Abstract
With the increasing aging problem, the number of fractures in the elderly is also increasing, of which hip fractures are more common, known as "the last fracture of life." Postoperative pneumonia (POP) is a common complication of hip fracture, which greatly increases the mortality of patients. It is particularly important to clarify the factors of perioperative pneumonia for the prevention and treatment process. In this paper, the factors causing POP mainly include demographic factors, pre-injury comorbidities, blood index parameters, major clinical interventions and related mechanisms were reviewed, and the risk degree of the factors causing postoperative pneumonia was mainly discussed, and they were divided into independent factors and risk factors. The objective is to make the most accurate POP prevention measures for hip fracture patients according to the classification of independent factors and risk factors, and reduce the incidence of postoperative pneumonia.