Costochondritis is a common disease in outpatient or postoperative cardiothoracic surgery and is divided into septic costochondritis and nonspecific costochondritis. The wide variety of treatment methods with poor results, prolonged course and easy recurrence have troubled patients and clinicians. The progress of the diagnosis and surgical treatment of this disease is reviewed as follows. Epidemiology and etiology: Patients aged 20-30 and 40-50 years are more common, with a similar incidence on the left and right side, and 70-80% are unilateral and solitary lesions, with no significant gender predilection, while domestic literature reports that females are more common. The etiology is unknown, and the following hypotheses have been suggested: most scholars believe that it may be related to microtrauma of the costal cartilage membrane and strain caused by abnormal local stresses in the ligaments of the sternocostal joints. It may be related to viral infection of the upper respiratory tract. It may be related to immune or endocrine abnormalities causing nutritional disorders of the rib cartilage. Pathology: Benign swelling hyperplasia of rib cartilage with increased cell volume, thickened cartilaginous membrane fibers, and excessive vascularization. The nonspecific chronic inflammatory response infiltrate consists of lymphocytes, plasma cells, and scattered macrophages, with no remaining abnormalities. Chondrocyte proliferation and thickening of cartilaginous fibers may be due to post-injury repair, causing adhesions to the periosteum, sclerosis, and imbalance in the dynamic balance of cartilage stress in the rib, increasing periosteal tension and stimulating the nerve endings of the anterior cortical branch of the intercostal nerve distributed on the surface of the cartilaginous membrane, resulting in persistent and well-localized pain. Clinical manifestations and diagnosis: The disease can develop in all rib cartilages, mostly in the parasternal 2-4 ribs, and also in the rib arch. In mild cases, only mild chest tightness is felt, and the anterior chest pain is mostly dull or vague, occasionally accompanied by stabbing pain, the pain point is fixed and does not move, and the pain is aggravated by excessive thoracic activity caused by coughing, deep breathing, and expansion of the chest wall. In severe cases, the shoulder and arm are afraid to move, or even involve half of the body. The course of the disease mostly heals on its own in 3-4 weeks, but some patients have recurrent episodes, which can be prolonged for months or even years. The affected costal cartilage is enlarged and elevated, hard, smooth and poorly defined, with significant local pressure pain, but no epidermal redness or heat, and the pain increases when the thorax is squeezed. In multiple cases, the involved costal cartilage may show a bead-like deformity. MRI can show active inflammatory changes in bone, cartilage, synovium and bone marrow with high specificity and sensitivity. A nuclear bone scan is extremely sensitive in showing inflammatory lesions of bone but lacks specificity. Ultrasound can show swelling and structural alterations of rib cartilage that cannot be shown by X-ray, avoiding false positives or false negatives of CT due to volumetric effects and postural influences, and easily observing swelling changes by bilateral comparison. The diagnosis of costochondritis is confirmed according to the clinical manifestations and signs of costochondritis after detailed history, careful physical examination and auxiliary examinations to exclude other diseases.