Bone Tuberculosis: Comprehensive Guide

Yes — TB can leave the lungs and settle in bones and joints, and the spine is the single most common site. This form is called skeletal or bone TB, and spinal TB specifically is known as Pott's disease. The infection reaches the bone through the bloodstream, usually from a lung or lymph-node source that may itself be silent by the time the bone disease shows up. Around 1–3% of all TB cases involve bone, with the spine accounting for roughly half of these; the hip and knee are the next most common. Because it develops slowly over months, bone TB is often mistaken for ordinary back pain, arthritis or a sports injury, and diagnosis is frequently delayed.

Persistent, deep bone pain that gets worse at night, along with low-grade evening fever, unexplained weight loss and night sweats, are the classic warning signs. In spinal TB the pain is usually in the mid or lower back and doesn't improve with rest or painkillers. Local swelling, restricted movement of the affected joint and eventually a visible bump on the back (kyphosis, or hunchback) can develop as vertebrae collapse. A cold abscess — a soft, painless swelling without redness or warmth — sometimes appears near the spine, groin or thigh. Neurological symptoms like leg weakness, numbness or difficulty passing urine are red flags for spinal cord compression and need urgent evaluation.

MRI is the most sensitive test for bone and spinal TB — it shows early bone marrow oedema, disc destruction, cold abscesses and any pressure on the spinal cord well before X-rays do. X-rays and CT scans help see bone destruction and deformity. To confirm the diagnosis, doctors take a biopsy of the affected bone or the pus from a cold abscess and send it for microscopy, TB culture and molecular tests like GeneXpert MTB/RIF, which also flags rifampicin resistance within hours. Blood tests (ESR, CRP) support the diagnosis but cannot confirm it. Chest X-ray is done to check whether the lungs are also involved, since around half of bone TB cases have a hidden pulmonary focus.

Bone TB is treated with the same four anti-TB drugs used for lung TB — isoniazid, rifampicin, ethambutol and pyrazinamide — but for longer, usually 9 to 12 months in total. The first two months use all four drugs; the remaining months use isoniazid and rifampicin. Bed rest, a brace to support the spine and gradual physiotherapy help protect the bone while it heals. Surgery is reserved for specific situations: severe spinal deformity, spinal cord compression not responding to medicines, large abscesses that need drainage or an unstable spine that needs fusion. Most people recover fully if treatment is started before major bone destruction, so early diagnosis really is the difference between full recovery and permanent disability.