I. Background The World Health Organization (WHO) launched a worldwide “Bone and Joint Decade” on January 13, 2000, to draw the attention of governments, medical research institutions, the public, and all sectors of society to bone diseases, including osteoarthritis (OA). This includes Osteoarthritis (OA), a common disease with increasing health consequences and medical costs. On October 12, 2001, the Ministry of Health (MOH) organized a campaign to raise awareness of World Arthritis Day and decided to establish the MOH Arthritis Prevention and Control Education Program Fund. With the support of this fund, a draft guideline for the diagnosis and treatment of osteoarthritis was drafted by domestic orthopedic and rheumatologic experts, which provides standardized guidance for the diagnosis and treatment of OA by physicians nationwide. However, it has been more than 4 years since the publication of the draft guideline, especially in recent years, with the in-depth understanding of the occurrence and development mechanism of OA, there are many urgent updates in the guideline, so the previous version of the guideline was revised on the basis of foreign OA guidelines and literature, taking into account the specific situation of China. This guideline is only an academic guideline, and its implementation must still depend on the patient and the specific medical situation. Before taking various preventive and therapeutic measures, you should refer to the relevant product descriptions. OA is a joint disease caused by a variety of factors that lead to fibrosis, cracking, ulceration, and loss of articular cartilage. The cause is not clear, its occurrence is related to age, obesity, inflammation, trauma and genetic factors. Its pathology is characterized by degenerative destruction of articular cartilage, subchondral osteosclerosis or cystic changes, osteophytes at the joint edges, synovial hyperplasia, joint capsule contracture, ligamentous laxity or contracture, and muscle atrophy and weakness. OA is more common in middle-aged and elderly patients, with more women than men, and the prevalence can reach 50% in people over 60 years of age and 80% in those aged 75 years. OA is more likely to occur in joints with high load, more activities, such as the knee, spine (cervical and lumbar spine), hip, ankle, hand and other joints. Third, the classification of OA can be divided into two categories: primary and secondary. Primary OA occurs mostly in the middle-aged and elderly, no clear systemic or local causes, and genetic and physical factors have a certain relationship. Secondary OA can occur in young adults, can be secondary to trauma, inflammation, joint instability, chronic and repeated cumulative strain or congenital diseases. Fourth, clinical manifestations (a) symptoms and signs 1, joint pain and pressure pain: the initial mild or moderate intermittent hidden pain, better at rest, increased after activity, pain is often related to weather changes. In the late stage, there may be persistent pain or nocturnal pain. There is localized pressure pain in the joints, which is especially obvious when accompanied by joint swelling. 2. Joint stiffness: stiffness and tightness of the joints when waking up in the morning, also known as morning stiffness, can be relieved after activity. Joint stiffness is aggravated when the air pressure decreases or the air humidity increases, and the duration is usually short, often a few minutes to ten minutes, rarely more than 30 minutes. 3. Joint enlargement: Enlargement and deformation of the hand joints are obvious, and Heberden’s nodes and Bouchard’s nodes may appear. Some of the knee joints may also be enlarged due to the formation of bone redundancy or joint effusion. 4. Bone rubbing sound (sensation): Due to the destruction of articular cartilage and uneven joint surface, bone rubbing sound (sensation) appears when the joint moves, mostly in the knee joint. 5, joint weakness, activity disorders: joint pain, decreased mobility, muscle atrophy, soft tissue contracture can cause joint weakness, walking with soft legs or joint strangulation, can not be fully straightened or activity disorders. (B) Laboratory tests: blood routine, protein electrophoresis, immune complexes and serum complement are generally within normal limits. Patients with concomitant synovitis may have mildly elevated C-reactive protein (CRP) and hematocrit (ESR). Patients with secondary OA may have abnormal laboratory tests of the primary disease. (C) X-ray examination: asymmetric joint space narrowing, subchondral bone sclerosis and/or cystic changes, joint edge hyperplasia and bone redundancy formation or with varying degrees of joint effusion, and free bodies or joint deformation visible in some joints. V. Diagnostic points According to the patient’s symptoms, signs, x-ray performance and laboratory tests, it is generally not difficult to diagnose OA, and the diagnosis can be made by referring to the diagnosis and assessment process of OA (Figure 1). This guideline proposes diagnostic criteria for knee and hip OA for reference (Table 1, 2). These diagnostic criteria are basically based on the criteria developed by Altman and discussed and determined by some orthopedic experts.