Epidemiology
Most common site for skeletal TB
- usually haematogenous spread
- can be direct from lung
3 patterns
1. Peridiscal (50%) - originating in metaphyseal region
2. Central - high incidence of vertebral collapse
3. Anterior - instability less common with less bony destruction
Pathology
Affects multiple contiguous vertebrae
- starts anterior 1/3 vert body
- doesn't stay within body
- spreads along fascial planes
- spreads under ALL
More likely to produce kyphosis
Disc sequestered rather than destroyed
Posterior elements frequently involved unlike pyogenic
Xray
Short kyphotic deformity
- known as Gibbus Deformity
DDx
May be mistaken for neoplasia
Similar Xray appearance
- brucellosis, hydatid disease
- fungus (aspergillosis / Cryptococcus / candidiasis)
Prognosis
Age influences risk of paralysis
Cervical in patient younger than 10 years
- 17% risk of cord injury
Cervical in patient older than 10 years
- up to 81% risk of paralysis
Management
Non operative
British Medical Research Council
- 77% settled with drug treatment alone
- no patients with neurology / paralysis
- drug treatment for 12/12
- spontaneous fusion can be expected
Operative
Indications for Surgery
1. Deformity
- kyphosis
- >50% verterbral body destruction
2. Neurology
3. Biopsy
4. Failure nonoperative treatment
Technique
Hong Kong Procedure
- debridement of infected bone
- decompression of spinal canal
- correction of kyphotic deformity using structure grafting
- instrumentation