Tuberculous spondylitis ("Pott's disease")
In tuberculous spondylitis the lumbar or lower thoracic spine is most often involved.
The disease usually begins in the anterior inferior vertebral body* and spreads beneath the anterior (or posterior) longitudinal ligament to involve adjacent vertebral bodies, and secondarily the intervening disc(s).
Osteonecrosis and wedging of vertebral bodies causes a typical gibbus deformity.
In South Africa, Pott’s disease is the commonest cause of kyphosis in adults.
Sagittal section of four lumbar vertebrae and their ligaments.
Image source (adapted from): http://en.wikipedia.org/wiki/File:Gray301.png