Extrapleural thoracoplasty is a procedure in which a group of ribs is removed under the periosteum, collapsing the local chest wall to reduce the size of the thoracic cavity in that area The new ribs from the periosteum will keep the local chest wall collapsed 6 to 8 weeks after the operation, shrinking the thoracic cavity forever. Thoracoplasty is commonly used for chronic pyothorax. Chest wall collapse can result from untimely or inappropriate treatment of acute pyothorax, retention of a foreign body in the chest cavity, failure to cure the primary disease causing the pyothorax, or idiopathic infection. Because the disease is a severe wasting disease, prompt treatment and nutritional supply should be ensured. The following diseases may cause chest wall collapse: 1, lung abscess lung abscess (lung abscess) is due to a variety of etiological factors caused by the purulent lesions of lung tissue, early for the purulent inflammation, followed by necrosis to form an abscess. It occurs more often in the prime of life and is more common in men than in women. According to the cause of the disease, there are 3 kinds of infections caused by transaerial infections, hematogenous infections and multiple abscesses and lung cancer, etc. Lung abscess can also be categorized according to the related pathogens, such as staphylococcal, anaerobic, or Aspergillus lung abscesses, and since antibiotics are widely used, the incidence of lung abscesses has been greatly reduced. Liver abscess can be caused by ameba protozoa or bacterial infection. The development of ameba liver abscess is closely related to amebic colitis and most of the abscesses are single; the bacterial invasion pathway of bacterial liver abscess can be caused by the direct spread of intra-abdominal infection in addition to septicemia, and it can also be caused by umbilical cord infection through umbilical blood vessels and portal vein into the liver, and biliary ascaris lumbricoides can also be the trigger of bacterial liver abscess. Biliary roundworm can also be the cause of bacterial liver abscess. Common bacteria include Staphylococcus aureus and streptococcus. Subphrenic abscess Any limited accumulation of pus located below the diaphragm and above the transverse colon and its mesentery is collectively called subphrenic abscess. Abscesses in the right posterior suprahepatic space are the most common, and their causes are related to the influence of lymphatic flow and respiratory movement, and the intra-abdominal pressure is the lowest in this space of the abdominal cavity. They are followed by abscesses in the right subhepatic space and the right suprahepatic anterior space, while subphrenic abscesses on the left side are relatively rare. Subdiaphragmatic abscesses are secondary infections whose location is related to the primary disease. It may occur in 1 or more than 2 interstitial spaces. Clinically significant systemic symptoms and insidious local symptoms characterize the condition. There are many complications, high mortality rate, and early surgical drainage is required. 4, acute pus chest Acute purulent pleurisy referred to as pus chest, also known as acute pus chest, for the pleural cavity infected by purulent pathogens, resulting in purulent exudate accumulation and become. According to the scope of involvement of the pleural cavity can be divided into limited (encapsulated) pyothorax and total pyothorax. If it is combined with pneumoperitoneum, it is called pyothorax. The disease starts rapidly, mostly spreads from the infection of neighboring organs, such as lung, esophagus or abdomen; or the pleural cavity is involved in sepsis or septicemia; or it can be the complication of penetrating trauma to the chest wall or the complication of chest surgery. 5.Osteomyelitis Osteomyelitis is a kind of bone infection and destruction, which can be caused by aerobic or anaerobic bacteria, mycobacteria and fungi. Osteomyelitis occurs in the long bones, the feet of diabetic patients, or at sites of penetrating bone damage caused by trauma or surgery. The most common site in children is the long bones with good blood supply, such as tibia or femur metaphysis. 6, chronic pyothorax Acute pyothorax in the course of more than 6 weeks, pus in the fibrous material deposited in the visceral, wall layer pleura, and gradually mechanized thickening, the formation of thick fibrous plate, so that the lungs can not be dilated, the pus cavity can not be narrowed, resulting in the opening of chronic pyothorax. Over time, the thickened and mechanized fibrous plate layer can lead to thoracic spinal deformity, mediastinal displacement and respiratory dysfunction due to scar tissue contraction.