Choose the true statement regarding the natural history of skeletal tuberculosis:

Ans. D. All of the aboveBone and joint tuberculosis are almost always secondary to some primary focus in the lungs, lymph nodes etc. Mode of spread from the primary focus may be either hematogenous or by direct extension.Inflammation as a result of TB results in trabecular necrosis and caseation. The intense local hyperemia leads to demineralization of the bone. If there is no interference at this stage, then the cortex also gets eroded. The infected granulation tissue and pus track beneath the subperiosteal planes and soft tissue planes, resulting in the formation of a cold abscess.