How is ankle joint tuberculosis caused?

summary

Ankle tuberculosis accounts for 3.4% of all bone tuberculosis, and the lowest incidence rate is in three joints of the lower extremities. Synovial tuberculosis of ankle joint is more common, and it is easier to turn into total joint tuberculosis than bone tuberculosis, especially talus tuberculosis and lower tibial tuberculosis. There are few soft tissues around the ankle joint, and the abscess of ankle is easy to break through the skin and form sinus, most of which are anterior and lateral. In the late stage, foot drop and varus deformity were found. How is ankle joint tuberculosis caused?

How is ankle joint tuberculosis caused?

According to the density of bone, bone tuberculosis can be divided into cancellous bone (or spongy bone) and dense bone (or cortical bone). Tuberculosis of cancellous bone can be divided into central type and marginal type. In central tuberculosis, infiltration and necrosis were the main causes. The necrotic bone tissue was dissociated to form dead bone, and bone cavity was left after absorption; Marginal tuberculosis is not easy to form large dead bone, small dead bone is often absorbed or discharged, forming a limited bone defect. Dense bone tuberculosis mostly starts from medullary cavity, mainly with localized bone destruction, and generally does not form dead bone. The purulent fluid can gather under the periosteum along the Volkmann canal, lift the periosteum and stimulate the periosteum to form new bone. Repeated times, periosteal new bone showed scallion skin appearance. Tubular metaphyseal tuberculosis is characterized by cancellous bone and dense bone.

Synovial tuberculosis the synovium is distributed in the joints, tendon sheath and the inner surface of the bursa. After infection, the synovium swells and congests, inflammatory cells infiltrate, exudates increase, and the synovium thickens in the late stage. The pathogenic bacteria of tuberculosis is Mycobacterium tuberculosis, which can not directly invade bone and joint. Therefore, the vast majority of bone and joint lesions are secondary.

The total joint tuberculosis joint is mainly composed of cancellous bone, articular cartilage and synovium. The earliest joint tuberculosis is simple bone tuberculosis or simple synovial tuberculosis. The further development of simple tuberculosis is that the granulation tissue invades from the edge of the cartilage surface and undergoes latent destruction under the cartilage surface. Finally, the whole cartilage surface and its attached bone tissue will be separated, and the cartilage surface will necrosis and fall off. The pus of cancellous bone tuberculosis can penetrate the articular surface and enter the articular cavity, causing the pathological changes of cartilage and synovium. At this time, the three kinds of joint tissues have been infected with tuberculosis, so it is called total joint tuberculosis.

matters needing attention

The symptoms of ankle tuberculosis are slow onset, often with a history of ankle sprain. The pain of simple bone tuberculosis and synovial tuberculosis was not obvious at the beginning, but was severe when abscess occurred or turned into total joint tuberculosis. When the disease is still or cured, the pain will be relieved or disappeared.