OR4.1 | Skeletal Tuberculosis — Practice Quiz

Correct. Skeletal TB is characterised by its indolent, chronic course — months of low-grade symptoms — unlike the acute toxaemic picture of pyogenic arthritis.

Skeletal TB has an insidious, indolent course with gradual joint destruction over months, unlike pyogenic arthritis which presents acutely with fever, rapid joint destruction within days to weeks, and constitutional toxicity.

Skeletal TB has a characteristically slow, insidious tempo. Pyogenic arthritis presents acutely with high fever, rapid joint destruction, and leucocytosis.

Correct. Pott's paraplegia (paraplegia of active disease) results from anterior cord compression by an epidural cold abscess, caseous material, or sequestrum tracking from the anterior vertebral focus.

Pott's paraplegia in the active phase is most commonly due to extradural compression by cold abscess, caseous material, or sequestrum pressing on the anterior aspect of the cord — not primary cord infarction. In healed disease, fibrosis or bony sequestrum causes paraplegia of the healed phase.

In Pott's disease, the focus begins anteriorly in the vertebral body and disc. Spread to the extradural space anteriorly compresses the cord from the front.

Correct. A psoas abscess from spinal TB at D–L level descends within the psoas fascial sheath and passes beneath the inguinal ligament to present in the femoral triangle as a cold fluctuant swelling.

In thoracic and lumbar TB, cold abscess tracks beneath the anterior longitudinal ligament and then along the psoas muscle sheath under the inguinal ligament to present as a psoas abscess in the femoral triangle.

The hallmark cold abscess from lumbar/lower thoracic TB tracks within the psoas sheath — hence 'psoas abscess' — and exits below the inguinal ligament in the femoral triangle.

Correct. Phemister's triad: juxta-articular osteoporosis + peripheral (marginal) erosions + gradual joint space narrowing. This triad on plain X-ray is characteristic of skeletal TB.

Phemister's triad for skeletal TB on X-ray: (1) juxta-articular osteoporosis, (2) peripheral erosions (marginal erosions), (3) gradual decrease in joint space — contrasting with the rapid joint space loss in pyogenic arthritis.

Remember Phemister's triad for TB joints: periarticular osteoporosis, marginal erosions, and slow progressive joint space loss (not the rapid destruction of pyogenic arthritis).

Correct. Anterior decompression (Hong Kong operation) is the procedure of choice for Pott's paraplegia with anterior cord compression. Posterior laminectomy is contraindicated as it does not address the anterior compressing lesion and destabilises a spine already weakened anteriorly.

Since the cord compression in Pott's disease is ANTERIOR (due to abscess/sequestrum), the appropriate surgical decompression is ANTERIOR — either costotransversectomy or anterolateral decompression (Hong Kong operation). Posterior laminectomy does NOT decompress the anterior cord and may worsen instability.

Because the cord compression in Pott's disease is ANTERIOR (abscess/sequestrum from vertebral body focus), the correct surgical approach is ANTERIOR debridement, not posterior laminectomy.

Correct. The WHO/RNTCP recommended regimen for drug-sensitive skeletal TB is 2HRZE/4HR — 2 months of HRZE followed by 4 months of HR, totalling 6 months.

Skeletal TB is treated with the standard DOTS regimen: 2 months intensive phase (HRZE) followed by 4 months continuation phase (HR) = 2HRZE/4HR. Total duration is 6 months for drug-sensitive skeletal TB per RNTCP/WHO guidelines.

Skeletal TB is treated with the standard 6-month DOTS regimen: 2HRZE/4HR. Monotherapy causes resistance. The 9-month regimen (2HRZE/7HR) was an older recommendation; current WHO guidelines support 6 months for most forms of skeletal TB.

Correct. Gibbus is the sharp, angular kyphosis that results from selective anterior vertebral body destruction in TB; the posterior elements are relatively spared, creating the characteristic abrupt angular deformity.

Gibbus (sharply angular kyphosis) in spinal TB results from destruction and collapse of the anterior vertebral bodies with relative preservation of posterior elements. Loss of anterior column height produces an abrupt angular deformity rather than the smooth curves of postural kyphosis.

Gibbus = abrupt angular kyphosis from anterior vertebral body collapse in TB. TB primarily destroys the anterior column (vertebral body and disc), while posterior elements are relatively preserved, producing the angular 'hump' rather than smooth round kyphosis.

Correct. In the synovitis stage of TB arthritis, there is only joint effusion and soft-tissue swelling; the articular cartilage is intact and the joint space is preserved. Bony changes and space loss occur in later stages.

In the early (synovitic) stage of TB hip, the joint space is preserved because cartilage destruction has not yet occurred. The disease typically passes through: (1) synovitis stage — effusion, no bony change; (2) early arthritis — periarticular osteoporosis, marginal erosions, gradual space loss; (3) advanced arthritis — joint destruction.

Joint space is preserved only in the early synovitis stage of TB arthritis, when the disease is confined to the synovium and cartilage destruction has not yet begun.