Patient: 45-year-old man from India Presentation: 4 months of progressive back pain, weight loss (8kg), and night sweats Relevant history: Immigrated to Australia 2 years ago. No known TB contacts or previous treatment. Non-smoker, no HIV risk factors disclosed. Examination findings:
| Test | Result | Normal Range | Interpretation |
|---|---|---|---|
| Hb | 108 g/L | 130-170 g/L | ↓ Anaemia of chronic disease |
| WCC | 8.2 ×10⁹/L | 4-11 ×10⁹/L | Normal |
| Platelets | 385 ×10⁹/L | 150-400 ×10⁹/L | Normal |
| CRP | 28 mg/L | <5 mg/L | ↑ Mildly elevated |
| ESR | 65 mm/hr | <20 mm/hr | ↑↑ Elevated |
| Albumin | 28 g/L | 35-50 g/L | ↓ Hypoalbuminaemia |
| QuantiFERON Gold | Positive | Negative | Indicates TB exposure |
| HIV | Negative | Negative | Important to exclude |
Image 1: Lateral Radiograph of Thoracolumbar Spine
Radiological features:
Image 2: Chest X-ray PA
Findings:
Image 3: MRI Thoracolumbar Spine (T1, T2/STIR, Post-contrast)
MRI findings:
Describe the investigation findings and differential diagnosis
How would you confirm the diagnosis?
What are the indications for surgery in spinal TB?
The biopsy confirms TB with ZN-positive AFB. What is your antibiotic regimen?
At 3 months, the patient develops new bilateral lower limb weakness. What is your management?
What is the prognosis and follow-up for spinal TB?
This pattern suggests Spinal Tuberculosis:
Distinguish from Pyogenic Spondylodiscitis:
| Feature | TB | Pyogenic |
|---|---|---|
| Onset | Insidious (months) | Acute (days-weeks) |
| WCC/CRP | Often normal/mildly elevated | Usually markedly elevated |
| Disc involvement | Preserved early | Destroyed early |
| Spread pattern | Subligamentous (under ALL) | Direct disc destruction |
| Abscess | Common (psoas) | Less common |
| Calcification | May be present | Rare |
Distinguish from Spinal Metastasis:
Q: "What is the most common site for spinal TB?"
The thoracolumbar junction (T12-L1) is most commonly affected, followed by lower thoracic and upper lumbar spine. Cervical involvement is less common but carries higher risk of neurological complications.
Q: "What is a 'cold abscess' and why is it called that?"
A cold abscess is a collection of caseous material and pus that forms without the classical inflammatory signs of warmth and erythema. It occurs because TB produces a granulomatous rather than acute inflammatory response. Can track along fascial planes (e.g., psoas abscess presenting in groin).
Q: "What is Frankel grading and how would you use it?"
Frankel grading assesses spinal cord function:
Used for documenting baseline deficit and monitoring improvement.
Q: "What are the risk factors for kyphosis progression?"
Children with >2 vertebral bodies destroyed may need prophylactic fusion to prevent severe kyphosis.