Knee tuberculosis is a secondary lesion like other bone and joint tuberculosis, and most of them are transformed from pulmonary tuberculosis. In the reports of large-scale tuberculosis cases in China, the incidence of knee tuberculosis is second only to spinal tuberculosis, ranking first among the six major joints. Foreign literature reports that the incidence of knee tuberculosis is also after the spine, ranking first or second among the six major joints. Knee tuberculosis is more common in children under 10 years old, with no obvious difference in gender. Children's knee tuberculosis has a long course and is prone to involving the epiphysis, so it often causes developmental and growth deformities of the affected limbs. Knee tuberculosis generally occurs unilaterally, and cases of bilateral tuberculosis are rare. It is usually divided into simple synovial tuberculosis, simple bone tuberculosis and whole-joint tuberculosis.