Rheumatoid arthritis (RA) is a chronic, inflammatory, systemic, autoimmune disease with predominantly arthritic lesions. The disease is common in peripheral joints, often symmetrical, with a chronic course, alternating episodes and remissions, with prolonged morning stiffness, often with subcutaneous nodules and erosive joint changes. In the early stages, the small joints of the hands, feet and wrists are painful, swollen and impaired; in the late stages, there is joint deformity, stiffness, loss of function and muscle atrophy around the joints. The prevalence of RA in China is about 0.3%, with no significant regional or racial differences. (I) Etiology The etiology of this disease is still unclear, and the factors that may be related to the occurrence of this disease are: infection, allergy, endocrine disorders, family genetics, immunopathology, etc. (B) Pathological process 1, arthropathy The basic pathological change is synovitis, usually in the peripheral joints of the limbs, the lesions in the synovial tissue and hyaline cartilage are progressively destroyed, the destruction of the articular cartilage surface, the destruction of the subchondral bone, and the occurrence of joint dislocation or deformity. 2, extra-articular lesions can occur subcutaneous nodules, vasculitis and other lesions. (3) Diagnosis 1. Clinical manifestations (1) The onset of RA is generally slow, with symptoms appearing gradually over several weeks or months. A small number of patients may have an acute onset. The onset of the disease is characterized by general malaise, malaise, low-grade fever, followed by redness, swelling and heat pain in the joints. The joints of the hands, wrists, knees and feet are most likely to be involved, while the elbows, shoulders, hips and upper cervical joints can also be affected. The affected joints are often symmetrical, but different joint lesions may occur sequentially. Distal interphalangeal joints are rarely involved. Symptoms may resolve with early systemic treatment. As the disease progresses, the symptoms become persistent, but they can be relatively mild and alternate. (2) Morning stiffness is a stiff, inflexible, gel-like sensation when the patient starts moving in the morning or after prolonged sitting. The morning stiffness will be temporarily relieved after the joint is moved. Morning stiffness remains with the patient throughout the course of the disease until the joint function is completely lost. The duration of morning stiffness varies with the disease. The duration of morning stiffness decreases when the disease is in remission and increases when the disease worsens. The phenomenon of morning stiffness has become a concise and clear objective indicator to evaluate the severity of the disease and the effectiveness of treatment. (3) Pain: Joint swelling and pain is the main manifestation of RA. The pain is persistent and generally severe, affecting sleep and daily activities. Pain is often accompanied by varying degrees of joint dysfunction and a feeling of heat in the joint. (4) Swelling: Mostly caused by fluid accumulation in the joint cavity or soft tissue inflammation around the joint. All affected joints can be swollen, mostly symmetrically. (5) Deformity: It is the main manifestation of the joint in the middle and late stage patients, gradually appearing flexion and bending, which may be accompanied by inversion or valgus deformity. Due to muscle atrophy, the knee joint appears more prominent. (6) Functional impairment: Both joint swelling and pain and structural damage can cause joint movement impairment. The American College of Rheumatology classifies the degree of life affected by this disease into four levels: Level I: able to perform daily life and various tasks as usual; Level II: able to perform general daily life and some occupational work, but limited in other activities; Level III: able to perform general daily life, but limited in some occupational work or other activities; Level IV: limited in the ability to take care of daily life and participate in work. In conclusion, the disease has the following characteristics: symmetric polyarthritis mainly involving small joints of hands and feet; the disease is chronic and recurrent; the development and progression of the disease varies greatly between individuals; if not treated early, the deformity rate is high, which seriously affects the quality of life of patients. X-ray examination is important for the diagnosis of the disease, the staging of joint lesions, and the monitoring of the evolution of lesions, among which hand arthroscopy is the most valuable. x-ray changes of RA can usually be divided into four stages: osteoporotic stage (stage I): mainly in the early stage of RA, characterized by periarticular swelling and osteoporosis at the joint end; destruction stage (stage II): due to cartilage destruction, the joint space is mildly narrowed, and the subchondral bone cortex is still intact. If the joint surface erosion is obvious, roughness or convexity can be seen, cystic translucent area is obvious or vacuolated, and bone is obviously loose; Severe destruction stage (stage III): joint space is obviously narrowed, bone is widely loose, subchondral bone is destroyed in many places, and even joint dislocation or deformation occurs; Ankylosis stage (stage IV): in addition to obvious joint destruction, there may be local fibrosis, showing joint surface fusion, joint space disappears, and joint Fibrous ankylosis or bony ankylosis, joint dislocation or subluxation, and abnormal changes such as bone spurs and bone redundancy can be seen. Laboratory tests (1) Blood picture: mild to moderate anemia, normal white blood cells and classification, and increased platelets during the active period. (2) Blood sedimentation: it is an indicator of the activity and severity of synovitis, but it is not specific. (3) Anti-“O”, ASO, rheumatoid factor: typical rheumatoid patients can have a positive anti-“O” test and ASO higher than normal, rheumatoid factor is mostly positive. 4, diagnostic criteria 1987 American Rheumatism Association RA diagnostic criteria: meet four or more of the following seven criteria, the diagnosis of RA: (1) morning stiffness in and around the joints for at least one hour, ≥ 6 weeks; (2) at least three joint sites of arthritis, three or more joints at the same time soft tissue swelling or fluid, ≥ 6 weeks; (3) wrist, metacarpophalangeal, proximal interphalangeal joints (4) symmetrical arthritis, ≥6 weeks; absolute symmetry is not required for proximal interphalangeal, metacarpophalangeal and toe joint involvement; (5) rheumatoid nodules observable bony prominences, subcutaneous nodules on extensor surfaces or proximal joint areas; (6) positive serum rheumatoid factor; (7) posteroanterior hand and wrist X-rays showing bone erosion or clear bone decalcification typical of rheumatoid arthritis changes. (iv) Treatment Once the diagnosis of RA is established, it means the beginning of a long treatment process. Therefore, it is important for the patient to gain confidence. At present, due to the in-depth research on rheumatoid research, most patients are able to control their symptoms well after systematic and regular treatment. At the same time, due to the improvement of surgical techniques, even patients with advanced disease can resume walking after surgery, which effectively improves the quality of life of patients. The goals of RA treatment are: to control symptoms, delay the development of the disease, prevent deformity, and restore joint function. The principles of RA treatment are: health education, rest and functional exercise combined with drug therapy, supplemented by surgery. 1, drug treatment (1) non-steroidal anti-inflammatory drugs; (2) chronic anti-rheumatic drugs; (3) immunosuppressive drugs. 2.Surgical treatment The significance of surgical treatment for RA is increasingly being recognized. Especially for knee RA, because of its rich synovial tissue, surgical treatment is more significant. (4) Arthroplasty: for patients with advanced lesions and severe joint destruction. Joint replacement can effectively restore joint function and significantly improve the quality of life of patients.