age-related arthritis and proliferative arthritis. Characteristics of osteoarthritis: A joint lesion that begins with cartilage degeneration. Statistical analysis shows that 80% of people older than 50 years of age have arthritis, and the spine and knee are usually the most commonly affected joints. The pathology of osteoarthritis: degeneration, wear and tear, loss of articular cartilage, exposure of subchondral bone, sclerosis, cystic changes of subchondral bone hematoma, formation of bone redundancy, synovial hyperplasia, effusion, degeneration and fibrosis of ligaments and menisci, muscle atrophy, and eventually extensive destruction of joint surfaces and joint deformity. Classification of osteoarthritis: Primary osteoarthritis apparently arises spontaneously, but may be associated with some minor recurrent injury as well as joint degeneration, heredity, body fat, middle-aged and elderly women with extensive lesions. Secondary osteoarthritis is caused by a known disorder, usually due to trauma, and is seen in young adults with limited lesions. Clinical symptoms of osteoarthritis: recurrent joint pain (pain going up and down stairs, pain squatting, pain walking), joint swelling, joint stiffness, deformity, and impaired mobility. In the past, treatment of osteoarthritis was generally conservative, and severe joint lesions were treated with major surgery such as arthrocentesis, osteotomy or replacement of artificial joints for some patients. With the invention of arthroscopic surgery, a newer, minimally invasive surgical treatment concept based on less trauma has emerged and been developed. Osteoarthritis is divided into early, intermediate and late stages. The three stages of treatment for osteoarthritis of the knee are early conservative treatment with Chinese and Western medicine, intermediate minimally invasive arthroscopic cleanup surgery, and late arthroscopic cleanup osteotomy or artificial joint replacement surgery. When osteoarthritis occurs in the knee joint, the first conservative treatment includes proper rest, weight reduction, oral pain medication and non-steroidal anti-inflammatory drugs, and occasionally intra-articular injections of steroid preparations. Intra-articular injections of hyaluronic acid may also be used. When conservative treatment fails, minimally invasive arthroscopic surgery can be performed, including flushing the inflamed joint, cleaning the cartilage surface and ruptured meniscus, removing part of the synovial membrane and sensitive bones causing soft tissue symptoms, and decompressing the subchondral bone bore. If the degeneration of the joint is so severe that various treatments fail to relieve the symptoms, arthrotomy, total knee arthroplasty or unicondylar replacement surgery may be used. The vast majority of patients with osteoarthritis can be treated with minimally invasive arthroscopic surgery to relieve pain, eliminate swelling, improve mobility, and enhance quality of life. To improve the therapeutic effect of minimally invasive osteoarthritis surgery is reflected in three aspects: 1. Master the indications for surgery and select suitable patients. Patients with mild symptoms or without regular conservative treatment and very serious signs and deformed joints should not undergo arthroscopic surgery. 2, arthroscopic surgery operation should be precise and accurate to avoid unnecessary injuries. 3. Systematic rehabilitation and a period of continuous drug consolidation therapy should be provided after surgery.