The earliest findings in the radiograms are regional bone atrophy, soft-tissue swelling, and capsular distention. These changes are due to synovitis and are nonspecific. As a rule, the bone decalcification in tuberculous arthritis is widespread, extending 3 to 5 cm. from the joint.
The joint space is widened and is preserved until late in the course of the disease.
Destruction of the hyaline cartilage by the tuberculous granulation tissue is a slow process. Eventually, with progression of the disease, the articular cartilage space will gradually narrow.
This is in contrast to pyogenic arthritis, in which the destruction of articular cartilage and narrowing of the joint space take place early in the course of the disease.
Bone destruction can be seen in the epiphysis or metaphysis as areas of radiolucency in which the normal trabecular structure of bone has disappeared
When affection of the joint is secondary to a tuberculous focus in the epiphysis or metaphysis the areas of bone destruction may be anywhere and are not distributed peripherally in the noncontact portions.
Reactive new bone formation is characteristically absent in the early stages of tuberculous arthritis; it is only in the late healing stages that it develops.
Sequestra may occasionally be present.
Eventually, in an untreated case, the entire articular cartilage will eventually be eroded and extensive destruction of subjacent bone will take place, resulting in gross deformity of the joint.
The general findings are those of a chronic illness. Hypochronic anemia is common. The leukocyte count may be normal, or there may be slight leukocytosis. An elevated erythrocyte sedimentation rate and positive tubercular skin test are almost always present.
The synovial fluid shows an elevated leukocyte count, a lowered sugar level, and poor mucin.
Tubercle bacilli may be seen on microscopic examination of sediment of the joint fluid. A finding of great help in differential diagnosis is the marked reduction or absence of glucose in the synovial fluid. Cultural studies and guinea pig inoculations will be positive for tuberculosis.
The diagnosis is also confirmed by histologic examination of synovial tissue. Most of the diagnosis in India is made on clinicoradiological changes
Early diagnosis and the use of antituberculous drugs have radically improved the prognosis of tuberculous arthritis. Other measures adopted are rest to the affected joint in functional position, traction when needed and dietary improvement.
Treatment consists of general medical measures, chemotherapy, local conservative orthopedic care, and surgery.